Dual Josephson Impedance Bridge: Towards a Universal Bridge for Impedance Metrology

Area of Science:

• Electrical Metrology
• Quantum Electrical Standards

Background:

• Accurate impedance measurements are crucial for electrical metrology.
• Traditional impedance bridges have limitations in frequency range and flexibility.
• Quantum Hall effect and Josephson voltage standards provide traceability for impedance.

Purpose of the Study:

• To fully characterize a Dual Josephson Impedance Bridge (DJIB) for high-precision impedance measurements up to 80 kHz.
• To evaluate the DJIB's performance against established impedance standards and international comparisons.
• To assess the DJIB's potential for simplifying impedance scale realization and detecting systematic errors.

Main Methods:

• Utilized a Dual Josephson Arbitrary Waveform Synthesizer (JAWS) source for flexible impedance comparisons.
• Compared impedance standards traceable to the quantum Hall effect and used in international comparisons.
• Analyzed uncertainty budgets for the DJIB and traditional METAS bridges.

Main Results:

• The DJIB demonstrated comparable measurement uncertainties to traditional bridges in the kilohertz range.
• The DJIB offers significant flexibility in comparing arbitrary impedances with variable ratios and phase angles.
• The DJIB proved to be a sensitive tool for identifying frequency-dependent systematic errors above 10 kHz.

Conclusions:

• The DJIB provides advantages in flexibility and frequency range without compromising measurement uncertainty.
• This instrument can simplify the realization and maintenance of electrical impedance scales.
• The DJIB is valuable for investigating systematic errors in impedance standards and Josephson voltage sources.