US3320538A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Carrier detection device
Assignee: United Airlines Inc
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Filing: 1963-06-27
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Granted: 1967-05-16
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Expires: 1983-06-27
Abstract
No abstract record available.
Inventors
- 👤 Kenneth J Rhead
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 18:16
CPC Classifications
H; H03; H03D; H03D1/00; H03D1/08; H03D1/10
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
88 words
IN A CARRIER DETECTION SYSTEM, THE COMBINATION COMPRISING A PAIR OF FREQUENCY MODULATION DEMODULATORS EACH HAVING AN ASYMMETRICAL FREQUENCY CHARACTERISTIC RELATIVE TO AN ORDINATE REFERENCE LINE, A SOURCE OF FREQUENCIES WITHIN A PREDETERMINED PASS BAND, MEANS CONNECTING BOTH OF SAID PAIR OF DEMODULATORS TO SAID SOURCE, SAID CHARACTERISTICS CROSSING SAID ORDINATE REFERENCE LINE AT DIFFERENT FREQUENCIES WITHIN SAID PASS BAND, WHEREBY THE AREAS OF SAID CHARACTERISTICS ABOVE AND BELOW SAID REFERENCE LINE WITHIN SAID PASS BAND ARE EQUAL, AND AN OUTPUT TERMINAL CONNECTED WITH BOTH OF SAID DEMODULATORS.
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) | 1970-05-15 | 1970-11-14 | 1971-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-05-15 | 1974-11-14 | 1975-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-05-15 | 1978-11-14 | 1979-05-16 | $7700.00 | Window Closed / Lapsed |