US3571597A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for phase stabilizing widely separated oscillators
Assignee: COMMERCE USA
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Filing: 1969-10-14
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Granted: 1971-03-23
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Expires: 1989-10-14
Abstract
Abstract A primary station and a remote secondary station generate a primary signal and an auxiliary signal, respectively, at slightly different frequencies. The primary signal is transmitted to the secondary station and mixed with the auxiliary signal, to give a first IF signal. The auxiliary signal is transmitted to the primary station and mixed with the primary signal to obtain a second IF signal, which is returned to the secondary station via an auxiliary FM link. The two IF signals are then mixed to give a signal at twice the IF frequency. A locally generated reference signal of frequency equal to the IF frequency is doubled and compared with the signal from the last mixer, to give an error signal that is applied to the voltage-tuned auxiliary signal oscillator. This established a closed feedback loop that maintains the phase of the auxiliary signal equal to the phase of the primary signal and the phase delay of the path between the stations. A secondary oscillator at the frequency of the primary signal is then phase locked to the auxiliary signal to provide a signal that is coherent with the primary signal. The primary and auxiliary signals may be transmitted as modulations on light beams directed over the path between the stations.
Inventors
- 👤 Lockett E Wood
- 👤 Moody C Thompson Jr
- 👤 William B Grant
- 👤 Dean Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:01
CPC Classifications
H; H03; H03L; H03L7/00; H03L7/06
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
299 words
A phase stabilization system comprising: a primary station; a secondary station located at a remote distance from said primary station; said primary station including means for generating a primary signal at a primary frequency, and means for transmitting said primary signal to said secondary station; said secondary station including means for receiving said primary signal, means for generating an auxiliary signal at a frequency slightly different from said primary frequency, means for mixing said received primary signal with said auxiliary signal to provide a first IF signal, and means for transmitting said auxiliary signal to said primary station; said primary station further including means for receiving said auxiliary signal, means for mixing said received auxiliary signal with said primary signal to provide a second IF signal, and means for transmitting said second IF signal to said secondary station; said secondary station further including means for receiving said transmitted second IF signal, means for mixing said received second IF signal with said first IF signal to provide a signal at twice the frequency of said IF signals; means for generating a reference signal at the frequency of said IF signals; means for doubling said reference signal; means for comparing said doubled reference signal with said signal at twice the frequency of said IF signals to provide a first error signal; means for applying said first error signal to tune said auxiliary signal generating means; means for generating a secondary signal at said primary frequency; means for mixing said secondary signal; with said auxiliary signal to provide a third IF signal; means for comparing said third IF signal with said reference signal to provide a second error signal; and means for applying said second error signal to said secondary signal generating means to lock said secondary signal to said primary signal.
Claim 2
Dependent Claim
299 words
A phase stabilization system comprising: a primary station; a secondary station located at a remote distance from said primary station; said primary station including means for generating a primary signal at a primary frequency, and means for transmitting said primary signal to said secondary station; said secondary station including means for receiving said primary signal, means for generating an auxiliary signal at a frequency slightly different from said primary frequency, means for mixing said received primary signal with said auxiliary signal to provide a first IF signal, and means for transmitting said auxiliary signal to said primary station; said primary station further including means for receiving said auxiliary signal, means for mixing said received auxiliary signal with said primary signal to provide a second IF signal, and means for transmitting said second IF signal to said secondary station; said secondary station further including means for receiving said transmitted second IF signal, means for mixing said received second IF signal with said first IF signal to provide a signal at twice the frequency of said IF signals; means for generating a reference signal at the frequency of said IF signals; means for doubling said reference signal; means for comparing said doubled reference signal with said signal at twice the frequency of said IF signals to provide a first error signal; means for applying said first error signal to tune said auxiliary signal generating means; means for generating a secondary signal at said primary frequency; means for mixing said secondary signal; with said auxiliary signal to provide a third IF signal; means for comparing said third IF signal with said reference signal to provide a second error signal; and means for applying said second error signal to said secondary signal generating means to lock said secondary signal to said primary signal.
Claim 3
Dependent Claim
70 words
A system as set forth in claim 1, wherein said means for transmitting said primary signal to said secondary station comprises: means for generating a first monochromatic light beam; means for plane polarizing a portion of said first monochromatic light beam; means driven by said primary signal for polarization modulating said polarized first monochromatic light beam; and means for directing said modulated first monochromatic light beam to said secondary station.
Claim 4
Dependent Claim
78 words
A system as set forth in claim 2, wherein said means for mixing said recieved primary signal with said auxiliary signal to provide said first IF signal comprises: means driven by said auxiliary signal for polarization modulating said modulated first monochromatic light beam to provide a component at said IF frequency; means for converting said polarization modulated first monochromatic light beam to intensity modulated light; and means for detecting the component of intensity modulation at said IF freqUency.
Claim 5
Dependent Claim
61 words
A system as set forth in claim 3, wherein said means for transmitting said auxiliary signal to said primary station comprises: means for generating a second monochromatic light beam; and means for directing a portion of said second monochromatic light beam through said polarization converting means and said polarization modulating means driven by said auxiliary signal, and to said primary station.
Claim 6
Dependent Claim
86 words
A system as set forth in claim 4, wherein said means for mixing said received auxiliary signal with said primary signal to provide said second IF signal comprises: means for directing said polarization modulated second monochromatic light beam through said polarization modulating means driven by said primary signal, to provide a component at said IF frequency, and through said plane polarizing means to convert said polarization modulated light to intensity modulated light; and means for detecting the component of intensity modulated light at said IF frequency.
References Cited (Backward Citations)
US3419814A
Cited
US3437820A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-03-22 | 1974-09-21 | 1975-03-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-22 | 1978-09-21 | 1979-03-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-22 | 1982-09-21 | 1983-03-23 | $7700.00 | Window Closed / Lapsed |