A Generalized Method for Computing Oscillator Phase Noise Spectra

This paper presents a generalized semi-analytic method for computingoscillator phase noise spectra, including the details veryclose to the oscillation frequency. The starting point is a generalrelation between an oscillator's output power spectral density andthe characteristics of the input noise processes. For weak inputnoise processes that vary sufficiently fast over time, this relation reducesto an analytic expression. For cases that do not satisfy theseconditions, the relation is, in part, evaluated numerically. This isaccomplished using techniques for exponential data fitting. The resultingmethod is able to compute oscillator phase noise spectra fora wide range of input noise characteristics.