Application of the Finite-Difference Time-Domain Method in Presence of Dispersive Medium

The Finite-Difference Time-Domain (FDTD) method is a popular numerical approach for solving Maxwell's equations in the time domain. While the FDTD method has been extensively applied to calculate propagation of electromagnetic waves in non-dispersive media, its application in the presence of dispersive materials presents additional challenges. Dispersive media, such as dielectrics and plasmas, exhibit frequency-dependent permit-tivity, which must be accurately accounted for in the FDTD formulation. This paper presents a study of the implementation of the FDTD method for modeling wave propagation in Transverse Magnetic (TM) mode, in the presence of dispersive media, considering the Total Field/Scattered Field (TF /SF) technique. The paper also investigates the use of the Drude model, and demonstrates how changing the temperature of the dispersive medium can modify its permittivity. Simulation results, using a Gaussian source, for a two-dimensional cylindrical geometry are presented. These results demonstrate the FDTD method's capability to accurately capture the medium's dispersive proper-ties, including the temperature-dependent permittivity variations described by the Drude model.