A General Finite Difference Time Domain Method For Hybrid Dispersive Media Model

There are several methods for Finite Difference Time Domain(FDTD) to deal withdispersive media, for instance, recursive convolution FDTD(RC-FDTD), auxiliarydifferential equations (ADEs), Z Transform, current density convolution (JEC)method.These methods need different recursive formulations and computionalprograms for different dispersive media.Therefore, the generality of programs andalgorithms is not good enough.Besides,they become so complicated that they are notconvenient for many practical engineering problems.In this paper, based on the characteristics of the permittivity of these three generaldispersive media models can be expressed by fractional polynomial with respect to jω,Shift Operator Finite Difference Time Domain(SO-FDTD) has been extended so that itis suitable for the need of electromagnetic computing on hybrid dispersive mediamodel.The time domain recursive formulas of general method for hybriddispersive media modelare given and the reflection coefficient of several hybridmodel slabs are computed.In addition, the shift operator method is applied in theproblem of the hybrid dispersive media model.A general proposal for solving the thinlayers according to the weighted average of Sample points parameters is introduced.So the algorithm presented in this paper has strong generality in deal with theelectromagnetic problems of hybrid model because of the shift operator is proposed tohand with the recursive formulas.The numerical results illustrate the efficiency andaccuracy of our method in this paper.