Patent US2811873A successfully refreshed from Google Patents.
Patent US5021739A successfully refreshed from Google Patents.
US5021739A
Expired / Lapsed
US
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Superconductor type radio frequency with adjustable inductance magnetic flux measuring circuit
Assignee: Hitachi Ltd
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Filing: 1989-10-25
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Granted: 1991-06-04
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Expires: 2009-10-25
Abstract
Abstract An RF magnetic flux measuring circuit uses a SQUID fluxmeter of which the input and output characteristics establish a periodic function, and in which a pick-up coil for picking up desired RF magnetic flux and an input coil of the SQUID fluxmeter are connected to form a closed loop which is a superconducting loop for transferring the magnetic flux to the SQUID. There is also provided an inductance adjusting device which adjusts the inductance of the superconducting loop to limit the magnetic flux that crosses the SQUID fluxmeter within a range of a single-valued function in said input and output characteristics.
Inventors
- 👤 Koichi Yokosawa
- 👤 Hideki Kohno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 10:19
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/02; G01R33/035; G01R33/0354; G01R33/0358; G01R33/20; G01R33/24; Y; Y10; Y10S; Y10S505/00; Y10S505/825; Y10S505/842; Y10S505/843; Y10S505/844; Y10S505/845; Y10S505/846
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
91 words
A magnetic flux measuring circuit for measuring the magnitude of radio-frequency (RF) magnetic flux comprising: a superconducting loop, said superconducting loop including a pick-up coil for converting said RF magnetic flux into an electric current that flows through said superconducting loop, and an input coil for a superconducting quantum interference device fluxmeter that converts said electric current into a voltage output; and an inductance adjusting means for adjusting the inductance of said superconducting loop; whereby the magnitude of said voltage output provides measurement of the magnitude of said RF magnetic flux.
Claim 2
Dependent Claim
91 words
A magnetic flux measuring circuit for measuring the magnitude of radio-frequency (RF) magnetic flux comprising: a superconducting loop, said superconducting loop including a pick-up coil for converting said RF magnetic flux into an electric current that flows through said superconducting loop, and an input coil for a superconducting quantum interference device fluxmeter that converts said electric current into a voltage output; and an inductance adjusting means for adjusting the inductance of said superconducting loop; whereby the magnitude of said voltage output provides measurement of the magnitude of said RF magnetic flux.
Claim 3
Dependent Claim
41 words
A magnetic measuring circuit according to claim 1, wherein said inductance adjusting means consists of an additional coil which is inserted in series with said input coil of said superconducting loop, and the inductance of said additional coil can be varied.
Claim 4
Dependent Claim
36 words
A magnetic flux measuring circuit according to claim 2, wherein the inductance of said additional coil is adjusted by adjusting the position of a rod having a predetermined permeability that is inserted in said additional coil.
Claim 5
Dependent Claim
34 words
A magnetic flux measuring circuit according to claim 2, wherein the inductance of said additional coil is adjusted by changing he kind of gas in a chamber in which said additional coil is placed.
Claim 6
Dependent Claim
26 words
A magnetic flux measuring circuit according to claim 2, wherein the inductance of said additional coil is adjusted by changing the shape of said additional coil.
Claim 7
Dependent Claim
42 words
A magnetic flux measuring circuit according to claim 1, wherein said inductance adjusting means consists of an additional coil which is connected in parallel with said input coil of said superconducting loop, and the inductance of said additional coil can be varied.
Claim 8
Dependent Claim
33 words
A magnetic flux measuring circuit according to claim 1, wherein said inductance adjusting means consists of a rod having a predetermined permeability which can be inserted in said pick-up coil at different depths.
Claim 9
Dependent Claim
20 words
Magnetic flux measuring circuit according to claim 1, wherein said inductance adjusting means changes the shape of said pick-up coil.
Claim 10
Dependent Claim
148 words
A magnetic flux measuring circuit for measuring the magnitude of radio-frequency (RF) magnetic flux comprising: a SQUID fluxmeter including a SQUID ring which derives an output voltage form input to said SQUID ring induced by said RF magnetic flux. a superconducting loop, said superconducting loop including a pick-up coil for converting said RF magnetic flux into an electric current that flows through said superconducting loop, and an input coil that induces a signal in said SQUID ring to produce said output voltage, and an inductance adjusting means for, prior to measurement of said to-be-detected RF magnetic flux, adjusting the inductance of said superconducting loop to a constant value so that the ratio of RF magnetic flux crossing said pick-up coil to said output voltage from said SQUID fluxmeter results in only one value of said input Rf magnetic flux corresponding to said output voltage of said SQUID fluxmeter.
Claim 11
Dependent Claim
148 words
A magnetic flux measuring circuit for measuring the magnitude of radio-frequency (RF) magnetic flux comprising: a SQUID fluxmeter including a SQUID ring which derives an output voltage form input to said SQUID ring induced by said RF magnetic flux. a superconducting loop, said superconducting loop including a pick-up coil for converting said RF magnetic flux into an electric current that flows through said superconducting loop, and an input coil that induces a signal in said SQUID ring to produce said output voltage, and an inductance adjusting means for, prior to measurement of said to-be-detected RF magnetic flux, adjusting the inductance of said superconducting loop to a constant value so that the ratio of RF magnetic flux crossing said pick-up coil to said output voltage from said SQUID fluxmeter results in only one value of said input Rf magnetic flux corresponding to said output voltage of said SQUID fluxmeter.
References Cited (Backward Citations)
US3528001A
Cited
US3965411A
Cited
JPS58169070A
Cited
JPS58174866A
Cited
JPS60143752A
Cited
US4864237A
Cited
JPS63235876A
Cited
US4875010A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-06-03 | 1994-12-03 | 1995-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-06-03 | 1998-12-03 | 1999-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-06-03 | 2002-12-03 | 2003-06-04 | $7700.00 | Window Closed / Lapsed |