Introducing the Filter DesignGuide

The Filter DesignGuide documentation provides an introduction to the Filter DesignGuide tool. The complexity of the Advanced Design System (ADS) is made easily accessible through the automated capability. A first-time or casual ADS user can begin using the capability of ADS quickly, while experienced ADS users can perform tasks faster than ever before. The Step-by-Step Example describes how a doubly terminated lowpass Chebyshev filter can be designed and verified, and a layout generated, in a few minutes.

The Filter DesignGuide provides SmartComponents and automated-assistants for the design and simulation. All SmartComponents can be modified. You simply select a SmartComponent and, with little effort, redesign or verify their performance. The "Using SmartComponents" section answers many common questions relating to DesignGuide use and the "SmartComponent Reference" describes each SmartComponent in detail. The section "Automated Design and Analysis" introduces Automated Assistants.

Step-by-Step Example

The step-by-step example takes you through the design, analysis and sensitivity simulation of a doubly terminated lowpass Chebyshev filter component. After completing this example, you should have a basic understanding of the DesignGuide and be ready to begin using the tool. Follow these steps to begin:

• Setting Up the Design Environment

• Designing and Analyzing a Network
  

  Note You should already be familiar with the basic features of Advanced Design System. For help with ADS basic features, refer to the Schematic Capture and Layout documentation.

Setting Up the Design Environment

Before you can use the Filter DesignGuide, you must set up the design environment by using these steps:

• Setting DesignGuide Preferences

• Opening a Project,

• Opening a Schematic Window,

• Opening the Filter DesignGuide,

• Displaying the SmartComponent Palette.
  

  Note Before beginning, you must have installed the DesignGuide with appropriate licensing codewords.

Setting DesignGuide Preferences

All DesignGuides can be accessed through either cascading menus or dialog boxes. You can configure your preferred method in the ADS Main window or from the Schematic window.
To configure access through menus or dialog boxes:

1. From the Main or Schematic window, choose DesignGuide > Preferences .
2. In the DesignGuide Menu Style group box, choose either Use a selection dialog box or Use cascade menus .
   
3. Close and restart the program for your preference changes to take effect.

   Note On PC systems, Windows resource issues might limit the use of cascading menus. When multiple windows are open, your system could become destabilized. Thus the dialog box menu style might be best for these situations.

The ADS Main window DesignGuide menu contains these choices:
DesignGuide Developer Studio > Start DesignGuide Studio is only available on this menu if you have installed the DesignGuide Developer Studio to open the initial Developer Studio dialog box.
DesignGuide Developer Studio > Developer Studio Documentation is only available on this menu if you have installed the DesignGuide Developer Studio to open the DesignGuide Developer Studio documentation.

Note Another way to access the DesignGuide Developer Studio documentation is by selecting Help > Topics and Index > DesignGuides > DesignGuide Developer Studio (from any ADS program window).

Add DesignGuide opens a directory browser in which you can add a DesignGuide to your installation. This is primarily intended for use with DesignGuides that are custom-built through the Developer Studio.
List/Remove DesignGuide opens a list of your installed DesignGuides. Select any that you would like to uninstall and choose the Remove button.
Preferences opens a dialog box that enables you to:

• Disable the DesignGuide menu commands (all except Preferences) in the Main window by unchecking this box. In the Schematic and Layout windows, the complete DesignGuide menu and all of its commands are removed if this box is unchecked.
• Select your preferred interface method (cascading menus vs. dialog boxes).

Opening a Project

The ADS design environment is set up within a project.
To create a new project:

1. From the ADS Main window, choose File > New Project or click Create a New Project on the toolbar.
   
2. In the dialog, define the location of the project and assign a project name.

Opening a Schematic Window

A new schematic design is needed to contain the lowpass component for this example.
To open a Schematic window:

1. From the ADS Main window, choose Window > New Schematic or click New Schematic Window on the toolbar. A new Schematic window appears.
   

   Note Depending on how your ADS preferences are set, a Schematic window can appear automatically when you create or open a project.

2. In the Schematic window, choose File > New Design to create a design named Example .

Opening the Filter DesignGuide

The Filter DesignGuide is accessed from the Tools menu or the DesignGuide menu in the Schematic window.
To open the Filter DesignGuide:

1. In the Schematic window, choose DesignGuide > Filter > Filter Control Window to open the Control window.

Using the Control Window

All DesignGuide features are available from the Control window. The Control window houses menus, a toolbar, and SmartComponent manipulation controls. The menus and toolbar buttons perform the basic functions of design, delete, and display the SmartComponent palette. Full features are available from each of the tab pages on the window. The window can be placed anywhere on the screen. Explore each tab page by clicking on the tab at the top of each page. Explore the window menus as well to familiarize yourself with the basic DesignGuide capabilities.
The pull down lists at the top of the Control window are designed to help you navigate multiple schematic windows and SmartComponents. You can use the Current Schematic drop-down list box to select any of the currently opened schematic windows. This field is updated any time the Filter Control window is selected from the Tools menu. From the SmartComponent drop-down list box, you can select any of the SmartComponents on the currently selected schematic window.

To close the Control window:

• Select File > Exit DesignGuide from the Control window menubar. (You can also close the window by clicking the x at the top of the window.)
  Continue the step-by-step example by Designing and Analyzing a Network.

Designing and Analyzing a Network

In this step-by-step example, you design and analyze a doubly terminated lowpass Chebyshev filter component. A component can be designed easily by using the default component parameter settings. Using the DesignGuide follows a normal design flow procedure:

• Select a component needed for your design from the component palette (Displaying the SmartComponent Palette) and placing the component in your design (Placing Example Component in the Design).

• Provide specifications (Changing SmartComponent Parameters).

• Design and analyze the component (Designing the SmartComponent) and Analyzing Yield of the Network).
  

  Note Before starting this section of the step-by-step example, confirm your setup (Setting Up the Design Environment).

Displaying the SmartComponent Palette

The program contains a SmartComponent palette, Filter DG - All , that provides quick and easy access to the SmartComponents. A blue accent in the upper-left corner of a palette button indicates the component is a SmartComponent.

You can display the SmartComponent palettes in one of these ways:

• By clicking Component Palette on the Control window toolbar
• By choosing View > Component Palette - All from the Control window menu
• By selecting the Filter DG - All palette from the Component Palette drop-down list box in the Schematic window toolbar (directly above the palette).

Continue the example by selecting the Filter DG - All palette. The palette displays in the Schematic window.

Placing Example Component in the Design

To place the SmartComponent in the design:

1. Click LCLowpassDT on the component palette to select the component.
   
2. Click within the schematic window to place the component.
   • You can change the orientation of the SmartComponent before placement by selecting from the Insert > Component > Component Orientation commands or by selecting Rotate by -90 repeatedly from the schematic toolbar.
   • The place component mode remains active until you choose End Command from the schematic toolbar.

     Note When a SmartComponent is placed initially, a temporary component is used to place and specify the parameters for the SmartComponent. This component does not contain a subnetwork design. After the DesignGuide has been used to design the SmartComponent, the temporary component is replaced with a permanent component. The SmartComponent is renamed to DA_ComponentName_DesignName and an autogenerated design is placed inside the SmartComponent's subnetwork design file. Subsequently, if the SmartComponent parameters are edited, the DesignGuide must be used again to update the subnetwork design file.

Changing SmartComponent Parameters

Parameters can be changed directly from the Control window.
To edit the LCLowpassDT component parameters:

1. In the Control window, select the LCLowpassDT ** component from the SmartComponent drop-down list. This ensures all changes are referenced to this component.
2. Select the Filter Assistant tab. Change the response type by selecting the Response Type drop-down menu box. Choose Chebyshev .

   Note See "Placing and Editing SmartComponents" for details on changing parameters in the design window or component dialog box.

Designing the SmartComponent

You can design and analyze the SmartComponent from the Control Window.
To start the simulation:

1. On the Filter Assistant tab, click Design to start a simulation and generate the design for the SmartComponent.

Examining the SmartComponent Design

You can look at the details of the autogenerated design inside the SmartComponent's subnetwork.
To examine the component's subnetwork:

1. Select the component LCLowpassDG .
2. Click Push Into Hierarchy on the schematic toolbar.
3. After examining the design, click Pop Out on the schematic toolbar to close the view.
   

To analyze (simulate) the network:

1. Select the Simulation Assistant tab on the Control window.
   
2. Confirm that Automatically Display Results is active.
3. Accept default frequency/display specifications. Click Simulate to start the analysis. Part of the analysis results are shown below.
   

Closing the Results Window

• To close the display window, choose File > Close Window from the menu.

Analyzing Yield of the Network

After the design process, the component sensitivities of the network can be checked using the Yield Assistant .
To find components to analyze:

1. Select the Yield Assistant tab on the Control window.
   
2. Click View Components . Then click Modify Statistics/Optimization . The network displays in the schematic along with a dialog box.
   

To choose components:

1. Choose Enabled from the Statistics Status drop-down menu.
   
2. Click Next to move on to the next component. Repeat this until all 3 components in the network are enabled, and then click Done .
3. Click Close in the Statistical Component Values dialog box.

To analyze yield sensitivity of the network:

1. In the Yield Assistant tab, click Automatically Set Frequencies .
2. Select by Simulate to start the Yield Assistant and analyze the yield sensitivity to the selected component values. The results display automatically. The sensitivity histogram for component C1 is shown here.
   
3. Choose File > Close Window from the menu to close the display window.

Deleting the SmartComponent

• To delete the LCLowpassDT SmartComponent, choose Tools > Delete SmartComponent from the Control window.

  Note The Delete button on the Control window is different from the Delete button on the ADS schematic window toolbar.

This completes the step-by-step example.