Twisted-Shaped Millimeter-Wave Hybrid Couplers in 150 nm GaN Technology for 5G Applications

This paper presents the first implementation of two innovative 90° hybrid couplers in Gallium Nitride (GaN) process designed for 5G applications. In a very compact design, both couplers target low insertion losses (IL) and large fractional bandwidth (FBW) to replace conventional couplers. The first coupler exhibits minimum insertion losses of 0.44 dB at 22 GHz with a fractional bandwidth of 31%. The second coupler was optimized to reach a minimum insertion loss of 0.28 dB at 25.5 GHz with a fractional bandwidth of 29%, making it suitable for wideband applications. Both couplers perform with an output phase imbalance of 93°±2°. Both circuits were designed using 150 nm GaN technology.