Push-Pull Class-B Oscillator With Transformer-Based 2nd Harmonic Tail Filter

What is it about?

The paper describes the design of a push-pull class-B oscillator with second-harmonic tail filter. A thorough analysis, using impulse sensitivity function (ISF), is able to capture the operation of the oscillator. The theory reveals the link between the high tail impedance (provided by the 2nd harmonic resonator) and the low phase noise through the ISF. Measurement results confirm the record high oscillator Figure of Merit.

Featured Image

Why is it important?

This work is important for two main reasons. First, because it describes and provides design guidelines for a high performance oscillator, with a peak Fom of 195.6dB. Second, because it provides the theoretical link between the second harmonic tail resonator and the impulse sensitivity function of the switching transistors, going beyond the intuitive argument that the tails resonator acts as a high impedance.