Hybrid integration of a Josephson series array and a 10 GHz planar oscillator

Author

Hebrank, Franz X. ; Vollmer, E. ; Funck, T. ; Kohlmann, J. ; Gutmann, P. ; Niemeyer, J.

Author_Institution

Phys. Tech. Bundesanstalt, Braunschweig, Germany

Volume

46

Issue

2

fYear

1997

fDate

4/1/1997 12:00:00 AM

Firstpage

242

Lastpage

245

Abstract

A computer-controlled Josephson voltage standard has been developed comprising the hybrid integration of a planar oscillator and a Josephson series array. A 10 GHz voltage controlled oscillator has been frequency-stabilized to a reference frequency by a phase-locked loop. A series array has been designed and fabricated in Nb/Al₂O₃/Nb technology. To obtain quantized voltage steps with a drive frequency of 10 GHz, the critical current density of the Junctions is reduced to below 2 A/cm² by variation of the oxidation parameters. The hybrid integration of a Josephson circuit with a planar MESFET oscillator produced quantized voltage steps up to 980 mV with a step width of 2 μA

Keywords

aluminium compounds; critical current density (superconductivity); hybrid integrated circuits; measurement standards; microwave oscillators; niobium; phase locked loops; physical instrumentation control; superconducting junction devices; voltage measurement; voltage-controlled oscillators; 10 GHz; 10 GHz planar oscillator; 2 muA; 980 mV; Josephson series array; Nb-Al₂O₃-Nb; Nb/Al₂O₃/Nb technology; computer-controlled Josephson voltage standard; critical current density; drive frequency; hybrid integration; phase-locking; planar MESFET oscillator; planar oscillator; quantized voltage steps; reference frequency; series array; voltage controlled oscillator; Frequency; MMICs; Microstrip; Microwave antenna arrays; Microwave circuits; Microwave oscillators; Niobium; Standards development; Voltage; Voltage-controlled oscillators;

fLanguage

English

Journal_Title

Instrumentation and Measurement, IEEE Transactions on

Publisher

ieee

ISSN

0018-9456

Type

jour

DOI

10.1109/19.571822

Filename

571822