A biconjugate gradient fft solution for scattering by planar plates

An efficient numerical solution of the scattering by planar perfectly conducting or resistive plates is presented. The electric field integral equation is discretized using roof–top subdo–main functions as testing and expansion basis and the resulting system is solved via the biconjugate gradient (BiCG) method in conjunction with the fast Fourier transform (FFT). Unlike other formulations employed in conjunction with the conjugate gradient FFT (CG–FFT) method, in this formulation the derivatives associated with the dyadic Green's function are transferred to the testing and expansion basis, thus reducing the singularity of the kernel. This leads to substantial improvements in the convergence of the solution as demonstrated by the included results.