US3886462A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit for reproducing reference carrier wave
Assignee: Mitsubishi Electric Corp
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Filing: 1973-12-21
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Granted: 1975-05-27
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Expires: 1993-12-21
Abstract
Abstract A signal splitter splits a 4 differential phase shift keyed signal into four signal portions which, in turn, are subject to phase shifts of O, pi , pi /4 and 5 pi /4 radians, respectively. Those signal portions phase shifted by O and pi radians are applied to an OR circuit to be switched with a predetermined threshold voltage. The remaining signal portions are similarly processed by a NOR circuit. The outputs from both circuits are added to each other. The added signal is fed back to the signal splitter through a loop filter and a voltage controlled circuit to reproduce a reference carrier wave for the phase shift keyed signal.
Inventors
- 👤 Akira Okano
- 👤 Yoichi Moritani
- 👤 Masahiro Murakami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:24
CPC Classifications
H; H04; H04L; H04L27/00; H04L27/18; H04L27/22; H04L27/227; H04L27/2271; H04L27/2272
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
172 words
A circuit for reproducing a reference carrier wave for a 4 differential phase shift keyed signal, comprising, in combination, a signal splitter circuit for splitting a 4 differential phase shift keyed signal applied thereto into four signal portions, phase shifter means for relatively shifting phases of said four signal portions so that, with respect to a selected one of said signal portions, the remaining three signal portions have phase shifts of pi , pi /4 and 5 pi /4 radians respectively, one phase detector for phase detecting each of the relative phase shifted signal portions, a pair of logic circuits each connected to one pair of the phase detectors producing detected outputs having a phase difference of pi radians to switch said detected outputs with a predetermined threshold magnitude, a composition circuit for adding the outputs from said pair of logic circuits, a loop filter coupled to said composition circuit, and a voltage controlled oscillator coupled to said loop filter and to said signal splitter circuit to form a phase locked loop.
Claim 2
Dependent Claim
172 words
A circuit for reproducing a reference carrier wave for a 4 differential phase shift keyed signal, comprising, in combination, a signal splitter circuit for splitting a 4 differential phase shift keyed signal applied thereto into four signal portions, phase shifter means for relatively shifting phases of said four signal portions so that, with respect to a selected one of said signal portions, the remaining three signal portions have phase shifts of pi , pi /4 and 5 pi /4 radians respectively, one phase detector for phase detecting each of the relative phase shifted signal portions, a pair of logic circuits each connected to one pair of the phase detectors producing detected outputs having a phase difference of pi radians to switch said detected outputs with a predetermined threshold magnitude, a composition circuit for adding the outputs from said pair of logic circuits, a loop filter coupled to said composition circuit, and a voltage controlled oscillator coupled to said loop filter and to said signal splitter circuit to form a phase locked loop.
Claim 3
Dependent Claim
73 words
A circuit for reproducing a reference carrier wave as claimed in claim 1, wherein a selected one of said four split signal portions from said signal splitter circuit is directly supplied to one of said phase detectors while the remaining three split signal portions are supplied to the remaining phase detectors through those portions of said phase shifter means effecting phase shifts of pi , pi /4 and 5 pi /4 radians respectively.
Claim 4
Dependent Claim
32 words
A circuit for reproducing a reference carrier wave as claimed in claim 1, wherein one of said logic circuit is an OR circuit and the other logic circuit is a NOR circuit.
Claim 5
Dependent Claim
39 words
A circuit for reproducing a reference carrier wave as claimed in claim 1, wherein said pair of logic circuits are connected to said composition circuit through individual frequency multipliers for doubling the frequency of the outputs from the same.
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) | 1978-05-26 | 1978-11-25 | 1979-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-26 | 1982-11-25 | 1983-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-26 | 1986-11-25 | 1987-05-27 | $7700.00 | Window Closed / Lapsed |