RELATIVE ACCURACY OF SEVERAL FINITE-DIFFERENCE TIME-DOMAIN METHODS IN 2 AND 3 DIMENSIONS

-A comparison of the accuracy of several orthogonal-grid finite-difference time-domain (FDTD) schemes is made in both two and three dimensions. The relative accuracy is determined from the dispersion error associated with each algorithm and the number of floating point operations required to obtain a desired accuracy level. In general, in both 2-D and 3-D, fourth order algorithms are more efficient than second order schemes in terms of minimizing the number of computations for a given accuracy level. In addition, in 2-D, a new second order approach proposed by Chen, Ney, and Hoefer is much more accurate than the popular Yee scheme for a given amount of computation and can be as efficient as the fourth order algorithms. In 3-D, Yee's algorithm is slightly more efficient than Chen's approach in terms of operations, but much more efficient in terms of memory requirements.