de-embedding hfss
I have seen an interesting test to determine the quality of an EM software's de-embedding.
Create a through transmission line; it doesn't matter if it is microstrip, stripline, or whatever, and the impedance of the line doesn't matter either. If fact, I think it's better if it's something non-standard, (not 50 ohms).
Set the de-embedding reference plane in from each port so that the reference planes will touch in the middle, effectively de-embedding out the entire problem.
If the EM solver is perfect and has excellent calibration, then |S11| is zero (minus infinity dB) and the through phase (Ang{S21}) is exactly zero.
The |S11| answers are quite telling. Try it any EM solver you like. The |S11| data will tell you something about the effective dynamic range of the simulator.
And the best thing about this test is that it doesn't depend on measurements--you know the right answer in advance.
--Max