Impact of Amplitude Phase Correlation on Oscillator Phase Noise Model

In this paper we study how the phase noise model of an LC oscillator changes by taking into consideration the impact of amplitude phase correlations for both white noise and flicker noise. A new circuit based analytical model of phase noise is used for this purpose and the oscillator topology chosen for study is a Differential Oscillator. We compare our results with simulation results. It is found that by taking amplitude correlation into consideration there is a correction in the phase noise model for white noise, which matches simulation results better. For flicker noise the uncorrelated results are closer to the simulation results. The noise results obtained from the correlated model are lower than that obtained from the uncorrelated model. We propose that this occurs due to mutual cancellation between the impacts of amplitude deviation and phase deviation on the overall phase noise.