A simple multigrid approach for calculating time-harmonic fields with FDTD

Abstract

A coarse-to-fine multigrid algorithm for the finite-difference time-domain (FDTD) method is proposed and applied to calculate the time-harmonic electromagnetic field in the presence of a resonant structure. The obtained results and the related efficiency are compared to those ones achieved with a conventional merely fine-grid FDTD run. The method is easy to implement into an existing FDTD framework, and most efficient if the steady-state electromagnetic field at a given frequency has to be computed within the entire solution domain.Index Terms-Finite-difference time-domain (FDTD).