28-38-GHz 6-bit Compact Passive Phase Shifter in 130-nm CMOS

In this letter, a highly compact, bidirectional, wideband 6-bit resolution passive phase shifter (PS) is presented in low-cost 130-nm CMOS technology. A compact Lange differential hybrid is designed in this letter to provide quadrature signals from the input. The compact Lange hybrid is followed by a switching matrix that generates weighted sums of the quadrature signals to cover 360° and additional controlled loss using single pole single throw (SPST) switches. The matrix consists of 12 transistors, each of which is controlled by a three-level gate voltage (0, 0.6, and 1.2 V) providing higher resolution in phase shifts. The chip achieves the state-of-the-art performance with 10-dB insertion loss across 28-38 GHz. The chip also achieves an rms gain error of 0.6 dB and an rms phase error of 3° in the bandwidth, consuming no dc power and only 0.15 mm2 including baluns.