Patent US3641558A successfully refreshed from Google Patents.
US2657360A
Expired / Lapsed
US
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Four-electrode transistor modulator
Assignee: AT&T Inc
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Filing: 1952-08-15
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Granted: 1953-10-27
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Expires: 1972-08-15
Abstract
No abstract record available.
Inventors
- 👤 Jr Robert L Wallace
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:41
CPC Classifications
H; H03; H03D; H03D7/00; H03D7/12; H03B; H03B5/00; H03B5/08; H03B5/12; H03B5/1203; H03B5/1231; H03B5/1296; H03C; H03C1/00; H03C1/36; H10; H10D; H10D99/00
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) | 1956-10-26 | 1957-04-27 | 1957-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-10-26 | 1961-04-27 | 1961-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-10-26 | 1965-04-27 | 1965-10-27 | $7700.00 | Window Closed / Lapsed |