IEEE Transactions on Applied Superconductivity

Millimeter-wave self-radiation from high-Tc Josephson junction arrays

Kiejin Lee, Ienari Iguchi, Jeha Kim, Seok-Kil Han, Kwang‐Yong Kang

Published Jun 1, 1997• 6 citations

Abstract

We report the strong microwave Josephson radiation from an array of high-T/sub c/ junctions on a MgO bicrystal substrate from centimeter- to millimeter-wave ranges. The dc bias current was fed to the junction array having parallel geometry with the pair of junctions shunted by superconducting loops. The configuration of bias leads was a series of interlocking dc SQUID's geometry which guaranteed the oscillation of all junctions at the same frequency. The phase differences between adjacent junctions with different I/sub c/R/sub n/ products could be controlled by an external small magnetic field. For a five-junctions array, we observed the coherent output power of about 13 pW without external magnetic flux, which was nearly five times higher than that of a single bicrystal junction. We observed the Josephson linewidth of the self-radiation in the coherent state to be less than 1 GHz by adjustment of the external flux.

DOI: 10.1109/77.622107

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