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 electromagnetic scattering from electrically large finite strip arrays on grounded dielectric slabs. The induced current is computed efficiently using the novel spectral algorithm, a recently proposed fast single‐level matrix‐vector product algorithm that reduces the operation count to O(N), where N is the number of unknowns. This algorithm was originally cast into a forward‐backward method, but it can equally be used to accelerate the matrix‐vector products on conjugate gradient techniques. Both, transverse magnetic and transverse electric polarizations have been considered.