Application of the infinite FSS spectral domain method in solving finite planar FSS problems with arbitrary illumination

Summary form only given. The scattered field from an infinite planar frequency selective surface (FSS) can be calculated conveniently by the spectral domain moment method. However, in typical FSS systems, the FSS is finite, curved, and/or has nonplanar illumination. An approximate method for solving the general FSS problem is the locally planar technique (LPT). However, the LPT can only be used when the incident field curvature and FSS surface curvature are small. For the case of the finite planar FSS, the infinite FSS theory can be applied to approximate surface truncation and arbitrary incident field effects. This method takes the infinite FSS´s unit cell to be defined as the complete finite FSS. The distance between unit cells can be varied to achieve accuracy in the representation of the truncation effect. The arbitrary incident field is defined over each unit cell in terms of the spatial distribution in the finite problem. The aperture electric field for an inductive FSS is represented by one or more rooftop basis functions in each direction. The number of apertures is limited by the size of the matrix equation to be solved.<>