Design of An 80GHz Passive Vector Modulated Phase Shifter in 22-nm CMOS SOI Technology

An 80GHz 5-bit passive vector modulated phase shifter (VMPS) with the ability of high accuracy and 360° range phase shifting was designed. The circuit consists of a 3dB 90° coupler, two identical X-type attenuators, and a Wilkinson-like power combiner. The passive X-type attenuator consists of a digitally controlled array of transistor units, which is used to perform the tuning of the transmission loss so as to achieve the phase shifting in four quadrants and thus obtain the 32 phase shifting states. Simulation results predict that the transmission coefficient S21 and reflection coefficient S11 are >: -14.5dB and <-20dB in the frequency range of 76–81 GHz, respectively. Also, it can provide a 360° range phase shifting with accurate phase tuning (the difference between the theoretical and simulated phase of S21 is <1.5°) and low transmission loss error between any two states of PS (<0.5 dB) throughout the frequency bandwidth of 70–90 GHz. The VMPS is planned to be implemented with 22nm fully depleted silicon on insulator (FDSOI) CMOS technology.