FDTD/PBC algorithm for skewed grid periodic structures

In this paper, an efficient finite-difference time-domain (FDTD) algorithm with a simple periodic boundary condition (PBC) is presented to analyze periodic structures with arbitrary skewed grid. The algorithm is easy to implement and efficient in both memory usage and computation time. The stability criterion of the algorithm is angle independent and therefore it is suitable for implementing incidence with angle close to grazing as well as normal incidence. The validity of this algorithm is verified through numerical examples with a Jerusalem cross frequency selective surface (FSS) configuration.