Development of a wide band TEM-based Bethe Hole coupler using ridge gap waveguide technology

Abstract

A 20 dB Bethe Hole coupler is designed and fabricated using ridge gap waveguide technology for operation at the Ku band. The use of ridge gap waveguide concept makes an opportunity to develop a low loss and wideband directional coupler because of supporting TEM wave propagation in air region. The simulation results show a very flat −20 dB coupling coefficient response, higher than 20 dB isolation and proper impedance matching over a wide frequency range which are in agreement with the measurement results.