Setting Up the Variables

You need to set up the variables for tuning and optimization. Lstub's tuning range should be from 120 to 320 mils in steps of 5 mils and it's optimization range should be from 120 mils to 280 mils. Sstub's tuning range should be from 120 to 300 in steps of 20 and it's optimization range should be from 120 to 300.

24.  Click on the Circuit Settings button in the Edit tab tool bar.

The Circuit Settings dialog box appears on your display. You may also open this dialog box using the menu command Circuit - Settings.

25.  Click on "Variables" in the sidebar menu in the Circuit Settings dialog box.

The Circuit Settings dialog box is updated to display the Variables page.

26.  Double-click on the Lstub entry.

The Add/Edit Variable dialog box appears on your display. You may also open this dialog box by selecting a variable entry then clicking on the Edit button.

27.  If it is not already open, click on the arrow to open the Interpolation, Tuning and Optimization controls.

The appearance of the dialog box is updated.

28.  Click on the Interpolation tab in the Add/Edit Variable dialog box.

The interpolation controls are displayed in the dialog box.

29.  Select the Interpolate this variable checkbox.

This enables interpolation for this variable. When interpolation is enabled, a set of values is defined at which the Sonnet analysis engine, em, performs a full electromagnetic simulation. For all other values, em performs an interpolation to calculate the response. This can reduce the number of full analyses that em needs to run when tuning or optimizing a variable. Interpolation can also help prevent stopping in a local minima rather than the global minima when optimizing.

Auto is the default selection that allows the software to determine the set of values at which a full analysis is done. The Manual setting allows you to manually set the resolution of the interpolation and should only be used by advanced users. For this tutorial, leave the setting on Auto. This will automatically set the interpolation resolution of Lstub to the cell size, which is 5 mils.

30.  Click on the Tuning tab in the Add/Edit Variable dialog box.

The controls tuning are displayed in the dialog box.

31.  Click on the Allow tuning of this variable checkbox to enable tuning of Lstub.

The rest of the controls in this section are enabled.

32.  Enter "120" in the Minimum text entry box, "320" in the Maximum text entry box and "5" in the Step text entry box. 

These values set the parameters for the tuning bar in ADS. When tuning is used for Lstub, the minimum value for the variable is 120 mils, the maximum value is 320 mils, and the step size between values is 5 mils.

33.  Click on the Optimization tab in the Add/Edit dialog box.

The optimization controls are displayed in the dialog box.

34.  Click on the Allow optimization of this variable checkbox to enable optimization of Lstub.

The rest of the controls in this section are enabled.

35.  Enter "120" in the Minimum text entry box and "280" in the Maximum text entry box. 

These values set the limits of the variable Lstub during an optimization. The range of the variable is 120 mils to 280 mils; only values in this range are used for the variable during the optimization. This completes the setup of Lstub.

36.  Click OK to close the dialog box and apply the changes.

Note that the Lstub entry on the Variable page of the Circuit Settings dialog box is updated. "I, T, O" appears in the options column to indicate that interpolation, tuning and optimization are enabled for the variable.

37.  Repeat steps 26 through 36 for SStub to enable the variable for interpolation, tuning and optimization. 

For tuning enter "120" for the Minimum, "300" for the Maximum and "20" for the Step. For optimization, enter "120" for the Minimum and "300" for the maximum.

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