how to simulate a capacitor in hfss

Hi everybody! i'm new to Hfss. I need to simulate a parallel plate capacitor with air as dielectric. I've designed it according to the hfss guide i've found on the web, but i would like to calculate the S and Y parameters for this structure (i think i'm gonna post the hfss file as soon as i'm home). How do i have to excite the capacitor and where? Is it possible to get a plot of the impedance value vs frequency? What boundaries do i have to use (i just have assigned the radiation boundary to the air, which sorround the whole structure)?
Looking forward to read your answers.
Thank you very much

Luca

You need to define a lumped port across your two plates. You can draw a 2D sheet with the draw line command that joins the two plates. Select that new sheet and assign it a lumped port. Add a new integration line and draw the arrow from one plate to the other. Then you can generate a report with S and Z parameters of that port. yes you need to have your object in the center of the box whose dimension is at least the wavelength of the frequency you are solving.

You can simulate it by drawing any object. Then select that object,
right click on it and select:
Assign boundary>Lumped RLC


But i dont the physical dimensions of a capacitor or a varactor??
Does anyone know?

Have you been able to solve this problem ?

I wont have to be a wavelength. Even for things designed to radiate like antennas, lambda/4 is ok. But for objects like a capacitor it could be much closer.