Suppression of late-time instabilities in 3-D-FDTD analyses by combining digital filtering techniques and efficient boundary conditions

A new computational procedure is developed to suppress late-time instabilities in three-dimensional finite-difference time-domain analyses. The method combines low-pass filtering schemes with absorbing boundary conditions. The computational domain is truncated at only a few cells from the scattering object. Applications concern the analysis of long transients exciting frequencies up to a few megahertz.