Frequency Sweep vs. Solution Frequency

Hello. What is the best option for the solution setup, solution frequency and frequency sweep?

Can i have a solution frequency of 7GHz with a frequency sweep that extends from 2 to 20 GHz?

Thanks
Kawther

The solution frequency should be equal to or greater than the maximum frequency in the frequency sweep.

Usually the best solution frequency is the maximum frequency of the frequency sweep which is in your case 20 GHz. HFSS meshes the design according to the solution frequency and then uses this same mesh at all the other frequencies. If you choose for example 7 GHz, lambda will be bigger than at 20 GHz thus the mesh may not be accurate at 20 GHz.

In addition to the above, the value used is entirely dependant on what your device is. You want the solution frequency to be sufficiently high, such that the mesh is accurate for higher frequencies, but you also want it close enough to your desired frequency range such that you aren't converging on an undesired mode.

For structures which support not many other modes, a high frequency is generally better, but if you're expecting many modes in your frequency range, a solution frequency close to your sweep range will probably be more accurate.