Fast transient analysis of electromagnetic scattering from three-dimensional dielectric inhomogeneities using a volume integral equation

A fast technique for analyzing transient electromagnetic scattering from three dimensional inhomogeneous dielectric targets is proposed. This technique solves a volume integral equation using a marching-on-in-time (MOT) scheme (Gres et al. 2000). The computational complexity of performing a volume-scattering analysis using the classical technique in Gres et al. is O(N/sub t/N/sub s//sup 2/), where the volume source density is represented by N/sub s/ spatial and N/sub t/ temporal samples. This cost is prohibitively high, rendering the method impractical for analyzing scattering from electrically large structures. The contribution of this work is to reduce the high cost of the classical scheme to O(N/sub t/N/sub s/) by augmenting it with the multilevel plane-wave time-domain (PWTD) algorithm (Ergin et al. 1999). It is shown that incorporation of the PWTD algorithm into the MOT scheme does not compromise the accuracy of the scattering solution.