Modal Analysis of Frequency Selective Surface Containing Ring Loops

Modal analysis of frequency selective surface (FSS) containing ring loops arranged periodically along any two skewed coordinates, will be calculated. In proposed modal analysis, a compatible set of orthonormal mode functions used for ring loops in addition to Floquet modes which are used in every infinite two dimensional arrays. This set of modes provides faster convergence in solving integral equation in accordance with this boundary condition problem. Calculations are compared with results of CST (Finite Integration Technique) and HFSS (Finite Element Method) full-wave simulators and they are in good agreement with each other.