Dispersion curve along a longitudinal slot in HFSS

Folks,

I'm looking for a method to generate the dispersion relationship (i.e. beta vs frequency) along a longitudinal slot on a traveling wave antenna. I've played with the HFSS fields calculator, but I've found it completely inexplicable. Does anyone have any experience in this area? Any ideas on how I'd go about doing this would be very welcome.

Thanks,
J

Hi jwh,

Are you looking to extract the dispersive properties from the scattering parameters? If so, all you need is the phase of S21, for which you don't even need the fields calculator.

If not, you should run an eigenmode simulation. There are great examples at EMTalk.

Good Luck

PlanarMetamaterials,

thanks for the reply. I would like to get the propagation constant from a driven modal model (i.e. the S parameters). The issue is that I'm looking for the propagation constant of the space leaky mode that's coupled from the slotline mode. If I setup a lumped parameter drive modal simulation and compare the S21 phases between the two ends of the slotted structure, I'll effectively be measuring the prorogation constant of the slotline mode (that energy not coupled into a radiated mode).

Am I completely off base here?

-J

Nope, that's correct. You just need to obtain the S-parameters of your desired mode. If a waveport can't generate this mode, then I think you're out of luck, and should try an eigenmode simulation.