On the Design of Active LC Oscillators Using Small-Signal Model Network Analysis

This work presents a simplified method to find the oscillation conditions for active LC networks. The method relies on finding the solution of the admittance or impedance determinantal equation of the small signal equivalent network model. The study presents four examples of the use of the method, and in particular it develops the conditions for a differential oscillator which is not a commonly discussed network in the literature. Results are verified by simulation for all the topologies and an experimental setup for a differential oscillator designed to operate at 30 MHz.