Spherical Convolution Matched Layer in Cartesian Coordinate System for the FDTD Solver

Spherical truncation boundary in non-spherical coordinate system for the finite-difference time-domain (FDTD) method is discussed in this paper. The convolutional perfectly matched layer has been optimized in non-physical division and enhanced weakly ability in absorbing evanescent wave. From the radiation simulation, we found that the wave profile only according to simulation time, which leads to spherical outline in three dimensional cases. We reconstruct regular cubic Yee cells in three-dimensional, and restricts computation domain in the spherical truncation boundary. This method effectively avoids the unnecessary computation in corner and edge areas, and greatly reduces the memory and running time. This is an essentially efficient modeling strategy, which is suitable for the FDTD method in solving three dimensional scattering problems.