Patent US3487320A successfully refreshed from Google Patents.
US3487320A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Biased bridge coupled bipolar amplifier
Assignee: International Business Machines Corp
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Filing: 1967-10-24
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Granted: 1969-12-30
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Expires: 1987-10-24
Abstract
No abstract record available.
Inventors
- 👤 Robert F Heidecker
- 👤 Joseph R Leonardi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:04
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/72; H03F1/00; H03F1/32; H03F1/3217; H03F3/30; H03F3/3066; H03F3/3083; H03F3/3086; H03F3/3091; H03K; H03K17/00; H03K17/51; H03K17/56; H03K17/60
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-12-29 | 1973-06-30 | 1973-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-12-29 | 1977-06-30 | 1977-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-12-29 | 1981-06-30 | 1981-12-30 | $7700.00 | Window Closed / Lapsed |