Glide-Symmetric SIH Unit Cells Implemented in Parallel-Plate Waveguides at mmWaves

This work studies the behaviours of unit cells based on substrate integrated holes (SIH) in parallel-plate waveguides (PPW). The basic SIH unit cell has been improved through the incorporation of a metallic patch. A comparison between the perfect dielectric hollow with patch unit cell and a SIH with patch unit cell has been carried out. The unit cell dimensions are used to study the different effective refractive indices. High order symmetries as a means to control dispersion and effective refractive indices are also introduced. By applying glide symmetry on different planes, we aim to enhance the effective refractive index and reduce dispersion across different frequency ranges. It is demonstrated that 1D glide-symmetric configurations reduce dispersion at higher frequencies, while 2D glide-symmetric configurations are able to reduce dispersion at high frequencies and also, to increase the effective refractive index simultaneously.