New numerical techniques for efficient and accurate analysis of FSSs, EBGs and Metamaterials

In this paper we present two numerically efficient and accurate techniques for the analysis of doubly-infinite periodic arrays, which find applications as Frequency Selective Surfaces (FSSs), Electronic Bandgap (EBGs) structures and Metamaterials (MTMs). The first method, suited for the analysis of periodic elements with fine features, processes the results of a truncated array, typically comprising of only four to six rings, to derive the response characteristics of its doubly-periodic infinite counterpart. The reduction of the matrix size to only two or three, combined with the use of Reciprocity Principle to compute the reflection and transmission coefficients of the array, leads to a considerable CPU time and memory saving. The second technique, which is formulated to address the analysis of arbitrary 3D periodic elements, utilizes a generalized version of the waveguide simulator (WGS) approach, which, in contrast to the conventional WGS approach, is designed to handle arbitrary angles of incidence.