Analyze and design 10-GHz 0.8-VDD -117dBc/Hz quadrature LC-VCO in 120nm CMOS technology

A low supply voltage low phase noise 10-GHz CMOS quadrature LC-VCO (LC-QVCO) is systematically analyzed and designed for low power applications in wireline and wireless communication systems. Using a semi-empirical model, the impacts on VCO oscillation magnitude, loaded quality factor (Q
_loaded
), and oscillation frequency from the parasitic components of passive and active devices are formulated in simple mathematic equations. The predicted VCO performance and the widely used linear model of LC-QVCO are verified by time-domain simulations, frequency-domain total loop gain analysis, and measurement data based on a 120 nm RF CMOS technology.