Patent US2955226A successfully refreshed from Google Patents.
US2955226A
Expired / Lapsed
US
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Backward-wave amplifier
Assignee: University of California Berkeley
•
Filing: 1955-06-13
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Granted: 1960-10-04
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Expires: 1975-06-13
Abstract
No abstract record available.
Inventors
- 👤 Malcolm R Currie
- 👤 John R Whinnery
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:43
CPC Classifications
H; H01; H01J; H01J25/00; H01J25/34; H01J25/36; H01J25/40
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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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) | 1963-10-04 | 1964-04-04 | 1964-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-10-04 | 1968-04-04 | 1968-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-10-04 | 1972-04-04 | 1972-10-04 | $7700.00 | Window Closed / Lapsed |