Discussion Forum

Dear Community members,

I was using Background and Scattered Field method simulating an infinite 2-dimensonal array, and the result matches almost perfectly with our experimental results. We wanted to get more physics from the simulation results, thinking about calculating whether there are higher order scatterings and how they behavior in the near-field or far-field. We utilized the far-field domain calculation by including enclosing surfaces of both our non-periodic ports along z-direction and the Flouquet boundary conditions along x and y directions. We have obtained a radar plot from that far field calculation, but we are unsure able the validity of Stratton-Chu formulae for 2-D periodic boundary conditions.

Does the far-field calculation in this case make any sense? From our intuition, waves doesn't comply with the periodic boundary conditions will vanish, which means we can only receive signal from the directions of diffraction orders. However, our far-field calculation show a non-zero broad peaks instead, so it implies some of the far-field calculation assumptions are not fulfilled or it is a consequence of the finite third dimension of a 2-D array, or the absorption of the materials in the unit cell?