A Low-Loss and High-Bandwidth Hollow Rectangular Dielectric Waveguide for Sub-THz Applications

This article proposes a hollow rectangular dielectric waveguide (HRDW) for sub-terahertz (sub-THz) applications. Comprising three layers of dielectric material, the HRDW features a hollow structure achieved by cutting a slot in the middle layer. In addition, the propagation constant of the HRDW is analyzed based on the effective dielectric constant (EDC) method. The HRDW and rectangular metallic waveguide transitions are designed, optimized, and fabricated by the printed circuit board (PCB) process and computer numerical control (CNC) machining, respectively. The HRDW supports monomode operation in the range of 90–294-GHz frequency. The measurement results show that the average attenuation constant of the HRDW is 0.028 dB/mm in the range of 220–294-GHz frequency. With its low-loss and high-bandwidth properties, the HRDW provides an innovative solution for sub-THz interconnects.