A 5GHz band low noise and wide tuning range Si-CMOS VCO

In this work, a fully integrated 5 GHz Voltage Controlled Oscillator (VCO) is presented. The VCO is designed with 0.18 mum mixed signal Complementary Metal Oxide Semiconductor (CMOS) process of Taiwan Semiconductor Manufactuning Company (TSMC), Limited. To achieve low phase noise, a varactor circuit is designed to cancel effects of 1/f noise and fluctuation of capacitance due to harmonics. The proposed VCO has tuning range from 5.1 GHz to 6.1 GHz (17.9%) and phase noise of lower than -110.8 dBc/Hz at 1MHz offset over the full tuning range. Figure-of-merit-with-tuning-range (FOMT) of the proposed VCO is -182dBc/Hz.