VCO with Miller theorem-based varactors

An inductor-capacitor voltage controlled oscillator (LC VCO) using Miller theorem-based varactors is presented in 90 nm CMOS technology for low-voltage applications. The VCO tuning range is effectively enhanced by incorporating a capacitive shunt-shunt feedback amplifier. Dissipating 3 mW from a 0.7 V supply, the VCO exhibits a phase noise of -111 dBc/Hz at 1 MHz offset from the oscillation frequency of 10.4 GHz. The frequency tuning range in percentage is 9.7 for a controlled voltage range of 0.1-0.5 V. The VCO achieves a high K_VCO of 2.5 GHz/V and a fair FoM of -186.6 dBc/Hz.