Implementation of Unsplit Perfectly Matched Layer Absorbing Boundary Condition in 3 Dimensional Finite Difference Time Domain Method

The C++ programming language was used to implement three-dimensional (3-D) finite-difference time-domain (FDTD) technique to simulate radiation of high frequency electromagnetic waves in free space. To achieve any meaningful results the computational domain of interest should have to be truncated in some way and this is achieved by applying absorbing boundary conditions. A uniaxial perfectly matched layer (UPML) absorbing boundary condition is used in this work. The discretised equations of the UPML in FDTD time stepping scheme were derived and has been successfully implemented using the computer program. Simulation results showed that the UPML behaves as an absorber. This was confirmed by comparing the results with another boundary condition, the Mur ABC.