An optimized artificially anisotropic WCS-FDTD method with reduced numerical dispersion

A three-dimensional artificial anisotropy weakly conditionally stable finite-difference time-domain (AA-WCS-FDTD) method is presented to reduce the dispersion error without introducing additional computational cost and complexity. The motivation is to equal the speed of light in the numerical simulation to the physical speed through manipulating the permittivity and permeability. The proposed AA-WCS-FDTD algorithm achieves the reduced dispersion error for the arbitrary incident angles, different time-step sizes and wide band frequency. The analyses of the stability and dispersion indicate that the proposed algorithm is weakly conditionally stable, and the Courant-Friedrich-Levy (CFL) condition is slightly changed. The numerical example demonstrate that the proposed method has a reduced dispersion error and high accuracy as compared to the WCS-FDTD method.