Josephson-type superconducting tunnel junctions as generators of microwave and submillimeter wave radiation

The use of Josephson-type superconducting tunnel junctions (two superconductors separated by a very thin insulating layer) as generators of radiation in the range 5 GHz to 1000 GHz is discussed. To this end, the results of recent experiments on the observation of X-band radiation from such junctions are presented, along with a complete discussion of the theory of such junctions. Their potential use as detectors, voltage sources, and harmonic multipliers is also discussed.