HFSS15: Derivative Tuning for Reports

The Derivative Tuning feature available in the results menu is based on the derivatives that you can request for selected variables in the solution setup. It is limited to quantities like S-parameters. Frequencies, and local quantities like fields cannot be tuned.

A common way to use this feature is to produce, for an output quantity of interest, two curves in one plot. One curve is produced with the Report dialog selection for the Context Derivative as <none>. The other has the All or specific variable selection.

This gives you a plot with initially two identical curves, one on top of the other. You can then right-click on Results in the Project tree and select Tune Reports. The Report Tuning window appears. You can use the slider to tune one curve interactively while the other curve stays to provide a reference. This way you can see interactively how small changes in variables affect the result. You can then apply those offsets to the original variable values and re-solve the design.

The overall procedure for Report Tuning follows.

1. Generate a solution with one or more variables for which you select Use on the Derivatives tab of the solution setup.

2. Use the Reporter to create one curve with Derivative selection in the Context panel of the report dialog set to None.

3. Then create another curve, but in the Context pane. select for Derivatives, All or the variable of interest. This gives you two identical curves, one top of the other.

4. Click the HFSS>Results>Tune Reports or right-click on Results in the Project tree and click Tune Reports from the short cut menu. The menu item is disabled if no variables have been selected in the Derivatives tab of the solution setup.

This displays a Report Tuning dialog which lists the variables available for tuning. The example above shows a Report Tuning dialog for a design with one variable.

5. You can use the slider to adjust the value of each available variable. When you move a slider, the Apply offsets to nominal design button and the Save all offsets buttons are enabled. The dialog displays the change to the variable selected. For example, if the variable is $length with a value of 1mm, and the slider shows 0.1mm, then the effective value of $length for the purpose of derivatives is 1.1mm. If you exit the dialog by applying the offset or offsets (click Apply offsets to nominal design), $length is assigned a value of 1.1mm. You can then re-solve, and get results based on the derivative’s prediction. The Close button lets you close the dialog.