2. Electronic Oscillator Fundamentals

This chapter provides a brief overview of traditional oscillator theory, which has been examined in minute detail in available text and specialized electronic engineering books, as well as numerous conference and journal papers. The main focus is on the S parameter (small, large signal)-free electronic oscillator design and performance evaluation scheme. It starts with examination of the loop equations, open- and closed-loop gain, and Barkhausen and Nyquist criteria. Next, the concept of negative resistance and its application to oscillators is examined, followed by detailed enumeration of common emitter feedback, common-base feedback, common-emitter negative resistance, and differential oscillator design equations and steps. The chapter also examines in detail main oscillator noise problem, phase noise, starting with the key concepts, followed by the linear Leeson’s noise model, its drawbacks, and various modifications to include the nonlinearities of an oscillator. The discrete Fourier transform, the key tool to analyze oscillator output in the frequency domain (using the oscillator output’s power spectrum), is also examined in detail.