Patent US3054503A successfully refreshed from Google Patents.
US3619782A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coherent catv transmission system
Assignee: Raytheon Co
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Filing: 1966-01-28
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Granted: 1971-11-09
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Expires: 1986-01-28
Abstract
Abstract A community antenna television system wherein one or more microwave transmission links are used between the CATV receiving unit and the user''s receivers. In accordance with the invention, the undesirable effects caused by slight frequency differences between the directly transmitted television signals and the relayed television signals are eliminated. This is accomplished by providing at the microwave transmitter a pilot signal having a frequency which is an integral submultiple of the microwave carrier frequency. This pilot signal is transmitted, together with the television broadcast signals over the microwave transmission link or links. At the microwave receiver the pilot signal, together with an integral submultiple of the local oscillator, is utilized in a phase-locked loop to synchronize the local oscillator frequency with the microwave carrier frequency.
Inventors
- 👤 Lyle S Stokes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:17
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/02
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
156 words
A television transmission system comprising, in combination, means adapted to receive television broadcast signals, said signals each having predetermined carrier frequencies within a given band of frequencies; means for generating a pilot signal having a frequency within said band; means for combining said pilot signal with said received television broadcast signals; means for converting said combined signals to an amplitude modulated single sideband signal in the microwave frequency region, the carrier frequency of said microwave signal being an integral multiple of said pilot frequency; means for transmitting said microwave signal over an extended signal wave transmission path; means for receiving said transmitted microwave signal; means for reconverting said signals to frequencies within said given band, said reconverting means including means responsive to said received pilot signal for synchronizing the carrier frequencies of said reconverted television signals with said predetermined carrier frequencies; and means for distributing said reconverted synchronized television signals to a plurality of utilization devices.
Claim 2
Dependent Claim
156 words
A television transmission system comprising, in combination, means adapted to receive television broadcast signals, said signals each having predetermined carrier frequencies within a given band of frequencies; means for generating a pilot signal having a frequency within said band; means for combining said pilot signal with said received television broadcast signals; means for converting said combined signals to an amplitude modulated single sideband signal in the microwave frequency region, the carrier frequency of said microwave signal being an integral multiple of said pilot frequency; means for transmitting said microwave signal over an extended signal wave transmission path; means for receiving said transmitted microwave signal; means for reconverting said signals to frequencies within said given band, said reconverting means including means responsive to said received pilot signal for synchronizing the carrier frequencies of said reconverted television signals with said predetermined carrier frequencies; and means for distributing said reconverted synchronized television signals to a plurality of utilization devices.
Claim 3
Dependent Claim
171 words
A television transmission system comprising, in combination, means adapted to receive television broadcast signals, said signals each having predetermined carrier frequencies within a given band; means for generating a pilot signal having a frequency within said band; means for combining said pilot signal with said received television broadcast signals; means for converting said combined signals to an amplitude modulated single-sideband signal in the microwave frequency region, the carrier frequency of said microwave signal being an integral multiple of said pilot frequency; means for transmitting said microwave signal over an extended signal wave transmission path; means for receiving said transmitted microwave signal; means for reconverting said received microwave signal to frequencies within said given band, said reconverting means including a mixer and a local oscillator signal source, said reconverting means including further means responsive to said received pilot signal for synchronizing the frequency of said local oscillator signal with the frequency of said microwave carrier; and means for applying said reconverted television signals to a low-frequency signal wave transmission path for utilization.
Claim 4
Dependent Claim
171 words
A television transmission system comprising, in combination, means adapted to receive television broadcast signals, said signals each having predetermined carrier frequencies within a given band; means for generating a pilot signal having a frequency within said band; means for combining said pilot signal with said received television broadcast signals; means for converting said combined signals to an amplitude modulated single-sideband signal in the microwave frequency region, the carrier frequency of said microwave signal being an integral multiple of said pilot frequency; means for transmitting said microwave signal over an extended signal wave transmission path; means for receiving said transmitted microwave signal; means for reconverting said received microwave signal to frequencies within said given band, said reconverting means including a mixer and a local oscillator signal source, said reconverting means including further means responsive to said received pilot signal for synchronizing the frequency of said local oscillator signal with the frequency of said microwave carrier; and means for applying said reconverted television signals to a low-frequency signal wave transmission path for utilization.
Claim 5
Dependent Claim
67 words
The system, according to claim 2, wherein said synchronizing means comprises a phase-locked loop capable of generating an error signal in response to differences in frequency and phase between said received pilot signal and an integral subharmonic of said local oscillator signal frequency, and wherein said local oscillator signal source includes means for varying the frequency thereof in response to said error signal to minimize said difference.
References Cited (Backward Citations)
US2530614A
Cited
US2710343A
Cited
US2831105A
Cited
US2854506A
Cited
US2871295A
Cited
US3041450A
Cited
US3182259A
Cited
US3202765A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-08 | 1975-05-10 | 1975-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-08 | 1979-05-10 | 1979-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-08 | 1983-05-10 | 1983-11-09 | $7700.00 | Window Closed / Lapsed |