Electromagnetic scattering by and transmission through a three-dimensional slot in a thick conducting plane

A hybrid numerical technique for a characterization of the scattering and transmission properties of a three-dimensional slot in a thick conducting plane is presented. The technique combines the finite element and boundary integral methods to formulate a system for the solution of the aperture fields and by virtue of the finite element method, it is applicable to inhomogeneously filled slots of arbitrary shape. The numerical implementation is described for the edge-based expansion functions associated with rectangular brick elements, and examples are presented demonstrating the validity, versatility, and capability of the technique. These also provide some understanding of the slots scattering and transmission properties as a function of its geometry and material filling