Application of Finite Difference Time Domain to Calculate the Transmission Coefficient of an Electromagnetic Wave Impinging Perpendicularly on a Dielectric Interface with Modified MUR-I ABC

MATLAB codes were implemented in this study for a one dimension wave formulation using the computational technique of finite difference time domain (FDTD) method. The codes have then been verified under two cases, one a simple one dimensional wave impinging perpendicularly on a dielectric layer from air interface and second is a one dimensional wave impinging momentarily on a small dielectric slab. The transmission coefficients under both the cases have also been verified. For the former case, there is a constant transmission coefficient irrespective of the frequency of the electromagnetic wave impinging on it and for the latter; there is a sinusoidal type variation due to multiple reflections along the wall of the dielectric slab. In the course of this implementation of the codes a novel technique to implement the absorbing boundary condition (ABC) on the dielectric interface has also been devised based on the Mur-I ABC which has been verified for a dielectric of dielectric constant 4єo. The implementation of the codes presents a recapitulation of the evolution of FDTD from Yee’s Algorithm to the latest modifications in the ABC. Defence Science Journal, 2012, 62(4), pp.228-235 , DOI:http://dx.doi.org/10.14429/dsj.62.792