Full-Wave Analysis of Periodic Dielectric Frequency-Selective Surfaces Under Plane Wave Excitation

A novel full-wave method for the modal characterization of dielectric electromagnetic band-gap structures under oblique plane wave excitation is presented, showing the dielectric lattice periodicity in both the longitudinal and the transverse propagation directions. In this method, an eigenvalue problem is obtained in terms of the generalized ABCD matrix of the periodic cell, whose solution provides not only the propagation constant of the fundamental Floquet mode, but also of the higher order modes of the global periodic structure. The proposed analysis technique has been successfully validated with a commercial software based on the frequency domain finite element method. The transmittance of a finite periodic material with a finite number of unit cells has also been successfully verified through comparisons with other theoretical results reported in the technical literature. Then, our new algorithm has been used to study band-gap materials made of rectangular dielectric parallel rods, investigating the variation of the dispersion diagram and the transmission and reflection transfer functions when modifying both geometrical and electrical parameters of this structure. Finally, the response differences when a periodical defect is considered in a finite periodic arrangement have also been highlighted.