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Josephson-Based Full Digital Bridge for High-Accuracy Impedance Comparisons



Frederic Overney, Nathan Flowers-Jacobs, Blaise Jeanneret, Alain Rufenacht, Anna Fox, Jason Underwood, Andrew D. Koffman, Samuel P. Benz


This paper describes a Josephson-based full digital impedance bridge capable of comparing any two impedances, regardless of type (R-C, R-L, or L-C), over a large frequency range. At the heart of the bridge are two Josephson arbitrary waveform synthesizer systems that offers unprecedented flexi-bility in high-precision impedance calibration, that is, it can compare impedances with arbitrary ratios and phase angles. This single bridge can thus fully cover the entire complex plane. In the near future, this type of instrument will considerably simplify the realization and maintenance of the various impedance scales in many National Metrology Institutes around the world.


Impedance comparison, ac coaxial bridge, AC Josephson voltage standard, digital bridge.


Overney, F. , Flowers-Jacobs, N. , Jeanneret, B. , Rufenacht, A. , Fox, A. , Underwood, J. , Koffman, A. and Benz, S. (2016), Josephson-Based Full Digital Bridge for High-Accuracy Impedance Comparisons, Metrologia, [online],, (Accessed April 14, 2024)
Created June 23, 2016, Updated January 4, 2022