waveport hfss guidelines

There is often a impedance difference (Zpi) of about 5 ohm for the two waveports of micrstrips in HFSS. How can I improve the accuracy of waveport?

I also met this problem before. Then I increase the length of the ms, and change delta S from 0.02 to 0.01, the two port impedance seems quite the same. But I also want to know what's going on there. Good luck!

In principle the length of ms and the delta s have no effect on the waveport impedance. It is very strange.

Does anyone meet this same problem?

Take a look at the online help notes on impedance calculations. Look into their guidelines for waveport size as well.