HFSS Wave port size in broad side coupled resonator
I need to simulate a broad side coupled transmission line structure in hfss. However I can't find any reliable source of wave port size guidlines for broad side coupled lines. Do I need to fix the waveport size by seeing the port fields or is there any other solution.If anyone has simulated some broad side coupled structures, any kind of help will be really appreciated
There are some rules of thumb, such as you want the wave port 4 times the dimensions of the TL, but essentially what you want to do is capture all of the modal fields. So yes, viewing the fields should give you an indication as to whether or not your size is appropriate.
Thank you for the help. I had one more doubt regarding modes if you could kindly clarify.
As i have gone through literature, the even and odd mode impedences in a broadside coupled stripline structure differ by a large value with the odd mode impedance being significantly smaller usually. Am i correct ? So how to take into account both the even odd mode propagation in HFSS. Is it by assigning modes to the waveports. I tried by defining 2 modes of the wave port but when I am viewing the fields, the even mode propagation isn't coming correctly. Should I be able to see the fields or does the modes in HFSS ports denote something else. Apologies if the question is silly.
Also is it possible to get correct results using lumped ports in this case.
Thanks very much for your time.
Good question: the modes you see should be the ones you expect. If you don't see the correct modes, then something is wrong with the setup (such as the waveport is not the correct size), or the solution is not sufficiently converged. In the analysis setup options, you can set the port impedance error to a much lower value (e.g., 0.1%) from its default value (2%). This usually helps lock onto the correct solution. Otherwise, try adjusting the size of the port.