A finite-difference time-domain (FDTD) method combined with Newmark algorithm in finite-element method for analysis of electromagnetic characteristics in dispersive media, named as extended Newmark-FDTD method, is presented. In the method, a unified time-domain updated formula can be applied to typical kind of dispersive model, i.e., Debye, Drude and Lorentz medium, and to novel dispersive models, i.e., modified Lorentz, quadratic complex rational function model and hybrid dispersive model as well, which has higher accuracy and better stability than traditional center difference scheme. Finally, validity of the algorithm is verified by several examples.

A novel finite-difference time-domain(FDTD) method combined with semi-analytical recursive convolution (SARC) algorithm in digital signal processing(DSP) techniques is presented to analyze electromagnetic scattering by dispersive media.Absolute stability,high accuracy,less storage and high effectiveness are retained while a unified update formulation is possessed.It can be applied to analysis of general dispersive media provided that the poles and corresponding coefficients in dispersive medium are given.Finally,the proposed SARC-FDTD approach is validated.RCS of an object coated with plasma are calculated.