25–40 GHz 180° Reflective-Type Phase Shifter using 65-nm CMOS Technology

This paper proposes a wideband reflection-type phase shifter (RTPS) suitable for 5G applications at mm-wave. In this phase shifter, a quadrature hybrid coupler was used as a transformer-based quadrature hybrid for broadband operation. In addition, the reflection term is composed of a varactor, an inductor, and a transmission line. The RTPS is cascaded to satisfy the phase shift range of 180°. The RTPS was fabricated in 1V 1-poly 9-metal 65-nm CMOS technology. The experimental results show that the constructed RTPS has a phase-shifting range of 184.9°, an insertion loss of 9.1 dB, a return loss of 8 dB, and an insertion loss variation of ±2.5 dB at an operating frequency of 25-43 GHz.