A compact moment method for determining the electromagnetic scattering of bodies of revolution

A compact implementation of a moment method solution of the integral equation that yields the scattering of a perfectly conducting body of revolution (BOR) is presented. The method is conceptually simple to derive and implement, and avoids most of the associated integrals. Its effectiveness stems from two basic facts: it is based on the radiation by loops of currents and charges (for which an efficient closed-form expression is derived); and point matching is used to handle the integral equation. We first derive a fast-converging series that yields the near-zone radiation produced by thin loops of currents and charges. The convergence of the series is discussed and its region of validity established. This series is then combined with a point-matching solution of the BOR electric field integral equation, to determine the corresponding electric surface current density. This method has been numerically implemented and successfully tested in several geometries, and representative results for the scattering by a sphere are presented.