Patent US4283062A successfully refreshed from Google Patents.
EP0285326A2
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EP
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Low noise magnetically tuned resonant circuit
Assignee: Raytheon Co
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Filing: 1988-03-24
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Granted: —
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Expires: 2008-03-24
Abstract
Abstract A magnetically tuned resonant circuit (10) includes a ferrimagnetic or gyromagnetic body (46) such as a YIG sphere which is disposed within a r.f. structure (30). The r.f. structure (30) is disposed between a pair of pole pieces (24,38) of a biasing magnet and flux return path (20). To reduce fluctuations in magnetic fields through the gyromagnetic body (46), the body (46) is isolated from conductive surfaces, or the bulk of conductive surfaces in the region adjacent to the magnetic body (46) are reduced. A break (131a,131b) may be provided in the electrical continuity around the r.f. structure (30). These features reduce the magnitude of thermally induced eddy current flow in conductive regions adjacent to the resonant body (46) and hence reduce random magnetic field variations which produce random variations in the frequency characteristics of the magnetically tuned resonant circuit (10).
Inventors
- 👤 Robert Dibiase
- 👤 Raymond C. Waterman, Jr.
- 👤 Ronald E. Blight
- 👤 Zvi Galani
- 👤 Ernst F.R.A. Schloemann
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 04:13
CPC Classifications
H; H01; H01P; H01P1/00; H01P1/20; H01P1/215; H01P1/218
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
101 words
A magnetically tuned resonant circuit, comprising: a) means for producing magnetic flux; b) means for providing a magnetic flux path, having a pair of opposing spaced surfaces; c) a magnetically inert member having an aperture in said inert member, said member being disposed between said pair of opposing spaced surfaces; d) a gyromagnetic member disposed through the aperture in said inert member, with said inert member disposed to have said magnetic flux directed through said gyromagnetic member; and e) means, disposed proximate to said pair of opposing, spaced surfaces, for reducing variations in the magnetic flux directed through said gyromagnetic member.
Claim 2
Dependent Claim
101 words
A magnetically tuned resonant circuit, comprising: a) means for producing magnetic flux; b) means for providing a magnetic flux path, having a pair of opposing spaced surfaces; c) a magnetically inert member having an aperture in said inert member, said member being disposed between said pair of opposing spaced surfaces; d) a gyromagnetic member disposed through the aperture in said inert member, with said inert member disposed to have said magnetic flux directed through said gyromagnetic member; and e) means, disposed proximate to said pair of opposing, spaced surfaces, for reducing variations in the magnetic flux directed through said gyromagnetic member.
Claim 3
Dependent Claim
43 words
A circuit according to claim 1, wherein said means for reducing magnetic field variations reduces thermally induced eddy current flow in conductive regions proximate to the gyromagnetic member and concomitantly therewith reduces the magnitude of magnetic fields induced by said eddy current flow.
Claim 4
Dependent Claim
52 words
A circuit according to claim 1, wherein said means for reducing magnetic field variations includes a pair of members disposed adjacent said inert member, said pair of members providing the pair of opposing spaced surfaces, at least one of said pair of members being comprised of a magnetically permeable, electrically insulating material.
Claim 5
Dependent Claim
32 words
A circuit according to claim 1, wherein said means for reducing magnetic field variations includes the magnetically inert member, with said inert member being comprised of a magnetically inert, electrically insulating material.
Claim 6
Dependent Claim
24 words
A circuit according to claim 4, wherein said magnetically inert member has disposed over surfaces thereof, a thin coating of an electrically conductive material.
Claim 7
Dependent Claim
42 words
A circuit according to claim 1, wherein said means for reducing magnetic field variations is the magnetically inert member, said inert member further comprising: means for interrupting the electrical continuity in a region of the inert member disposed around the gyromagnetic member.
Claim 8
Dependent Claim
47 words
A circuit according to claim 1, wherein said gyromagnetic member is a sphere having a selected diameter and said means for reducing magnetic field variations is said magnetically inert member, said aperture having a diameter at least equal to five times the diameter of said gyromagnetic sphere.
Claim 9
Dependent Claim
33 words
A circuit according to claim 1, wherein said means for reducing magnetic field variations in said inert member comprises a high resistivity material having a resistivity of greater than about 100 micro ohms-cm.
Claim 10
Dependent Claim
35 words
A circuit according to claim 8, wherein said resistivity material is selected from the group consisting of 67Cu-5Ni-27Mn alloy, 80 Ni-20Cr alloy, 75Ni-20Cr-3Au + remainder Fe or Cu alloy, 72Fe-23Cr-5Al-0.5Co alloy, BeO, Al₂O₃, and S₁O₂.
Claim 11
Dependent Claim
114 words
A filter circuit comprising: means for producing magnetic flux; a housing comprised of a magnetically permeable material having a pair of opposing spaced surfaces; a r.f. structure having an aperture therein, being disposed between said pair of opposing spaced surfaces; a gyromagnetic member disposed in said aperture and disposed to have said magnetic flux directed through said gyromagnetic member; means for providing an input radio frequency signal to, and an output radio frequency signal from said gyromagnetic member with said output signal having a frequency related to the magnetic flux directed through the gyromagnetic member; and means, disposed proximate to said pair of opposing spaced surfaces, for reducing frequency noise in the output signal.
Claim 12
Dependent Claim
114 words
A filter circuit comprising: means for producing magnetic flux; a housing comprised of a magnetically permeable material having a pair of opposing spaced surfaces; a r.f. structure having an aperture therein, being disposed between said pair of opposing spaced surfaces; a gyromagnetic member disposed in said aperture and disposed to have said magnetic flux directed through said gyromagnetic member; means for providing an input radio frequency signal to, and an output radio frequency signal from said gyromagnetic member with said output signal having a frequency related to the magnetic flux directed through the gyromagnetic member; and means, disposed proximate to said pair of opposing spaced surfaces, for reducing frequency noise in the output signal.
Claim 13
Dependent Claim
58 words
A circuit according to claim 10, wherein said means for reducing frequency noise in the output signal includes a pair of members disposed adjacent said r.f. structure, said pair of members providing the pair of opposing spaced surfaces of said housing, at least one of said pair of members being comprised of a magnetically permeable, electrically insulating material.
Claim 14
Dependent Claim
31 words
A circuit according to claim 3 or 11, wherein said member comprised of the magnetically permeable, electrically insulating material has disposed over surfaces thereof, a coating of an electrically conductive material.
Claim 15
Dependent Claim
40 words
A circuit according to claim 12, wherein said magnetically permeable, electrically insulating material is a ferrite and wherein said coating has a thickness in the range of about one to ten skin depths at the resonant frequency of said circuit.
Claim 16
Dependent Claim
30 words
A circuit according to claim 10, wherein said means for reducing frequency noise in the output signal includes the r.f. structure being comprised of a magnetically inert, electrically insulating, material.
Claim 17
Dependent Claim
25 words
A circuit according to claim 14, wherein said magnetically inert r.f. structure has disposed over surfaces thereof, a thin coating of an electrically conductive material.
Claim 18
Dependent Claim
48 words
A circuit according to claim 5 or 15, wherein said magnetically inert electrically insulating material is selected from the group consisting of Al₂O₃, BeO, SiO₂, and said coating has a thickness in the range of about one to ten skin depths at the resonant frequency of said circuit.
Claim 19
Dependent Claim
42 words
A circuit according to claim 10, wherein said means for reducing frequency noise in the output signal is the r.f. structure, said structure further comprising: means for interrupting the electrical continuity in a region of the structure disposed around the gyromagnetic member.
Claim 20
Dependent Claim
37 words
A circuit according to claim 6 or 17, wherein said means for interrupting electrical continuity includes at least one passageway in said magnetically inert structure or member, with said passageway being filled with an electrically insulating material.
Claim 21
Dependent Claim
23 words
A circuit according to claim 18, wherein said passageway severs a portion of said structure and member is filled with an insulating material.
Claim 22
Dependent Claim
31 words
A circuit according to claim 18, wherein said passageway is provided through a radial portion of said structure or member and does not sever a portion of said structure or member.
Claim 23
Dependent Claim
50 words
A circuit according to claim 10, wherein said gyromagnetic member is a sphere having a selected diameter and said means for reducing frequency noise in the output signal includes said aperture in said r.f. structure having a diameter equal to at least five times the diameter of said gyromagnetic sphere.
Claim 24
Dependent Claim
31 words
A circuit according to claim 10, wherein said means for reducing frequency noise in the output signal comprises a high resistivity material having a resistivity of greater than 100 micro ohms-cm.
Claim 25
Dependent Claim
31 words
A circuit according to claim 22, wherein said high resistivity material is selected from the group consisting of 67Cu-5Ni-27Mn alloy, 80Ni-20Cr alloy, 75Ni-20Cr-3Au + remainder Fe or Cu alloy, 72Fe-23Cr-5Al-0.5Co alloy.
Claim 26
Dependent Claim
166 words
A low noise oscillator comprising: means, having an input and an output, for providing at the output thereof, an electrical signal having a predetermined amplitude; and means for feeding a portion of said signal back to said input of the amplitude means, further comprising: means for providing a predetermined phase shift characteristic to said signal portion fed back to the input of said amplitude means, comprising: means for producing magnetic flux; means for providing a closed magnetic flux path, comprising: i) a housing comprised of a magnetically permeable material having a pair of opposing, spaced surfaces; ii) a magnetically inert member having an aperture, said inert member being disposed between said pair of opposing spaced surfaces; iii) a gyromagnetic member disposed through the aperture in said inert member, with said inert member disposed to have said magnetic flux directed through said gyromagnetic member; iv) means, disposed proximate to said pair of opposing, spaced surfaces, for reducing variations in the magnetic flux directed through said gyromagnetic member.
Claim 27
Dependent Claim
166 words
A low noise oscillator comprising: means, having an input and an output, for providing at the output thereof, an electrical signal having a predetermined amplitude; and means for feeding a portion of said signal back to said input of the amplitude means, further comprising: means for providing a predetermined phase shift characteristic to said signal portion fed back to the input of said amplitude means, comprising: means for producing magnetic flux; means for providing a closed magnetic flux path, comprising: i) a housing comprised of a magnetically permeable material having a pair of opposing, spaced surfaces; ii) a magnetically inert member having an aperture, said inert member being disposed between said pair of opposing spaced surfaces; iii) a gyromagnetic member disposed through the aperture in said inert member, with said inert member disposed to have said magnetic flux directed through said gyromagnetic member; iv) means, disposed proximate to said pair of opposing, spaced surfaces, for reducing variations in the magnetic flux directed through said gyromagnetic member.
Claim 28
Dependent Claim
46 words
An oscillator according to claim 24, wherein said means for reducing magnetic field variations is the magnetically inert member, said member further comprising: means for interrupting electrical continuity in the inert member to prevent eddy current flow around the aperture wherein is disposed the gyromagnetic member.
Claim 29
Dependent Claim
28 words
An oscillator according to claim 24, wherein said means for reducing magnetic field variations comprises a high resistivity material having a resistivity of greater than 100 micro ohms-cm.
Claim 30
Dependent Claim
21 words
An oscillator according to claim 26, wherein said high resistivity metal is selected from the group consisting of Al₂O₃, BeO, SiO₂.
Claim 31
Dependent Claim
160 words
A low noise oscillator comprising: means for producing voltage controlled oscillations having a predetermined frequency modulation noise characteristic; a feedback circuit disposed around said voltage controlled oscillation means including: a frequency discriminator circuit, said frequency discriminator circuit comprising: a low noise magnetically tuned filter comprising: means for producing magnetic flux; a housing comprised of a magnetically permeable material having a pair of opposing spaced surfaces; a magnetically inert member having an aperture in said inert member, being disposed between said pair of opposing spaced surfaces; a gyromagnetic member disposed in said aperture and disposed to have said magnetic flux directed through said gyromagnetic member; means for providing an input radio frequency signal to and an output radio frequency signal from said gyromagnetic member with said output signal having a frequency related to the magnetic flux directed through the gyromagnetic member; and means, disposed proximate to said pair of opposing spaced surfaces, for reducing frequency modulation noise in the output signal.
Claim 32
Dependent Claim
160 words
A low noise oscillator comprising: means for producing voltage controlled oscillations having a predetermined frequency modulation noise characteristic; a feedback circuit disposed around said voltage controlled oscillation means including: a frequency discriminator circuit, said frequency discriminator circuit comprising: a low noise magnetically tuned filter comprising: means for producing magnetic flux; a housing comprised of a magnetically permeable material having a pair of opposing spaced surfaces; a magnetically inert member having an aperture in said inert member, being disposed between said pair of opposing spaced surfaces; a gyromagnetic member disposed in said aperture and disposed to have said magnetic flux directed through said gyromagnetic member; means for providing an input radio frequency signal to and an output radio frequency signal from said gyromagnetic member with said output signal having a frequency related to the magnetic flux directed through the gyromagnetic member; and means, disposed proximate to said pair of opposing spaced surfaces, for reducing frequency modulation noise in the output signal.
References Cited (Backward Citations)
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