K-band 360° Passive Vector Modulator Phase Shifter with Coupled Line Qadrature Coupler and Passive Transistor Array

This letter introduces a passive vector modulator phase shifter fabricated by 65-nm CMOS technology. Coupled line quadrature coupler is used to obtain broader bandwidth and more accurate quadrature signals. This work sums up an integrated method to analyze and improve the performance of the passive transistor array, and focuses on the impact of the matching impedance of the transistor array on the circuit performance. The proposed vector modulator phase shifter achieves a phase shift with range of 360° by 5.625° step, and an insertion loss of 11-14dB from 16-26GHz. The minimal RMS of phase error is 1.2° at 21GHz, and the maximum loss difference is 2dB in working frequency.