Learning Forum

[hedayat99]

Hi,

I have an HFSS structure with differential ports. I want to match this differential port impedance with a frequency-dependent complex impedance using the parametric sweeping of various lengths and widths of my structure. The differential ports do not accept the complex port impedance. Also, when I define a real-valued frequency-dependent impedance as a design dataset and try to put it as a port impedance, it gives me an error. However, it works when my ports are simply single-ended. I have attached the screenshots.

I would appreciate it if someone could help me solve this issue.

 

[Faezeh Ladani]

Hi! 

Try Driven Modal Solution Type. The two modes you define for the port there will be similar to differential and common modes in Driven Terminal. In the Waveport definition, post processing Tab, you can renormalize specific modes to your desired impedance(complex and frequency dependent as well) with the format of resistance+1i*reactance

[hedayat99]

Hi Faezeh,

Thank you for your reply. My ports are internal to the structure (mm-wave IC circuit). I can use the PEC backing for the wave ports but I don't have enough space to accommodate the large dimension of wave ports. Another issue is that, to my understanding, for a wave port to work as a differential port, the two input signal lines should be covered by one single port. However, my two signal lines are separated by some distance (I have some other structure between them). Could you please suggest me an alternate solution?

Thank you for your help.