Phase locking of Josephson junction arrays achieved by a non-traditional bias scheme

We propose to modify the usual biasing scheme of a two dimensional Josephson junction array by connecting the wires in a special cross-type fashion. Numerical simulations show that a simple two dimensional circuit of Josephson junctions with the new biasing scheme, to the contrary of the traditional scheme, one can achieve a stable frequency locked state without the use of an external load. We also show that four of these circuits can be series connected and that the output voltage is further increased. The new scheme may dramatically improve the performance of Josephson junction microwave oscillators.