A Comparison of Two Conformal Methods for FDTD Modeling - Electromagnetic Compatibility, IEEE Transactions on

Wo conformal finite-difference time-domain (FDTD) methods are considered, the contour path (CPFDTD) method of Jurgens et al. 141 and the overlapping grid (OGFDTD) method of Yee et al. [6]. Both TE and TM scattering from a two-dimensional (2-D), perfectly Conducting circular cylinder are used to test the accuracy of the methods for curved surfaces. Also, TE and TM scattering from a 244 perfectlyconducting rotated square cylinder are used to test the accuracy for corners and edges. It is shown that the conformal method proposed by Yee et aL provide significant improvement in accuracy over the original FDTD algorithm for most of the geometries studied in this paper. However, implementation becomes more difficult as geometries become more complex. The conformal method proposed by Jurgens et aL provide significant improvement in accuracy as well for most of the geometries studied in this paper. However, improvement does not occur for the TM case when the square cylinder is not aligned properly with the grid. Implementation of the CPFDTD method is relatively straightforward. For the majority of the cases studied, the OGFDTD method is more accurate than the CPFDTD method.