Dispersion Analysis of Glide-Symmetric Holey Metasurface Based on Multimodal Transfer-Matrix Approach

The dispersion behaviors of a glide-symmetric holey metasurface is investigated, with special interest in its stopband attenuation. The unit cell of the periodic surface is described by its multimodal transfer matrix in order to account for the higher-order modal couplings between adjacent cells. This multimodal transfer matrix is obtained from the generalized scattering matrix (simulated by CST) that relates multiple modes on each cell boundary. Then, the complex modal wavenumbers (both the phase and attenuation constants) are calculated from a generalized eigenproblem. This simulation-aided approach proves to be a highly efficient and very accurate tool for the Bloch analysis of glide-symmetric metasurfaces. Additionally, it enables the study of some unnoticed phenomena that cannot be captured by a commercial eigenmode simulator; among them, the existence of complex modes and the anisotropy in the stopbands. The reported findings can be beneficially employed for the design of such glide-symmetric holey surface as an EBG for gap-waveguide technology. .