Generalised 3-D ADI-FDTD algorithm for the modeling of wave propagation in dispersive media

A 3D alternating-direction-implicit finite-difference time-domain algorithm is presented for problems that involve material frequency dispersion described by generalised modified Lorentzian terms. The implementation exploits the auxiliary differential equations formulation and applies an order reduction technique in order to achieve synchronisation with the two-step procedure. The efficiency of the proposed method is validated in a benchmark problem of a resonant metallic cavity filled with plasma.