Patent US4864312A successfully refreshed from Google Patents.
US4864312A
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Device for optical control of a beam-scanning antenna
Assignee: Thales SA
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Filing: 1988-04-11
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Granted: 1989-09-05
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Expires: 2008-04-11
Abstract
Abstract Beam-scanning of an antenna by means of microwave phase shifts is achieved by N electrooptical modulators which receive two collinear beams having different frequencies. The modulators define optical paths having different wavelengths. N photodetectors make it possible to receive the beams reflected by the modulators and to control antenna elements during a 2 π phase excursion.
Inventors
- 👤 Jean P. Huignard
- 👤 Claude Puech
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 23:14
CPC Classifications
G; G02; G02F; G02F2/00; G02F2/002; H; H01; H01Q; H01Q3/00; H01Q3/26; H01Q3/2676
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
207 words
A device for optical control of a beam-scanning antenna in which provision is made for an array of antenna elements, the different elements being arranged in a predetermined order and each controlled by a microwave generator, wherein said device further comprises: a light source for simultaneously emitting at least two collinear beams having different frequencies; optical transmission means for determining optical paths including a plurality of spatial modulators having controlled transmission and corresponding to the number of optical paths and which correspond in number to the microwave generators, which are arranged in the same order as the antenna elements and each of which has an entrance for receiving the two beams emitted by the laser source and for retransmitting them to a photodetector at an exit, and each optical path of predetermined rank being of greater length than the optical path of lower rank; an array of photodetectors, each photodetector being optically coupled with one exit of an optical path, the function of each photodetector being to detect the light intensity derived from said exit and to deliver to a microwave generator an intensity control signal having a frequency which represents the beat arising from the two frequencies of the two beams emitted by the laser source.
Claim 2
Independent Claim
207 words
A device for optical control of a beam-scanning antenna in which provision is made for an array of antenna elements, the different elements being arranged in a predetermined order and each controlled by a microwave generator, wherein said device further comprises: a light source for simultaneously emitting at least two collinear beams having different frequencies; optical transmission means for determining optical paths including a plurality of spatial modulators having controlled transmission and corresponding to the number of optical paths and which correspond in number to the microwave generators, which are arranged in the same order as the antenna elements and each of which has an entrance for receiving the two beams emitted by the laser source and for retransmitting them to a photodetector at an exit, and each optical path of predetermined rank being of greater length than the optical path of lower rank; an array of photodetectors, each photodetector being optically coupled with one exit of an optical path, the function of each photodetector being to detect the light intensity derived from said exit and to deliver to a microwave generator an intensity control signal having a frequency which represents the beat arising from the two frequencies of the two beams emitted by the laser source.
Claim 3
Dependent Claim
57 words
A control device according to claim 1, wherein the transmission means include a number of spatial modulators having controlled reflectivity and corresponding to the number of optical paths, the function of the different modulators being to receive the two beams emitted by the laser source, each modulator being intended to reflect the two beams toward a photodetector.
Claim 4
Dependent Claim
20 words
A control device according to claim 2, wherein the distances between the different modulators of the light source are different.
Claim 5
Dependent Claim
52 words
A control device according to claim 2, comprising a semireflecting mirror for receiving on the one hand the two light beams derived from the light source and for retransmitting said beams to the modulators and on the other hand the beams reflected from the modulators and for retransmitting them to the photodetectors.
Claim 6
Dependent Claim
20 words
A control device according to claim 2, wherein the modulators are modulators of flat shape and disposed in parallel relation.
Claim 7
Dependent Claim
14 words
A control device according to claim 2, wherein each modulator has a liquid-crystal cell.
Claim 8
Dependent Claim
19 words
A control device according to claim 2, wherein each modulator is a device having birefringence induced by magnetooptic effect.
Claim 9
Dependent Claim
23 words
A control device according to claim 2, wherein each modulator is a device of semiconductor materials having reflection properties which are controlled electrically.
Claim 10
Dependent Claim
21 words
A control device according to claim 1, wherein the transmission means include one optical fiber in respect of each optical path.
Claim 11
Dependent Claim
68 words
A control device according to claim 10, wherein the different modulators are disposed in a predetermined direction and the light source emits said light beams parallel to said direction, the transmission means being further provided with a first series of semireflecting mirrors disposed in the direction of said light beams, each mirror being associated with a modulator so as to transmit part of the two light beams thereto.
Claim 12
Dependent Claim
52 words
A device according to claim 11, wherein the transmission means include a second series of semireflecting mirrors each associated with a modulator and disposed in a direction parallel to the directions aforesaid, the light beams which pass through each modulator toward a photodetector being reflected from said second series of semireflecting mirrors.
Claim 13
Dependent Claim
70 words
A control device according to claim 2, wherein the modulators are disposed in a predetermined direction and the light source emits said light beams parallel to said direction, the transmission means being provided with a series of semireflecting mirrors disposed in the direction of said light beams, each mirror being associated with a modulator so as to transmit part of the two light beams at right angles to said modulator.
Claim 14
Independent Claim
208 words
A device for optical control of a beam-scanning antenna in which provision is made for an array of antenna elements, the different elements being arranged in a predetermined order and each controlled by a microwave generator, wherein said device further comprises: a light source for simultaneously emitting at lease two collinear beams for having different frequencies; optical transmission means for determining optical paths including a plurality of spatial modulators having controlled reflectivity and corresponding to the number of optical paths and which correspond in number to the microwave generators, which are arranged in the same order as the antenna elements an each of which has en entrance for receiving the two beams emitted by the laser source and for retransmitting them to a photodetector at an exit, and each optical path of predetermined rank being of greater length than the optical path of lower rank; an array of photodetectors, each photodetector being optically coupled with one exit of an optical path, the function of each photodetector being to detect the light intensity derived from said exit and to deliver to a microwave generator an intensity control signal having a frequency which represents the beat arising from the two frequencies of the two beams emitted by the laser source.
Claim 15
Independent Claim
208 words
A device for optical control of a beam-scanning antenna in which provision is made for an array of antenna elements, the different elements being arranged in a predetermined order and each controlled by a microwave generator, wherein said device further comprises: a light source for simultaneously emitting at lease two collinear beams for having different frequencies; optical transmission means for determining optical paths including a plurality of spatial modulators having controlled reflectivity and corresponding to the number of optical paths and which correspond in number to the microwave generators, which are arranged in the same order as the antenna elements an each of which has en entrance for receiving the two beams emitted by the laser source and for retransmitting them to a photodetector at an exit, and each optical path of predetermined rank being of greater length than the optical path of lower rank; an array of photodetectors, each photodetector being optically coupled with one exit of an optical path, the function of each photodetector being to detect the light intensity derived from said exit and to deliver to a microwave generator an intensity control signal having a frequency which represents the beat arising from the two frequencies of the two beams emitted by the laser source.
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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) | 1992-09-04 | 1993-03-06 | 1993-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-04 | 1997-03-06 | 1997-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-04 | 2001-03-06 | 2001-09-05 | $7700.00 | Window Closed / Lapsed |