Multi-harmonic generator based on the synchronization of a nonlinear bipolar oscillator

A multi-harmonic generator, based on the synchronization of a bipolar oscillator at the fundamental frequency is presented. The fact that the oscillator generates, by itself, the high harmonic content reduces the requirements of RF input power. The first-harmonic injection enables a relatively large synchronization band. The design is based on a bipolar transistor oscillator, spending a long fraction of its period in the saturated regime. The circuit is simulated through harmonic balance, performing stability and phase-noise analyses. The possibility of frequency conversion between different harmonic components of the oscillator has also been evaluated. A prototype providing harmonics between 0.24 and 2.4 GHz has been manufactured, with very good agreement with experimental results.