Patent US3113545A successfully refreshed from Google Patents.
Patent EP0503512A2 successfully refreshed from Google Patents.
EP0503512A2
Expired / Lapsed
EP
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Method and apparatus for communicating amplitude modulated signals over an optical communication path
Assignee: Arris Technology Inc
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Filing: 1992-03-07
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Granted: —
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Expires: 2012-03-07
Abstract
Abstract A block of amplitude modulated television channel signals frequency modulates an optical communication path. In one embodiment, the AM modulated channel signals FM modulate an RF subcarrier which, in turn, is used to intensity modulate an optical carrier for transmission. Frequency modulation of the RF subcarrier by the amplitude modulated channel signals is advantageously performed at microwave frequencies. The FM modulated subcarrier signal is then converted down to a frequency range compatible with transmitter and receiver components used in the system. The frequency modulation and conversion can be performed by a pair of voltage controlled oscillators coupled in a push-pull mode of operation. The outputs of the oscillators are combined in a double balanced mixer to down convert the FM signal spectrum. In another embodiment, the optical frequency of an optical carrier is FM modulated by the block of AM signals. Receivers for the FM modulated band of AM channel signals are also disclosed.
Inventors
- 👤 David R. Huber
- 👤 Joseph B. Glaab
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 20:26
CPC Classifications
H; H04; H04N; H04N7/00; H04N7/22; H04B; H04B10/00; H04B10/25; H04B10/2575; H04B10/25751; H04B10/50; H04B10/501; H04B10/503; H04B10/504; H04B10/516; H04B10/548
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
41 words
A method for transmitting communication signals over an optical communication path comprising the steps of: providing a carrier; frequency modulating said carrier by a block of amplitude modulated channel signals; and transmitting said FM modulated carrier over an optical communication path.
Claim 2
Dependent Claim
31 words
A method in accordance with claim 1 wherein said FM modulated carrier is an RF subcarrier that is used to intensity modulate an optical carrier for transmission over said communication path.
Claim 3
Dependent Claim
29 words
A method in accordance with claim 2 comprising the further step of: converting said FM modulated RF subcarrier to an appropriate frequency range for modulation of said optical carrier.
Claim 4
Dependent Claim
63 words
A method in accordance with claim 3 comprising the further steps of: receiving the intensity modulated optical carrier from said optical communication path; recovering said frequency modulated RF subcarrier from the received optical carrier; converting the recovered frequency modulated RF subcarrier to an appropriate frequency range for demodulation; and FM demodulating the RF subcarrier to recover said block of amplitude modulated channel signals.
Claim 5
Independent Claim
52 words
A method in accordance with one of claims 1 to 3 comprising the further steps of: receiving the modulated optical carrier from said optical communication path; recovering said frequency modulated RF subcarrier from the received optical carrier; and FM demodulating the RF subcarrier to recover said block of amplitude modulated channel signals.
Claim 6
Dependent Claim
25 words
A method in accordance with claim 1 wherein said FM modulated carrier is an optical carrier having its optical frequency modulated during said modulating step.
Claim 7
Dependent Claim
21 words
A method in accordance with claim 6 wherein said optical carrier is directly modulated by said block of AM channel signals.
Claim 8
Dependent Claim
27 words
A method in accordance with claim 6 wherein said optical carrier is modulated by a frequency modulated RF subcarrier carrying said block of amplitude modulated channel signals.
Claim 9
Dependent Claim
38 words
Apparatus for transmitting communication signals over an optical communication path comprising: means for frequency modulating a carrier by a block of amplitude modulated channel signals; and means for transmitting the frequency modulated carrier over an optical communication path.
Claim 10
Dependent Claim
39 words
Apparatus in accordance with claim 9 wherein said FM modulated carrier is an RF subcarrier, and said transmitting means comprise: means for intensity modulating an optical carrier with the FM modulated RF subcarrier for transmission over said communication path.
Claim 11
Dependent Claim
28 words
Apparatus in accordance with claim 10 further comprising: means for converting said FM modulated RF subcarrier to an appropriate frequency range for intensity modulation of said optical carrier.
Claim 12
Dependent Claim
60 words
Apparatus in accordance with claim 11 wherein said frequency modulating and converting means comprise: a pair of voltage controlled oscillators coupled in a push-pull mode of operation; means for inputting said block of amplitude modulated channels signals to said pair of oscillators; and double balanced mixer means coupled to the outputs of said oscillators for providing said converted RF subcarrier.
Claim 13
Dependent Claim
17 words
Apparatus in accordance with claim 12 wherein said voltage controlled oscillators operate in the microwave frequency range.
Claim 14
Dependent Claim
32 words
Apparatus in accordance with claim 9 wherein said carrier is an optical carrier and said modulating means directly modulate the optical frequency of said carrier with the block of AM channel signals.
Claim 15
Dependent Claim
47 words
Apparatus in accordance with claim 14 wherein said frequency modulating means modulate each of a plurality of different carriers with a different block of amplitude modulated channel signals, said apparatus further comprising: means for combining said plurality of modulated carriers for transmission over said optical communication path.
Claim 16
Dependent Claim
39 words
Apparatus in accordance with claim 9 wherein said FM modulated carrier is an RF subcarrier, and said transmitting means comprise: means for frequency modulating an optical carrier with the FM modulated RF subcarrier for transmission over said communication path.
Claim 17
Dependent Claim
55 words
Apparatus in accordance with claim 16 wherein each of a plurality of different optical carriers is frequency modulated by a different FM modulated RF subcarrier carrying a different block of amplitude modulated channel signals, said apparatus further comprising: means for combining said plurality of frequency modulated optical carriers for transmission over said optical communication path.
Claim 18
Dependent Claim
76 words
Receiver apparatus for recovering a block of amplitude modulated channel signals from an optical carrier, comprising: means for receiving an intensity modulated optical carrier from an optical communication path, said carrier containing a frequency modulated RF subcarrier modulated by a block of amplitude modulated channel signals; means for recovering said frequency modulated RF subcarrier from the optical carrier; and means for FM demodulating the recovered RF subcarrier to recover said block of amplitude modulated channel signals.
Claim 19
Dependent Claim
34 words
Apparatus in accordance with claim 18 further comprising: means coupled between said recovering means and said FM demodulating means for converting the recovered frequency modulated RF subcarrier to an appropriate frequency range for demodulation.
Claim 20
Independent Claim
54 words
A method for transmitting communication signals over an optical communication path comprising the steps of: producing an optical carrier; modulating the optical frequency of said optical carrier with a block of AM subcarriers to produce an optical frequency modulated communication signal; and transmitting said optical frequency modulated communication signal over an optical communication path.
Claim 21
Dependent Claim
35 words
A method in accordance with claim 20 comprising the further steps of: receiving the optical frequency modulated carrier from said optical communication path; and recovering the block of AM subcarriers from the received optical carrier.
Claim 22
Dependent Claim
71 words
Receiver apparatus for recovering a block of amplitude modulated channel signals from an optical frequency modulated carrier comprising: means for receiving an optical carrier that is frequency modulated by a block of amplitude modulated channel signals; and an optical FM discriminator for recovering the block of amplitude modulated channel signals from the received optical carrier and outputting an optical signal that is intensity modulated by said block of AM channel signals.
Claim 23
Dependent Claim
28 words
Receiver apparatus in accordance with claim 22 further comprising: means for converting said intensity modulated optical signal to an RF subcarrier containing said block of AM channel signals.
Claim 24
Dependent Claim
45 words
Receiver apparatus in accordance with claim 22 wherein said FM discriminator recovers the block of amplitude modulated channel signals within a frequency modulated RF subcarrier that is modulated by the block of FM channel signals, and intensity modulates said optical signal by said RF subcarrier.
References Cited (Backward Citations)
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