A superconducting tunnel diode oscillator

We have performed some preliminary measurements on a type of tunnel diode oscillator stabilized by two additional cavities. With proper choice of the couplings among cavities and their quality factors, it is possible to tightly lock the oscillator´s frequency to a high-Q, superconducting cavity. Although the system is now operating with parameters not yet optimal, we have observed improvements in the stability performance of the three-cavity oscillator over the single-cavity one of a few orders of magnitude.