Modeling of periodic structures using the finite difference time domain (FDTD)

Two-dimensional planar periodic structures find many applications in practice because of their spatial filtering characteristics. A periodic array of conducting patch or aperture elements is often referred to as a frequency selective surface (FSS), or a dichroic filter. Such arrays are frequently analyzed via the method of moments (MoM) utilizing a periodic Green´s function. The waveguide simulator approach is employed in this paper to model periodic structures that can have three-dimensional elements and can be embedded in inhomogeneous dielectrics. Comparisons with the MoM and/or analytical results are included and very good agreement is observed.