Setting Up a Sensitivity Analysis

Following is the general procedure for setting up a sensitivity analysis. Once you have created a setup, you can Copy and Paste it, and then make changes to the copy, rather than redoing the whole process for minor changes. You can create a sensitivity setup before defining variables but all variables must be defined before you start the sensitivity analysis.

1. Before a variable can be included in a sensitivity analysis, you must specify that you intend for it to be used during a sensitivity analysis in the Design Properties dialog box.
2. Click HFSS> Optimetrics Analysis> Add Sensitivity . You can also select the Simulation tab in the ribbon, and select Parametric from the drop-down menu under the Optimetrics icon:

   

   The Setup Sensitivity Analysis dialog box appears.

3. Under the Calculations tab, type the maximum number of iterations per variable value that you want the software to perform in the Max. No. of Iterations/Sensitivity Variable text box.
4. Set up an output parameter calculation and select a Primary Output.
5. Specify the value of the design point at which the sensitivity analysis should stop in the Approximate Error in Primary Output text box.
6. In the Variables tab, specify the Min/Max values for variables included in the optimization, and the Initial Displacement (Initial Disp.) for the analysis.

   You may also override the variable starting values by clicking the Override check box and entering the desired value in the Starting Value field.

7. In the General tab, specify whether Optimetrics should use the results of a previous Parametric analysis or perform one as part of the optimization process.

   Checking the Optional Worst Case Analysis option does an extreme value analysis that focuses on the upper and lower boundaries of all the analyzed parameters. Some setup is required before performing Worst Case Analysis.

8. Under the Options tab, if you want to save the field solution data for every solved design variations in the optimization analysis, select Save Fields And Mesh.
   Note:

   Do not select this option when requesting a large number of iterations as the data generated will be very large and the system may become slow due to the large I/O requirements.

   You may also select Copy geometrically equivalent meshes to reuse the mesh when geometry changes are not required, for example when optimizing on a material property or source excitation.This will provide some speed improvement in the overall optimization process.

   The following optional sensitivity analysis setup options can also be used:

   • Modify the starting variable value.
   • Modify the minimum and maximum values of variables that will be solved.
   • Exclude variables from the sensitivity analysis.
   • Set the initial displacement.
   • Modify the values of fixed variables that are not being modified during the sensitivity analysis.
   • Set linear constraints.
   • Request that Optimetrics solve a parametric sweep before a sensitivity analysis.
   • You can also request that Optimetrics solve a parametric sweep during a sensitivity analysis.