Hello,
I'm trying to simulate microstrip-antennas with ADS in the range up to 1 GHz. I defined a 1.6 mm FR4-Substrate with two conductor layers. On the upper layer i built my antenna and on the lower layer i built the ground. There is one differential port with at the antenna and at the ground. After simulating with FEM and Momentum, i could find huge differences between the results. While the Momentum results showing an antenna efficiency of about 1 %, the FEM results showing an efficiency of about 60 %. Even the farfields look quite different. Both simulations were done with default settings. Which result is the correct one or what should i change to get more similar results?
Thanks.
Hello,
sounds like a modelling mistake to me. For most PCB antennas, you should get about the same results.
Only at the "horizon" (0° elevation) the Momentum results will be different, because Momentum simulates with infinite substrate size. This means that for antennas with main lobe in the substrate plane, e.g. Vivalidi, Momentum is not appropiate. For most other PCB antennas, I have seen small differences between Momentum and FEM results which make physical sense, resulting from the finite size of the substrate near the radiator etc.
Can you show some screenshots of your model and settings?
You wrote "ground" - does that mean you have built an explicit drawn ground plane in Momentum, or have you used the infinite bottom ground boundary? Are the top and bottom of the Momentum stackup properly defined? If there is no infinite ground, have you disabled port calibration?
Regards
Volker