An Efficient One-Step Leapfrog WCS-FDTD Method

For solving the electromagnetic problems with fine structures in two directions, this letter presents an efficient three-dimensional (3-D) one-step leapfrog weakly conditionally stable finite-difference time-domain (WCS-FDTD) method, in which the updating manner of field quantities is the same as that of the traditional FDTD method that electric and magnetic fields are calculated at every full time-step but interlaced half a step apart in both time and space. Furthermore, by introducing an auxiliary field variable group denoted by m, the proposed algorithm is reformulated in a much simpler form with more concise right-hand sides for an efficient implementation. Compared to the original WCS scheme in Chen and Wang's work (IEEE Trans. Electromagn. Compat., vol. 49, no. 2, pp. 419-426, May 2007), the proposed method is more efficient while keeping the same numerical properties.