MoM/RCWA analysis of frequency selective surfaces with inhomogeneous, periodic substrates

This paper presents a numerical technique for the analysis of a metamaterial that may be considered as a new type of frequency selective surfaces (FSS), consisting of printed metal patches on inhomogeneous, periodic substrates. Such structures are more promising for EMC shielding than common FSS structures because both the effective dielectric permittivity and loss of the substrate can be controlled. To analyze these structures a series equation obtained from the Rigorous Coupled Wave Analysis (RCWA) is solved by the Method of Moments (MoM) with sub-domain rooftop basis functions and Galerkin testing functions. Several examples are outlined and analyzed using the MoM/RCWA technique. In order to validate the procedure, comparisons with a commercial time domain solver are performed.