Improved Artificial Anisotropy HIE FDTD Algorithm for Periodic Structures at Oblique Incidence

This communication presents a high-efficiency hybrid implicit-explicit finite-difference time-domain (HIE FDTD) algorithm for solving the problem of periodic structures at the oblique incident. First, some perturbation terms are added to the basic HIE equations to make the stability condition loose. And then, the artificial anisotropy parameters are applied to the equations to reduce the dispersion error. After that, with similar number of arithmetic operations, memory allocation and better computational accuracy, the Courant-Friedrich-Lewy stability condition of the proposed algorithm can be relaxed approximately two times than previous algorithm. Numerical example demonstrates that the proposed algorithm is more efficient while having better numerical properties in comparison with the existing HIE FDTD method.