High-Resistivity Silicon Dielectric Ribbon Waveguide for Single-Mode Low-Loss Propagation at F/G-Bands

In this paper, dielectric ribbon waveguides (DRWs) are designed and characterized to work in the F (90-140 GHz) and G (140-220 GHz) frequency bands. High resistivity silicon (HR-silicon) due to its high transparency in these bands, and its low-cost fabrication process, were selected for the fabrication of these waveguides. The guided modes of DRW are studied using Marcatili and multi-line methods. A design procedure for optimal single-mode propagation was introduced. The wave attenuation inside the waveguide is discussed. Our experiments show that HR-silicon DRW has less than 0.087 dB/cm (0.01 cm^-1) of loss over the guiding bandwidth. The designed DRWs were realized using microfabrication techniques. The measurements are in very good agreement with theoretical predictions.