US3559083A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Digital demodulator for frequency shift keying systems
Assignee: International Business Machines Corp
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Filing: 1967-10-13
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Granted: 1971-01-26
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Expires: 1987-10-13
Abstract
Abstract DIGITAL LOGIC DEVICES RESPOND TO INCOMING TRANSMISSION SIGNALS IN A FREQUENCY SHIFT KEYING SYSTEM AND DETERMINE THE FREQUENCY OF EACH HALF CYCLE OF THE INCOMING SIGNAL. CONSEQUENTLY, A MAXIMUM DATA TRANSMISSION RATE CAN BE ACHIEVED WITH EACH HALF CYCLE OF THE CARRIER REPRESENTING A BIT OF INFORMATION. MONOSTABLE DEVICES RESPONSE TO EACH CHANGE IN AMPLITUDE OF THE INCOMING SIGNAL AND CONTROL A SAMPLING CIRCUIT TO IDENTIFY THE INCOMING SIGNAL FREQUENCY.
Inventors
- 👤 William G Crouse
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:38
CPC Classifications
H; H04; H04L; H04L27/00; H04L27/10; H04L27/14; H04L27/156; H04L27/1563
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-25 | 1974-07-27 | 1975-01-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-25 | 1978-07-27 | 1979-01-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-25 | 1982-07-27 | 1983-01-26 | $7700.00 | Window Closed / Lapsed |