Phase locking in two-dimensional arrays of Josephson junctions: effect of critical-current nonuniformity

Numerical simulations are used to study mutual phase locking in two-dimensional arrays of Josephson junctions for parameters typical of successful millimeter-wave oscillators. Such arrays are shown to be very tolerant of random critical-current nonuniformities. However, comparison with an equivalent series array reveals that the locking between rows in a two-dimensional array is principally due to feedback through the external load and not to internal coupling between rows.<>