Discrete-Time Representation of Generalized Frequency-Dependent Permittivity within FDTD
ZHANG Xiao-guang
SU Zhi-guo
WANG Zhong-qing
RUAN Dian-xu
Abstract：Based on the recursive convolution method, which is only suitable for the dispersive media whose permittivity changes smoothly with the frequency, a direct algorithm incorporating frequency-dependent permittivity into a finite difference time domain (FDTD) was presented. The frequency-dependent permittivity was approximated by a rational function Debye to obtain the simulation result. The same permittivity was represented as a non-uniform discrete- time modified impulse response directly implementing a convolution in FDTD algorithm to obtain the simulation result. These two simulation results were compared and showed very good agreement. The proposed method is accurate and stable, and suitable for the case that the permittivity changing complex with frequency.
Keywords：finite difference time domain (FDTD)non-uniformpermittivityconvolution
Publication Date：2010-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)