Abstract
The paper presents a numerically efficient and accurate technique for the analysis of large, finite and conformal Frequency Selective Surfaces (FSSs) that are not amenable to analysis by using conventional methods applicable to infinite, planar and doubly-periodic FSSs. The proposed technique begins by employing the Characteristic Basis Functions (CBFs) to describe the currents induced on the elements. The reaction integrals needed to derive the reduced matrix elements are either computed in the spatial domain or in the spectral domain, depending on their separation distance, so as to make the process numerically efficient.