A novel concept for phase noise improvement in monolithic differential LC-VCOs

摘要

A novel concept for improvement of phase noise in differential LC-VCOs is proposed. Being based on quality factor (Q) enhancement through conversion of the lossy inductor to a virtual inductor conditionally approaching the ideal lossless limit, the basics of the concept are illustrated and explained. Practical realization of the concept is discussed, and its application in design of a CMOS based Giga Hertz range low phase noise monolithic differential LC-VCO is investigated. Advanced Design System (ADS) simulations using CMOS 0.18 μm TSMC RF design kit are used for evaluation.