A Millimeter-Wave Six-Port Junction Based on Ridge Gap Waveguide

The current paper presents a six-port low-loss waveguide coupler based on ridge gap waveguide structure with potential application in various mmWave wireless systems. The challenges in the fabrication faced in mmWave frequencies can be overcome by using the gap waveguide technology. The excitation of presented six-port junction is done by standard WR-28 waveguide flanges at the bottom. The performance of the proposed structure is confirmed by the fabrication and measurement. The measured results show that the proposed six-port junction operates in 30 GHz with 15% bandwidth with return loss in both input ports and isolation level better than 15 dB and 15 dB, respectively. The findings are valuable for the design and development of mmWave junctions for use in various high-frequency applications.