Research on a Novel Ka-Band Low Insertion Loss Transmission Line Based on H-Guide

H-guide and nonradiative dielectric (NRD) waveguide have more favorable prospects in the millimeter wave and even terahertz bands comparing to other waveguides, such as surface plasmon polaritons transmission lines and Goubau line. Basically, the H-guide described in this letter can avoid many of the disadvantages of the other more-conventional guides, such as high losses, low Q -factors, poor field confinement and leakage, low power rating, small dimensions leading to severe tolerance problems, and expensive fabrication. In this letter, we analyze the characteristics of H-guide and design an adapter from microstrip line to H-guide. The experimental results are in good agreement with the simulation ones. The measured insertion loss of H-guide with back-to-back transitions ranges from 1.8 to 3.1 dB during 33-37 GHz, where the length of the H-guide reaches 200 mm.