Discretization errors in finite methods: issues and possible solutions

In this paper, we review many of the sources of discretization error when f inite methods is applied to high frequency electromagnetic problems. A majo r source of error is the numerical dispersion error. This error is probably the most serious error for electrically large geometries, and we review pa st efforts to reduce this error. We also present a new edge-based finite di fference method which offers several improvements to current finite differe nce. This new method has less numerical dispersion error and less errors du e to material discontinuities than current finite difference methods. We co mpare its performance to vector finite elements and show its superior accur acy. Finally, we propose a new subgridding scheme to reduce discretization error which maintains second-order accuracy. (C) 1999 Elsevier Science S.A. All rights reserved.