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.

Superconductor Science and Technology



Kent D. Irwin, Michael D. Niemack, Joern Beyer, Hsiao-Mei Cho, William B. Doriese, Gene C. Hilton, Carl D. Reintsema, Daniel R. Schmidt, Joel N. Ullom, Leila R. Vale


Multiplexed superconducting quantum interference device (SQUID) amplifiers have recently enabled the deployment of kilopixel arrays of superconducting transition-edge sensor (TES) detectors on a variety of receivers for astrophysics. Existing multiplexing techniques for TES arrays, however, have constraints due to aliasing of SQUID noise, the size of the required filtering elements, or the complexity of the room-temperature electronics that make it difficult to scale to much larger arrays. We have developed a Walsh code-division SQUID multiplexer that has the potential to enable the multiplexing of larger arrays or pixels with faster thermal response times. The multiplexer uses superconducting switches to modulate the polarity of coupling between N individual TES detectors and a single output SQUID channel. The polarities of the detector signals are switched in the pattern of an N N Walsh matrix, so that a frame composed of N orthogonal samples can be used to reconstruct the detector signals without degradation. We present an analysis of the circuit architecture and preliminary results.
Superconductor Science & Technology


SQUID, multiplexer, Walsh code


Irwin, K. , Niemack, M. , Beyer, J. , Cho, H. , Doriese, W. , Hilton, G. , Reintsema, C. , Schmidt, D. , Ullom, J. and Vale, L. (2010), Superconductor Science and Technology, Superconductor Science & Technology, [online], (Accessed June 18, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created February 22, 2010, Updated February 19, 2017