Large finite periodic strip arrays

Finite-sized periodic structures abound in electromagnetics. Frequency selective surfaces (FSS) and array antennas are two prominent applications of these structures. FSS are commonly analyzed using Floquet mode expansion. This type of analysis is only rigorous for infinite structures, but for large FSS the results are very accurate. Array antennas are typically analyzed using the moment method or other full-wave methods. We apply a combination of Floquet mode expansion and the moment method to the problem of plane wave scattering from large finite periodic arrays of infinitely long strips. By solving rigorously only for the currents on strips close to the edges of the array, we save time and computer memory while retaining a high solution accuracy.