Extended Newmark-FDTD Method for Analysis of Electromagnetic Characteristics of Complex Dispersive Media

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.