This work discusses the Finite-Difference Time-Domain (FDTD) technique to simulate an electromagnetic wave assuming one, two and three dimensions. The propagation medium is assumed to be a free space bounded by two absorbing boundaries, perfect matched layer (PML) and perfect electric conductor (PEC). The FDTD-1D is considered in free space while FDTD-2D and 3D are considered both in free space and in a free space-medium consisting of dielectric sphere and cylinder in the center. In this case, we model the incident and the scattered electromagnetic fields reflected back from hitting the dielectric cylinder and sphere. Moreover, the simulation starts by generating an electromagnetic pulse either in the middle or at one end of the medium and this pulse can be either Gaussian or sinusoidal. For the FDTD-3D, an antenna dipole is assumed to be the source generator of the electromagnetic pulse. We also provide the analytic solutions to confirm the accuracy of the FDTD technique.
Double absorbing boundaries for finite-difference time-domain electromagnetics
