Electromagnetic Scattering From Dispersive Dielectric Scatterers Using the Finite Difference Delay Modeling Method

A new method for solving the time-domain integral equations of electromagnetic scattering from dispersive dielectric bodies is proposed. The method is based on the finite difference delay modeling scheme, which accomplishes the temporal discretization by substituting a
z
-domain finite-difference approximation for the continuous time Laplace domain
s
parameter. The inverse
z
-transform used for computing the temporal kernels is calculated numerically using the trapezoidal rule and inverse discrete Fourier transform. Arbitrary dispersive models can be simulated without extraneous convolution using the new technique. The normal field equations are augmented to the standard tangential equations to solve the low-frequency instability problem.