Primary Voltage Standard: Josephson Junction Arrays

Primary Voltage Standard: Liquid Helium System
November 15, 2017
photo of amplifier module next to a dime
Digital Amplifier Module
November 15, 2017
Show all
HYPRES all-Nb voltage standard chips were developed through close collaboration with the National Institute of Standards and Technology and define the standard volt worldwide. HYPRES is the sole commercial supplier of both 1-volt and 10-volt standard chips and systems made with its all-refractory Nb technology.

HYPRES is the only commercial manufacturer of the superconducting integrated circuit used in Primary Voltage Standard Systems. HYPRES chips are used in the primary voltage standards in national laboratories around the world including Italy, France, United Kingdom, Australia, China, Malaysia, Japan, Canada, Korea, Singapore, Norway, United States, Netherlands and Mexico.

The HYPRES Josephson Junction Array Voltage Standard circuits provide the ultimate accuracy for realizing and maintaining the SI Volt.


  • Niobium/Aluminum Oxide/Niobium, SiO2 dielectric, Niobium wiring technology.
  • All Niobium technology. Refractory. Impervious to moisture and thermal cycling.
  • 20,208 Josephson junctions (10 V chip) 3,660 Josephson junctions (1 V chip)
  • 18 x 38 micrometers junction area.
  • Installed in a FR-4 epoxy glass mount.
  • RF input WR-12 waveguide flange.
  • RF Distribution – 16 way parallel x 1263 cells in series (10 V) – 4 way parallel x 915 cells in series (1 V)
  • Designed for a frequency range of 72-78 GHz
  • Operating temperature of 4.2 K
  • Common DC terminal resistance is < 1 Ohm – typical
  • Approximately 10 mW operating power at the input flange for 10 V chip (2 mW for 1 V)
  • -11V to +11 V range for 10 V chip.
  • -2.5 V to + 2.5 V range for 1 V chip.
  • Stability time is typically 1 hour for the 10 V chip, 5 hours for the 1V chip
  • 0.005 PPM accuracy at 10 V (10 V chip)
  • 0.05 PPM accuracy at 1V (1V chip)
  • Calibration certificate supplied with each chip.
  • 2 Year Warranty.

HYPRES maintains an in-house Primary Josephson Array Voltage Standard System. Each Josephson Junction Array is thoroughly tested and characterized in this system prior to delivery.

The standard Volt worldwide is based on a superconducting Josephson junction array, and its realization at many International Standards Laboratories, including the Bureau International de Poids et Mesures (BIPM) in Paris, currently uses HYPRES superconducting 1-Volt and 10-Volt standard chips incorporating over 3,000 and 20,000 Josephson junctions respectively. HYPRES is the sole commercial supplier of both 1-Volt and 10-Volt voltage standard chips, made with our all refractory Niobium (Nb) technology. The circuits made with this process have demonstrated no signs of aging or deterioration when used for many years. The HYPRES all-Nb voltage standard chips were developed into a commercial product through close collaboration with the National Institute of Standards and Technology (NIST), which developed the original design of this device.