Fast analysis of electromagnetic scattering from finite strip gratings on a grounded dielectric slab

A fast and accurate algorithm is explored for solving two-dimensional elect romagnetic scattering from electrically large finite strip arrays on ground ed dielectric slabs. The induced current is computed efficiently using the novel spectral algorithm, a recently proposed fast single-level matrix-vect or product algorithm that reduces the operation count to O(N), where N is t he number of unknowns. This algorithm was originally cast into a forward-ba ckward method, but it can equally be used to accelerate the matrix-vector p roducts on conjugate gradient techniques. Both, transverse magnetic and tra nsverse electric polarizations have been considered.