Reply To: Ansys HFSS, Lumped port impedance affects Z-parameters

[Gia]

This is the expected behavior. You can consider HFSS to provide equivilent measurement data as a Vector Network Analyzer (VNA). All S, Y, and Z parameters also assume a specified refrence characteristic impedance, 'Z0'. For lumped ports in HFSS, the user can set the chacteristic impedance of the port to any arbitrary value and the resulting S,Y, and Z parameters will be scaled accordingly. For example, if you compute the Z parameters with a lumped port set to Z0 = 50 ohm, and then you change this value to Z0 = 75 ohm, then the change in Z parameters that you observe will be the same that you would observe if you were to measure the Z Parameters using a VNA with Z0 = 50 ohm ports, and then compare to the same measurement but using a different VNA with Z0 = 75 ohm ports.