3-D Isotropic Dispersion FDTD Algorithm for Rectangular Grid

An updated equation of the 3-D isotropic dispersion finite-difference time-domain (ID-FDTD) scheme is proposed for a rectangular grid. The scaling and weighting factors are formulated to reduce the anisotropic dispersion error. Especially, the least mean square (LMS) method is used to calculate the weighting factors to minimize the fluctuation of the dispersion over an entire spatial domain. The dispersion behavior of the proposed ID-FDTD scheme is characterized. Then, the formulated 3-D ID-FDTD scheme is verified for two scattering problems.