A General ADE-FDTD Algorithm for the Simulation of Dispersive Structures

A finite-difference time-domain general algorithm, based on the auxiliary differential equation (ADE) technique, for the analysis of dispersive structures is presented. The algorithm is suited for cases where materials having different types of dispersion are modeled together. While having the same level of accuracy, the proposed algorithm finds its strength in unifying the formulation of different dispersion models into one form. Consequently, savings in both memory and computational requirements, compared to other ADE-based methods that model each dispersion type separately, are possible. The algorithm is applied in the simulation of surface plasmon polaritons using the multipole Lorentz-Drude dispersion model of silver.