Multi-Scale Approach for the Electromagnetic Simulation of Finite Size and Thick Frequency Selective Surfaces

The scattering analysis from metallic Grid FSS consisting of rectangular perforations on a thick metallic screen illuminated by an oblique incident plane wave is presented. The grid structure is analyzed using Scale Changing Technique (SCT) which is based on the partition of the grid-plane into planar sub-domains deflned at various scale-levels. Electromagnetic interaction between subsequent scales is modeled by mutually independent Scale-Changing Networks and flnally the complete structure is simply represented by a cascade of these networks. Very good agreement is obtained between simulation results from SCT and the Finite Element Method (FEM) when computing the re∞ection/transmission coe-cients and electromagnetic fleld backscattered by thick and flnite size frequency selective surfaces. The computation time is signiflcantly reduced when using SCT-based software compared with the FEM simulation tool. The accurate prediction of the electromagnetic scattering by flnite size arrays is of great practical interest in the design and optimization of modern frequency selective surfaces (FSSs), re∞ect-arrays and transmit-arrays. A complete full-wave analysis of these structures requires generally enormous computational resources due to their large electrical dimensions which would require prohibitively large number of unknowns to be solved. The unavailability of e-cient and accurate design tools for these applications limits the engineers with the choice of low performance simplistic designs that do