I am simulating a patch antenna in HFSS with a probe feed. The probe is excited by waveport on a coax similar to the HFSS example. My coax height is just 2mm and radius is 1.6mm. Coax pin is 1mm radius. My bandwidth frequencies are 2-2.8 GHz. I am using the Driven Terminal solution. I am not sure if the size of the waveport radius of 1.6mm is correct. Is their a relationship between it and the impedance of the port? Also, I am renormalizing the port to 50 ohm impedance. What should the coax and waveport size be?
Also, the airbox size should be λ/4 away. Should it be λ/4 away from bottom or top of substrate? The HFSS example is from bottom, however the substrate thickness there is only 3mm. My substrate thickness is 15mm.
Also, I tried using a λ/2 away airbox and the S-parameter results are different. I even went to 1λ to see what results I will get, and they, too, where different.
Your help is sincerely appreciated.