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:
Jan. 21, 1997
Filed:
Sep. 15, 1994
Seiko Instruments Inc., , JP;
Abstract
DC-SQUID includes an input coil for transmitting an external magnetic field signal as a signal current from a detection coil, a washer coil to which the signal current is input as a signal magnetic flux, two Josephson devices for converting the signal magnetic flux transmitted to the washer coil to a signal voltage, shunt resistors and a damping resistor which are connected to each of the Josephson devices in parallel and in series respectively to extinguish the hysteresis of the current-voltage characteristic, and a feedback modulation coil to which a feedback and modulation current is transmitted from an external control circuit. The feedback modulation coil is arranged so as to linearly traverse over the upper portion or lower portion of the washer coil. The mutual inductance Mms between a washer coil and a feedback modulation coil is set to be smaller than the self inductance Lw of the washer coil, to thereby making the magnetic field sensitivity excellent, the SN ratio of an DS-SQUID is improved, and RF noises are reduced.