A reduced order model for electromagnetic scattering using multilevel Krylov subspace splitting

Traditional moment matching (Taylor expansion) based reduced order modeling in electromagnetics is known to be narrowband due to ill-conditioned moment generation process. In recent years, multipoint well-conditioned broadband asymptotic waveform evaluation techniques have been introduced that use implicit orthogonalization. These techniques are inherently sequential and difficult to parallelize. This paper introduces an elegant subspace splitting technique that is parallelizable and easy to implement. The technique is shown to match moments and is thus accurate. A wideband scattering problem is used to demonstrate the technique.