centered cubic (FCC). We analyze the influence of time step on the numerical dispersion of
both methods has been analyzed, respectively. For the FCC-FDTD (2, 2) method, numerical
calculation result shows that the maximum time step defined by the Courant-Friedrichs-Levy
(CFL) condition is the optimal time step to minimize the numerical dispersion in the constant
spatial steps. On the contrary, with the time step approaches the CFL condition, the …