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We have evaluated a Josephson arbitrary waveform synthesizer (JAWS) in the voltage range from $1~\mu \text{V}$ to 1 mV at frequencies from 60 to 1000 Hz for the use in the calibration of lock-in amplifiers. The uncertainty contribution from the JAWS system is 45 nV for 1 mV at 1000 Hz and $k=2.0$. We anticipate that the JAWS will help extend the lower voltage and frequency range of ac voltage metrology and improve the uncertainties by one order of magnitude compared to conventional techniques. [ABSTRACT FROM AUTHOR]

We have developed a system to extend, by a factor of up to 1000, the voltage range over which Josephson arbitrary waveform synthesizers (JAWS) can be used in ac voltage metrology. The system is based on a precision inductive voltage divider, with a lock-in amplifier as the detector. Using a JAWS with a maximum output voltage of 250 mV (root mean square), we have made accurate voltage measurements up to 120 V at 60 Hz with expanded uncertainties ($k = 2$) of no more than 1.5 $\mu \text{V}$ /V and demonstrate that the system can operate up to 1 kHz. We anticipate that our JAWS-based system will improve uncertainties in ac voltage metrology by one order of magnitude compared to techniques based on thermal voltage converters. [ABSTRACT FROM AUTHOR]

We have used the Josephson arbitrary waveform synthesizer (JAWS) to provide traceability for the phase of the harmonics, relative to their fundamental frequency, of a distorted waveform. For distorted waveforms with rms values from 0.154 to 0.2 V and harmonic magnitudes from 5% to 40% of the fundamental, our system can generate odd harmonics up to the 39th with best phase uncertainties from 0.001° to 0.010° ($k = 2.0$), depending on the harmonic number and harmonic magnitude. We anticipate that the ability of the JAWS to generate distorted waveforms with the lowest possible uncertainty in the magnitude, and phase spectra will make it a unique tool for low-frequency spectrum analysis. [ABSTRACT FROM AUTHOR]

We have developed a programmable Josephson voltage standard that can generate voltages up to 20 V with a resolution of 10 nV. The standard has two superconductor–normal metal-superconductor junction arrays connected in series and driven by two radio frequency oscillators. The standard has been integrated into a digital voltmeter calibration system for voltages from 10 nV up to 1000 V. The expanded uncertainty (k = 2) of the system is approximately 10 nV for voltages up to 20 V and 0.9 \mu\V/V in the voltage range from 20 to 1000 V. [ABSTRACT FROM PUBLISHER]

Measurements of the ac–dc difference of a thermal converter have been performed using a Josephson waveform synthesizer and a precision buffer amplifier at frequencies from 10 Hz to 4 kHz, showing agreement with conventional standards of better than 1 \mu\V/V up to 1 kHz. In addition, a method of finding the operating parameters of the programmable Josephson array that corresponds to minimal uncertainty is discussed. [ABSTRACT FROM PUBLISHER]

A system designed for precision measurement of ac–dc difference of thermal voltage converters in terms of a programmable Josephson voltage standard is under development at the National Measurement Institute, Australia, in collaboration with the National Institute of Advanced Industrial Science and Technology, Japan. The agreement between the new system and calculable thermal converters is presently better than 0.5 \mu\V/V at frequencies up to 40 Hz and voltages up to 0.75 V. [ABSTRACT FROM AUTHOR]

We are developing a programmable Josephson voltage standard (PJVS) system based on a compact cryocooler. The system is capable of generating two arbitrary waveforms by use of a dual-output PJVS (DO-PJVS) device. Owing to this dual-output feature of the PJVS system, the low-frequency characteristic in the ac–dc transfer difference of a thermal converter has been investigated using the 90^\circ addition method. The evaluation of the low-frequency characteristic of a thermal converter is of great importance for connecting conventional ac–dc transfer standards and new Josephson-based ac voltage standards. To fulfill this purpose, a dual-heater thermal voltage converter (DH-TVC) with improved low-frequency performance has been developed. The low-frequency ac–dc transfer difference of the DH-TVC was evaluated to be smaller than 1 \mu\V/V at frequencies of as low as 1 Hz. [ABSTRACT FROM PUBLISHER]