FDTD Modelling of Electromagnetic waves in Stratified Medium

Abstract

A time domain numerical procedure is presented for a simulation of electromagnetic wave phenomena. The technique is an adaptation of the finite-difference time domain (FDTD) approach usually applied to model electromagnetic wave propagation. In this paper a simple 2D  implementation of FDTD algorithm in mathematica environment is presented. Source implementation and the effect of conductivity on the incident field are investigated. Simple illustrations of propagation in a non-conducting, partial conducting and conducting medium are provided. For the computational space, Cartesian grids of fixed size were used as it makes grid generation to be relatively easy. The numerical data generated by the program code were sampled at various time steps from t0=1 to 90 along the computational space. The simulation results show the advancement of the pulse into the medium at various time stepping, shift in the peak of the amplitude was observed on the pulse for all the time steps. An attempt to further show the attenuation as the wave propagates into the stratified medium is made. The amplitude of the pulse falls sharply from 0.006 to 1x10^-11 for t0=1 and t0=50. The results indicate the working of the model and it could be used to study the behavior of the wave as it does propagate across the medium.

Keywords: Stratified Medium, Finite Difference Time Domain (FDTD), mathematica, Maxwell’s Equations, Electromagnetic Waves (EM)