This paper presents a new CMOS LC-VCO with a 2.95–3.65 GHz tuning range.The large tuning range is achieved by tuning curve compensation using a novel varactor configuration,which is mainly composed of four accumulation-mode MOS varactors(A-MOS)and two bias voltages.The proposed varactor has the advantages of optimizing quality factor and tuning range simultaneously,linearizing the effective capacitance and thus greatly reducing the amplitude-to-phase modulation(AM-PM)conversion.The circuit is validated by simulations and fab- ricated in a standard 0.18μm 1P6M CMOS process.Measured phase noise is lower than–91 dBc at 100 kHz offset from a 3.15 GHz carrier while measured tuning range is 21.5%as the control voltage varies from 0 to 1.8 V.The VCO including buffers consumes 2.8 mA current from a 1.8 V supply. This paper presents a new CMOS LC-VCO with a 2.95-3.65 GHz tuning range. The large tuning range is achieved by tuning curve compensation using a novel varactor configuration, which is mainly composed of four accumulation-mode MOS varactors (A-MOS) and two bias voltages. The proposed varactor has the advantages of optimizing quality factor and tuning range simultaneously, linearizing the effective capacitance and thus reducing reducing the amplitude-to-phase modulation (AM-PM) conversion. The circuit is validated by simulations and fab - ricated in a standard 0.18 μm 1P6M CMOS process. Measured phase noise is lower than-91 dBc at 100 kHz offset from a 3.15 GHz carrier while the tuning range is 21.5% as the control voltage varies from 0 to 1.8 V. The VCO including buffers consumes 2.8 mA current from a 1.8 V supply.