Designs

A design is a collection of related items that fully define an electrical circuit. A design contains a parts list, which is updated automatically as you add parts. Your design can contain other items such as a schematic, a layout, and notes. The parts list, schematic, and layout provide different ways to create, modify, and view your circuit. The schematic is the view most often used to create a design. The names of all design items display on tabs at the bottom of the Design window.

The figure below shows a design that includes a schematic and a note:

To create a design with a schematic and a note:

1. Click the New Item button ( ) on the Workspace Tree toolbar and select Add Schematic from the Designs menu.
2. Define the design properties and click OK.
3. Add parts by clicking each part in the Part Selector and clicking in the schematic.
4. Connect parts by dragging their nodes together or by dragging connecting wires from one node to another.

   Note If a part is in an awkward position, click the part and use the Edit menu to rotate it.

5. Double-click parts to open their properties windows and define values.

   Note Note: Parts turn purple or orange to alert you to problems.

6. Add input and output ports to parts so that you can run an analysis.
7. Right-click a tab at the bottom of the Design window and select Add Note.
8. Type information about the design.
9. Click the PartList tab to view the parts list.
10. Click the Schematic tab to return to the schematic view.

Using the Design Wizard

The Design Wizard makes designing easier and quicker if you are new to Genesys or if you want to automate the design process.

To create a design using the Design Wizard:

1. Click the New Item button ( ) on the Workspace Tree toolbar and select Design Wizard from the Designs menu.
2. Type a name for the design in the Enter the New Design's Name box.
3. Click a button to specify whether you want to base your design on an existing design, a blank schematic, a blank layout, or another kind of design.
4. Do one of the following:
   • Click Finish if you selected to base your design on a blank schematic or a blank layout.
   • Click Next if you selected to base your design on an existing design or another type design.
5. If you selected Based on a Design in an Existing Library, do the following:
   • Select the name of the library from the Select the Library Which Contains the Prototype list.
   • Select a prototype from the Select a Prototype list.
6. If you selected Another Kind of Design, do the following:
   • Click one of the buttons to indicate your intended use for the design.
   • Click Next.
   • Click any of the boxes to select initial components to add to your design.
   • Click Finish.

Creating a Design

To create a design with a schematic :

1. Select the Designs folder in the Workspace Tree.  Click the New Item button ( ) on the Workspace Tree toolbar and select Designs/with a Schematic... from the Designs menu.

   Note If you create the new design in the wrong folder, simply drag it to the Designs folder.

2. If desired, change the design name and add a brief description of the design.  Click OK.  Note: If your workspace has a default design "Sch1", then you should right-click on the name in the workspace tree and delete it.
3. Your screen should look like this:
   
4. Dock the toolbar at the top next to the main toolbar by dragging the title bar until it clicks into the top.
5. Open Part Selector A by selecting "Docking Windows / Part Selector A" from the View menu. Dock it right. Then zoom in on a portion of the schematic by clicking the zoom (magnifying glass) tool and dragging a rectangle on screen. Alternates: Ctrl+Shift+A opens part selector. Your screen should look like this:
   
6. Change the Category to Basic in the part selector and click the Input (AC Pow) port. Click anywhere on the left of the schematic. Your screen should now look like:
   
7. Type an R and click on the pink dot of the port. This places a resistor. Type C and click on the pink dot on the resistor. This places an ideal capacitor. Finally, click the basic toolbar button on the Schematic toolbar, click the output port icon on the basic toolbar, then click on the pink dot on the capacitor.  

   Note To place a capacitor with Q: Double-click on the capacitor, click on the General tab, press Change Model, and select CAPQ.

   Your screen should now look like this:
   

8. The R and C values are in Red because we haven't entered valid values for them. Later you will find how to create your own custom parts with default values. For now, double click each part then type in the parameters of 50 for R and 1000 pF for C. You will get a dialog like this. Click in the value field and type the value.
   
    
9. Your schematic should look like this:
   
10. To see another view of this design click the PartList Tab (at the bottom of the design window). Enable the model and symbol display by right-clicking the header bar (where it says Name Description) then checking on the Model and Symbol entries in the menu that drops down.
    
11. If you want to add a Note to this design right-click the PartList tab and select Add Note. Then type or paste something in there, to look, perhaps like this. You can similarly add local design equations and a layout to this design.
    
12. Click the Schematic tab to go back to the schematic.

Creating a Design With a Schematic

A schematic helps you quickly and easily create a circuit description for your design needs. It is the basic building block for your circuit. Genesys includes all basic component models for use in a schematic such as resistors, capacitors, inductors, and amplifiers. You can also use distributed elements such as microstrip and stripline.

The schematic below contains an amplifier with input and output ports:

To create a design with a schematic:

1. Click the New Item button ( ) on the Workspace Tree toolbar and select With A Schematic from the Designs menu.
2. Define the design properties and click OK.
3. Use the Part Selector to add parts to the schematic. The new parts are automatically added to the parts list.

Creating a Design With Parameters

Create a design with parameters to help design custom models. When this design is used a model the parameters in the Parameter tab become the part model parameters.

To create a design with parameters:

1. Create a design with a schematic.
2. Right-click a tab on the Design window and select Add Parameters.
3. Add new parameters by clicking the Add Parameter button.
4. Copy selected parameters (from the parts in the design) into the list by clicking the Copy Parameters button.  A selection dialog box is displayed.  Select individual parameters (to copy from the base design) by placing a checkmark beside each parameter you wish to copy.  Then click OK.
   Tip:  This is the recommended way of adding parasitics (etc.) to an existing part (a "user model").
5. Delete unwanted entries with the Delete Selected Parameter button.

• Name - The name of the parameter.
• Description - A short description of the parameter
• Default Value - The normal, standard value for this parameter
• Units - The units-of-measure for this parameter
• Tune - Is it normally tuned?
• Show - Is it normally shown on a schematic?
• Initially Use Default - Should the Default value be used when the part is placed on a schematic?
• Validation - Usage rules to which determine if a parameter value is valid and in-range.
• <None> - No validation will be performed
• Floating point number - 1.0, 1e-6, etc. are valid entries
• Text - The parameter is a string; any text is valid
• Positive integer - Only numbers like 1, 2, 3, ... are allowed
• Warn if negative - Posts a warning if the value is < 0
• Warn if non-positive - Posts a warning if the value is < 1
• Warning - Always generates a warning
• Error if negative - Posts an error if the value is < 0
• Error if non-positive - Posts an error  if the value is < 1
• Error - Always generates an error

As you simulate this design in the workspace, the default parameter values will be used in the simulation. When you use this design as a model in a part, the part parameters override these default parameter values.

Using the PartList

Every design has a partlist by default. It contains a text listing of all of the parts in your design and a description of each part.

If you are starting from a blank design, the parts list remains empty until you add parts to your design using a schematic. Each time you add a part, that part displays automatically in the parts list. You can change the way parts display in the parts list. Modify the columns and display exactly the same way you modify the Part Selector.

To use the parts list:

1. Click the PartList tab at the bottom of  the Design window.
2. View the parts in the list.

To change the way parts display in the parts list:

1. Click the View Style ( ) button on the Parts List toolbar.
2. Select an option indicating how you want parts to display in the parts list. Selected options have a large dot next to them.

To change the column contents

1. Right-click the column heading and add or remove columns by checking and un-checking the column names. Common column names include ParamSet (the parameters) and Netlist (the connections).
   

Adding Notes to Designs

A note helps document your design. You can add only one note per design.

To add a note to your design:

• Right-click any tab at the bottom of  the Design window and select Add Note.

To delete a note from your design:

• Right-click the Notes tab at the bottom of the Design window and select Delete Note.

Adding Scripts to Designs

Scripts control Genesys operations. Add a script to your design to load files, save files, save data sets, and change object parameters.

To add a script to a design:

1. Right-click a tab on the Design window and select Add Script.
2. Type or paste the script in the window.
3. To run this script, copy the text and paste it into the Script Processor, then select Run.

Adding Equations to Designs

The Genesys equation block lets you define component values with algebraic expressions. Genesys has a set of mathematical functions, operators, and control statements with automatic parsing. It lets you gang-tune elements and create your own user functions.

To add a local equation to a design:

1. Right-click a tab at the bottom of the Design window and select Add Equation.
2. Type or copy an equation in the window.

   Note these equations are local to the design. Other parts of your workspace can not access the variables in this equation set.

Adding Substrates to Designs

Designs can contain any number of local substrates. This is used mainly when creating models so that a model can have an underlying substrate. When your model looks for a substrate it will look first in the Substrates container in the design and then in the workspace. Other designs can not access substrates in this design's local container.

To add Substrates to a Design

To add a substrate container to your design:

• Right-click any tab at the bottom of  the Design window and select Add Substrates.

To delete the substrate container from your design:

• Right-click the Substrates tab at the bottom of the Design window and select Delete Substrates.

To add a substrate to the container

• Click the Add Button
• Click From Library to select from the Substrate libraries.

Changing a Design

Make changes to your design if you are dissatisfied with the results. There are several ways you can change your design:

• Add or delete parts
• Rearrange the order of parts
• Change the connectivity of parts
• Change parameter values of a part

Be sure to save the changes you make to a design.

To change a design:

1. Add a part by clicking each part in the Part Selector and clicking in the schematic, or delete a part by right-clicking a part and selecting Delete from the Edit menu.
2. Rearrange the order of parts by dragging the parts to different areas in the schematic.
3. Change the connectivity of parts by dragging their nodes to other parts or by dragging connecting wires from one node to a different node.

   Note If a part is in an awkward position, click the part and use the Edit menu to rotate it. Change the parameter values of a part by double-clicking the part to open its properties window and redefine the properties.

To save a design:

1. Click File on the Genesys menu and select Save.
2. Select where you want to save the file from the Save In list.
3. Type the name of the file in the File Name box.
4. Select a file type from the Save As Type list.
5. Click Save.

Using Schematics

This section describes how to use the schematic piece of a design. The Genesys Schematic feature is a graphical way of describing a network using the standard schematic symbols and interconnects.

Creating a Simple Schematic

The following steps take you through the process of creating a sample design with a schematic. If you make a mistake while going through this exercise, use the Undo feature on the Edit menu to undo the last operation.

To create a simple design with a schematic:

1. Click the New Item button ( ) on the Workspace Tree toolbar and select With a Schematic from the Designs menu. The Design Properties window appears:
   
2. Type Bridge-T in the Name box, and then click OK to open a blank schematic in your design window.
   Note: The Schematic menu displays on the Genesys menu. Also, the Schematic toolbar displays below the Genesys toolbar.
3. Click the Lumped button ( ) on the Schematic toolbar to display the Lumped toolbar.
4. Click the Resistor button ( ) on the Lumped toolbar.
5. Click in the Schematic window to place the resistor.
   Note: When a part is initially placed, it is drawn using a purple highlight if the part is not fully defined. You must enter all the required parameters (such as resistance) to see the part in its normal colors. Any unconnected terminals are also marked with purple circles. If the part has a local error, which happens in SPECTRASYS when a part goes into compression, the part is drawn in orange. (The purple or orange highlights are not shown when printing or copying to the clipboard.)
6. Press the space bar to reselect the Resistor button.
   Tip: You can use the space bar to repeat the last part placement. If you repeatedly press the space bar, all the components you placed are cycled through.
7. Click in the schematic to place the second resistor. Be sure to click very close to the first resistor's terminal so that the parts snap together.
8. Click the Capacitor button ( ) on the Lumped toolbar.
9. Click in the schematic and drag to place the capacitor above the two resistors, as shown in the figure below. Note that the capacitor is not yet connected to the resistors.
   
10. You are now ready to enter component values.
11. Double-click each part in your schematic, and then click the Parameters tab.

    For this part	In this box	Type this value
    Capacitor (C1)	Capacitance	47
    Resistor (R1)	Resistance	50
    Resistor (R2)	Resistance	50
    Inductor (L1)	Value	120

    Note: Designators, such as C1, are automatically created. You can turn off the auto-designator feature in the Schematic Global Options window.

12. Click OK after each entry.

    Tip: After you finish creating a schematic, you might find that your parts are labeled somewhat haphazardly. You can fix this by clicking Edit on the Genesys menu and selecting All from the Select menu. Next, click the Schematic menu and select Reapply Auto-Designators to relabel all your parts using left-to-right ordering. Use the Renumber Nodes option to reorder all your net names using the same left-to-right ordering.

Simulating a Simple Schematic

This section shows how to simulate the Bridge-T circuit you just created. Simulation is the process of running an analysis on a circuit (design). For more information on simulation, see the Simulation manual.

To simulate the simple schematic:

1. Click the New Item button ( ) on the Workspace Tree toolbar and select Add Linear Analysis from the Analyses menu.
2. Type the following values in the Linear Analysis Properties window:

   Start Frequency (MHz)	10
   Stop Frequency (MHz)	200
   Linear: Number of Points	11

3. Click OK or Calculate Now to run a linear analysis of the Bridge-T circuit.

Modifying Elements on a Schematic

Elements placed in a schematic are subject to a variety of manipulations. Move, pan, mirror, or delete elements to better suit your needs for the schematic.

Selecting Elements in a Schematic

You must select elements in a schematic before you can manipulate them. An element is shown in red when it is selected. Once a selection is made, you can place the element on the Windows clipboard using Edit or Copy and then paste it into other programs like Microsoft Word.

To select a single element:

• Click the element.
• Note that the element whose center is closest to the mouse will get selected.

To select multiple elements by drawing a rectangle around them:

1. Click in an open space in the schematic.
2. Drag the mouse until a box is drawn completely around the elements you want selected.
3. Release the mouse button.

To individually select multiple elements:

• Press and hold down the Ctrl key, and then click elements to add or remove to your selection.

On Screen Editing

Genesys 2007 introduces On Screen Editing of part parameters. To edit a part:

• Right-click the part and select Parameters... from the menu

or

• Select the part (click it) then click inside the text area when the cursor looks like an I-Beam (the text edit cursor).

Things you can do when editing a single part:

• Type a new value
  • Click outside the box or click Accept to close/accept the changes
  • Click a different part to Accept and switch parts (if pinned)
• Click in the S column to set a parameter show/hide
• Click in the T column to set a parameter tunable/fixed
• Click up/down arrows to edit other parameters
• Use a button to do more

The buttons on top:

Keys Supported:

Things you can do when editing multiple parts:

• Type a new value. This new value will become the value for all selected parts
  • Click outside the box or click Accept to close/accept the changes
  • Click a different part to Accept and switch parts (if pinned)
• Click in the S column to set a parameter show/hide for all selected parts
• Click in the T column to set a parameter tunable/fixed for all selected parts
• Press up/down cursor keys (or click the parameter) to edit other parameters
• Click Tune or Show to affect all parts (i.e. make resistance tunable for all parts by clicking on the T in the Tune column)
  • Note: If you type a value by mistake in a multi-valued entry you can enter - to say "don't change".
• Values shown as "-" (a hyphen) are multiple values (different for the parts). If you don't change that value the part values will not change (so they will remain different). If you type a new value, all parts will inherit that new value.

Moving Parts

Once a part is selected, you can move it. Watch the small green circle when moving parts with a mouse. It shows the active terminal that snaps to connections and grid points. The active circle is on the terminal closest to the cursor when you click.

When you move parts that are connected, they remain connected if you enable the Keep Parts Connected option in the Schematic Global Options window. Press the Alt key before you start dragging to temporarily toggle the Keep Parts Connected setting.

To move a part:

1. Click the element.
2. Drag the part to the location you want.

Using the mouse to drag text to any location:

1. Click the part.
2. Click inside the block of text.
3. Drag the text to the area you want.

Using the keyboard to put text in a common spot:

1. Press F4 to cycle the text through the possible locations

Using the mouse to put text in a common spot:

1. Right-click the part and select Format / Text to pick from Top, Bottom, Right and Left location. Note that the text formats differently in the different locations.

Using the AutoWire Tool

The AutoWire tool makes it easier for you to connect parts. The exercise below shows you how to connect parts using the Bridge-T circuit as an example.

To connect parts using the AutoWire tool:

1. Move your mouse over any part terminal while the cursor is in arrow mode. The cursor changes to the AutoWire tool.
2. Drag a connection wire to the destination coordinates.
   
3. Press and hold down the Shift key and drag to insert an angled wire:
   

Mirroring and Rotating Elements

You can mirror and rotate the position of labels and elements in a schematic. For example, use mirroring to flip the label (text) to the other side of simple (two-lead) components such as resistors and capacitors.

To mirror or rotate an element:

1. Click the element you want to mirror or rotate.
2. Click Edit on the Genesys menu and select Mirror, Rotate, or Rotate Counterclockwise.
3. Repeat step 2 until the element is in the position you want.

Panning a Schematic

There are times when you must pan (scroll) to see all of the elements in your schematic.

To pan a schematic:

• Use the scroll bars to move the page up and down or left and right. or
• Select the Pan Tool  (keyboard P ) from the schematic toolbar. Click and drag the schematic to pan it along with the mouse.

Zooming a Schematic

When you use a zoom option in a schematic, only the on-screen view is modified. The actual schematic is unchanged.

Ways to zoom a schematic:

• Click one of the following buttons on the Schematic toolbar to use a tool:

  Click this button	To select this tool	Keyboard
  	Pan the schematic.	P
  	Zoom the schematic.	Z

  After selecting the tool, click and drag in the schematic to use the tool. When you let up on the mouse the tool reverts to Select. Zoom in on a rectangular area of the schematic by click-dragging with the zoom tool.  Click the left button to zoom in; click the right button to zoom out.

• Click one of the following buttons on the Schematic toolbar to automatically zoom to a region:

  Click this button	To select this tool	Keyboard
  	Zoom the schematic to page.	Ctrl+End
  	Maximize the schematic elements.	Ctrl+Home.

• Move the mousewheel in/out to zoom the schematic in/out
• Use the keyboard + and - keys to zoom in and out.

Deleting Elements

You can delete any element from a schematic.

To delete an element from a schematic:

1. Click the element(s) you want to delete.
2. Click Edit on the Genesys menu and select Delete. or
   Press the Del key

Working with Schematics

Genesys offers several features that help simplify working with a schematic. These features are discussed in the sections that follow.

Reusing Designs as Subcircuits

Sometimes it is necessary to use a design within another design. This is done a lot with models.

There are two easy ways to use a schematic as a subcircuit.

Use a NET block
The button for reusing designs is accessed from the Basic toolbar.
To reuse a network using a NET block:

1. Click the Reused Schematic button ( ).
2. Select the number of ports on the network to reuse.
3. Select the design to reuse.
4. Click to place the NET symbol on the schematic.
5. Click OK.

Use a design as a model

1. Place any part with the correct number of ports.
2. Double-click the part and change the model. Edit the model name to the name of the design you plan to reuse.

Defining Ports and Impedances

All schematics must have ports. These ports must be unique and numbered sequentially. They correspond directly to the port numbers used in measurements. Ports are entered using the input ( ) and output ( ) buttons on the Basic toolbar. The standard INP and OUT ports have three parameters:

• Designator – For documentation only; not currently used by any simulators.
  Note: Previous versions of Genesys used this field to name networks. Network names are now shown in the Design window.
• Port Number – Identifies the port number for measurements. This value is not tunable.
• Port Impedance or Filename – Contains a port impedance or a filename. Specify either a terminating resistance value/equation or a filename containing frequency-dependent one-port device data. Because this box might contain either numbers or a filename, you must use an equal sign (=) in front of the entry if you want to use an equation expression or variable name. For example, type =Z to use the value from variable Z . You can specify a tunable value such as 50.

There are Input sources available as well: INP_VDC, INP_IDC, INP_VAC, INP_IAC, INP_PAC, INP_VPULSE, INP_IPULSE, INP_VPWL, and INP_IPWL.

For an example that uses complex port termination files, see "Genesys\Examples\Matching\Ill Behaved Load.wsx."

Changing Schematic Properties

A schematics properties page is displayed in its Design Properties dialog box.

To change the properties of a schematic:

1. Double-click any empty area of a schematic.
2. Click the Schematic tab (if it's not already selected).
3. Make the changes you want.
4. Click OK.

• Page Width & Height – The size of the paper (in current units).
• Standard Part Length –  The length of a resistor part.  Defaults to 1 inch.  This setting controls the schematic scaling.  (If standard part length is set to 0.5, all parts on the schematic will be half-size.)
• Grid Spacing – The distance between grid dots.
• Units – The units used by the schematic for its settings.

Adding a Title Block

A title block contains text which documents the schematic.  It often contains information regarding the name of the schematic, the name of the person who drew it, copyright information, etc.  The Large (standard) title block looks like this (after some example information has been entered):

Genesys now allows for the title block to be placed anywhere on the schematic (not just the lower-right corner).  You can now create custom title blocks (via the symbol editor) which can contain any annotation (such as a logo bitmap).  You may also place more than 1 title block on a schematic.

To place a title block, click the Schematic menu and select "Add Title Block...".  Then select a title block from the library of standard title block symbols (or your own custom library).

 

Drag the title block to the desired position and double-click it.  Enter the appropriate information into the dialog box:

• Item - Name of the piece of information.  (This can only be changed on a custom title block symbol, not in this dialog box.)
• Text - The actual text string to be drawn in the title block.
• Scale X & Y - Stretches the title block.  For example, 0.5 is half-size.
• Draw semi-transparent - Draws a faded title block, so that it is less distracting.  It will be draw normally (non-faded) on printouts.

Creating a Custom Title Block
The easiest way to create a custom title block is to start with one of the existing ones.

1. If necessary, use the View | Docking Windows | Library Selector menu to enable the Library Selector.
2. Double-click one of the title blocks to add it to the current workspace.
3. Edit it as needed, using annotations:
   • The text annotation Name will be used as the Item Name in the Title Block Properties dialog box.
   • The text annotation Lines of Text will be used as the Text in the Properties dialog box.  For best results, only use 1 line of text and keep it fairly short.
   • Images, like a company logo, or any other annotation can be placed on the custom symbol.  If more than one Genesys user will be accessing the workspace, the image file should be on a shared network drive (or website) that is available to all users.
4. Save the file.
5. On workspace tree, right-click the symbol and use "Copy To" to place the symbol in a new (or existing, custom) library.
6. To use your new custom title block on a schematic, use "Add Title Block..." and select the custom library and symbol.

• Font - The page font, which is used for part text.
• Show Page Frame - When checked, the schematic page frame is drawn.
• Symbol Options - (only available when the Design's Intended Use is set to Symbol)
• Scaling - Sets the size of the symbol.  1.0 is actual size, 2.0 is twice as big, and 0.5 is half-size.
• Rotation - Sets the rotational offset of the symbol.  (Is usually 0, but is 90 for parts like Ground.)
• CenterX and CenterY - Sets the center point of the symbol, which is used during rotation.

Annotating Schematics

The Annotation button ( ) on the Schematic toolbar gives you access to the Annotation toolbar.

The Annotation toolbar provides tools like lines, circles, and text that you can use to point out details of interest on a schematic, draw a box around a group of components, etc.

Text annotations can display model and parameter info when used within a custom symbol. This is implemented via macro-text-substitution. When symbol text is drawn on a schematic, the displayed text is modified prior to output. For example, Name=%Model% would be displayed as "Name=Resistor" on a symbol using a resistor model. The recognized macro strings are:

1. %Des% - Displays the part's designator.
2. %Model% - Displays the name of the model attached to the part.
3. %MODEL% - Displays the model name in UPPERCASE.
4. %ParameterName% - Displays the value of the specified model parameter attached to the part. E.g. R, C, L, QL, MODE, etc.

Adding Comment Text

You can place comment text in a schematic using the Schematic toolbar.

To add comment text:

1. Click the Annotation button ( ) to display the Annotation toolbar.
2. Click the Text button ( ).
3. Click in the Schematic window where you want to place the text.
4. Type your comments in the box.

Specifying Schematic Part Layout Options

Often in RF circuits, you want to model packaging or component parasitics. You do this by placing lumped elements in series or parallel with the actual part. However, you do not want these parts to display in the layout.

To keep a schematic part from displaying in a layout:

1. Double-click a part in the schematic.
2. Click the Simulation tab.
   
3. Click an option. For capacitors, select Replace Part with Open. For inductors and resistors, select Replace Part With Short.
4. Click OK.

Using DisCos

Inserting discontinuities such as bends and tees for distributed elements is simplified with elements called DisCos. These small symbols are easily added to any schematic that uses microstrip lines or similar distributed elements. This avoids the need to manually add these models by disconnecting the elements, selecting the discontinuity from toolbars, reconnecting the parts, and defining parameters.

Using Distributed Elements

You can use distributed elements such as microstrip lines as schematic objects. Place distributed elements in a schematic the same way as lumped elements such as resistors and capacitors. Also, it is now easier to insert discontinuities such as bends and tees in a schematic.

To add a microstrip:

1. Click the New Item button ( ) on the Workspace Tree toolbar and select With a Schematic from the Designs menu.
2. Click the Microstrip button ( ) on the Schematic toolbar.
3. Click the Microstrip Line button ( ) on the Microstrip toolbar, and then click in the Schematic window to place the part.
4. Press the spacebar to repeat the selection.
5. Click the right terminal of the first part to place the second part.
6. Add input and output ports.
7. Continue to add microstrip parts as shown below. Double-click each part to enter values (width and height).

To add discontinuities:

1. Right-click the node in the schematic that connects the three line segments.
2. Select Add Tee DisCo. A small symbol appears. This DisCo (discontinuity) functions the same as the tee element from the Microstrip window.
3. Right-click the bend.
4. Click the Chamfered Corner DisCo check box.
5. Place an End DisCo on the open terminal. The resulting schematic is shown below.
   

Reviewing Rules for Using DisCos

The following rules apply for using DisCos:

• DisCos can connect only to a node with one or more transmission lines.
• All connected transmission lines must be the same type and use the same substrate.
• The number of transmission lines connected to a node is one factor in determining the DisCos to apply.

  Number of Lines	Possible DisCos
  1	End Effect
  2	Step or Bend
  3	Tee
  4	Cross

• A bend is inserted at a node where two transmission lines meet at a right angle in a schematic.
• A step is applied at a node between two transmission lines of unequal widths.

Reviewing Tips for Using DisCos

The following tips apply for using DisCos:

• When generating the original schematic, be aware that the orientation of parts affects the application of DisCos. For example, transmission line elements meeting at right angles result in a "bend" DisCo when converted. The same orientation is important when layouts are generated from the schematic.
• If more than one line type is used in a schematic, you can still use DisCos by right-clicking each node. Note that DisCos can connect only to a node with one of more transmission lines, still applies.
• The option of preserving circuit response when possible is useful if the circuit response is already optimized. This minimizes the need for major changes in components to compensate for the discontinuities.

Using Substrates

If your schematic contains any elements that use a substrate (such as microstrip, slabline, stripline, coax, and waveguide), you must add one or more substrates to your design before you can analyze it. Genesys lets you add and change substrates using the Substrate Properties window. You can also add a substrate from the Genesys library or a user library.

Adding and Changing Substrates

A substrate is required whenever a physical component is used in a schematic or a netlist. Components that require substrates are:

• Coaxial
• Microstrip
• Slabline
• Stripline
• Waveguide

You can also use substrates to provide metal and substrate characteristic information to EMPOWER by selecting the substrate name in the EMPOWER Layer table.

To add a new substrate:

1. Click the New Item button ( ) on the Workspace Tree toolbar and select Add Substrate.
2. Type substrate and metal layer parameter values.
3. Click OK.

To add a library substrate:

1. Click the New Item button ( ) on the Workspace Tree toolbar and select From Library.
2. Select the Substrate type of library
3. Open a substrate library
4. Locate the substrate you want to add, and then click Open or double-click the substrate.

To change substrate properties:

1. Right-click the substrate in the Workspace Tree and select Properties.
2. Make the changes you want.
3. Click OK.

To change substrate properties of ALL the parts in a schematic (to use a tuned variable, etc.):

1. Click the New Item button ( ) on the Workspace Tree toolbar and select From Library.
2. Select the Script type of library
3. Add the ReplaceSubstrates script to your workspace
4. Double-click to open the script, edit it according to the instructions in the script.
5. Run the script.

Exporting IFF Files

Export any schematic created in Genesys to another program using Interchange File Format (IFF). This lets you use your schematic in programs other than Genesys, such as ADS.

Exporting IFF Files That are ADS Compatible

Only schematics are supported for export to IFF files.

To export a schematic to an IFF file:

1. Open a schematic.
2. Click File on the Genesys menu and select*IFF Schematic File* from the Export menu.
3. Save the file in .iff format.
4. Now open the IFF file in ADS.

Translating Direct Parts to IFF

When a part in Genesys is the same as a part in ADS, Genesys uses that ADS part. Parts are considered the same if:

• The part symbols are exactly the same size.
• The parameters are compatible. The parameter names do not have to match exactly, but the parameters from Genesys must be convertible with a simple mapping table or formulas.

For example, a resistor maps to IFF because the standard resistor size is one inch and the parameter R (resistance) has a standard meaning.

Translating Custom Parts to IFF

If a part does not directly translate to IFF, Genesys creates a custom part and symbol in ADS. This creates an additional network in ADS, and possibly a netlist file, to support the new part. These custom networks use a standard naming convention so that your ADS designs are easily shared and edited.

Translating DisCos to IFF

While DisCos are not directly supported in ADS, Genesys recreates these elements with the additional terminals necessary for ADS compatibility. All DisCos work in ADS without manual modifications.

Exporting Other Items to IFF

In addition to a schematic, other items are automatically exported to IFF files. These include:

• All equations
• Substrates used by the schematic
• Linear simulations

Using Custom Mapping Files for IFF Export

Genesys IFF file export is controlled by a sophisticated internal mapping file. You can create a user mapping file if you want to customize the IFF export. For more information on this mapping file and customization services, please contact Agilent or your local distributor.

Exporting and Translating to SPICE

SPICE files are exported from a schematic. This is because many SPICE device models are significantly different from linear simulator models. Terminations are often handled differently in SPICE and linear simulators. In Genesys, oscillators are analyzed open loop while the loop is closed for SPICE analysis. These differences are resolved in the schematic.

Translating Parts to SPICE

There are three categories of part translation to SPICE:

• Direct
• Compound
• Incompatible

For translations of specific parts, see the Element Catalog.

Direct – Direct parts are translated on a one-to-one basis. Examples include capacitors, inductors, resistors, signal ground (DC voltage source), and electrical transmission lines.

Compound – Compound parts are translated as SPICE subcircuits. They include mutual inductors, op-amps, VCC, and Crystal. This provides comparable simulations in Genesys and SPICE. For example, an Genesys VCC is modeled by two resistors and a voltage controlled current source. To use just the SPICE VCC device without the resistors, you can override the default translation by double-clicking the VCC device to open the properties window. Select G from the SPICE Device list and click OK to save the changes.

Please note the following:

• The SPICE opamp E model (Genesys translates OPA as an E model) is ideal in that the unity crossover frequency is infinite. You can substitute a SPICE library model or subcircuit for the opamp. Most opamp manufacturers have SPICE models for their products.
• The Genesys TRF device (ideal transformer) is not supported in SPICE. You should specify mutually coupled inductors (MUI). You need to specify appropriate winding inductance and coupling.
• The Genesys FET and BIP devices do not include any biasing information and, therefore, are not translated. You can specify how to translate these parts by defining the translation device in the properties window.

Incompatible – Incompatible parts are those parts that have no simple SPICE equivalent, including physical models, S-parameter or Y-parameter devices, and internal transistor models (FET and BIP). Incompatible parts are identified in the translated SPICE file with an exclamation point (!) at the front of the part line. You can assign a SPICE model (.MODEL) or subcircuit to that part in the properties window.

You must also place a SPICE model definition (.MODEL block) in the exported SPICE file. This is done either through SPICE command text or manually after exporting. If the SPICE simulator supports libraries (both PSPICE and IsSPICE support libraries), the library reference is included in SPICE command text entries.

Using Parts

Parts are used in Genesys to create circuits. You can access a part from the Part Selector or from the Schematic toolbar. Genesys also lets you import parts, or you can build a custom part using the Part wizard. Vendor parts come in Part Libraries that are loadable.

A part in the Part Selector is really just a bunch of descriptive information. The following diagram illustrates the pieces of a part

• When you place a part on a schematic Genesys finds the part symbol in its library, positions that symbol on the sheet of paper, finds terminal names from the port names of the symbol, gets the default model parameters and applies any overrides, then shows Model Parameters and Custom Properties that are checked as Shown.
• When you run an analysis on a circuit the netlist is created and for each part Genesys finds the model in the model library, applies the parameters defined by the netlist, then inserts the model into a model tree for analysis. Instantiating a model is the process of creating the mathematical model with parameters.
• When you create a layout Genesys finds the footprint for each part in the footprint library (using default footprints as necessary) then drops each copper footprint into the layout.
  Important: If you have a design (model or symbol) in the workspace with the same name as the Model or Symbol defined for a part, then that design will override the library lookup. This makes it easy to test and customize a model or symbol.

  Hint: When you edit a part in the part selector, you are changing the default interpretation of place this part .

  You usually place parts in a schematic. Each part is represented by a symbol, and a designator. The part also includes a list of properties, which you can change using the properties window.

Here's an Air Core Inductor definition:

General
The general information just includes descriptive information for the air core inductor. You can add a part number (if it's a vendor part) and set the default designator (such as L for an inductor). Add a description if desired.

Definition
Here the Air Core inductor has three possible models. AIRIND1 is the default model. It has one symbol (INDUCTOR) and one footprint.

When you edit the placed Air Core Inductor click Change Model in the part properties to see the 3 available models in the pull-down.

Advanced: to see the three models, open  the design selector and you see that the Genesys Model library includes all three models (editable). Edit one to see the actual design/model used for an Air Core Inductor.

Parameter Overrides
This page shows the default model parameters for this part. The entries in Pink are where we have overridden the defaults for our custom version of the Air Core Inductor.

The figure below is a part that represents an air core inductor.

The color of a part parameter changes to red, orange, or purple whenever there is a problem. A missing property value or error is indicated by the color red. A warning is colored orange.

To place a part:

1. Click a part in the Part Selector list. Notice the part details that display in the information window.
2. Click in the Schematic window to place the part.

To display a part without properties information:

1. Double-click a part.
2. Click the Parameters tab.
3. Clear the Show check box for each property you do not want to show, or click the Hide All button to hide all of the property information.
4. Click OK.

Setting Part Properties in a Schematic

When you place a part in a schematic you will almost always change one or more parameter values. You can do this via on-screen editing or in the Part Properties dialog. Access the dialog by double-clicking the placed part or by right-clicking the part and selecting Part Properties...

The pages in this section refer to the following part:

Part General Tab

Within this page you define how the part is simulated, shown, and placed into a layout.

Part Properties Parameters

This tab is the default view when you double-click a part to set part values. In this tab you select a value, tell whether to show a parameter, tune a parameter, or just use the default value. This tab can be widened by pulling the side of the dialog.

Part Properties Simulation

The simulation tab lets you override the interpretation of the part during simulation. Use this to compare a subcircuit with measured data, or to temporarily override a part with an equivalent subcircuit. This is not the way to define a part using SData or a subcircuit but specifically for 'swapping out' a part temporarily. If you want an SData part look at the NPOD model. If you want a subcircuit part read the section on models and set the model name to the subcircuit name.

Use the simulation parameter override section to have the simulators temporarily change the way they simulate this part.You can replace the part's model with an open or short or a subnetwork or dataset or datafile.

Use the Layout Options to use an open or short in the layout instead of the part's footprint.

Part Properties Statistics

In this tab you set the default part statistics. When a part parameter is used in a Monte Carlo or Yield evaluation these statistics will become the initial values. Not all parameters need distributions.

Part Properties Custom

Here you can create custom parameters to be shown on the schematic or used by scripts. The part definition may also include custom parameters.

Part Properties Schematic Element

This tab can easily change the way a part is shown on the schematic as well as the part positioning. You can change scaling and rotation here (as well as by the mouse or menus) and add notes. The position is in Page coordinates where usually 1000 units=1 inch for the schematic.

Part Properties Netlist

The netlist tab shows the current connections of the part. This is editable only if there is no schematic. When you double-click a part in a partlist-only design (such as a SPICE import) these fields are editable to let you set the netlist. The terminal names come from the symbol port names.

Part Properties for Scripts

A part in Genesys consists of a footprint and any number of sections, with each containing a model and a symbol. For example, a dual op-amp part might have a footprint (perhaps SOIC) and two identical sections. Each section contains an op-amp model and an op-amp symbol. For ease in drawing schematics, Genesys also supports a short symbol (accessed with the Shift key when you place a part).

To change the values entered in a part, double-click the part in the schematic and select parameter options.

Each section of a part can contain a list of models and symbols that are standard alternates for the part. Property names are case-sensitive.

Parts might also contain reference information in the form of Web pages or files, default settings to set default parameters, a category list to select from a part library, and a button ID for more information.

Standard Library Properties

Standard Part Properties

Customizing Parts

You can change the model, symbol, footprint, and default values of a part to better suit the needs of your design environment. This is especially helpful if you must repeatedly use the same part because you do not have to re-enter the values each time you use it.

You can only customize parts in your custom libraries. Genesys libraries are all internal to the program and marked read-only.

If you want to use an existing part as a prototype just Copy it to your personal custom library or use the Part wizard.

To customize a part definition:

1. Find the part in the Part Selector
2. Double-click the part ( alternate: right-click and select Edit)
3. Click OK when finished

Example: we would like to create a simple bypass capacitor..

Steps to follow:

1. Right-click the capacitor in the Eagleware part library and select My Parts from the Copy To menu. If you don't have a My Parts library, create one (use Copy To New Library).
   
2. Switch to the My Parts library in the Part Selector by using the library pulldown.
   
3. Double-click the Capacitor in the MyParts library to bring up the Part Properties.
   
4. Now edit the part front page as desired and the properties, as desired.
   
   
5. When you place this part it will look like this
   

Using the Create Part Wizard

The Create Part Wizard (in the Action menu) automates the process of creating a custom part.

To create a part using the Create Part Wizard:

1. Click Action on the Genesys menu and select Create Part Wizard.
2. Browse for an existing part to use as a starting point or start with a blank part.
   .
3. Click Next.
4. Fill in the descriptive fields as you want. By default they will agree with your source part properties.
   
   Note: The RefInfo string is composed of |-delimited "name|reference-link" pairs of substrings. Each pair consists of a menu item and a command, usually a URL, directory path, or file (.doc, .txt, .htm, etc.)
5. Click Next.
6. Select the model to use. Note that the <registered> models are internal to Genesys and not displayed in the Model library..
   .
7. Click Next.
8. Select a symbol and a footprint from the next two pages, then decide on which library to put the new part.
   

Part Parameter Distributions

Parts often come with known precision (10% resistors or 2% capacitors). In the Part Properties dialog you can set the precision of parts by specifying the probability distribution of each parameter. This distribution will be used by default for Yield and Monte Carlo evaluations.

To set a parameter distribution, edit the part properties and select the Parameter Statistics tab.

In this example image we have 4 parameters with different distributions. The probability distribution column shows a summary of each parameter's settings.

To change a parameter, click the parameter in the Parameter column. The right hand side will be populated with that parameter's settings. Change the distribution, limits and settings then click OK or change parameters.

To create a library part with parameter distributions

You may want a library of parts with 5% precision normally distributed, or perhaps set the precision to an equation variable. To do this,

• place the part in a schematic
• set the part parameter distributions
• right-click the part and select Copy To (and a library) to copy it to a custom part library
• When you place that new library part it will use your set distributions

Distribution List

The distributions are as follows:

None Distribution

Uniform Distribution

Normal Distribution

Lognormal Distribution

Beta Distribution

Discrete Distribution

Using Layouts

Layout creates a board description for sending to a board plotter or for simulating the EM effects using EMPOWER simulation. You can export the layout for milling or etching in standard industry formats such as GERBER, DXF, and GDSII. You can also create a layout from scratch.

Creating Layouts

A layout is the physical arrangement of parts on a circuit board. It creates a board description that you can send to a circuit board manufacturer or use to simulate electromagnetic effects through EMPOWER or Sonnet. You can export a layout for milling or etching in standard industry formats such as Gerber, DXF, and GDSII. You can create a layout based on a schematic, from scratch, or from artwork imported from a file.

You can create a layout from scratch or based on a schematic.

To create a design with a layout:

1. Click the New Item button *( ) on the Workspace Tree toolbar and select *Add Layout from the Designs menu.
2. Define the layout properties and click OK.
3. Use the layout toolbar to add metal to the layout.
4. To add parts to a layout, place them in the associated schematic.

To create a design with a layout based on a schematic:

1. Create a design with a schematic.
2. Use the Part Selector to add parts to your schematic.
3. Right-click the Schematic tab and select Add Layout.
4. Select a component and click the Change Footprint button ( ) on the Layout toolbar to change the footprint used for specific components. For example, change the footprint used by a specific capacitor to a larger or smaller footprint.
5. Move and rotate footprints to the positions you want.
6. Place lines and arcs as required to connect footprints and resolve the rubber band lines.
7. Place any other required objects, such as text, connectors, non-schematic footprints, and ground planes.
8. Send the finished layout to a printer, plotter, or file.We can add a layout to our current design..

The layout is automatically generated and added to the design.

Advanced technique - multiple windows

Select Window / New Window from the menu, then resize and rescale ( hint: use Ctrl+Home to maximize the parts ) the schematic to get this..

Changing Layout Properties

Changing Layout General Properties

Use the Layout Properties General page to change the general properties of a layout.

To change the general properties of a layout:

1. Click Layout on the Genesys menu and select Layout Properties.
2. Click the General tab.
3. Make the changes you want.
4. Click OK.

• Designs to Include - This grid shows all available designs to place on the layout. If a box is checked, the layout will contain footprints and rubber band lines corresponding to the parts in that design. These footprints and rubber-bands will automatically update as needed.
• Drawing Style - This is the fill mode for all metal filled objects (lines, rectangles, polygons, etc).
  • Solid Drawing Mode - Classic opaque fill.
  • "X-Ray" Drawing Mode - Semi-Transparent fill that allows users to see overlapping layers.
  • Hollow Drawing Mode - Emphasizes edges, with a faint interior fill.
• Units - The available units for dimensioning objects on the layout. If you enter a number for a custom unit, simply use a constant multiplier for converting the unit to millimeters. Some common numbers are:

  mm	1
  mils	.0254
  meters	1000
  inches	25.4

• Object Dimensions - Default sizes for most commonly used objects. These numbers define the default dimensions line and pad widths, and the drill diameter for viaholes.
• Box Settings - Determines how the page is displayed on the layout screen. You can use the page as a board edge indicator, for use in placing the footprints. This box also corresponds to the EMPOWER box. The following options are available:
  • Widths - The available widths for lines and arcs. The widths shown here are available in the Line Width combo box on the main LAYOUT screen.
  • Remove - Removes the selected width from the Widths box (see above).
  • Add New - Adds a new width to the available list in the Widths box (see above).
  • Grid Spacing - The on-screen vertical and horizontal grid spacing, using the selected units. Parts are placed on this grid by default, so this number determines the resolution for part placements.
  • Grid Spacing X, Grid Spacing Y - These control the cell size for the EMPOWER run as well as the grid snap feature in LAYOUT. When using the EMPOWER Grid Style, there will be LAYOUT snap points between each grid line which allow lines to be centered between two grid points if necessary. They are often referred to as dx and dy and should be small with respect to a wavelength at the maximum frequency to be analyzed, preferably less than l/20 and always less than l/10. These parameters correspond directly to the DELTA statement in the TPL file.
  • Show EMPOWER Grid - Turning on this check box forces LAYOUT to display the rectangular EMPOWER grid. It also allows different grid spacings in the X and Y dimensions. It is strongly recommended to turn this check box on whenever you are creating a layout for EMPOWER.
  • Box Width (X,Y) - The desired width and height of both the page and the surrounding EM analysis box, using the units selected in the Units box.
  • Origin - The origin for mouse cursor measurements. The on-screen coordinates display information relative to this origin. The absolute origin is at the lower left of the page. To specify a new origin, enter coordinates relative to the absolute origin, using the selected units. For example, if your page is 100 x 200 mils and you want the origin at the upper left, you would enter 0, 100.
  • Show Box (Check box) - Shows or hides the page boundary.
  • Show Grid Dots (Check box) - Shows or hides the part placement grid.
• Drawing Options - The following options are available:
  • Port Size - The size (using the current units) for drawing ports.
  • Rotation Snap Angle - The incremental angle (in degrees) used for rotating objects. This can be any number, but should be positive and < 360.
  • Multi Place Parts (Check box) - Turns on or off multiple placement. In the main LAYOUT window, you click an object button (such as the Line button), to place an object on the layout. Normally, the object button must be selected every time the object is to be placed. The Multi Place Parts option allows you to place as many parts as you like by selecting the object button only once. Press Escape when done placing parts.
  • Default Viahole Layers - The Start Layer and End Layer combo boxes control the default layers for the viaholes. These layers can be overridden individually for each viahole if necessary. Currently, viaholes in EMPOWER can only go from the metal layer through one substrate layer to either the top or bottom cover.

Changing Layout Layer Properties

Use the Layout Properties Layer page to make changes to any of the layers in a layout.

To change the general layer properties of a layout:

1. Click Layout on the Genesys menu and select Layout Properties.
2. Click the General Layer tab.
3. Use the Show Columns check-boxes at the top to control which cells are displayed in the information grid.
4. Make the changes you want.
5. Click OK.

• Name - The name assigned to each layer. This name is used throughout the program to identify the layer. Although you can type anything for the layer name, you should limit the length to about 12 characters, since combo boxes within the program are not wide enough to display lengthy names.
• # - Layer number
• Color - Shows the selected color for each layer. Click the button for any layer to select another color.
• Layer Type - Identifies the layer type. Available options are:
  • None - This layer is considered blank (it is not used).
  • Metal - All conductive traces and pads go on a metal layer.
  • Substrate - Separates metal layers, and is used to indicate board dimensions. Any cuts or holes in the board (screw holes, etc.) go on a substrate layer.
  • Silk - Silk screen is used for labeling on the final board. It is often white or yellow for easy identification.
  • Mask (Solder Mask) - This is a negative layer - objects on this layer indicate an absence of solder mask. This layer is automatically generated from pads and viaholes.  

    Note: Momentum will project mask layer objects onto the closest metal layer (as copper).

  • Assembly - Indicates exact positions for component placement. It is used as a diagram for placing components at the production stage, and does not actually get used during board creation.
  • Paste - Indicates where solder paste should be placed.
• Hide - When selected, the corresponding layer is not shown in the layout.
• On Bottom (Mirrored) - When selected, the corresponding layer is mirrored (shown reversed) in the layout. This is useful for bottom layers, which would be reversed when viewing the top layer.
• Plot - Selects whether to plot the corresponding layer, when generating output (printing, exporting as Gerber, etc.)
• Etch Factor - Adds an etch factor to the corresponding layer, using the Layout units (mils, etc.) selected on the General tab.
• Use - Check this box to include the corresponding layer in the EM simulations (Momentum and/or Empower); uncheck it to omit the layer from EM simulations.
• Momentum-only Parameters:
  • Use Layer Mesh Density - When checked, Momentum will override its default layer mesh density with the per-layer value specified in the next column on the right.
  • Mesh Density - The mesh density, specified as an integer number of cells / wavelength; the default is 30.
  • Use Layer TL Mesh - When checked, Momentum will override its default layer transmission line mesh setting with the per-layer value specified in the next column.
  • TL Mesh - Transmission Line Mesh - An integer number of cells / width.  0 is automatic.
  • Edge Mesh - When checked, Momentum will override its default edge mesh width setting with the per-layer value specified in the next column.
  • Edge Mesh Width - The width of the edge mesh, using the Layout units (mils, etc.) selected on the General tab.
  • Via Model
  • Default - Use the via setting specified in the Momentum GX analysis.
  • Lumped - simulate the via using lumped elements.
  • 1D, 2D, 3D - Use 1 (wire), 2 (planar - no horizontal currents), or 3-dimentional (spacial - includes horizontal currents) simulation for the via.
• Strip Model - not available when the layer is a "physical slot"
  • Default - Use the strip model setting specified in the Momentum GX analysis.
  • 2D, 3D - Use 2 or 3-dimensional simulation.
• Type - Other entries in this table are different for each type of layer. To find help on each column, see the section below for the type of layer: Top/Bottom Cover, Air Above/Below, Metal, or Substrate layers.
• Top Cover & Bottom Cover - Describes the top and bottom covers (ground planes) of the circuit. Types include:
  • Lossless: The cover is ideal metal.
  • Physical: The cover is lossy. These losses are described by Rho (resistivity relative to copper).  Momentum assumes a cover thickness of 0, while Empower uses the Thickness and Surface Roughness parameters as well.
  • Electrical: The cover is lossy and is described by an impedance or file. See the description below under metal for more information.
  • Open: In Momentum, no cover will be simulated, also "Open" is not supported in box simulation mode.  In Empower (which always uses a box), the design is simulated as if the box walls and uppermost substrate/air layer extend up or down forever (an infinite tube).  In earlier versions of Genesys, this option was known as "Semi-Infinite Waveguide".
  • Magnetic Wall: The cover is an ideal magnetic wall. This setting is only used in advanced Empower (no Momentum) applications.
  • Substrates: Choosing a substrate causes the cover to get the rho, thickness, and roughness parameters from that substrate definition. We recommend using this setting whenever possible so that parameters do not need to be duplicated between substrates and layouts.  Momentum ignores Thickness and Surface Roughness. For cover it always uses 0 thickness.
• Air Above & Air Below - The presence of air at the top of the box (as in microstrip) or the bottom of the box (as in suspended microstrip) is so common that special entries have been provided for these cases. Checking the box to turn these layers on is the equivalent of adding a substrate layer with Er=1, Ur=1, and Height (in units specified in the Dimensions tab) as specified.  For "Open" cover the Height of the cover air is ignored, when the other Air dielectric parameters (Er, Ur, Tand) define the free space dielectric parameters.

  Caution: When setting up a new circuit, be sure to check the height of the air above, as it is often the only parameter on this tab which must be changed, and is therefore easily forgotten.

• Metal Layers - Metal layers are used for metal and other conductive material such as resistive film. The following types are available:
  • Lossless: The layer is ideal metal.
  • Physical: The layer is lossy. These losses are described by Rho (resistivity relative to copper), Thickness, and Surface Roughness.
  • Electrical: The layer is lossy and is described by an impedance or file. This type is commonly used for resistive films and superconductors. If the entry in this box is a number, it specifies the impedance of the material in ohms per square. If the entry in this box is a filename, it specifies the name of a one-port data file which contains impedance data versus frequency. This data file will be interpolated/extrapolated as necessary. See the Device Data section for a description of one-port data files.
  • Substrates: Choosing a substrate causes the layer to get the rho, thickness, and roughness parameters from that substrate definition. We recommend using this setting whenever possible so that parameters do not need to be duplicated between substrates and layouts.

    Caution: Unless thick metal is selected, thickness is only used for calculation of losses. It is not otherwise used, and all strips are calculated as if they are infinitely thin.

Metal layers have additional settings available:

• Metal Thickness - Thickness of the metal layer on a substrate.
• Rho - "Resistivity (relative to copper) is usually 1.0.
• Current Direction - Specifies which direction the current flows in this layer. The default is along X and Y. "X Only" and "Y Only" can be used to save times on long stretches of uniform lines. "Z Up", "Z Down", "XYZ Up", and "XYZ Down" allow the creation of thick metal going up/down to the next level or cover.
• Thick Metal - Checking this box instructs the EM analysis to model the metal including thickness. Empower does this by putting two metal layers close together, duplicating the traces on each, and connecting them with z-directed currents. If thick metal is used, then Current Direction is ignored.
• Element Z-Ports - Specifies the default direction for automatically created element ports, either to the level above or to the level below. Generally, you should choose the electrically shortest path for this direction.
• Physical Slot - Slot Type - In Momentum, if the Momentum Slot-Type combo-box is set to "Slot", check this box to swap the metal and non-metal areas of the metal layer.  (In Strip mode, this setting is ignored).  In Empower, check this box to simulate the non-lossless-metal areas (as opposed to the metal areas). Use this for ground-planes and other layers which are primarily metal. Do not use this for lossy layers. See your Empower manual for details.
• Rough - Check this box to specify metal roughness in Empower. (This field is ignored by Momentum.)
• Substrate Layers - These layers are used for substrate and other continuous materials such as absorbers inside the top cover. An unlimited number of substrate/media layers can be used. The following types are available:
  • Physical w/Tand: The layer is lossy. The layer is described by Height (in units specified in the Dimensions tab), Er (relative dielectric constant), Ur (relative permittivity constant, normally 1), and Tand (Loss Tangent).
  • Physical w/Sigma: The layer is lossy. The layer is described by Height (in units specified in the Dimensions tab), Er (relative dielectric constant), Ur (relative permittivity constant, normally 1), and Sigma (Bulk Conductivity).
  • Substrates: Choosing a predefined Substrate causes the cover to get the height, Er, Ur, and Tand parameters from that substrate definition. We recommend using this setting whenever possible so that parameters do not need to be duplicated between schematics and layouts.

    Caution: For true stripline (triplate), be sure to check the Use 1/2 Height check box if you are using a Substrate. This forces Empower to use 1/2 of the Substrate height for each substrate (above and below) so that the total height for both media layers is correct.

Substrate layers have additional settings available:

• 1/2 Height - If the layout is a stripline circuit and is using a named substrate, checking this box forces Empower to use 1/2 of the Substrate height for each substrate (above and below) so that the total height for both media layers is correct.
• Height - Height (thickness) of the substrate.
• Er - The "relative dielectric constant quantifies a material's ability to store charge when used as a capacitor dielectric, which affects the properties of transmission lines. The higher the constant the higher the energy stored within the capacitor.  Er is defined as the ratio of a material's capacitance to the capacitance of air.  (Air = 1.0)
• Tand / Sigma - Tand and Sigma share the same column, since the parameters are mutually exclusive.  Tand - the "dielectric loss tangent - is defined as the real part of relative permittivity / the Imaginary part of the relative permittivity.  Sigma is the dielectric "Bulk Conductivity" value.
• Ur - The Relative Permeability of the substrate is also know as the magnetic constant is usually 1.0.
• Surface Impedance Value or File - The impedance of the surface of the substrate OR the name of a file Empower (only) to use instead.  This field is only available for metal and covers, when Type is set to Electrical.
  
• Momentum Slot-Type - This setting affects any layer with a check mark in the Physical Slot column.  The combo-box has two choices, which indicate how Momentum should analyze the layout.
  • Strip - Momentum will interpret metal layers with "Physical slot" checked just like Empower, i.e. without swapping the layer's metal and non-metal areas. This allows for the creation of layouts which are compatible with both Empower and Momentum: Empower never swaps metal with non-metal areas in the "physical slot" metal layers - it simulates "Slot" layers internally.
  • Slot - Each layer's "Physical slot" check box indicates that Momentum should swap its metal and non-metal areas.  (Momentum changes the slot layer topology of the layout).  
• Insert Layer - Inserts a new layer at the current cursor position.
• Delete Layer - Deletes the layer at the current cursor position.
• Up / Down - Moves a layer up (or down) in the layer stack.
• Show / Hide All - Shows or hides all the layers (by checking all the check-boxes in the Hide column).
• Use All / Use None - Checks all the "Use" column check-boxes, which indicates which layers will be simulated by Momentum or Empower.
• Load From Layer File - Loads a new layer configuration from a file.  
• Save To Layer File - Saves the current layer configuration to a new file.  Currently, only general and color info is retained (no Momentum, EM, or Empower layer data is saved).

Changing Layout Associations Properties

Use the Layout Properties Associations page to determine which footprint to initially use for each type of design element using the Association table. The Association table is generally modified only when a new layout is created. It is automatically saved using the current name when you close the window, or you can save the table to a new name. You can also load a previously saved table.

• Element Type - The category of parts for which footprints are loaded.
• Default Footprint - The footprint which is selected for the corresponding category (given in the Name column).
• Library - The name of the library containing the footprint for the corresponding category (given in the Name column).
• Change Button - Allows you to select a new footprint for the corresponding category (given in the Name column).
• Current Table - The file name of the current footprint association table.
• Save Table As Button - Saves the current table into a new file.
• Load Table Button - Loads a different footprint association table from a file.

To modify an entry in the Association table:

1. Click Layout on the Genesys menu and select Layout Properties.
2. Click the Associations tab.
3. Scroll the table to find the entry you want.
4. Click the Change button to open the Choose Footprint Library window.
5. Click a footprint library in the Select Library box.
6. Click a footprint in the Available Footprints box.
7. Click OK.

To save the Association table to a new file:

1. Click Layout on the Genesys menu and select Layout Properties.
2. Click the Associations tab.
3. Click the Save Table As button.
4. Type a name in the File Name box.
5. Click Save.

To open a previously saved Association table:

1. Click Layout on the Genesys menu and select Layout Properties.
2. Click the Associations tab.
3. Click the Load Table button.

   Note: If the current table is already modified, a message asks whether to save the current table. Click Yes to continue.

4. Type a name in the File Name box.
5. Click Open.

Changing Layout Font Properties

Use the Layout Properties Fonts page to change the default font properties for a layout. You can change only the font type and size. If you want to change the individual text in a layout, use the Text Properties window.

To change the default font properties of a layout:

1. Click Layout on the Genesys menu and select Layout Properties.
2. Click the Fonts tab.
3. Click a font in the Choose New Default Font box.
4. Type a font size in the Default Size box.
5. Click OK.

• Choose New Default Font - Lists the available fonts. The default font is automatically selected when the dialog is opened. To choose a new default font, simply select another font in this box. All text already placed on the layout will be updated to incorporate the new font. For a description of each font, please refer to Reviewing Layout Fonts.
• Old Default - The old default font. If you have not selected a new font since opening the dialog, this font stays selected in the Choose New Font box. This font will remain the default style if you select Cancel on the dialog, even if you have selected another.
• Default Size - This is the default size for text placed on the layout. Changing this number will update any text already on the layout that has the Use Default Size box checked in its properties box.

Manipulating Layouts

Objects in a layout are manipulated much like objects in any modern drafting or drawing program. Features like selecting objects, dragging, using object handles, grouping, and panning are included.

Changing Object Properties

Object properties windows are used to adjust any properties of an object. These window are especially useful when you must enter exact coordinates for objects. They appear automatically during construction of ports, text, viaholes, and pads.

To change object properties:

1. Double-click any of the following objects in a Layout window:
   • ARC
   • Component
   • EM Port
   • Group
   • Line
   • Pad
   • Polygon
   • Port
   • Pour
   • Rectangle
   • Text
   • Viahole
2. Make the changes you want.
3. Click OK.

Selecting Objects

Generally, you must select objects before you can manipulate them. Objects change color when selected.

To select an object:

1. Click the Select button ( ) on the Layout toolbar. This button indicates that no object is currently being constructed.
2. Click the object you want to select.

To select multiple objects:

1. Click the Select button ( ) on the Layout toolbar.
2. Drag the mouse until a box is drawn completely around the items you want selected.

   Note: The window pans automatically if you drag the mouse off the layout.

To individually select multiple objects:

1. Click the Select button ( ) on the Layout toolbar.
2. Hold down the Shift key while clicking each object. Other selected objects remain selected.

To select all objects:

• Click Edit on the Genesys menu and select All from the Select menu. All the objects in the layout are selected.

To select an object hidden behind other objects:

1. Click the Select button ( ) on the Layout toolbar.
2. Click where the object should be. If several objects overlap, continue clicking in the same spot until the object is selected. The layout cycles through the overlapped objects with each click. Do not click too fast (double-click) because the object's properties window might appear.

   Note: Another method of finding hidden objects is to use the X-ray mode. This makes the parts semi-transparent. You can find this option by using the General tab in the Layout Properties window.

Grouping and Ungrouping Objects

With the exception of port objects, you can combine objects into groups. This keeps objects together as you move or rotate them. You can also nest groups so that one group contains other groups. When objects are grouped, there is no change to the final output generated by the layout.

Whenever any element of a group is selected, the entire group is selected. If you want to ungroup elements after they are grouped, you must break apart the entire group.

To group two or more objects:

1. Select the objects you want to group.
2. Click the Group Objects button ( ) on the Layout toolbar.

To ungroup previously grouped objects:

1. Select the group you want to ungroup.
2. Click the Ungroup button ( ) on the Layout toolbar.

Converting a Component to a Group

When a component is placed in a layout, you can make only simple changes to it:

• Move, rotate, or move the component to a new layer.
• Change or remove text.
• Move text using object handles.
• Hide the silk screen using the Component Properties window.

If you need to make other changes to the object, use the Footprint editor. However, if the change is unique, such as removing unused pins from an edge connector, make the change in the Layout window by first converting the component to a group.

To convert a component to a group:

1. Click the Component Footprint button ( ) on the Layout toolbar to place the component if it is not already in the layout.
2. Select the component you want to group.
3. Click the Group Objects button ( ) on the toolbar.

   Note: If a message appears stating you cannot change the object to a group because it has associated schematic elements, follow the instructions in the Deleting Objects section to remove the link.

Using Object Handles

You can modify objects in various ways using object handles. Object handles are small squares that appear when an object is selected. You can manipulate object handles only with a mouse.

On rare occasions, you might want to manipulate object handles without snapping to the grid, nodes, or a specific angle. Be aware that when doing so, it is easy to break electrical connections or to rotate parts to nonstandard angles, so only do so when necessary.

To use an object handle:

1. Select the objects you want to move.
2. Drag an object handle to manipulate the object. An outline image updates as changes are made.

   Note: The window pans automatically if you drag the mouse off the layout.

To use an object handle without snapping to grid, nodes, or angles:

1. Select the objects you want to move.
2. Hold down the Shift key and drag an object handle to manipulate the object. An outline image updates as changes are made.

   Note: The window pans automatically if you drag the mouse off the layout.

Moving Objects

Often, you must move objects to complete a layout. In addition, on rare occasions, you might want to move objects to a point not on the grid.

To move an object:

1. Select the object you want to move.
2. Drag the mouse until the outlined image is in the location you want. Do not drag using an object handle. The image snaps to the grid.

   Note: The window pans automatically if you drag the mouse off the layout.

To move an object without snapping to grid or nodes:

1. Select the object you want to move.
2. Hold down the Ctrl key and drag the mouse until the outlined image is in the location you want. Do not drag using an object handle.

Cutting, Copying, and Pasting Objects

You can cut, copy, or paste layout objects. When you cut an object, you remove it from the layout. Copying an object leaves the object in the layout. Once cut or copied to the buffer, you can paste duplicates of objects back to the layout.

Cutting and pasting objects allows for the easy duplication of objects. The layout remembers the last cut or copied object until you exit Genesys. Only one cut or paste buffer is used for both the standard Layout editor and the Footprint editor, allowing you to cut and paste objects between them.

You can paste as many duplicates as you want. Duplicates are always pasted to the same place as the original objects. You can move them to a different location.

To cut an object:

1. Select the object you want to cut.
2. Click Edit on the Genesys menu and select Cut.

To copy an object:

1. Select the object you want to copy.
2. Click Edit on the Genesys menu and select Copy.

To paste duplicates of the last object cut or copied:

1. Click Edit on the Genesys menu and select Paste.
2. Move the object to the location you want.

   Note: Objects you paste are not associated with schematic elements even if the original objects have associated schematic elements.

Connecting Layout Parts Automatically

A layout can automatically snap parts together. This is very useful for microstrip and stripline circuits that have parts automatically created from a schematic (such as files from M/FILTER). For example, in two easy steps you can turn this layout:

into this layout:

To automatically connect objects:

1. Select the objects you want to connect.
2. Click Layout on the Genesys menu and select Connect Selected Parts.

Adding Lines, Rectangles, and Arcs

Lines and arcs are typically used to make electrical connections. In layouts strictly for EMPOWER, you should turn off the round ends for these lines and arcs. For most other purposes, you should use round ends, because they make better connections. Also, in layouts for EMPOWER, you might find it easier to use rectangular objects for most purposes.

Using the Layout toolbar, you can set round or square ends, width, and layer information for lines and arcs. You can also make lines orthogonal (90 degrees) using the Layout toolbar or the Line properties window.

To draw a straight line:

1. Click the Line button ( ) on the Layout toolbar.
2. Click in the layout at the starting point of the line.
3. Drag your mouse to the ending point of the line.

To draw two connected orthogonal (90 °) lines:

1. Click the Line button ( ) on the Layout toolbar and draw a straight line.
2. Draw a second line perpendicular to the first line and connect one end of the second line to one end of the second line (green dots).
3. Click one of the lines.
4. Press the O key to convert the line to two orthogonal segments.
5. Press the F key to flip the orthogonal direction, if necessary.

To draw a rectangle:

1. Click the Rectangle button ( ) on the Layout toolbar.
2. Click in the layout where you want the upper-left corner of the rectangle.
3. Drag the mouse to the lower-right corner of the rectangle.

To draw an arc:

1. Click the Arc button ( ) on the Layout toolbar.
2. Click in the layout at the starting point of the arc.
3. Drag your mouse to the ending point of the arc. You see a thin line between the starting point and the mouse position as you drag the mouse.
4. Move the mouse to define the curvature of the arc.
5. Click to finish drawing the arc.

Deleting Objects

When you delete objects from a layout, the objects are not placed into a buffer the same as when you cut or copy objects. Deleting removes objects from the program, and you cannot paste deleted objects back into the layout.

To delete layout objects:

1. Select the object you want to delete.
2. Click Edit on the Genesys menu and select Delete.

To remove a schematic from a layout:

1. Click Layout on the Genesys menu and select Layout Properties.
2. Click the General tab.
3. Click the check box for your layout in the Designs to Include box.
4. Click OK. All parts and rubber bands from the schematic are removed.

To remove a layout object with an associated schematic element:

1. Click Layout on the Genesys menu and select Layout Properties.
2. Click the Schematic tab.
3. Click the schematic element that corresponds to the layout element you want to delete.
4. Double-click the element to open its properties window.
5. Click the Layout button.
6. Click either the Replace Part With Open or Replace Part With Short button.
7. Click OK to close the Layout Options window.
8. Click OK to close the properties window.

Changing an Association Table

The Association table is used whenever a new layout is created or any time a layout is updated with new elements in the design. It is only used once for any given element. Association tables are used by a layout to determine which footprint to initially use for each type of design element. You can later change this footprint from within the layout to override the Association table.

Whenever a file containing a layout that depends on a schematic is loaded, the date of the schematic file is checked against the date of its Association table. If the Association table is newer than the schematic file, a message appears. This message is useful to help ensure that outdated footprints are not accidentally used in a layout.

The following information helps clarify the use of an Association table:

• A new schematic is created containing a capacitor, C1.
• A new layout is created. In the Association table, the entry for CAP shows the library name SM782.LIB, and the footprint shows the name CC1005 [0402] Chip Capacitor. This footprint is automatically placed in the layout for the capacitor.
• If the Association table is later changed, it has no effect on the capacitor that was already placed.
• If the footprint for the existing capacitor is changed (for example, to CC2012 [0805] Chip Capacitor), it is not automatically changed back to the Association table entry.
• Even if the schematic is modified, the capacitor does not automatically move or change back to the Association table entry.
• If the schematic element is deleted, the corresponding part in the layout is deleted.
• If the Association table contains a multi-part footprint (such as a quad op-amp footprint), all devices in each component is used before beginning a new one. For example, if a schematic contains seven op-amps and the OPA entry in the Association table contains a quad op-amp footprint, two components are placed. The first component uses all four devices, and the second component uses three of its four devices.

Changing the Component Footprints

Once a component is automatically generated for a schematic element, you can change its footprint. The component continues to use the new footprint even if the schematic is modified.

To change a component's footprint:

1. Select the component you want to change.
2. Click the Change Footprint button ( ) on the Layout toolbar to open the Choose Footprint Library window.
3. Click a footprint library in the Select Library box.
4. Click a footprint in the Available Footprints box.
5. Click OK.

Adding Text and Changing Fonts

You can add text to your layout to label objects or to convey information on silk layers. Included in Genesys is a variety of different fonts that you can use for text objects in a layout. You can also use your own TrueType font.

Adding Text to Layouts

Once you add text to a layout, you can edit it, change the font, or change the size.

To add text to a layout:

1. Click the Text button ( ) on the Layout toolbar.
2. Click in the layout where you want to place text. The Text Properties window appears.
3. Type the text in the Text box.
4. Make any other changes you want.
5. Click OK.

To change the text in an existing text object:

1. Select the text you want to edit.
2. Click Edit on the Genesys menu and select Parameters to open the Text Properties window.
3. Edit the text in the Text box.
4. Click OK.

To change the font used by an existing text object:

1. Select the text whose font you want to change.
2. Click Edit on the Genesys menu and select Parameters to open the Text Properties window.
3. Select a font in the Font list.
4. Click OK.

To change the size of an existing text object:

1. Select the text whose size you want to change.
2. Click Edit on the Genesys menu and select Parameters to open the Text Properties window.
3. Clear the Use Default Size check box if it is selected.
4. Type the new text size in the Text Size box. The size is given in the units specified in the General tab of the Layout Properties window.
5. Click OK.

Changing the Default Text

Most text placed in a layout is associated with a footprint, and you cannot control the font and size. However, you can change the default font and size, which changes the text for all other objects simultaneously. This process adjusts the font and size of all text objects that are marked (in their properties windows) to use the default font or the default size. This includes all text in footprints from libraries supplied with layouts.

To change the default font and size:

1. Click Layout on the Genesys menu and select Layout Properties.
2. Click the Fonts tab.
3. Click a font in the Choose New Default font list.
4. Type a new size in the Default size box.
5. Click OK.

Reviewing Layout Fonts

The provided fonts are all in Eagleware-Elanix font (.EWF) format, which is a proprietary font format. They are located in the Font subdirectory of the main Eagleware-Elanix directory (C:\Genesys\Font). If additional fonts are needed, you can copy TrueType fonts (.TTF) into this directory, with the following constraints:

• There are many different TrueType font formats available and not all are guaranteed to work in a layout.
• When text using a TrueType font is converted to Gerber format, each letter of the text is converted into a filled polygon. Extremely large Gerber files result if TrueType fonts are used extensively. TrueType fonts are best used for highlights and user instructions, such as a company's name and logo or jumper settings. In contrast, the size of text in a Gerber file using an .EWF font is roughly proportional to the complexity of the .EWF font.

Layout includes the following fonts (complexity directly relates to Gerber file size):

Reviewing Nodes and Rubber Band Lines

Nodes (shown as green dots) are shown in a layout where you can make electrical connections. Any objects placed or handles moved snap automatically to a nearby node to ensure a true connection. These nodes allow consistent electrical connections even when parts do not line up on a grid. (If you do not want to snap to the grid or to a node, hold down the Shift key while moving or constructing an object.)

Rubber band lines (shown as thin white lines) are shown in a layout where you can make electrical connections. These connections are determined from the designs. The rubber band lines update whenever the designs change. Rubber band lines disappear automatically as connections are made.

Rubber band lines show only one possible set of connections. For example, figure (a) below shows three elements that can connect. The most obvious connection method is shown in figure (b). However, you do not need to follow the rubber band lines exactly. The connections in figure (c) also resolve the rubber bands because they electrically connect the three nodes.

You cannot use objects other than lines, arcs, or viaholes to resolve rubber bands. For example, if a polygon is placed between two nodes, those two nodes are not considered connected, even if the polygon appears to connect the two nodes.

The automatic resolution, or removal, of rubber band lines is intelligent. You can use any combination of lines, arcs, and viaholes to make connections. The layout resolves the rubber bands properly no matter how complex the interconnections.

Reviewing Rubber Band Resolutions

You can use the Statistics window (sometimes referred to as a scorecard) to review your progress resolving rubber bands. This window tells how many rubber bands there were initially and how many rubber bands are successfully resolved.

To review your progress resolving rubber bands:

• Click Layout on the Genesys menu and select Statistics.

Using Layers

A layout recognizes six distinct layer types, which are considered a Layer table:

• Metal – Used for all conductive traces. Only traces on metal layers are used to automatically resolve rubber bands.
• Silk – Used for labels on the final board. It is generally white or yellow on the production board. Silk screen objects should not overlap with solder mask objects.
• Substrate – Used to designate cuts in the circuit board. If automatic cutting is employed, you should use only straight or orthogonal rounded-end lines. The center of these lines represents the saw path for cutting.
• Assembly – Used to indicate exact placement of components. This is an intermediate layer. It is only used as an aid in the production process and is not seen on the final board.
• Mask (Solder Mask) –  Objects indicate an absence of solder mask. This is a negative layer. It is automatically generated from pads and viaholes and generally does not require user intervention.
• Paste (Solder Paste) – Objects indicate places to use solder paste. If a solder paste layer is required, you must manually generate it.

Reviewing the Types of Layers

A layout can deal with almost any board configuration, from a simple one-layer board to a complex sixteen or more layer board. Mixed media, such as combining microstrip with stripline, are easily accommodated. There are up to 128 different layers to use, and you can use each type as often as you want. Some possible layer setups are:

For a simple, single-layer board or prototype with a solid ground plane (no traces or cutouts on the ground plane) (SIMPLE.LYR):

• Silk
• Metal

For a typical single-layer production board (SINGLE.LYR):

• Top Assembly
• Top Silk
• Top Mask
• Top Metal
• Substrate
• Bottom Metal (Mirrored)
• Bottom Mask (Mirrored)
• Bottom Silk (Mirrored)
• Bottom Assembly (Mirrored)

For a four-layer production board (FOUR.LYR):

• Top Assembly
• Top Silk
• Top Mask
• Top Metal
• Substrate 1
• Metal 2
• Substrate 2
• Metal 3
• Substrate 3
• Metal 4
• Substrate 4
• Bottom Metal (Mirrored)
• Bottom Mask (Mirrored)
• Bottom Silk (Mirrored)
• Bottom Assembly (Mirrored)

Selecting a Drawing Style

Several drawing styles are available to facilitate the construction and manipulation of objects on various layers. The drawing styles are:

• Solid (Opaque)
• X-ray Mode
• Hollow

To select a drawing style:

1. Click Layout on the Genesys menu and select Layout Properties.
2. Click the General tab.
3. Click a button to indicate the drawing mode.

   Note: Use the hollow or x-ray modes to make all objects visible, regardless of the layer.

4. Click OK.

Hiding Layers

Often it is necessary to turn off the display of certain layers. For example, if an assembly layer is not being modified, you can hide it:

To hide a layer:

1. Click Layout on the Genesys menu and select Layout Properties.
2. Click the Layer tab.
3. Scroll down to the layer you want.
4. Click the check box in the Hide column.
5. Click OK.

Mirroring Layers

Be sure to mirror layers on the back side of a board. For example, when viewing from the top of the board, the lettering and component footprints are reversed. When a layer is marked as mirrored, all future text and components placed on that layer are mirrored.

To mark a layer as mirrored:

1. Click Layout on the Genesys menu and select Layout Properties.
2. Click the Layer tab.
3. Scroll down to the layer you want.
4. Click the check box in the Mirror column.
5. Click OK.

Using Layer Files

You can save layer setups into files for later use in other boards. Unlike Footprint library files, layer files (LYR) do not remain associated with a particular layout. If layer settings are saved to an LYR file and the settings are later changed in the current layout, the LYR file does not update automatically. If the LYR file is later changed, no layouts are changed unless the LYR file is explicitly loaded.

To save layer settings into an LYR file:

1. Click Layout on the Genesys menu and select Layout Properties.
2. Click the Layer tab.
3. Click the Save to Layer File button.
4. Type a name in the File Name box.
5. Click Save.

To load layer settings from an LYR file:

1. Click Layout on the Genesys menu and select Layout Properties.
2. Click the Layer tab.
3. Click the Load from Layer File button.
4. Type the name of the Layer file to load in the File Name box.
5. Click Open.

Adding Footprints to Layouts

A footprint is a pattern of metal, silk, and other layers that generally corresponds to a physical part, such as SOT23 or 0603 packages. You can create or edit footprints using the Footprint editor and then save the footprints into a footprint library. If a footprint library is changed, all components in all layouts using that footprint are changed. You can associate footprints with parts using the Association table or by editing a part in the Part Selector to add a footprint property to the part.

Creating and Saving Footprints

You can create and save footprints to use in other layouts. Store the footprints in a library you create.

To create a new footprint:

1. Click Tools on the Genesys menu and select New Footprint from the Footprint Editor menu.
2. Place objects in the Footprint editor.
3. Place pads wherever you want to make solder connections.
4. Place silk screen objects (for example, designators).
5. Place ports. Always place ports before saving a footprint.
6. Click Tools on the Genesys menu and select Save Footprint from the Footprint Editor menu to save the footprint in a library file.

To save an existing footprint:

1. Click Tools on the Genesys menu and select Save Footprint from the Footprint Editor menu.
2. Click the library that contains the old footprint in the Select Library box.
3. Click the footprint in the Available Footprints box.
4. Click OK.

To add a new footprint to an existing library:

1. Click Tools on the Genesys menu and select Save Footprint from the Footprint Editor menu.
2. Click the library to add the footprint to in the Select Library box.
3. Click <New Object> in the Available Footprints box.
4. Click OK.
5. Type a new name for the footprint in the box.
6. Click OK.

To create a new library and save the current footprint into it:

1. Click Tools on the Genesys menu and select Save Footprint from the Footprint Editor menu.
2. Click <New File> in the Select Library box.
3. Ensure that <New Object> is selected in the Available Footprints box.
4. Click OK.
5. Type a name for the new library file in the File Name box, and then click Save.
6. Type a new name for the footprint in the box.
7. Click OK.

Creating Multi-Part Footprints

Multi-part footprints (for example, bus resistors) are created by assigning port numbers to different parts within the footprint. The first part (schematic element) within the footprint is usually labeled part A. For example, the first resistor in a bus package is part A.

The first pin of part A is labeled pin 1, so the port that designates the first pin of part A is labeled A1 on the footprint. This is shown in the Footprint Example 2 section.

Using the Footprint Libraries

Four footprint libraries are included with a layout. You can use these libraries to add footprints to your layouts. Certain footprints, such as 14-pin DIP packages, have hundreds of possible uses. They can be a quad op-amp or a multiple transistor package. Port assignments in these devices are sequential, such as pin 1 through 14. When you use such a device, you must create a specific footprint with different port numbering.

You can create new footprints based on a footprint in one of these footprint libraries. Just load an existing footprint, modify it as necessary, save it with a new name, and store it in a new footprint library.

• SM782.LIB - A library based on the IPC SM 782 surface mount standard (SM782.LIB). There footprints are from the Institute for Interconnecting and Packaging Electronic Circuits SM 782 standard, Revision A, August 1993. You can contact IPC at 7380 N. Lincoln Ave., Lincolnwood, IL, 60646.
  This standard is very specific on dimensions for the landing patterns. In general, maximum dimensions are used in creating the library footprints.
  The silk screens are generated by Agilent based on general industry convention determined by reviewing several PWBs.
• LEADED.LIB - A leaded component library (LEADED.LIB). These are leaded element footprints. They are generated from data provided by the following manufacturers: Coilcraft, ITT, J.W. Millar, Kyocera AVX, Motorola, Murata, Panasonic, R-Ohm, and Toko.
  The through holes in this library are typically 20 mils larger than the lead diameter, and the pads are 35 mils larger than the through hole diameter. In certain active devices, such as DIP ICs and TO-92 transistors, sufficient spacing is not available and smaller margins are used.
  The silk screens are generated by Agilent based on general industry convention determined by reviewing several PWBs.
• HPLIB.LIB - A library of sample footprints (SAMPLE.LIB). These transistor footprints are taken from the HP Communications Components GaAs & Si Products data book.
• SAMPLE.LIB - A small library of active RF devices (HPLIB.LIB). These miscellaneous leaded and surface mount footprints are for objects such as mounting screws, coplanar grounds, grounds with via holes, grounds with wagon wheel pads and a sample quad operational amplifier.

Generating Transmission Lines Automatically

In typical digitally oriented PCB layout or CAD programs, you must manually generate transmission lines and their junctions (discontinuities). This is often tedious, time consuming, and error prone.

In contrast, a layout automatically generates footprints for microstrip and stripline elements entered in a schematic. The dimensions of these footprints are automatically determined from the schematic elements and substrate parameters, ensuring that the board is laid out exactly as simulated. The table that follows lists [ element types|superstar_elements] that are handled automatically by a layout (and, correspondingly, are not listed in the Association table).

When a layout containing these elements is created, footprints for these elements are generated automatically and are connected by rubber bands initially just like any other elements. The main difference is that instead of connecting these elements with lines, they are normally mirrored, moved, and rotated until their nodes join, eliminating the rubber band lines. You can manually or automatically join these parts.

To automatically join multiple microwave footprints:

1. Select the objects you want connected.
2. Click Layout on the Genesys menu and select Connect Selected Parts.

To manually join together two microwave footprints:

1. Select the first object.
2. Click the Mirror button ( ) on the Layout toolbar if the first object must be mirrored.
3. Use the object handles to rotate and move the object as necessary. For unusual positioning or rotation angles, use the Component Properties window.
4. Select the second object.
5. Click the Mirror button on the Layout toolbar if the second object must be mirrored.
6. Use the object handles to rotate the object as necessary. For an unusual rotation angle, use the Component Properties window.
   A rubber band now connects a node on the first object (node A) with a node on the second object (node B).
7. Drag node B to node A. The two objects snap together, eliminating the rubber band.

Placing Component Objects

Component objects in a layout represent lumped elements, such as resistors, transistors, and integrated circuits. You can also use component objects if a complex pattern needs repeating in many layouts, such as connectors.

All components are based on a footprint in a footprint library. If a footprint library is changed, all components in all layouts using that footprint are changed.

If a layout is based on one or more designs, components and rubber bands are automatically placed corresponding to the design topologies. The General tab of the Layout Properties window controls which designs to include in the layout. You can use the Association table to determine which footprint to use for each type of element. If any components are added, modified, or deleted in the designs, the layout components and rubber bands are automatically added, modified, or deleted.

To place a component object:

1. Click the Component Footprint button ( ) on the Layout toolbar.
2. Click the library that contains the footprint in the Select Library box.
3. Click the multi-part footprint in the Available Footprints box.
4. Click OK.
5. Click in the layout where you want to place the component.

Switching Parts in Multi-Part Footprints

Multi-part footprints such as resistor packs or quad op-amp integrated circuits (ICs) are supported in a layout. You can move two or more individual parts with associated schematic elements into a multi-part footprint.

Sometimes, you might want to switch existing component associations. For example, if there are two quad op-amp packages in the layout, each with four associated schematic elements, you can change which part is associated with which element.

To switch parts with associated schematic parts into a multi-part footprint:

1. Select the part you want to switch.
2. Click the Change Footprint button ( ) on the Layout toolbar.
3. Select the desired multi-device footprint from the library window.
4. Choose Switch/Move Parts from the Layout Menu. For the next several steps, help will appear on screen in the status bar.
5. Select the next component to place into the multi-part package.
6. Select the component with the multi-device footprint to place the second component into.
7. A message will appear stating that the original component no longer is associated with any schematic elements and asking if the original part should be deleted. Normally, you will press the "Yes" button.
8. Repeat steps five through seven for any remaining individual parts to place into the multi-part footprint.

Sometimes, you may want to switch existing component associations. For example, if there are two quad op-amp packages on the layout, each with four associated schematic elements, you may want to change which device is associated with which element.

To switch schematic part associations between two component devices:

1. Choose Switch/Move Parts from the Layout Menu. For the next several steps, help will appear on screen in the status bar.
2. Select the first component's device to switch. This component must have an associated schematic element.
3. Select the multi-device footprint to switch with or move into.
4. If a message appears stating that the original footprint no longer is associated with any schematic elements and asking if the original part should be deleted, you will normally press he "Yes" button.

Loading and Merging Footprints

To load an existing footprint:

1. Click Tools on the Genesys menu and select Load Footprint from the Footprint Editor menu.
2. Click the library that contains the footprint in the Select Library box.
3. Click the footprint in the Available Footprints box.
4. Click OK to load the footprint.

To merge an existing footprint with the current footprint:

1. Click Tools on the Genesys menu and select Merge Footprint from the Footprint Editor menu.
2. Click the library that contains the footprint in the Select Library box.
3. Click the footprint in the Available Footprints box.
4. Click OK to merge the footprint.

Renaming and Deleting Footprints

You can change the name of a footprint or delete a footprint if it is no longer needed.

To rename a footprint:

1. Click Tools on the Genesys menu and select Modify Footprint Library from the Footprint Editor menu.
2. Click the library that contains the footprint in the Select Library box.
3. Click the footprint in the Available Footprints box.
4. Click the Rename button.
5. Type a new name for the footprint in the New Name box.
6. Click OK.

To delete a footprint:

1. Click Tools on the Genesys menu and select Modify Footprint Library from the Footprint Editor menu.
2. Click the library that contains the footprint in the Select Library box.
3. Click the footprint in the Available Footprints box.
4. Click the Delete button.

Using the Footprint Editor

Layouts in Genesys also include an editor for creating and editing footprints and libraries. The figure below shows a Footprint Editor window.  

To open the Footprint editor:

• Click Tools on the Genesys menu and select New Footprint from the Footprint Editor menu.

Reviewing Layers in the Footprint Editor

The following layers are available in the Footprint editor:

• Top Assembly
• Top Silk
• Top Paste
• Top Mask
• Top Metal
• Sub Above
• Metal
• Sub Below
• Bottom Metal
• Bottom Mask
• Bottom Paste
• Bottom Silk
• Bottom Assembly

For almost all components, place pads on the metal layer and not the top metal layer. Place all silk screen objects on the top silk or bottom silk layers.

Placing Objects in the Footprint Editor

Objects in the Footprint editor are placed exactly the same way that they are placed in the Layout window. Whenever you select an object, the Layout toolbar shows the available options for that object. You can change any of these options before placing the object. The available objects are listed on the toolbar at the top of the Footprint Editor window. They are as follows:

• Lines ( )
• Rectangles ( )
• Arcs ( )
• Polygons ( )
• EM Ports ( )
• Text ( )
• Viaholes ( )
• Pads ( )

To place an object in the Footprint editor:

1. Click the appropriate button on the Layout toolbar.
2. Click in the Footprint editor to place the object.

   Note: If the object's properties window appears, specify the options you want and then click OK.

Placing Pads in the Footprint Editor

You should place pads wherever solder connections are made. Pads always have a node at the center, regardless of the pad shape.

To place a pad in the Footprint editor:

1. Click the Pad button ( ) on the Layout toolbar.
2. Click in the Footprint editor to place the pad.
3. Select the options you want in the Pad Properties window.
4. Click OK.

Placing Ports in the Footprint Editor

You must place ports before you can save a footprint to a library. Ports designate where layout parts connect (for example, lines, arcs, or other footprints). For multiple component footprints such as a quad op-amp IC, ports identify the different components. For example, port A1 is used for pin 1 of op-amp #1. Port D-3 is pin 3 of op-amp #4.

To place a port on the footprint:

1. Click the EM Port button ( ) on the Layout toolbar.
2. Click in the Footprint editor to place the port. The Port Properties window appears.
3. Select the device that the port belongs to from the Device list. For example, if this is the second component in a package, select B.
4. Type the port number in the Port Number box. This is the pin within this device that the port belongs to. For example, if this is pin # 3 of an op-amp (the output), type 3.
5. Make any other changes you want.
6. Click OK.

Using Power and Ground Connections

Some multi-part footprints contain extra ports that are not used by any device (marked with * or None, in the Footprint editor). These ports are most commonly used for power and ground connections and are connected manually; no rubber bands appear to ensure their connection.

Footprint Example 1: 0805 Capacitor

This example demonstrates how to create a layout footprint for an 0805 capacitor in the Footprint editor. The figure below shows the dimensions of a standard 0805 capacitor footprint:

You can create the above example as follows:

1. Create a footprint
2. Place the first pad
3. Place the second pad
4. Draw the silk screen
5. Place the designator text
6. Place footprint ports

To create a footprint:

1. Click Tools on the Genesys menu and select New Footprint from the Footprint Editor menu.
2. Double-click in the Footprint editor to open the Layout Footprint Editor Properties window.
3. Click the General tab.
4. Select mil from the Units list.
5. Click OK.

To place the first pad:

1. Click the Pad button ( ) on the Layout toolbar, and then click in the Footprint editor.
2. Click the Square/Rect button in the Pad Properties window.
3. Type 33 in the Pad Width box.
4. Type 40.6 in the Pad Height box.
5. Select Metal from the Layer list to place the pad on metal.
6. Type 0, 0 in the Location boxes to place the pad center at the origin.
7. Click OK.

To place the second pad:

1. Repeat steps 1-5 above.
2. Type 48.3, 0 in the Location boxes as the second pad location. This sets the center-to-center pad spacing to 48.3 mils as shown in the figure.
3. Click OK.

To draw the silk screen:

1. Click the Line button ( ) on the Layout toolbar.
2. Draw a line in the Footprint editor, and then double-click the line.
3. Type 10 (mils) in the Line Width box.

   Note: To prevent silk screen interference with metal layer objects, all silk is kept at least 10 mils from the nearest metal.

4. Click the Rounded Ends check box to change the line shape to round.
5. Select Top Silk from the Layer list to place the line on the top silk layer.
6. Type -31.5, 35.5 in the Start boxes.
7. Type 79.8, -35.3 in the End boxes.

   Note: The Start and End figures include 10 mils beyond the pad width plus 5 mils for half the silk line width.

8. Click OK.
9. Press the O key to create a 90-degree line.

This figure shows a silk line before pressing the O key:

This figure shows a silk line after pressing the O key:

1. Draw another rounded line on silk from -31.5, 35.3 to 79.8, -35.3.
2. Press the O key to create another angle, and then press the F key to flip the angle. This creates a box around the pads with a 10 mil clearance.

To place the designator text:

1. Click the Text button ( ) on the Layout toolbar.
2. Click in the Footprint editor to open the Text Properties window.
3. Type @DES in the Text box. This allows the schematic element using this footprint to fill in the element designator on the layout.
4. Select Top Silk from the Layer list.
5. Click the Use Default Size check box to allow text sizing later when the footprint is used in a layout.
6. Type 24.15, 50.3 in the Location boxes. This centers the text horizontally and allows a 10 mil vertical clearance for the silk screen box.
7. Click the Center X button for X-justification. This forces the text to always center horizontally and keeps the 10 mil clearance from the part box.
8. Click the Bottom button for Y-justification. Any other Y-justification allows the text to expand downward with increasing size, breaking the 10 mil separation rule.
9. Click OK.

To place footprint ports:

1. Click Layout on the Genesys menu and select Place Footprint Port. 
2. Click the center of the first pad to place a footprint port on that pad. The Port Properties window appears.
3. Type 25 in the Draw Size box.
4. Click OK.
5. Repeat steps 1-4 to place a footprint port on the second pad.

   Note: Be sure to place footprint ports on the same metal layer as the pad.

The final footprint is shown below:

Footprint Example 2: LF347 Quad Op-Amp

This example demonstrates how to construct a footprint for a Texas Instruments LF347 quad op-amp in the footprint editor. The figure below shows the dimensions of the LF347 package:

For this example, you set the current units to mils and place the pads first. Because this is a leaded part, use through holes at each pad location. The pins are 100 mils apart, so set the pad center spacing at 100 mils. The hole diameter must be at least 21 mils to accommodate the pins, but not exceed 33 mils, which is the width of the seating flange. For this example, the pad width is 75 mils, and the through-hole diameter is 30 mils.

The figure below shows a pin-out diagram for the LF347 package:

You can create the above example as follows:

1. Place a viahole and pad
2. Place ports for the first op-amp
3. Place the positive power supply port
4. Place ports for the second op-amp
5. Place ports for the third op-amp
6. Place the negative power supply port
7. Place ports for the fourth op-amp
8. Draw a silk screen box inside the pad perimeter
9. Place the designator text
10. Label the type of package

Please note the following:

• Three ports are used for each of the op-amps shown in the pin-out diagram. Each op-amp is considered a part, so the footprint has four parts with three ports each.
• The port numbers are assigned according to the order that the associated schematic element uses. The order is found in the schematic element's diagram in the Reference manual.
• In the OPA model, the non-inverting input is pin 1, the inverting input is pin 2, and the output is pin 3.

To place a viahole and pad:

1. Create a design with a layout.
2. Click the Viahole button ( ) on the Layout toolbar.
3. Click in the Layout window to open the Viahole Properties window.
4. Type 30 in the Drill Diameter box.
5. Type 0,0 in the Location boxes because this is the first pad.
6. Click the Square/Rect button for the pad shape. This identifies pin 1 during assembly.
7. Type 75 in both the Pad Width and Pad Height boxes.
8. Click OK.
9. Repeat steps 2-7 to place a viahole with a round pad at location 100, 0, which properly spaces the hole centers. Specify 75 mils for the drill diameter and 30 mils for the pad width and height.
10. Place the remaining five pads for the first side at 100 mil increments as in step 8, with the final pad for the first side (labeled pin 7 above) set at 600, 0.
11. Place the remaining viaholes at the same X-offset as the first side, with a Y-offset of 310 mils (the distance given in the first figure above for the pin-to-pin cross dimension). The drill diameter and pad dimensions are the same as before.

To place the ports for the first op-amp:

1. Click the Port button ( ) on the Layout toolbar.
2. Click in the Footprint editor to open the EM Port Properties window.
3. Type 25 in the Draw Size box. This specifies a drawing size of 25 mils for the ports, which is large enough to see against a 75-mil pad.
4. Assign this port to the first op-amp by choosing "A" in the "Device:" combo.
5. Type 3 in the Port Number box. This assigns the op-amp output to pin 1 on the physical package.
6. Select Top Metal from the Layer list. This places the layout objects on the metal layer before connecting to the pad.
7. Type 0, 0 in the Location boxes. This centers the port on the first pad.
8. Click OK.
9. Repeat steps 1-8 to place ports 2 and 1 for device A on top of pads 2 and 3 at locations 100 , 0 and 200, 0.

To place the positive power supply port:

1. Click the Port button ( ) on the Layout toolbar.
2. Click in the Footprint editor to open the EM Port Properties window.
3. Type 300, 0 in the Location boxes.
4. Since this port is not assigned to a schematic object, choose "None" in the Device: combo
5. Type 1 in the Port Number box.

To place ports for the second op-amp:

1. Click the Port button ( ) on the Layout toolbar.
2. Click in the Footprint editor to open the EM Port Properties window.
3. Type 400, 0 in the Location boxes.
4. The device should be set to "B", since this is the second op-amp in the package.
5. Type 1 in the Port Number box. This corresponds to the non-inverting input.
6. Repeat steps 1-5 to place two more ports for device B at locations 500, 0 and 600, 0. Number the ports 2 and 3, corresponding to the inverting input and the output.
   The footprint should look like this:

To place ports for the third op-amp:

1. Click the Port button ( ) on the Layout toolbar.
2. Click in the Footprint editor to open the EM Port Properties window.
3. Type 600, 310 in the Location boxes.
4. The device should be set to "C", and the pin number set to "3".
5. Type 3 in the Port Number box.
6. Repeat steps 1-5 to place two more ports for device C at locations 500, 310 and 400, 310. Number the ports 2 and 1, corresponding to the inverting input and the output.

To place the negative power supply port:

1. Click the Port button ( ) on the Layout toolbar.
2. Click in the Footprint editor to open the EM Port Properties window.
3. Type 300, 310 in the Location boxes.
4. The device should be set to "None".
5. Type 2 in the Port Number box.
6. Click OK.

To place ports for the fourth op-amp:

1. Click the Port button ( ) on the Layout toolbar.
2. Click in the Footprint editor to open the EM Port Properties window.
3. Type 200, 310 in the Location boxes.
4. The device should be set to "D"
5. Type 1 in the Port Number box.
6. Repeat steps 1-5 to place two more ports for device D at locations 100, 310 and 0, 310. Number the ports 2 and 3. corresponding to the inverting input and the output.

To draw silk screen box inside the pad perimeter:

1. Click the Line button ( ) on the Layout toolbar.
2. Click in the Footprint editor to open the Line Properties window.
3. Select Top Silk from the Layer list to place the line on the top silk layer.
4. Type 10 (mils) in the Line Width box.

   Note: To prevent silk screen interference with metal layer objects, all silk is kept at least 10 mils from the nearest metal.

5. Type -32.5, 257.5 in the Start boxes.
6. Type 632.5, 52.5 in the End boxes.
7. Click OK.
8. Press the O key to create a 90-degree line.

   Note: All of the above steps clear the pads by 10 mils, and extends to the edge of the pads on the open ends of the footprint.

9. Draw another 10 mil line on Top Silk from -32.5, 257.5 to 632.5, 52.5. Press the O key to create a 90-degree line and then press the F key to flip the angle.

To place the designator text:

1. Click the Text Button ( ) on the Layout toolbar.
2. Click in the Footprint editor to open the Text Properties window.
3. Select Top Silk from the Layer list.
4. Type @DES in the Text box.
5. Click the Use Default Size check box.
6. Type 300, 357.5 in the Location boxes.
7. Click the Center X button for X-justification.
8. Click the Bottom button for Y-justification.
9. Click OK.

To label the type of package:

1. Click the Text Button ( ) on the Layout toolbar.
2. Click in the Footprint editor to open the Text Properties window.
3. Type LF347 in the Text box.
4. Type 65 in the Size box. This text does not change with the default settings, and it is always the width of the silk screen box.
5. Type 90 in the Angle box. This rotates the text counter-clockwise 90 degrees.
6. Select Top Silk from the Layer list.
7. Type 300, 357.5 in the Location boxes.
8. Set the location to "-47.5,155".
9. Click the Center X button for X-justification.
10. Click the Bottom button for Y-justification. This places the text at the left edge of the silk screen box with a clearance of 10 mils.
11. Click OK.

The footprint is now complete. The figure below shows the final footprint:

Using Pads in Layouts

A pad is a flat surface used to make electrical contact. There are three types of pads available: round, square, and wagon wheel. These three pad types are shown in the figure below:

Placing Pads in Layouts

You should place a pad in a layout wherever solder connections are made.

To place a pad in a layout:

1. Click the Pad button ( ) on the Layout toolbar.
2. Click in the layout where you want to place the pad. The Pad Properties window appears.
3. Make the changes you want.
4. Click OK.

Marking Pads as Grounded Objects

When pouring a ground plane polygon, the keep away applies to pads as well as to other objects. If a pad is marked as User Ground, the ground plane touches the pad (and any lines and arcs connected to it) instead of avoiding it.

To mark a pad as a grounded object:

1. Double-click the pad to open its properties window.
2. Click the User Ground check box.
3. Click OK.

Disabling Mask Generation for a Pad

The solder mask layer for a pad is automatically generated. If the pad's layer is marked as mirrored in the Layer table, the mask goes on the next mask layer below the pad's layer. Otherwise, the mask goes on the next mask layer above the pad's layer. If a mask is not needed for a particular pad, you can turn it off for that pad.

To disable mask generation for a pad:

1. Double-click the pad to open its properties window.
2. Click the Don't Create Mask check box.
3. Click OK.

Using Viaholes in Layouts

Viaholes are drilled, plated, through holes used to connect traces on different layers. Some viaholes are blind or buried, meaning they are not drilled through all layers. Viaholes automatically place a pad (round, square, or wagon wheel) on each metal layer between the start (top) and end (bottom) of the viahole, including pads on the start and end layers. The drill hole is always in the center of the pad. Electrically, viaholes connect every layer between the start and end layers.

Viaholes automatically generate solder mask for the two top and bottom pads. The shape of the mask that is placed is identical to shapes placed for pads and is shown in the figure below.

If a mask is not needed for a particular viahole, you can turn it off.

Placing Viaholes in Layouts

Most viaholes are drilled through all layers. Blind or buried viaholes are not drilled through the entire board. These viaholes are useful in multilayer boards to connect some layers while leaving other layers unaffected. However, the production of boards with blind and buried viaholes is often more expensive.

To place a viahole in a layout:

1. Select the Viahole button ( ) on the Layout toolbar.
2. Click in the layout where you want to place the viahole. The Viahole Properties window appears.
3. Make the changes you want.
4. Click OK.

To place a blind or buried viahole in a layout:

1. Select the Viahole button ( ) on the Layout toolbar.
2. Click in the layout to place the viahole. The Viahole Properties window appears.
3. Clear the Use Default Layers check box if it is selected. This lets you change the start and end layers.
4. Select the start and end layers from the Start and End Layer lists.
5. Make any other changes you want.
6. Click OK.

Marking Viaholes as Grounded Objects

When pouring a ground plane polygon, the keep away applies to viahole pads as well as to other objects. If a viahole is marked as User Ground, then the ground plane touches the viahole pads (and any lines and arcs connected to them) instead of avoiding them.

To mark a viahole as a grounded object:

1. Double-click the viahole to open its properties window.
2. Click the User Ground check box.
3. Click OK.

Disabling Mask Generation for a Viahole

The solder mask layer for a viahole is automatically generated. If the viahole's layer is marked as mirrored in the Layer table, the mask goes on the next mask layer below the viahole's layer. Otherwise, the mask goes on the next mask layer above the viahole's layer. If a mask is not needed for a particular viahole, you can turn it off for that viahole.

To disable mask generation for a particular viahole:

1. Double-click the viahole to open its properties window.
2. Click the Don't Create Mask check box.
3. Click OK.

Adding Polygons, Pours, and Ground Planes

Polygons are filled areas on the layout. You can use polygons on any layer, create one of any shape, and even have ones with cutouts (holes). A pour is a polygon that is poured around other objects on the same layer. Pouring a polygon causes it to keep away from other objects by a specified distance. Pours are especially useful for constructing ground planes, which can touch objects marked as User Ground while keeping away from other objects.

Constructing Polygons

Polygons are often used for landing pads with unusual shapes. Use polygons only when necessary if you plan to create a Gerber file from the layout, because polygons can drastically increase the disk size of a Gerber file. Some typical polygons are shown below:

To construct a polygon:

1. Click the Polygon button ( ) on the Layout toolbar.
2. Click the first vertex (corner) of the polygon.
3. Click the next vertex.

   Note: If the last point placed is incorrect, press the Backspace key to remove it.

4. Continue clicking all vertices.
5. Double-click the last vertex (or click the first vertex again) to complete construction of the polygon.

To add a cutout (hole) to a polygon:

1. Select the polygon you want to add a cutout.
2. Click the Cutout button ( ) on the Layout toolbar.
3. Click the first vertex (corner) of the cutout. Make sure that all vertices and lines of the cutout are within the original polygon and not overlapping any other cutouts in that polygon.
4. Click the next vertex.
5. Continue clicking all vertices.
6. Double-click the last vertex (or click the first vertex again) to complete the cutout.

Pouring Polygons

The figure below shows a polygon that has been poured around two pads and a line. The keep away distance is the distance that the pour stays from the line and pads and is the width of the white space in the figure. Pours are often used for coplanar ground planes. You should only use pours when necessary if you want to create a Gerber file from the layout, because the use of pours can drastically increase the disk size of a Gerber file.

To pour a polygon:

1. Select the polygon you want to pour.
2. Click the Pour Polygon ( ) button on the Layout toolbar. The Pour Properties window appears.
3. Type the keep away distance in the Keep Away box. The units for keep away and resolution are the current units as specified on the General tab of the Layout Properties window.
4. Type the resolution in the Tolerance box.
5. Type the number of segments in the # Segments box.
6. Click OK to begin pouring the polygon. A window appears showing the status of the pour.

Using Ground Plane Pours

Ground plane pours can touch objects that are marked as User Ground and keep away from other objects. Lines and arcs that touch grounded viaholes and pads are also considered grounded. This is similar to the intelligence used to resolve rubber bands.

To pour an existing polygon as a ground plane:

1. Select the polygon you want to pour.
2. Select the Pour Polygon ( ) button on the Layout toolbar. The Pour Properties window appears.
3. Type the keep away distance in the Keep Away box. The units for keep away and resolution are the current units as specified on the General tab of the Layout Properties window.
4. Type the resolution in the Tolerance box.
5. Type the number of segments in the # Segments box.
6. Click the Ground Plane check box.
7. Click OK to begin pouring the polygon. A box appears showing the status of the pour.

Importing and Exporting Layout Files

Genesys lets you import or export layouts using many file types. Importing a layout lets you use layouts created in other programs. Exporting a layout using one of the supported file types lets you use a Genesys layout in other programs and ensures it is understood by a boarding manufacturer.

Importing Layout Files

You can import a layout using any of the following file types:

• 6.x Model Library
• DXF File
• Excellon (Gerber) Drill List
• GDSII File
• Gerber File
• XML File

To import a layout file:

1. Click File on the Genesys menu and select a file type from the Import menu.
2. Follow the instructions in the windows that appear.

Exporting Layout Files

You can export a layout using any of the following file types:

• ASCII Drill List
• Bill of Materials
• DXF File
• Excellon (Gerber) Drill List
• GDSII File
• Gerber File
• HPGL File
• Part Placement List
• XML File

To export a layout file:

1. Open (or select) the layout window to make the Layout the active window.
2. Click File on the Genesys menu and select a file type from the Export menu.
3. Follow the instructions in the windows that appear.

Using Gerber Files

A Gerber file lets you export layouts using a commonly used format. This lets you use layouts in other programs or export them to board manufactures in a standard format they understand. A circuit board can have many layers; therefore, a Gerber file is created for each layer.

Importing Gerber Files

You can import Gerber files for use in generating or modifying layouts.

To import a Gerber file:

1. Click File on the Genesys menu and select Gerber File from the Import menu.
2. Click the file you want to import.
3. Click Open.
4. Specify options for importing the file.
5. Click OK.

Exporting Gerber Files

You can write a Gerber file for the current layout.

To export a Gerber file:

1. Click File on the Genesys menu and select Gerber File from the Export menu.
2. Specify options for exporting the file.
3. Click OK.
4. Click the name of the file.
5. Click Save.

Using Custom Apertures

Custom apertures are apertures created by a layout specifically for each Gerber file. The Aperture list contains a list of user apertures defined by users for specific needs. Generally, you should use user apertures only if your company has a standard set of apertures to which Gerber exports must conform. Otherwise, you should use custom apertures.

A layout has a built-in optimization routine that selects the best list of apertures for efficient polygon fills and flashes. These custom apertures result in the smallest possible Gerber files, whereas a user list can give very inefficient, incorrect, and large files.

Editing the Aperture List

Use the Editing Aperture List window to customize apertures in a Gerber file.

To edit an aperture list:

1. Click File on the Genesys menu and select Gerber File from the Import menu.
2. Click the Options tab.
3. Clear the Generate Custom Apertures check box.
4. Click the Edit DEFAULT.APL button.
5. Make the changes you want.
6. Click OK.

Using Models

User models (or sub circuit models) allow the creation of new elements by the user. These models behave just as if they were built into Genesys. This capability is one of the more powerful features in Genesys. A user model is a design that is used to model the way a part reacts to a simulation.

To create a new user model, you generally define three things:

1. An equivalent circuit for the model. If there is no schematic there must at least be a part list (netlist).
2. Optional equations which define the component values in the equivalent circuit.
3. Optional parameters that will be specified (if any) each time that the model is used. You can name and give descriptions for each of parameters.

A model can be created from any existing schematic or from scratch. A simple subcircuit can be used as a user model with no equations and no parameters. A model can also be created by importing a netlist or a spice model.

You may create a symbol for this model. See the section on symbols for details. If you associate a model with a symbol you have a part. For the part to simulate correctly name the model ports the same as the symbol ports. If they are all named Port_nnn then only the port numbers are used. If the symbol port names do not agree with the model port names then Genesys will use the port numbers to associate pins, but warn you.

Genesys comes with a number of models that you can examine in the Genesys Design library named Models.

If you are familiar with spice models, a user model is almost identical to a spice model (except that it can have a schematic).

You can easily examine the subcircuit models delivered by Genesys. Just right-click a subcircuit part (such as a PLC) and select Open / Model/Subcircuit and the library-based model will open in the workspace.

Creating Models

Creating a Model is identical to creating a design. In fact, there is no difference between a Model and a design other than the icon shown on the tree. You can tell Genesys that you intend to use a design as a Model by

1. right-click the design
2. Select Properties
3. Set the Intent of the design to Model
4. Click OK

Once the design property says the intent is as a model the design is automatically included in the Workspace Models section of the Change Model option for all parts.

To create a model:

1. Click the New Item button ( ) on the Workspace Tree toolbar and select Design Wizard from the Designs menu.
2. Enter the Design name
3. Select Another Kind of Design
4. Click Next
5. Select Model
6. Click Finish

A new design will be built with an icon indicating that it will be used as a model and with a Partlist, Schematic, and Parameters

To use the model as a part's model

1. Double-click the part
2. In the General tab click Change Model
3. Select the user model

   Note: you can use any design as a part's model simply by setting the model name to the design name.

To copy the model to a design library

1. Click the part in the workspace tree
2. From the item menu select Copy To
3. Pick a design library or New Library

   Note: that you can not write to the internal design libraries, so your first custom user model will need to go to a new library.

To edit a library-based model

1. Bring up the library and model in the Design selector (or use the Library Manager)
2. Double-click the model to embed it in your workspace for editing.

Because Genesys will use in-workspace models before in-library models you can edit and tweak a library model this way. When you're finished with it, copy it back to the model library and delete it from your workspace. Genesys will then revert to the library model.

Setting Model Parameters

A Model is a design with Parameters (and often Equations).

When the model is used in a part the Parameters defined in the model become the Part Parameters. You set the parameters in the Parameters tab of the model.

Here are some sample parameters for an airwound inductor defined by the form and the amount of copper.

Using Model Equations

The equations in a model are generally there to convert parameter entries into circuit parameters. Also, you want each instance of a model to have its own local equations, because each model has its own parameters. Thus, the equations are embedded into the design (model).

Here, for example are the equations for AIRIND1. Note that this is a tab in the AIRIND1 design.

Here D, WD, and L are three of the air wound inductor parameters, used as input into the equations.

Important: always use Use MKS for equations that are in models. This guarantees portability to other countries and units of measure. In Use MKS the equation variables are interpreted in MKS units when used in subcircuit parameters. Also, the input parameters (here, D, WD, and L) are in MKS no matter what unit the user has defined for the model parameters.

Modelithics Substrate-Dependent Models

The Modelithics library of surface-mount capacitor models covers a variety of body-sizes and part values from multiple vendors. The equivalent circuit models are extracted from precision impedance and S-parameter measurements and include advanced features such as substrate scaling, representation of high-order resonant effects, and accurate effective series resistance. Most models in the library are valid through at least 10 GHz.

The models in the current library are intended for use with microstrip interconnects; custom-model extraction can be performed On-Demand™ for alternative transmission lines, such as coplanar waveguide and grounded coplanar waveguide.  If you need a part that is not listed in the table, contact Agilent. The list of components is constantly expanding and custom modeling services are available.

Model

The Modelithics library consists of special models that are associated with a particular family of parts. Each family pertains to a given body style (e.g., 0201, 0402, etc.) and typically covers component values over 2-3 decades (e.g., 1-1800 pF). For these models, all equivalent circuit parameters, and therefore the parasitic effects, scale with the nominal part value. The use of these special models eliminates the need to manually substitute individual models during a design sequence.

Substrate Scaling

A surface-mount component can be considered a complex, strip-like transmission line with the PCB back plane serving as its ground. Variations in the substrate parameters have a dramatic effect on the frequency response. Modelithics models incorporate features that enable very accurate accounting of substrate-related effects, by appropriately scaling affected model parameters. The substrate-scalable models include require the substrate thickness, dielectric constant, loss tangent and the metal thickness used in the pad stacks to be specified within the Genesys workspace.

Each model is generated from multiple sets of S-parameter measurements, made with the parts mounted in different PCB test fixtures. For example, many of the models in the Modelithics library are extracted from measurements using 5, 14, 31 and 59 mil-thick FR4 and 25 mil-thick Alumina test fixtures.

The models are valid over the range of substrate thickness used in the model extraction for the same or similar dielectric constant (e.g., 5-59 mil thick substrate, Er = 4.3 +/- 0.5). More generally, the valid range is determined by the span of h/Er values of the test fixtures used for characterization (where h = substrate thickness). For example, test fixtures consisting of 5-59 mil thick FR4 (Er = 4.3) translate into h/Er values from 0.86 13.0 mils.

Effective Series Resistance

Each model in the Modelithics library is based on precise Effective Series Resistance (ESR) measurements taken on individual parts. The empirical data is used to generate a frequency-dependent expression for ESR that is incorporated into the models. The ESR is important in the performance of low loss circuits such as filters, matching networks and couplers.

Model Accuracy

Model accuracy is quantified based on the magnitude of the vector difference |D _vector | between measured and model-generated S-parameters:

where S _{i ,j} is a measured S-parameter and S _i,j is a model-generated S-parameter. This measure of accuracy accounts for magnitude and phase difference. The typical vector difference for Modelithics models is <0.05 across the valid frequency range, which extends to 10 GHz or greater for most models in the library. The vector difference may exceed the 0.05 limit near frequencies where higher-order resonant responses occur.

Example Model Application

Model Setup: After placing a model into the schematic, double-click to open the Part Properties dialogue box and enter the capacitance value. The Sim_mode parameter can be set to 0 (default) to activate the full parasitic model, or to 1 to activate an ideal capacitor model. A substrate definition must exist in the workspace with the relevant substrate properties; if multiple substrate definitions exist specify the correct one to associate with the capacitor model.

Model Simulation: The simulated S-parameters for the CAP_CADA model (S ₁₁ , S ₂₁ ) are compared to measurement data (S ₃₃ , S ₄₃ ) in the following figures, along with a plot illustrating the vector difference between the simulated and measured data. It is typical for peaks in the vector difference to occur at frequencies surrounding higher-order resonances. The results pertain to the 5-mil FR4 substrate as outlined above.

Parameter Sweeps

Any input parameter to the models (part value and substrate properties) can be swept uniformly over the valid range of values.

For example, to study the effect of a +/- 5% part value tolerance on the frequency response of a circuit:

• Define a variable in the Equations window as follows: CADA_Part_Value =? 10
• Assign the input parameter to the model to CADA_Part_Valuee
• Define a Parameter Sweep that will step CADA_Part_Value from 9.5 to 10.5 with the desired number of steps

(As vendors typically provide components from the same part number family with multiple tolerance values, the user should check vendor data sheets for the proper values to be used for a specific vendor part> number.)

For circuit optimization, it may be more desirable to allow the part value in the model only to fall on the discrete part values that are available from the manufacturer. The discrete part selection can be accomplished by placing the following statements into the Equations window:

'Define a list of the valid discrete part values separated by semicolons,
CADA_Part_List = 10;11;12;15;18;20
'Define an index variable,
CADA_Index = ?1
'Define the part value variable as a vector,
CADA_Part_Value = CADA_Part_List[CADA_Index]

As before, you can now assign the input parameter to the model to CADA_Part_Value and proceed with the normal optimization setup sequence. A list of discrete parts value for each Modelithics model is available below.

Warnings Issued During Simulation

When a model is simulated outside its range of validity, local error/warning messages will be generated. The following conditions are flagged:

• Minimum/Maximum Substrate Thickness Exceeded_ Action: The substrate thickness is set equal to the nearest limit (H_sub_min = &., H_sub_max = &.).
• Minimum/Maximum Metal Thickness Exceeded_ Action: The metal thickness is set equal to the nearest limit (T_mtl_min = &., T_mtl_max = &.).
• Minimum/Maximum Substrate Dielectric Constant Exceeded_ Action: The substrate dielectric constant is set equal to the nearest limit (Er_sub_min = &., Er_sub_max = &.).
• Minimum/Maximum Substrate Loss Tangent Exceeded_ Action: The substrate loss tangent is set equal to the nearest limit (TanD_min = &., TanD_max = &.).
• Minimum/Maximum Part Value Exceeded_ Action: All intrinsic and substrate-related parasitic effects are turned off and the model defaults to an ideal element.
• Minimum/Maximum Substrate Height-to-Dielectric Constant Ratio Exceed_ Action: All intrinsic and substrate-related parasitic effects are turned off and the models defaults to an ideal element.

Currently Available Components

For a list of currently available components, see Eagleware's web site. Each family can be ordered separately using the part number, or the entire library is available at a significant discount. If you need a part that is not available, contact Agilent. The list of components is constantly expanding and custom modeling services are available.

Using Symbols

You can easily create new schematic symbols. Collect these symbols into libraries for use in future Genesys designs. You create a new schematic symbol from any existing schematic symbol or from scratch.

A symbol is a kind of design that is used to display a part in a schematic. Symbols always contain a schematic - which becomes the picture.

In a symbol, the ports determine the Terminals of the symbol. The port names are the terminal names and the port numbers are the terminal numbers (for modelling). Symbols treat 0,0 as a start point where you place the symbol when you click in the schematic and as a center when you rotate the symbol. You can change the center point of the symbol in the Schematic properties dialog.

Genesys comes with a number of "user symbols" that you can examine in the Genesys Design library named Symbols. You can also click any placed part and select Open / Symbol to have the part's symbol loaded into the workspace.

Creating Schematic Symbols

Symbols are simply another type of Design and are very similar to Schematics. In fact, the main difference between a Symbol and some other design is simply the icon shown on the tree. You can tell Genesys that you intend to use a Design as a Symbol by doing the following:

1. Right-click the design (or double-click a schematic, etc.)
2. Select Properties
3. Set the Intended Use of the design to Symbol (on the General tab)
4. Click OK

Once the design property says the intent is as a symbol the design is automatically included in the Workspace Symbols section of the Change Symbol option for all parts.

To create a Symbol:

1. Click the New Item button ( ) on the Workspace Tree toolbar and select Design Wizard from the Designs menu.
2. Enter the Design name
3. Select Another Kind of Design
4. Click Next
5. Select Symbol
6. Click Finish

Draw in the schematic area to create a symbol. You might want to use the Annotation toolbar to create complex symbols, or place parts to use preexisting symbols within a symbol. The placed ports (input or output) determine the symbol terminals.

Displaying Parameter Values on a Symbol:

When a symbol is used (actually placed on a schematic), the text is processed prior to display, using a technique called Macro Substitution.  

For example, when "Impedance = %L%" is drawn on a schematic, the value of parameter 'L' is retrieved from the attached model and the result would be something of the form "Impedance = 1.5". Another common use is to place the model name in the center of a symbol.

To use this advanced feature, place special "macro" strings in the symbol text annotations:

1. Place a Text annotation
2. Double-click it and change the text, so that it includes one or more macros from the table below.  
3. Click OK

   Macro	Result
   %Model%	Name of the model attached to the schematic part
   %MODEL%	Name of the model in UPPERCASE
   %Des%	The part's Designator: R1, L3, etc.
   %ParameterName%, where the name is any parameter of the model, such as R, C, L, etc.	The actual value of the parameter.

Placing Terminal

The terminal connection dots (the highlighted dot when a symbol is being moved) determine the symbol connection points in the schematic.

Here are few general guidelines for placing symbol terminals:

• Leave some space between the blocks of the symbol and the terminals for best esthetic appearance.
• Put Port 1 at 0,0 on the schematic. Then when the user places the part with that symbol he will be clicking the Port 1 location.

Using Custom Symbols

To change the symbol for a part, double-click the part in the schematic and select Change Symbol.

Creating a Sample Schematic Symbol

In this simple example we're going to create an ISO resistor symbol.

To create a Symbol:

1. Click the New Item button ( ) on the Workspace Tree toolbar and select Design Wizard from the Designs menu.
2. Enter the Design name
3. Select Another Kind of Design
4. Click Next
5. Select Symbol
6. Click Finish

The screen now looks like this

Place an input port and an output port roughly the right distance apart (usually 6 gridlines). Make sure the first port goes at 0,0 for the user. Rename the port names so that the terminals are named Input and Output (usually not done for a resistor!).

1. Click the Annotation button to bring up the annotation toolbar
2. Draw a solid box between the two ports
3. Draw two connectors between the ports and the box

1. Create a blank design with a schematic and drop a resistor.
2. Double-click the resistor
3. In the General Tab, change the resistor symbol to MySymbol

It should look like this...

We don't really want a red resistor, so

1. click the red box to select it
2. in the annotation toolbar change the fill color to white

To save the symbol for use in other workspaces

1. right-click the symbol in the workspace tree
2. Select the Copy To menu option

Changing Design Properties

There are several tab pages that you can use to change the properties of a Design (tabs vary according to objects in the Design):

• General Tab
• Schematic Tab

To change the properties of a LiveReport:

1. Double-click a schematic.
2. Click the desired tab.
3. Make the changes you want.
4. Click OK.

Design General Tab

Use the General Properties tab page to change the general properties of a Design.

• Name – The name of the Design.
• Description – The Design description (optional).
• Intended Use – What kind of Design is it?  This setting controls the Design's icon on the workspace tree and Genesys' interpretation of how the design is intended to be used.  (If it's a symbol, you can select it for a schematic part's symbol, if it's a model, you will be able to select it as an electrical model, etc.)

Creating a Design From a SPICE File

Importing a SPICE File

One of the easiest ways to get nonlinear device models into Genesys is to import them from a manufacturer supplied SPICE file. SPICE files have the following advantages over other methods of using nonlinear device data:

• They are often supplied by manufacturers.
• Entering device data manually is tedious and error-prone.
• SPICE files often contain very complete macro-model device characterizations.
• They are in plain text format and can be corrected in any text editor.

To import a SPICE file:

1. Click File on the Genesys menu and select SPICE File from the Import menu. Select the SPICE file and click Open.
   
2. The models are imported into your workspace, but if you also want to add them to a design library, check Automatically import these models into library and select a library from the drop-down list.
3. If you want to store the original SPICE code with the models (recommended), check Embed the original spice file into a notes section.
4. Some devices, such as transistors, normally have their nodes reversed in the SPICE file. Genesys does not have enough information to know what device is described by any particular SPICE subcircuit, so you have to tell it whether the first two nodes of any model with 3 to 5 total nodes should be reversed. Netlist options for devices with 3 to 5 nodes allow you to set node reversal for the whole file or receive a separate prompt for each device found.
5. Click OK.

Notes:

1. The import operation may take up to several minutes, depending on the number of models in your SPICE file. A whole library of models can reside in one file.
2. Genesys will not allow two models with the same name in one workspace. If a name conflict happens, you can either replace the existing model, or rename the new model in the SPICE file and try importing it again.
3. For a model with more than 5 nodes Genesys will issue a warning (an integrated circuit can have a number of transposed nodes).
4. You can edit the design's netlist in Genesys (after the model is imported) to fix the issues beyond the node 1 & 2 reversal.
5. Occasionally SPICE files have errors in them, mostly simple typos. Those need to be corrected in a text editor prior to importing the file.

Once imported, the model can be used just like any design created in Genesys.

Quite often SPICE models are organized into a hierarchy, in which case you need to have all of the model's dependents available in order to use the model. Sometimes dependents will be in a different SPICE file which you will need to import into the same workspace or design library.

SPICE File Compatibility

SPICE file import in Genesys is mainly based on the PSpice Version 10.0 specification. Where possible, Genesys has also been made compatible with other SPICE flavors. The following devices are recognized:

C - Ideal Capacitor
D - Nonlinear Diode
E - Voltage-Controlled Voltage Source
F - Current-Controlled Current Source
G - Voltage-Controlled Voltage Source
H - Current-Controlled Current Source
I - Independent Current Source
J - Nonlinear JFET
K - Mutual Inductance (coupling of two inductors only)
L - Ideal Inductor
M - Nonlinear MOSFET
Q - Nonlinear BJT
R - Ideal Resistor
T - Ideal Transmission Line
V - Independent Voltage Source
X - Subcircuit
Z - Nonlinear MESFET (model types NMF and PMF)

The intent of the SPICE file import facility in Genesys is to capture parameters of real manufacturer parts rather than to represent more abstract models, and thus only SPICE commands directly related to concrete device modeling are supported: .SUBCKT, .ENDS, .MODEL and .PARAM.

Expressions are supported only as far as they are compatible with the Genesys equation parser, and .FUNC command is not supported. Also unsupported in this release are options VALUE, TABLE, LAPLACE, FREQ and CHEBYSHEV.

Subcircuits can have parameters, but not optional nodes, and option AKO is not supported in models.

Based on the extensive review of available SPICE files these limitations don't seem too restrictive, however, SPICE file compatibility will be improving in future releases.

New Spice model import supports the LEVEL keyword for JFET, MOSFET and MESFET models.

The value of the parameter LEVEL may be numerical or string. The string format is:

<Model Name>@<Full Path to model>

Use the string format to define an external link to a Genesys VerilogA model. The parameter list may be unknown to Genesys, but for the import it's compiled from the VerilogA file.

For example:

BSIM4_NMOS@bsim4.va

ANGELOV_NFET@c:\Program Files\Genesys2006.04\Model\VerilogA\angelov.va

The numerical values of the LEVEL parameter are defined from the tables:

Table 1. MESFET models LEVEL parameter value ( TYPE = NFET, PFET)

Table 2. MOSFET models LEVEL parameter value ( TYPE = NMOS, PMOS)

Table 3. JFET models LEVEL parameter value ( TYPE = NJF, PJF)