Two-band model of super-regenerative oscillators

Abstract

Super-regenerative oscillators (SROs), based on the switching of an oscillator, enable a high-gain amplification with the advantages of low cost, compact size, and low consumption. These advantages come at the expense of a complex operation, which, in addition to the timescale of the oscillation, involves the timescale of the quench signal. Most previous works describe the SRO with idealized models of the SROs of the Van der Pol type or numerical models valid only under certain conditions. This work presents a new outer tier semianalytical model that accounts for the two timescales by means of a two-band nonlinear formulation. Unlike previous approaches, the new model can predict the dynamic effects associated with the circuit elements in the band of the quench signal. The new formulation identifies the baseband component that determines the oscillator stability properties under the variation of the quench frequency; thus, it provides useful insight into the switched oscillator behavior. The parameters of the two-band model are easily extracted from harmonic balance. The model can be used for a system-level description of the SRO since it can efficiently predict its response under arbitrary input modulations and choices of the frequency and shape of the quench signal. The developed model will be validated through its application to an SRO at 2.8 GHz, which has been manufactured and experimentally characterized.