A 0.18μm 1V 5GHz LC VCO designed for WSN applications

A 1V 5GHz LC voltage controlled oscillator (VCO) fabricated in 0.18μm RF/MS CMOS process is proposed. To conquer the problems brought by low voltage, VCO's structure is carefully selected. Also, switched capacitor array and 2 stages buffer are introduced. Against different phase noise sources, corresponding phase noise and power performance optimization is realized. The die area of the VCO is 0.52×0.86 mm
²
. The measured phase noise of the VCO is -113.4dBc/Hz @1MHz and -124.5dBc/Hz @ 3.5MHz respectively while the tuning range is 4.56-5.32GHz. The figure of merits (FOM) of the VCO is -185dBc/Hz and the power consumption is 2.3mW.