A fast time domain integral equation based scheme for analyzing scattering from dispersive objects

A fast integral equation-based scheme for analyzing transient scattering from inhomogeneous dispersive bodies is presented. A time domain integral equation in terms of the electric flux inside the body is constructed by invoking the volume equivalence principle, i.e., by equating the sum of the incident electric field and that radiated by equivalent volume polarization currents to the total electric field. The proposed algorithm for solving this time domain integral equation incorporates a recursive convolution scheme that updates the polarization current from knowledge of the electric flux. To reduce the computational cost and memory requirement of the resulting marching-on-in-time scheme, it is augmented with the plane wave time domain algorithm. Numerical results that validate the proposed approach and demonstrate its accuracy are presented.