UNCONDITIONALLY STABLE FDTD SCATTERED FIELD FORMULATION FOR DISPERSIVE MEDIA

摘要

A new unconditionally stable scattered field (SF) formulation for the finite difference time domain (FDTD) technique applied to dispersive media is presented. The scheme is based on alternating direction implicit (ADI) principle but, unlike ADI, it does not require computation and storage of field values at the intermediate time steps which reduces computational costs and memory. Dispersive media characterized by Debye and Lorentz models are incorporated in the proposed SF FDTD scheme by auxiliary differential equation (ADE) method. For each of the dispersive media unconditional stability and accuracy of the scheme are validated by numerical tests. The scheme can perform faster than the explicit FDTD scheme at Courant number as low as three. (C) 2016 Wiley Periodicals, Inc.