Patent US4254357A successfully refreshed from Google Patents.
US4254357A
Expired / Lapsed
US
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Multi-arrayed micro-patch emitter with integral control grid
Assignee: United States Department of the Navy
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Filing: 1979-09-14
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Granted: 1981-03-03
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Expires: 1999-09-14
Abstract
Abstract A multi-arrayed electron emitter for microwave tubes in which the emittingurface is an array of continually replenished low-work-function regions, (micro-patches), whose boundaries include a control grid which is integral with the cathode surface and which controls emission from the low-work-function micro-patches. The continually replenished low-work-function regions are uniformly positioned relative to a matrix of uniformly spaced openings through which the low-work-function material is released.
Inventors
- 👤 George A. Haas
- 👤 Richard E. Thomas
- 👤 Richard F. Greene
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:22
CPC Classifications
H; H01; H01J; H01J23/00; H01J23/02; H01J23/04; H01J19/00; H01J19/42
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
121 words
An electron-emitter cathode assembly with an integral control grid which comprises: a container for low-work-function material having a porous metal top serving as a cathode, the low-work-function material being dispensed from the pores to the cathode when the container is heated to provide an array of low-work-function electron-emitting areas centered at the pores; and an insulated grid disposed on the porous metal top of the container and having a plurality of openings, each opening being aligned with a single respective pore to control electron emission from the respective low-work-function electron-emitting area centered at the pore and to contain the spread of low-work-function material, the grid being made of a material to which the low-work-function material will not adhere at operating temperatures.
Claim 2
Dependent Claim
121 words
An electron-emitter cathode assembly with an integral control grid which comprises: a container for low-work-function material having a porous metal top serving as a cathode, the low-work-function material being dispensed from the pores to the cathode when the container is heated to provide an array of low-work-function electron-emitting areas centered at the pores; and an insulated grid disposed on the porous metal top of the container and having a plurality of openings, each opening being aligned with a single respective pore to control electron emission from the respective low-work-function electron-emitting area centered at the pore and to contain the spread of low-work-function material, the grid being made of a material to which the low-work-function material will not adhere at operating temperatures.
Claim 3
Dependent Claim
29 words
The electron-emitter cathode assembly with an integral control grid recited in claim 1 including: an insulator disposed between the insulated grid and the porous metal top of the container.
Claim 4
Dependent Claim
23 words
The electron-emitter cathode assembly with an integral control grid recited in claim 1 wherein: the top of the container is made of iridium.
Claim 5
Dependent Claim
20 words
The electron-emitter cathode assembly with an integral control grid recited in claim 1 wherein: the grid is formed of zirconium.
Claim 6
Dependent Claim
20 words
The electron-emitter cathode assembly with an integral control grid recited in claim 1 wherein: the grid is formed of tantalum.
Claim 7
Dependent Claim
22 words
The electron-emitter cathode assembly with an integral control grid recited in claim 1 wherein: the grid insulator is formed of boron nitride.
Claim 8
Dependent Claim
27 words
The electron-emitter cathode assembly with an integral control grid recited in claim 2 wherein: the isulator is made of the same material as that of the grid.
Claim 9
Independent Claim
127 words
A method of forming an electron-emitter cathode assembly with an integral control grid comprising the steps of: forming a container for low-work-function material; providing a porous metal top for the container to serve as a cathode, the low-work-function-material being dispensed from the pores to the cathode when the container is heated to provide an array of low-work-function electron-emitters areas centered at the pores; disposing on the porous top of the container an insulated grid having a plurality of openings, the grid being made of a material to which the low-work-function material will not adhere at operating temperatures; aligning each opening with a single respective pore to control electron emission from the respective low-work-function electron-emitting area centered at the pore and to contain the spread of low-work-function material.
Claim 10
Independent Claim
127 words
A method of forming an electron-emitter cathode assembly with an integral control grid comprising the steps of: forming a container for low-work-function material; providing a porous metal top for the container to serve as a cathode, the low-work-function-material being dispensed from the pores to the cathode when the container is heated to provide an array of low-work-function electron-emitters areas centered at the pores; disposing on the porous top of the container an insulated grid having a plurality of openings, the grid being made of a material to which the low-work-function material will not adhere at operating temperatures; aligning each opening with a single respective pore to control electron emission from the respective low-work-function electron-emitting area centered at the pore and to contain the spread of low-work-function material.
Claim 11
Dependent Claim
25 words
The method recited in claim 8 including the step of: disposing an isolator between the insulated grid and the porous metal top of the container.
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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) | 1984-03-02 | 1984-09-01 | 1985-03-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-02 | 1988-09-01 | 1989-03-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-02 | 1992-09-01 | 1993-03-03 | $7700.00 | Window Closed / Lapsed |