US3732459A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetrons
Assignee: Hitachi Ltd
•
Filing: 1971-05-20
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Granted: 1973-05-08
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Expires: 1991-05-20
Abstract
Abstract In a magnetron having lead wires for passing heating current to the cathode filament, each of the lead wires comprises a coaxial cable including a core conductor for passing the filament heating current, at least one insulator layer having a large microwave loss surrounding the core conductor, and an outer conductor surrounding the insulator layer.
Inventors
- 👤 T Oguro
- 👤 M Watanabe
- 👤 H Takatsuki
- 👤 K Okamoto
- 👤 T Suda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 06:29
CPC Classifications
H; H01; H01J; H01J23/00; H01J23/14; H01J23/15
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
152 words
A magnetron comprising a cathode, an anode electrode coaxial with said cathode, magnet means for supplying a magnetic field to an interaction space between said cathode and said anode electrode, a shield casing secured to a conductive magnetron cover enclosing at least portions of said cathode and anode electrode, and filament lead wires extending through said shield casing and connecting the terminals of the filament of said cathode with external source terminals, each of said lead wires comprising a coaxial cable including a core conductor for passing filament-heating current to said filament terminal, at least one noise-absorbing insulator layer having a large microwave loss characteristic surrounding said core conductor, and an outer conductor of good conductivity surrounding said insulator layer, opposing portions of said shield cover and said casing being clamped around said outer conductor so that said outer conductor is grounded through said shield casing and cover to provide electrostatic shielding.
Claim 2
Dependent Claim
152 words
A magnetron comprising a cathode, an anode electrode coaxial with said cathode, magnet means for supplying a magnetic field to an interaction space between said cathode and said anode electrode, a shield casing secured to a conductive magnetron cover enclosing at least portions of said cathode and anode electrode, and filament lead wires extending through said shield casing and connecting the terminals of the filament of said cathode with external source terminals, each of said lead wires comprising a coaxial cable including a core conductor for passing filament-heating current to said filament terminal, at least one noise-absorbing insulator layer having a large microwave loss characteristic surrounding said core conductor, and an outer conductor of good conductivity surrounding said insulator layer, opposing portions of said shield cover and said casing being clamped around said outer conductor so that said outer conductor is grounded through said shield casing and cover to provide electrostatic shielding.
Claim 3
Dependent Claim
25 words
The magnetron according to claim 1, wherein said one noise-absorbing insulator layer comprises a layer of high molecular compound containing a powder of ferromagnetic material.
Claim 4
Dependent Claim
25 words
The magnetron according to claim 1, wherein said one noise-absorbing insulator layer comprises a layer of high molecular compound containing fine particles of electroconductive material.
Claim 5
Dependent Claim
43 words
The magnetron according to claim 1, wherein the noise-absorbing insulator layer of said coaxial cable comprises a layer of high molecular compound having a large microwave loss surrounding said core conductor, and further including an insulation strength-improving layer surrounding said noise-absorbing insulator layer.
References Cited (Backward Citations)
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Cited
US3191132A
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US3573676A
Cited
US3456151A
Cited
US3551858A
Cited
US3541473A
Cited
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-07 | 1976-11-06 | 1977-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-07 | 1980-11-06 | 1981-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-07 | 1984-11-06 | 1985-05-08 | $7700.00 | Window Closed / Lapsed |