The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 20, 1996
Filed:
Dec. 29, 1994
Seiko Instruments Inc., , JP;
Abstract
A DC SQUID has a first washer coil for forming a superconducting ring, Josephson junctions and a dampening resistor coupled to both ends of the first washer coil, and a shunting resistor connected in parallel to the Josephson junctions. An input coil is magnetically coupled with the first washer coil, and a first modulation coil is also magnetically coupled with the first washer coil. A ground plane comprising a superconducting film is disposed to cover an area of the Josephson junctions without covering the first washer coil for shielding the Josephson junctions from a magnetic noise. The ground plane prevents a magnetic flux trap from occurring, thus enabling stable operation of the DC SQUID. A washer cover comprising a superconducting film is disposed to cover only a slit portion of the first washer coil to prevent leakage of a magnetic field from the slit portion. The ground plane and the washer cover are simultaneously formed in a same layer of the DC SQUID. A second washer coil can be connected in series, or in parallel, with the first washer coil for forming the superconducting ring. The second washer coil is effective for canceling a uniform magnetic flux, thereby improving the operation of the DC SQUID.