Millimeter-Wave Three-Way Coupler Based on Ridge Gap Waveguide Technology

A three-way coupler based on ridge gap waveguide (RGW) technology is proposed, which can be applied to the construction of beamforming networks such as Butler matrices. Meanwhile, benefiting from the employment of RGW, the design bears the characteristics of low loss. Within the working frequency from 27.50 GHz to 28.34 GHz, the design enables the trisection of power at the output ports. A constant phase difference of –120°, 0° and 120° can be realized when the input port is excited, respectively. The reflections and isolation coefficients of each port are all lower than –15 dB. The three-way coupler has a wide application prospect in 5G applications for working in the frequency of millimeter-wave.