Low-noise SQUID
Patent 6023161 Issued on February 8, 2000. Estimated Expiration Date: 
February 27, 2018. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
February 27, 2018. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesMultispectral superconductive quantum detector Complex superconducting quantum interference device and circuit Patent #: 5625290 InventorsApplicationNo. 032171 filed on 02/27/1998US Classes:324/248, Superconductive magnetometers505/162, Magnetic field sensing system or device (e.g., SQUID, etc.)505/846Using superconductive quantum interference device (i.e., SQUID): (Class 324/248)ExaminersPrimary: Patidar, JayAttorney, Agent or FirmInternational ClassesG01R 033/02G01R 033/035 AbstractThe present invention comprises a high-transition-temperature superconducting device having low-magnitude low-frequency noise-characteristics in magnetic fields comprising superconducting films wherein the films have a width that is less than or equal to a critical width, wC, which depends on an ambient magnetic field. For operation in the Earth's magnetic field, the critical width is about 6 micrometers (μm). When made with film widths of about 4 μm an inventive high transition-temperature, superconducting quantum interference device (SQUID) excluded magnetic flux vortices up to a threshold ambient magnetic field of about 100 microTesla (μT). SQUIDs were fabricated having several different film strip patterns. When the film strip width was kept at about 4 μm, the SQUIDs exhibited essentially no increase in low-frequency noise, even when cooled in static magnetic fields of magnitude up to 100 μT. Furthermore, the mutual inductance between the inventive devices and a seven-turn spiral coil was at least 85% of that for inductive coupling to a conventional SQUID.Other References
Field of SearchSuperconductive magnetometersMagnetometer: (Class 324/248) Using superconductive quantum interference device (i.e., SQUID): (Class 324/248) Measuring or testing system or device Magnetic field sensing system or device (e.g., SQUID, etc.) Josephson Weak link (e.g., narrowed portion of superconductive line) With additional electrode to control conductive state of Josephson junction Particular barrier material Particular electrode material High temperature (i.e., >30o Kelvin) | |
