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 proper account of the static singularity in the kernel function and of the edge conditions at both apertures, to yield complete and convergent current expansions. Coupling of the electromagnetic field into the tapered interior of the open scatterer can be substantial, even in electrically narrow cross sections, due to the focusing action of the conical transmission line