Patent US1779382A successfully refreshed from Google Patents.
US1779382A
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Negative impedance circuit
Assignee: AT&T Inc
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Filing: 1927-08-01
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Granted: 1930-10-21
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Expires: 1947-08-01
Abstract
No abstract record available.
Inventors
- 👤 Robert C Mathes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:18
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/02; H04B3/04; H04B3/16
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1933-10-20 | 1934-04-21 | 1934-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1937-10-20 | 1938-04-21 | 1938-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1941-10-20 | 1942-04-21 | 1942-10-21 | $7700.00 | Window Closed / Lapsed |