Showing papers by "Hideaki Takayanagi published in 1981"
TL;DR: In this paper, a mm-wave Josephson integrated mixing circuit has been fabricated using superconducting microstriplines using Si wafer as the dielectric layer and the signal and local powers were fed through tapered ridge waveguides, which were coupled into the stripline with small loss.
Abstract: A mm‐wave Josephson integrated mixing circuit has been fabricated. In the circuit, an Nb‐Te‐Nb sandwich Josephson junction was used as the active element. Both RF and IF circuitries were made in the form of superconducting microstriplines using Si wafer as the dielectric layer. The signal and local powers were fed through tapered ridge waveguides, which were coupled into the stripline with small loss. The circuit was tested at 50‐GHz signal frequency and the conversion efficiency was measured at −7.4 dB, for a junction with 0.4‐mV ICRN product. The measured efficiency showed good agreement with the theoretical prediction.
1 citations
TL;DR: In this article, a study was made on Nb based Josephson junctions with evaporated Te barriers, and the smooth surface Nb electrode enabled the formation of a pinhole free barrier.
Abstract: A study was made on Nb based Josephson junctions with evaporated Te barriers. As the first step, a Nb-Te-Pb configuration was tested. The smooth surfaced Nb electrode enabled the formation of a pinhole free barrier. Supercurrent density was found to be large compared to that for surface oxidized junctions. As the second step, a Nb-Te-Nb structure was tested. Although the junction uniformity was not as good as that of the Nb-Te-Pb junctions, the aging property was drastically improved. Considerations were made on the origin of the remaining aging. The junctions showed excellent response to 50 GHz signals.
1 citations