Electromagnetic scattering from multiple sub-wavelength apertures in metallic screens using the surface integral equation method

Abstract

This work presents a novel finite-element solution to the problem of scattering from multiple two-dimensional holes with side grating in infinite metallic walls. The formulation is based on using the surface integral equation with free-space Green's function as the boundary constraint. The solution region is divided into interior regions containing each hole or cavity as a side grating and exterior region. The finite-element formulation is applied inside the interior regions to derive a linear system of equations associated with nodal field values. The surface integral equation is then applied at the opening of the holes as a boundary constraint to connect nodes on the boundaries to interior nodes. The technique presented here is highly efficient in terms of computing resources, versatile and accurate in comparison with previously published methods. The near and far fields are generated for different single and multiple hole examples.