An Analysis of $1/f$ Noise to Phase Noise Conversion in CMOS Harmonic Oscillators

We present a study of tail-bias-current 1/fnoise upconversion into 1/f3phase noise for both CMOS Colpitts and differential-pairLCoscillators. We focus on the incremental Groszkowski effect, i.e., the modulation of the shift in oscillation frequency induced by the higher current harmonics flowing into theLCtank of a harmonic oscillator induced by bias instabilities, as we show that there is no upconversion of 1/fnoise into phase noise from the core MOS transistors in either topologies. Quantitative results match very well numerical simulations run with spectreRF, and show that the Groszkowski effect may indeed be a dominant cause of 1/f3phase noise generation.