Phase error reduction in general FDTD methods via optimum configuration of material parameters

The study of wave-interaction phenomena with the standard finite difference time domain (FDTD) method is seriously affected by numerical dispersion, especially in the case of coarse mesh resolutions. To alleviate this problem, we propose the implementation of higher order FDTD approaches, combined with a simple correctional technique. The latter ensures a more precise numerical wave speed by properly adjusting the properties of the modeled materials at a pre-processing stage and, therefore, does not increase the overall computational burden. Although the correction is carried out on a single-frequency basis, error reduction is observed at a wide part of the frequency spectrum, thus enabling the execution of more reliable wideband simulations as well. Numerical verification of the proposed scheme is finally obtained for two test configurations.