Dear all,

I am planning to simulate, and in a single setup, an FSS-Antenna system. I need to study the effect of different field patterns of a source antenna on the performance of an FSS structure. The simulation scenario has the following givens:

1- An antenna, in both the radiative-near-field (Fresnel region) and far-field (Fraunhofer region), shines its fields on the FSS structure.
2- The FSS structure is a periodic one.
3- I need to observe the transmission/reflection coefficients from the Antenna's input port and the FSS's output port as a whole system, and of course, the same for each of the structures individually.

I have used a waveguide port for the antenna input, and exploited the Floquet port as an output port for the FSS. Now what I would love to know, is how to couple the field generated from the antenna to the input of the FSS so that it becomes the source of the incident wave. What port do I need to assign to set my antenna's output fields as an incident wave on the FSS, instead of shining a pure plane-wave using another Floquet port as a "deembed"ed input (like what's in the manual). I am also wondering whether there is another way in which I can save the fields of the antenna separately then shine them on my FSS alone to avoid wasting time in simulating the whole system, but certainly get me reliable results. Could anyone PLEASE help me with that?

Great thanks in advance!