A 60 GHz 360° phase shifter with 2.7° phase resolution and 1.4° RMS phase error in a 40-nm CMOS technology

This paper presents a vector modulator based active phase shifter for the 56-65 GHz frequency band in a 40-nm digital CMOS technology. The design comprises a magnetically-enhanced quadrature hybrid with better than 1-degree phase imbalance and 18 dB tuning range variable gain amplifiers with transformer broadband matching to generate 360° full-range phase tuning. It achieves 2.7° phase resolution for the first time. The rms phase error of the phase shifter is 1.4° and the rms gain error is 0.13 dB at 60 GHz. The insertion loss is 0.4 dB. The power consumption is 38 mW.