The frequency-dependent FDTD and the digital signal processing techniques

A new method for modeling wave propagation in arbitrary frequency-dispersive dielectric media using FDTD and DSP is discussed. This approach involves modeling the simulation region of dispersive media as an IIR digital filter, whereby the difference equations in the time domain are obtained directly and are used to model the transform function ε(t). In order to verify this approach, the authors simulate Gauss pulse plane wave propagation on an air/water interface and compare the numerical reflection/transmission coefficients with analytic results. The study shows that the numerical results are consistent with the analytic solution.