Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Tapered Transmission Lines with Dissipative Junctions

Published

Author(s)

Paul D. Dresselhaus, Mike Elsbury, Samuel P. Benz

Abstract

NIST is optimizing the design of a 10 V programmable Josephson voltage standard so that it uses less microwave power by use of fewer parallel-biased arrays with higher voltage per array. Increasing the voltage per array by adding more junctions is challenging because the dissipation of the over-damped Josephson junctions limits the total number that may be located in each array. If there is too much dissipation in the array, the junctions at the end receive too little microwave power compared with the junctions at the beginning of the array. To compensate for the junction attenuation, tapered impedance transmission lines were used to maintain a nearly constant microwave current along the lossy transmission line. Simulation and testing have improved the microwave uniformity of our designs for tapered impedances from 85 Ohms to 5 Ohms. Low-leakage bias tees for various characteristic impedances were designed so that sub-arrays could be measured within long arrays. These tapered arrays have improved the bias current margins, junction number, and bandwidth of NIST junction arrays. By measuring the microwave power from the output of these long arrays, harmonic generation and the nonlinear properties of dissipative junction arrays may be studied.
Citation
IEEE Transactions on Applied Superconductivity
Volume
19
Issue
3

Keywords

Josephson arrays, Superconducting transmission lines, Nonlinear circuits, Superconductor-normal-superconductor devices

Citation

Dresselhaus, P. , Elsbury, M. and Benz, S. (2009), Tapered Transmission Lines with Dissipative Junctions, IEEE Transactions on Applied Superconductivity, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=33154 (Accessed July 23, 2024)

Issues

If you have any questions about this publication or are having problems accessing it, please contact reflib@nist.gov.

Created June 3, 2009, Updated February 19, 2017