Wide-band phase locking of Josephson junctions in a resonator

We found that the chain of junctions acts both as the source of radiation and as a part of the superconducting resonator when the effective capacitance of the resonator is larger than the total capacitance of all junctions. At this condition junctions are synchronized in-phase not only at the resonance steps but also in the whole hysteretic region of I-V characteristics below the resonant frequency. The maximal allowable Spread of critical currents for this effect v; about 5 10% We analyzed the origin of the effect both numerically and by the method of slowly varying amplitudes [GRAPHICS] (C) 2009 WILEY-VCH Verlag GmbH & Co KGaA, Weinheim