Hybrid PO-PWTD scheme for analyzing of scattering from electrically large PEC objects

Recently, there has been growing interest in developing hybrid physical optics (PO)-integral equation schemes, both in the time and frequency domains. This paper presents a fast hybrid physical optics - time domain integral equation (TDIE) scheme for analyzing transient scattering from electrically large, perfect electrically conducting (PEC) objects. The scheme requires the user to delineate regions on the scatterer where currents are computed either using a TDIE scheme or by PO. In non-PO regions, currents are updated by solving a time domain combined field integral equation by marching on in time. Everywhere else, PO updates are effected by considering not only incident fields, but also fields radiated by all currents on the scatterer. The computation of the latter fields is accelerated by the plane wave time domain (PWTD) scheme. Multiple PO bounces are inherently captured by this formulation. Several examples that demonstrate the efficacy of this solver will be presented.