1–2 GHz 2 mW injection‐locked ring oscillator based phase shifter in 0.18 µm CMOS technology

A new phase shifter based on injection‐locked ring oscillator is proposed. By using a multi‐stage phase generator with voltage‐controlled injection locking technique, the proposed phase shifter is able to generate a flexible combination of coarse and fine‐tuned phase delays over a wide range of operating frequencies while a small silicon area is maintained. Fabricated in a 0.18 µm RF CMOS process which only occupies 50 × 40 µm, a proposed three‐stage phase shifter achieves flexible phase delays and a measured operating frequency up to 2 GHz with a maximum power consumption of 2 mW from a 1.8 V supply.