Title :
A planar gradiometer based on a microwave RF-SQUID
Author :
Muck, Matthias ; Diehl, D. ; Heiden, C.
Author_Institution :
Res. Centre Julich GmbH, Germany
fDate :
3/1/1991 12:00:00 AM
Abstract :
A type of gradiometer, working on the basis of a planar microwave RF SQUID, is described. In this type of RF SQUID, a superconducting half-wavelength stripline resonator serves as tank circuit, into which the SQUID is integrated. If a gradiometer configuration is used for the SQUID (i.e. two loops), a certain asymmetry of the stripline resonator should be provided to ensure sufficient coupling between gradiometer and resonator. Gradiometers were prepared from thin niobium films on sapphire substrates, having either microbridges or tunnel junctions as Josephson elements. When operated in hysteretic mode, modulation voltages of about 100 μV were measured for both microbridge and tunnel junction SQUIDs
Keywords :
Josephson effect; SQUIDs; magnetometers; resonators; solid-state microwave devices; strip line components; superconductive tunnelling; 100 muV; Al2O3; Josephson elements; Nb-Al2O3; coupling; hysteretic mode; microbridges; microwave RF-SQUID; modulation voltages; planar gradiometer; superconducting half-wavelength stripline resonator; tank circuit; tunnel junctions; Coils; Copper; Coupling circuits; Feedback; Frequency; Niobium; SQUIDs; Stripline; Superconducting transmission lines; Voltage;
Journal_Title :
Magnetics, IEEE Transactions on
