A Long, Winding Road

There is a great deal of literature concerning oscillator noise. The problem of oscillator noise has been considered from intuitive to mathematically sophisticated viewpoints. In recent years, treatments of oscillator noise have concentrated on equations that are easier to use or are more complete in their characterization of nonlinearities and noise sources. Oscillator noise analysis has reached a level of sophistication that allows several general theories to be constructed. This article presents a historical tour of oscillator noise analysis and will not go into detail on any one method. It provides a brief tutorial on oscillator noise, and a survey of many of the papers that have contributed to our present understanding. Because many authors use different approaches and notation, there will be a number of different equations presented without derivation. The various equations cited will be described in enough detail to show how they contribute to understanding oscillator noise, and the reader is encouraged to refer to the original papers for detailed discussions. The “History” section will present a family tree of oscillator noise, and the “Present Models” section will review some of the more seminal papers. Tutorials on phase noise can be found in handbooks and in the references from this article. Please see ”Oscillator Noise Basics“ for background information on oscillation and noise.