Reduction of numerical dispersion by optimizing second-order cross product derivative term in the ADI-FDTD method

Abstract

We propose a new adaptive alternating-direction implicit finite-difference time-domain (ADI-FDTD) to reduce the anisotropy in the numerical phase velocities. The proposed form has two anisotropic parameters on the first order terms of the time step and one parameter on the second order term. of the time step. We introduce a new approach of reducing the error of the numerical phase velocity by controlling the three parameters. The numerical stability, is discussed and compared with the previous approach of reducing the numerical dispersion. (C) 2007 Wiley Periodicals, Inc.