Optimization of tunable oscillators with AM to FM conversion for near-carrier phase noise

Nonlinearity in the resonating tank of an oscillator results in conversion of amplitude fluctuations into frequency fluctuations. The effect of this AM to FM (AM2FM) transformation on phase noise is especially important in high-Q oscillators with a wide tuning range. The author develops a quantitative time-variant model of near-carrier phase noise incorporating AM2FM conversion, which is both mathematically rigorous and intuitive, and propose new techniques to reduce AM2FM-induced noise in tunable oscillators.