Design of an Ultra Low-Power Tunable Ring VCO in 65 nm CMOS Technology for 2.9-4.5 GHz

The design of a tunable ring voltage-controlled oscillator (VCO) using TSMC 65 nm CMOS technology and a 1 V power supply is presented. The design consists of three inverter stages and capacitive loads for adjusting the frequency. Capacitive loads are implemented as MOS varactors connected to the output of the inverter stages. It is shown that the resulting design has a power dissipation of 0.65 mW, provides a tunable frequency range from 2.9 GHz to 4.5 GHz for -1.5 V to 1.5 V control voltage and phase noise of -90dBc/Hz is adequate for tuner application. The proposed VCO provides the frequency control in a wide tuning range and to adjust the oscillation amplitude without increasing the power consumption during the tuning.