The Josephson two-terminal-pair impedance bridge

We present the connection of two programmable Josephson arrays generating synchronous waveforms to measure impedance ratios?the Josephson two-terminal-pair impedance bridge. This approach is more flexible than conventional bridges at the same level of uncertainty. The Josephson bridge can measure over a wider frequency range, over a wider range of impedance ratios than conventional two-terminal-pair bridges. Furthermore, the phase angle between the two impedances can take any value. As a first application, we present measurements of a 1?:?1 resistance ratio at the 10?k? level in the frequency range between 25?Hz and 10?kHz. The uncertainties are better than a few parts in 108 and hence comparable to those of conventional impedance bridges. Quantization at up to 10?kHz was confirmed by varying the bias current of the Josephson arrays, resulting in constant resistance ratios within the measurement resolution.

[1]  Peter Warnecke,et al.  High-precision resistance ratio measurements by means of a novel Josephson potentiometer , 1987, IEEE Transactions on Instrumentation and Measurement.

[2]  P. Patel,et al.  Investigation of binary Josephson arrays for arbitrary waveform synthesis , 2002 .

[3]  Torsten Funck,et al.  Measuring resistance standards in terms of the quantised Hall resistance with a dual Josephson voltage standard using SINIS Josephson arrays , 2002, Conference Digest Conference on Precision Electromagnetic Measurements.

[4]  Ralf Behr,et al.  Improved 1 V programmable Josephson voltage standard using SINIS junctions , 2002 .

[5]  Ralf Behr,et al.  Modeling and Measuring Error Contributions in Stepwise Synthesized Josephson Sine Waves , 2009, IEEE Transactions on Instrumentation and Measurement.

[6]  Thomas L. Nelson,et al.  Precision Differential Sampling Measurements of Low-Frequency Synthesized Sine Waves With an AC Programmable Josephson Voltage Standard , 2009, IEEE Transactions on Instrumentation and Measurement.

[7]  Panu Helistö,et al.  Realization of a square-wave voltage with externally-shunted SIS Josephson junction arrays for a quantum AC voltage standard , 2005, IEEE Transactions on Instrumentation and Measurement.

[8]  S. P. Benz,et al.  1 V and 10 V SNS Programmable Voltage Standards for 70 GHz , 2009, IEEE Transactions on Applied Superconductivity.

[9]  Samuel P. Benz,et al.  AC Josephson voltage standard: progress report , 1997 .

[10]  Luis Palafox,et al.  Achieving Sub-100-ns Switching of Programmable Josephson Arrays , 2007, IEEE Transactions on Instrumentation and Measurement.

[11]  C. Hamilton,et al.  Josephson D/A converter with fundamental accuracy , 1995 .

[12]  Jürgen Schurr,et al.  Realizing the farad from two ac quantum Hall resistances , 2009 .

[13]  J. Melcher,et al.  Direct Comparison of Josephson Waveforms Using an AC Quantum Voltmeter , 2007, IEEE Transactions on Instrumentation and Measurement.

[14]  Thomas J. Witt,et al.  Using the Allan variance and power spectral density to characterize dc nanovoltmeters , 2000, Conference on Precision Electromagnetic Measurements. Conference Digest. CPEM 2000 (Cat. No.00CH37031).

[15]  Stephane Solve,et al.  A review of Josephson comparison results , 2009 .

[16]  Thomas L. Nelson,et al.  Error and Transient Analysis of Stepwise-Approximated Sine Waves Generated by Programmable Josephson Voltage Standards , 2008, IEEE Transactions on Instrumentation and Measurement.

[17]  Frédéric Overney,et al.  Strong Attenuation of the Transients' Effect in Square Waves Synthesized With a Programmable Josephson Voltage Standard , 2010, IEEE Transactions on Instrumentation and Measurement.