Ultra-Wideband Homogenization of a Glide-Symmetric Parallel-Plate Waveguide

Glide-symmetric metasurfaces present the low-dispersive and low-loss characteristics required by modern communication devices in the millimeter-wave frequency band. Simple changes of their characteristic dimensions allow for a smooth variation of their effective refractive index. However, the lack of analytical models for these structures makes it difficult to foresee the effect of these changes on the effective index, requiring cumbersome numerical studies to properly size them. Here, a glide-symmetric corrugated parallel-plate waveguide is homogenized at low-frequencies, yielding an analytical expression of its effective refractive index. Numerical results show that this leads to a wide-band characterization of the glide-symmetric structure, due to its low-dispersive behavior.