I'm just starting to use Momentum and I'm trying to perform a simple simulation of a microstrip matching network. The problem is that I'm getting that error when simulating, and the result doesn't seem accurate, especially at high frequencies, when compared to the circuit simulation. I'm using standard FR4 substrate, Er 4.5 and 1.6 mm thickness, 35 micron of conductor. My ports have been defined as "single" which I think that may be the reason of the error, but I'm neither sure if it's correct, nor able to change it to differential. I'm simulating from 100 MHz, to 10 GHz.
Thank you very much in advance