Multilevel plane wave time domain-enhanced MOT solver for analyzing electromagnetic scattering from objects residing in lossy media

Marching-on-in-time (MOT) based time domain integral equation (TDIE) methods provide an appealing avenue for analyzing transient electromagnetic scattering from objects that reside in lossy media, were it not for their computational cost. Recent developments, however, permit the acceleration of these methods. One scheme is a lossy medium scalar plane wave time domain (PWTD) kernel that permits the fast evaluation of far-field interactions (Jiang, P.L. et al., IEEE Antennas and Propag. Soc. Int. Symp., 2003). This scheme evaluates transient scalar fields radiated by bandlimited sources residing in lossy media by expanding them in plane waves via a three-stage, fast multipole inspired scheme comprising aggregation, translation, and disaggregation steps. The paper outlines the formulation and implementation of a hybrid multilevel PWTD accelerated MOT solver for the efficient analysis of transient electromagnetic scattering from perfect electrically conducting (PEC) objects residing in lossy media. The proposed solver uses a vector extension of the original scalar PWTD scheme. A numerical example is presented to demonstrate the efficacy of the proposed hybrid scheme.