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US2707235A
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Frequency selective systems
Assignee: AT&T Inc
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Filing: 1947-04-26
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Granted: 1955-04-26
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Expires: 1967-04-26
Abstract
No abstract record available.
Inventors
- 👤 Charles H Townes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:34
CPC Classifications
H; H03; H03L; H03L7/00; H03L7/26; H03C; H03C3/00; H03C3/30; H03C7/00; H03C7/02
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2106770A
Cited
US2077314A
Cited
US2085406A
Cited
US2173234A
Cited
US2423383A
Cited
US2624840A
Cited
US2457673A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1958-04-25 | 1958-10-25 | 1959-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1962-04-25 | 1962-10-25 | 1963-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1966-04-25 | 1966-10-25 | 1967-04-26 | $7700.00 | Window Closed / Lapsed |