periodic structures and excitation (CSTor HFSS)

Hi,
I'm trying to simulate a chiral media and retrieve its parameters. I almost read all threads about this topic. But they all discuss obtaining constitutive parameters from S-parameters.
I need help with the previous step! How to extract S-parameter. I already used HFSS for antenna simulation, but it is a special case. My media is large to process and I should use periodic structures. I have problem with Master Slave BCs in HFSS and periodic BCs in CST, and also port excitation in this conditions(plane wave? waveguide port?). Can anyone help me?

Hi Shekoofeh,
Scattering parameters really only make sense when used to analyze finite arrays. The larger the array, the better, but obviously there are practical limitations. Without using finite arrays and scattering parameters, you'd need a different analysis method.
Try looking into Floquet ports in HFSS -- they allow you to extract scattering parameters for the case of propagation normal to an infinite array, if that's what you need.

Thank you.
I used unit cell in CST and the problem with ports solved. But again there was errors I didn't understand. I asked them here:
https://www.edaboard.com/thread362994.html

Can you post the warning message which you are getting