Abstract
Josephson Junctions, J.J.'s, can be switched from the superconducting state into the voltage state when the current through the junction is less the critical current, I”, by thermal noise. Accurate I0 measurements of a J.J. are very hard to make in presence of thermal noise. A method of accurately estimating the I0 of a J.J. with thermal noise was developed by measuring the effective thermal noise temperature of a J.J. The effective thermal noise temperature of various J.J. devices was measured and calculated. The J.J. devices evaluated included inductively and resistively coupled logic devices and J.J. devices in the presence of various noise sources. The noise sources included room temperature resistors, switched J.J. devices, and J.J. devices in the linear I-V region beyond the gap. © 1993 IEEE