Amplification by a voltage locked array of Josephson junctions
Donald G. McDonald, Nolan V. Frederick
We have studied a new type of Josephson junction amplifier which is based on a two-junction array; the junctions are mutually phase locked at the Josephson self-oscillation frequency. With this frequency at 82 GHz, the voltages of the junctions remain equal (locked) for a bias current range as large as 60% of the critical current. Over a much smaller bias range, with an applied signal frequency of 1 kHz, a small-signal power gain of 19 dB was measured, accompanied by a negative resistance input impedance. This performance is consistent with a quasistatic theory of the amplifier.
Applied Physics Letters•Sep 1, 1985•12 citations