Full 360circ Vector-Sum Phase-Shifter for Microwave System Applications

An innovative vector-sum phase shifter with a full 360◦ variable phase-shift range is proposed and experimentally demonstrated in this paper. It employs an active balun and a very high-speed CMOS operational transconductance amplifier (OTA) integrator to generate the four quadrature basis vector signals. The fabricated chip operates in the 2–3 GHz, it exhibits an average insertion gain of 1.5 dB at midband, and has an RMS phase error below 5◦ over the measured frequency span. The chip consumes 24 mW of DC power and is highly compact, measuring only 0.38 mm including bonding pads.