ELECTROMAGNETIC PLANE-WAVE EXCITATION OF AN OPEN-ENDED CONDUCTING FRUSTUM

A Chebyshev-Galerkin solution of the electric field integral equation for the surface current induced on a conducting frustum by an incident plane wave is presented. The physically motivated mathematics takes p roper account of the static singularity in the kernel function and of the edge conditions at both apertures, to yield complete and convergen t current expansions. Coupling of the electromagnetic field into the t apered interior of the open scatterer can be substantial, even in elec trically narrow cross sections, due to the focusing action of the coni cal transmission line.