Multi-scale Approach for the Electromag- Netic Simulation of Finite Size and Thick Fre- Quency 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 defined at various scale-levels. Electromagnetic interaction between subsequent scales is modeled by mutually independent Scale-Changing Networks and finally 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 reflection/transmission coefficients and electromagnetic field backscattered by thick and finite size frequency selective surfaces. The computation time is significantly reduced when using SCT-based software compared with the FEM simulation tool.