A novel hybrid algorithm based on FDTD and WCS‐FDTD methods

Abstract

In this article, a hybrid algorithm based on traditional finite-difference time-domain (FDTD) and weakly conditionally stable finite-difference time-domain (WCS-FDTD) algorithm is proposed. In this algorithm, the calculation domain is divided into fine-grid region and coarse-grid region. The traditional FDTD method is used to calculate the field value in the coarse-grid region, while the WCS-FDTD method is used in the fine-grid region. The spatial interpolation scheme is applied to the interface of the coarse grid region and fine grid region to insure the stability and precision of the presented hybrid algorithm. As a result, a relatively large time step size, which is only determined by the spatial cell sizes in the coarse grid region, is applied to the entire calculation domain. This scheme yields a significant reduction both of computation time and memory requirement in comparison with the conventional FDTD method and WCS-FDTD method, which are validated by using numerical results.