The reformulation of the scattering problem for an aperture in a perfect electric conductor - A hybrid method approach for scattering problems

In this paper, a hybrid approach to treat scattering from a large predominantly PEC scatterer with a small perturbation is outlined. The method is not a hybrid method in the classical sense. The problem is decomposed into two scattering problems, one pure exterior PEC scattering problem denoted as the reference problem and one antenna type of problem denoted as the delta problem. It is suggested that the reference problem is solved using high frequency techniques while the delta problem is solved using integral equation techniques. The electric surface current on a portion of the reference problem is required as input data to the delta problem. Thus the reference problem has to be solved prior to the delta problem. It is suggested that the computational domain of the delta problem is truncated away from the perturbation. An example of a derivation for a PEC scatterer with a perturbation consisting of a cavity filled with a homogeneous material is given.