A colpitts LC VCO with Miller-capacitance gm enhancing and phase noise reduction techniques

A 60 GHz Colpitts LC VCO with Miller-capacitance gm enhancing and phase noise reduction techniques is realized in 90 nm CMOS. With the Miller capacitance, the tuned-input tuned-output oscillator and the conventional Colpitts oscillator are combined together, thereby solving its start-up issues and improving phase noise performance. Moreover, it is found that the oscillator is robust to the tank mistuning. The proposed oscillator achieves a phase noise of -102 dBc/Hz at 1 MHz offset from 57.6 GHz, consuming 7.2 mW from a power supply of 0.6 V. The tuning range is from 55.8 GHz to 61.1 GHz and the measured single-ended output power is about -7 dBm. Accordingly, the figures-of-merit are FOM -189 and FOM_T -188 respectively.