US2768322A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Interdigital filter circuit
Assignee: AT&T Inc
•
Filing: 1951-06-08
•
Granted: 1956-10-23
•
Expires: 1971-06-08
Abstract
No abstract record available.
Inventors
- 👤 Robert C Fletcher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:11
CPC Classifications
H; H01; H01J; H01J23/00; H01J23/16; H01J23/24; H01J23/28
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US2074478A
Cited
US2289756A
Cited
US2280026A
Cited
US2323613A
Cited
US2289952A
Cited
US2403795A
Cited
US2508280A
Cited
US2653270A
Cited
US2532545A
Cited
US2567339A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-10-23 | 1960-04-23 | 1960-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-10-23 | 1964-04-23 | 1964-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-10-23 | 1968-04-23 | 1968-10-23 | $7700.00 | Window Closed / Lapsed |