A modificatory algorithm for electrically thin dispersive layers base on shift operator finite-difference time-domain method

Abstract

A novel technique for treating electrically thin dispersive layer with the finite difference time domain (FDTD) method is introduced. The proposed model is based on modifying the node update equations to account for the layer, where the electric and magnetic flux densities are locally averaged in the FDTD grid. Then, based on the characteristics that the complex permittivity and complex permeability of three kinds of general dispersive media model, i.e. Debye model, Lorentz model, and Drude model, may be described by rational polynomial fraction in jω, the shift operator method is then applied to obtain the recursive formulation for D and E, B and H available for FDTD computation is obtained. The model is validated with several numerical examples. The computed results illustrate the generality, memory and time step economy and the precision of presented scheme.