TWO-DIMENSIONAL, JOSEPHSON-ARRAY, VOLTAGE-TUNABLE, HIGH-FREQUENCY OSCILLATOR

A two-dimensional array of Josephson junctions is used as a high-frequency oscillator capable of emitting coherent power of predetermined frequencies since the geometry of the two-dimensional array allows the individual Josephson junctions to phase lock at predetermined frequencies. The array is controlled at a given voltage and excited by the application of DC current through the array, in effect providing a rapidly tunable DC-to-AC converter at GHz and THz frequencies. The oscillator operates without the application of external high frequency signals or a connection to a cavity resonator. Load matching and other adjustments can be made by selecting the appropriate number of Josephson junctions in the array, selecting a damping factor which determines non-hysteretic operation, adding resistive shunts or a superconducting ground plane. The two-dimensional array used as an oscillator has advantages over one dimensional arrays in that voltage equalization from junction-to-junction occurs naturally so that phase locking is less likely to be affected by non-identical junctions, greater power output can be realized, an output having a narrower line width is produced and impedance matching is relatively easy.