A Wideband 90° continuous phase shifter for 60GHz phased array transceiver in 90nm CMOS technology

This paper presents a wideband reflective-type phase-shifter in 90 nm CMOS technology. The proposed phase shifter, employs a broadside coupler in the multi-layer metal structure in CMOS technology to attain 3-dB coupling at coupled and through ports where the phase difference between these two ports is 90deg. The reflective load contains a NMOS CMOS varactor with a tuning ratio of 3. Applying a 0-1 V DC tuning voltage, the overall phase shifter provides 0-87deg continuous phase shift, where the insertion loss of the phase shifter alters between 4.5-8 dB at the frequency range of 50-65 GHz and occupies chip area of 0.3 times 0.25 mm2. The overall phase shift achieved by this design can be extended to 180 and 360 degree.