Development and numerical solution of integral equations for electromagnetic scattering from cavities

One particular area in which the integral equation approach has been extensively used is that of calculating the scattering from an indentation in a perfectly conducting ground plane. The first and most widely used technique, the generalized network formulation, was proposed by Harrington and Mautz (1976), but it suffers from the problem of spurious resonances at the eigenfrequencies of the cavity. Hansen and Yaghjian (1992) studied low-frequency scattering from a two-dimensional trough in a ground plane. Asvestas and Kleinman (1994) developed a set of coupled vector integral equations for a three-dimensional unfilled cavity-backed aperture in a perfectly conducting ground plane. Wood (1995) generalized the equations to handle material-filled cavities. Here, we derive a set of integral equations, analogous to those of Wood, for the case of a material-filled two-dimensional trough in a ground plane.