Efficient FDTD algorithm with isotropic numerical dispersion on an overlapped lattice

Abstract

A second order algorithm is developed for electromagnetics on an overlapped discrete lattice and the results are compared with the standard Yee algorithm. The present algorithm maintains the locality and simplicity of the Yee algorithm while improving on errors introduced by numerical dispersion. In addition, the present algorithm is stable for time steps larger than those required for the Yee algorithm. For a given physical problem and a given error bound, the present algorithm is shown to require approximately half the memory of the Yee algorithm and only one half to one third the computation time due to its improved isotropic numerical dispersion and increased time step.