ansoft designer variables
some additional thoughts and caveats on the subject of optimizing designs in Ansoft Designer and/or Ansoft HFSS.
first (in my opinion) it is necessary to have at least a basic knowledge of microwave circuits and electromagnetics in order to appreciate the significance and validity of results produced by these programs.
second, it is important to understand the limitations of the programs: for example, Ansoft Designer Planar EM uses the method of moments and has limited application in the modeling of complex interconnects (where HFSS or some other program would be a better choice).
third, the accuracy of results is highly dependent on the density and type of meshing and the degree to which the models are converged - a good understanding of s-parameters is critical for this.
fourth, before optimizing a design, it is important to start from a reasonable initial design (you can't make a silk purse out of a sow's ear).
fifth, before proceeding with an automatic optimization, i prefer to do a few hand optimizations by varying one or two circuit parameters (such as the width of a microstrip). this will give you a feel for the sensitivity of the design to the relevant parameters and will allow you to set up meaningful ranges and step sizes for the automatic optimization.
unfortunately, the tutorials and user guide information that are readily available online tend not to address these issues.
N.