Modeling of a Quasi-Optical Josephson Oscillator

We have developed a computer model of a Josephson tunnel junction embedded in a general circuit with frequency dependent impedance using the harmonic balance method. This model has been applied to the analysis of a two-dimensional Josephson junction array with integrated coupling structures, called a quasi-optical Josephson oscillator. The simulations are done for a junction with dipole, slotline, and bow tie antennas. The results show that the junction with a bow tie antenna gives the best performance and the output power from an array of 4000 junctions can reach 25.7 mu W at a frequency as high as 1091 GHz for niobium junctions deposited on a 0.207-mm thick quartz substrate.