Millimeter-wave beamforming circuits in SiGe BiCMOS

Integrated millimeter-wave 2 bit and 3 bit phase shifters and 4 channel beamforming network are presented in this paper. The 2 bit phase shifter exhibits 4° RMS phase error and a RMS gain error < 1 dB. In the 55–67 GHz range, the 3 bit phase shifter shows RMS phase error < 7° and a RMS gain error < 1 dB. The 4 channel beamforming network consists of four 2 bit RF phase shifter and a fully differential passive power distribution network. Between the 4 channels, the beamforming network exhibits less than 4° and 0.6 dB RMS phase and amplitude mismatch, respectively. The beamforming chip and the phase shifters are fabricated in SiGe BiCMOS technology. The 2 bit and 3 bit phase shifters draws 7 mA and 10 mA respectively from a 3.3 V supply. The circuits are well suited for highly integrated beamforming millimeter-wave transceivers.