Thermal-Transfer Standard Validation of the Josephson-Voltage-Standard-Locked Sine-Wave Synthesizer

This paper describes a Josephson-voltage-standard-locked synthesizer where a calibrator is used as a sine-wave generator, output whose is controlled by the calculable fundamental of the stepwise sinusoidal wave generated by a programmable Josephson junction array. Such a system combines the versatility of a calibrator with the stability and the accuracy of the Josephson voltage standard. The validity of this method was confirmed with the ac-dc difference measurements of a calibrated thermal-transfer standard. The synthesizer uncertainty inferred is below 1.2 μV/V for waveform frequencies up to 1 kHz and root-mean-square amplitudes ranging from 100 mV to 1 V.