Implementation of Floquet boundary condition in FDTD for FSS analysis

A computational FDTD (finite-difference time-domain) space with Floquet phase shift boundary condition has been created by exciting the space with phase-quadrature sinusoidal plane waves and extracting the phasor for Floquet phase shifting. The versatility of the FDTD approach allows one to handle arbitrary periodic elements. And yet, the proposed method obviates the need for large memory storage that would be required in the conventional FDTD approach implemented strictly in the time domain. The proposed method is applicable to a doubly-infinite periodic structure, such as an FSS (frequency selective surface), whose periodic elements can be arbitrarily inhomogeneous and arbitrarily shaped as well.<>