Application of the generalized biconjugate gradient FFT method for analysing planar frequency selective surfaces

A computationally efficient method is presented for analysing the scattering from frequency selective surfaces (FSS) composed of arbitrarily shaped patches with finite conductivity. In this technique the generalised biconjugate gradient (BiCG) method and fast Fourier transform (FFT) are used to solve for the induced current densities. It is shown that this method requires fewer iterations than the conjugate gradient (CG) or the preconditioned CG method