A 5 GHz wide-range CMOS active phase shifter for wireless beamforming applications

A CMOS 5.2 GHz active phase shifter is presented. Based on a tunable all-pass filter, this implementation achieves a wide phase-shift range with low loss, and minimizes the number of on-chip passive elements. Fabricated in a subset of a 0.25 /spl mu/m SiGe BiCMOS process, measurements of the active phase shifter show an insertion loss of 2 dB, an IIP3 of 1 dBm, and a phase shift range of 240/spl deg/. Power consumption of the core circuitry is 36.3 mW from a single 2.5 V power supply.