Stable inclusion of a priori knowledge of field behaviour in the FDTD algorithm: application to the analysis of microstrip lines

A general methodology for incorporating a priori knowledge into the FDTD algorithm has been presented. In this contribution the technique has yielded a modified FDTD algorithm for the analysis of a microstrip; this method has been shown to be both more accurate than the standard FDTD technique and entirely stable. It is clear that the use of the methodology described herein can easily be extended to enable the improved treatment of any structure for which a priori knowledge of the fields exists.