A 2.4 GHz high-linearity low-phase-noise CMOS LC-VCO based on capacitance compensation

A 2.4 GHz high-linearity low-phase-noise cross-coupled CMOS LC voltage-controlled oscillator(VCO)is implemented in standard 0.18-μm CMOS technology.An equalization structure for tuning sensitivity base on the three-stage distributed biased switched-varactor bank and the differential switched-capacitor bank is adopted to reduce the variations of the VCO gain,achieve high linearity,and optimize the phase-noise performance.Compared to the conventional VCO,the proposed VCO has more constant gain over the entire tuning range.The tuning range is about18.7% from 2.23 to 2.69 GHz,and the phase noise is-95 dBc/Hz at 100-kHz offset and-117 dBc/Hz at 1-MHz offset from the carrier frequency of 2.42 GHz.The power dissipation is 2.1 mW from a 1.8 V power supply.The active area of this VCO is 500 × 810 μm2.