A 1-mW 12-GHz LC VCO in 65-nm CMOS technology

A low-power current-reused LC VCO circuit is implemented in 65-nm CMOS technology. The VCO covers frequency ranges (9.2 → 10.4) GHz and (10.6→12.4) GHz. The VCO core consists of two parallel active sections to adapt Gm with the operating frequency. Adaptive body-biasing technique using a new amplitude detector circuit is proposed. Switched varactor-bank circuit with boosted on-voltage is implemented to achieve a wide tuning range of 29% without sacrificing the phase noise and power. The VCO consumes 0.93 mA from 1.1-V supply at 12 GHz. The post-layout simulated phase noise is -105.3 dBc/Hz at 1 MHz offset from 12-GHz carrier frequency. The proposed VCO achieves FOMt of -196.35 dBc/Hz.