Infinite board in CST MWS?

Hi,
I have infinite board (material with eps.r) and I would like to simulate S parameter - exactly S11 and S21 in CST MWS. Is it possible? How can I simulate reflection and insertion lost this board? Can I use "waveguide port" in free space?
Thank you very much!

So, my question, my answer: :)
It is easy! It is about set correct boundaries only :) That is all.

hello mauloftin,
I have a same problem to solve. What are the dimensions you choose for the slab?
Thanks

Hi,
dimensions for the slab is no problem, try it. Is not good to do it very very small, try one size and after one large size and result must be same, if wouldn't be same, first size is too small.

I chose a 100x100x50 mm dimension slab of air,used a waveguide port and the same boundary conditions as specified in your figure. But S11 comes out to be 0.9...I can't understand the reason. Also I specify only one mode for the source (shows as a warning).

Hello mauloftin,
PFA the cst file. This is a sample problem with only one layer but I have many layers in actual problem.