Design and Analysis of a 26-32-GHz 6-bit Passive Vector Modulation Phase Shifter for CMOS Bidirectional Transceiver

This article presents a 26-32-GHz 6-bit bidirectional passive vector modulation phase shifter (PVM-PS) in 40-nm CMOS for phased array systems. The passive phase shifter comprises a center-tap transformer-based quadrature generator/combiner, two 6-bit X-type attenuators, and a differential Wilkinson power combiner/divider. The symmetric design enables bidirectional signal propagation and offers flexible system configuration. Passive switches are sized to optimize the tradeoff among gain variation, insertion loss, and linearity. The phase shifter implemented in 40 nm covers a range of 360 ^{\circ} with 5.625 ^{\circ} resolution and the rms phase error is between 0.4 ^{\circ} and 1.3 ^{\circ} . It exhibits