This paper proposes a dual-conduction class-C VCO for ultra-low supply voltages. Two cross-coupled NMOS pairs with different bias points are employed. These NMOS pairs realize an impulse-like current waveform to improve the phase noise in the low supply conditions. The proposed VCO was implemented in a standard 0.18 μm CMOS technology, which oscillates at a carrier frequency of 4.5 GHz with a 0.2-V supply voltage. The measured phase noise is -104 dBc/Hz@l MHz-offset with a power consumption of 114μW, and the FoM is -187dBc/Hz.
展开▼
