US3859558A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetron having spurious signal suppression means
Assignee: Hitachi Ltd
•
Filing: 1973-08-28
•
Granted: 1975-01-07
•
Expires: 1993-08-28
Abstract
Abstract In a magnetron, at the end of the cathode terminal thereof is provided a noise-eliminating filter comprising at least two inner conductors of microstrip type transmission line, disposed substantially parallel to and near each other, and an outer conductor partially wrapping the inner conductors, with microwave attenuating substance filled between the inner conductors and between the inner conductors and the outer conductor.
Inventors
- 👤 Akikazu Harada
- 👤 Hiroshi Hisada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:07
CPC Classifications
H; H01; H01J; H01J23/00; H01J23/14; H01J23/15
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
144 words
A magnetron comprising an anode and a cathode to define an operating space together with said anode; a plurality of cathode support bars to support said cathode; cathode leads connected with said plural cathode support bars and cathode lead-out wires connected with an external power source to supply electric power from said source for said cathode; a filter to eliminate noise signals connected between said cathode leads and said cathode lead-out wires; a stem to connect said cathode support bars with said cathode leads in vacuum condition; and a shield case to contain therein said filter and said stem, wherein said filter includes at least two microstrip type transmission lines having a configuration for choking at least one predetermined frequency component of an electromagnetic wave propagating therethrough and microwave attenuating substance covering said transmission lines for attenuating the wave over a wide frequency range.
Claim 2
Dependent Claim
144 words
A magnetron comprising an anode and a cathode to define an operating space together with said anode; a plurality of cathode support bars to support said cathode; cathode leads connected with said plural cathode support bars and cathode lead-out wires connected with an external power source to supply electric power from said source for said cathode; a filter to eliminate noise signals connected between said cathode leads and said cathode lead-out wires; a stem to connect said cathode support bars with said cathode leads in vacuum condition; and a shield case to contain therein said filter and said stem, wherein said filter includes at least two microstrip type transmission lines having a configuration for choking at least one predetermined frequency component of an electromagnetic wave propagating therethrough and microwave attenuating substance covering said transmission lines for attenuating the wave over a wide frequency range.
Claim 3
Dependent Claim
56 words
A magnetron as claimed in claim 1, wherein said filter comprises said microstrip type transmission lines disposed near and substantially parallel to each other, serving as inner conductors; an outer conductor enveloping portions of said inner conductors; said microwave attenuating substance being filled between said inner conductors and between said inner conductors and said outer conductor.
Claim 4
Dependent Claim
37 words
A magnetron as claimed in claim 2, wherein each of said inner conductors has at least one projection whose length is such as to choke at least one predetermined frequency of the wave propagating through said conductor.
Claim 5
Dependent Claim
28 words
A magnetron as claimed in claim 3, wherein each of said inner conductors has a meander line inserted in a portion thereof surrounded by said microwave attenuating substance.
Claim 6
Dependent Claim
69 words
A magnetron as claimed in claim 2, wherein said outer conductor is electrically connected with said shIeld case, and wherein the extension of one end of said inner conductors is drawn out of said shield case to serve as one of said cathode lead-out wires while the extension of the other end of said inner conductor is bent toward said stem to serve as one of said cathode leads.
Claim 7
Dependent Claim
37 words
A magnetron as claimed in claim 5, wherein each of said inner conductors has at least one projection whose length is such as to choke at least one predetermined frequency of the wave propagating through said conductor.
Claim 8
Dependent Claim
28 words
A magnetron as claimed in claim 6, wherein each of said inner conductors has a meander line inserted in a portion thereof surrounded by said microwave attenuating substance.
Claim 9
Dependent Claim
23 words
A magnetron as claimed in claim 2, wherein said microwave attenuating substance is one selected from among sintered ferrite and rubber containing ferrite.
Claim 10
Dependent Claim
22 words
A magnetron as claimed in claim 2, wherein an insulating layer is provided between said microwave attenuating substance and said outer conductor.
Claim 11
Dependent Claim
45 words
A magnetron as claimed in claim 2, wherein each of said inner conductors has at least one looped portion whose length along the normal to the inner conductor is such as to choke at least one predetermined frequency of the wave propagating through said conductor.
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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) | 1978-01-06 | 1978-07-08 | 1979-01-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-06 | 1982-07-08 | 1983-01-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-06 | 1986-07-08 | 1987-01-07 | $7700.00 | Window Closed / Lapsed |