US3878520A
Expired / Lapsed
US
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Optically operated microwave phased-array antenna system
Assignee: SRI International Inc
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Filing: 1973-01-24
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Granted: 1975-04-15
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Expires: 1993-01-24
Abstract
Abstract An optical processing technique is employed to optically generate a set of properly phase-controlled signals that are appropriate to forming and steering, in space, a beam from a twodimensional phased array antenna.
Inventors
- 👤 Maynard L Wright
- 👤 Matt Lehmann
- 👤 Raymond C Cumming
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:21
CPC Classifications
H; H01; H01Q; H01Q3/00; H01Q3/26; H01Q3/2676
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
175 words
In a phased-array antenna system of the type having an array of antenna elements to which excitation is applied, the method of exciting said elements comprising illuminating a two-dimensional area with an optical analog of a two-dimensional excitation pattern for said antenna elements, comprising generating a reference light beam, generating a plurality of separately operable, normally closed light shutters in a two-dimensional array, directing a different one of said plurality of different radio frequency, modulated light beams at one side of a different one of said normally closed light shutters, opening desired ones of said light shutters to enable light to emanate from different positions in said two-dimensional array, directing light emanating from said different positions at said two-dimensional area, and directing said reference light beam at said two-dimensional area, generating a plurality of electrical signals responsive to said optical pattern at a plurality of locations over said twodimensional area, equal in number to the number of antenna elements to be excited, and applying said plurality of electrical signals to said plurality of antenna elements.
Claim 2
Dependent Claim
175 words
In a phased-array antenna system of the type having an array of antenna elements to which excitation is applied, the method of exciting said elements comprising illuminating a two-dimensional area with an optical analog of a two-dimensional excitation pattern for said antenna elements, comprising generating a reference light beam, generating a plurality of separately operable, normally closed light shutters in a two-dimensional array, directing a different one of said plurality of different radio frequency, modulated light beams at one side of a different one of said normally closed light shutters, opening desired ones of said light shutters to enable light to emanate from different positions in said two-dimensional array, directing light emanating from said different positions at said two-dimensional area, and directing said reference light beam at said two-dimensional area, generating a plurality of electrical signals responsive to said optical pattern at a plurality of locations over said twodimensional area, equal in number to the number of antenna elements to be excited, and applying said plurality of electrical signals to said plurality of antenna elements.
Claim 3
Dependent Claim
150 words
In a phased-array antenna system of the type having an array of antenna elements to which excitation is applied, the method of exciting said elements comprising: illuminating a two-dimensional area with an optical analog of a two-dimensional excitation pattern for said antenna elements, including generating a reference light beam, generating a modulated light beam, moving one of said reference light beam or said modulated light beam to different locations over a two-dimensional region, directing the other one of said reference light beam or said modulated light beam at said two-dimensional area, and directing light emanating from one of said different locations at said two-dimensional area, generating a plurality of electrical signals responsive to said optical pattern at a plurality of locations over said two-dimensional area equal in number to the number of antenna elements to be excited, and applying said plurality of electrical signals to said plurality of antenna elements.
Claim 4
Dependent Claim
150 words
In a phased-array antenna system of the type having an array of antenna elements to which excitation is applied, the method of exciting said elements comprising: illuminating a two-dimensional area with an optical analog of a two-dimensional excitation pattern for said antenna elements, including generating a reference light beam, generating a modulated light beam, moving one of said reference light beam or said modulated light beam to different locations over a two-dimensional region, directing the other one of said reference light beam or said modulated light beam at said two-dimensional area, and directing light emanating from one of said different locations at said two-dimensional area, generating a plurality of electrical signals responsive to said optical pattern at a plurality of locations over said two-dimensional area equal in number to the number of antenna elements to be excited, and applying said plurality of electrical signals to said plurality of antenna elements.
Claim 5
Dependent Claim
111 words
A method as recited in claim 2 wherein said method of generating a modulated beam comprises: generating a vertically polarized laser beam, circularly polarizing said laser beam, separating said circularly polarized beam into vertically polarized light components and horizontally polarized light components, gating said vertically polarized and horizontally polarized light components at a desired frequency to provide a horizontally polaRized, gated, light beam and a vertically polarized, gated, light beam, phase delaying said horizontally polarized modulated light beam a predetermined amount, rotating said phase delayed horizontally polarized gated light beam until it is vertically polarized, and combining both said vertically polarized gated light beams to provide a composite modulated light beam.
Claim 6
Independent Claim
143 words
The method of exciting a two-dimensional phased-array antenna comprising: generating a reference light beam, moving said reference light beam to desired positions in a two-dimensional plane, generating a microwave modulated light beam, establishing a two-dimensional region, directing said reference light beam from said desired positions at said two-dimensional region, directing said modulated light beam at said two-dimensional region to provide a light pattern which propagates across said two-dimensional region in a direction determined by the spatial position of said reference light beam relative to said modulated light beam and with a predetermined velocity, generating a plurality of radio frequency signals responsive to said light pattern at a plurality of locations over said two-dimensional region, equal in number to the number of antenna elements to be excited in said two-dimensional phased-array, and driving said two-dimensional phased-array antenna with said plurality of radio frequency signals.
Claim 7
Independent Claim
143 words
The method of exciting a two-dimensional phased-array antenna comprising: generating a reference light beam, moving said reference light beam to desired positions in a two-dimensional plane, generating a microwave modulated light beam, establishing a two-dimensional region, directing said reference light beam from said desired positions at said two-dimensional region, directing said modulated light beam at said two-dimensional region to provide a light pattern which propagates across said two-dimensional region in a direction determined by the spatial position of said reference light beam relative to said modulated light beam and with a predetermined velocity, generating a plurality of radio frequency signals responsive to said light pattern at a plurality of locations over said two-dimensional region, equal in number to the number of antenna elements to be excited in said two-dimensional phased-array, and driving said two-dimensional phased-array antenna with said plurality of radio frequency signals.
Claim 8
Independent Claim
215 words
A system for exciting elements of a phased-array antenna of the type having an array of antenna elements which are excited by radio frequency waves comprising: a plurality of light to radio frequency signal transducer means for converter light into radio frequency signals, said plurality of light to radio frequency signal transducer means being positioned in an array to establish a two-dimensional region with their inputs, means for illuminating said two-dimensional region with an optical analog of a two-dimensional excitation pattern for the elements of said phased-array antenna, comprising means for generating a reference light beam, means for generating a plurality of different radio frequency, modulated light beams, a plurality of separately operable normally closed light shutters positioned over a two-dimensional array, means for directing each of said plurality of different radio frequency, modulated light beams at a different one of said normally closed light shutters, means for opening desired ones of said normally closed light shutters to enable light to emanate from different positions in said two-dimensional array, means for illuminating said two-dimensional region with light passing through said normally closed shutters, and means illuminating said two-dimensional region with said reference light beam, and means for applying the outputs from said light to radio frequency signal transducer means to the elements of said antenna.
Claim 9
Independent Claim
215 words
A system for exciting elements of a phased-array antenna of the type having an array of antenna elements which are excited by radio frequency waves comprising: a plurality of light to radio frequency signal transducer means for converter light into radio frequency signals, said plurality of light to radio frequency signal transducer means being positioned in an array to establish a two-dimensional region with their inputs, means for illuminating said two-dimensional region with an optical analog of a two-dimensional excitation pattern for the elements of said phased-array antenna, comprising means for generating a reference light beam, means for generating a plurality of different radio frequency, modulated light beams, a plurality of separately operable normally closed light shutters positioned over a two-dimensional array, means for directing each of said plurality of different radio frequency, modulated light beams at a different one of said normally closed light shutters, means for opening desired ones of said normally closed light shutters to enable light to emanate from different positions in said two-dimensional array, means for illuminating said two-dimensional region with light passing through said normally closed shutters, and means illuminating said two-dimensional region with said reference light beam, and means for applying the outputs from said light to radio frequency signal transducer means to the elements of said antenna.
Claim 10
Dependent Claim
63 words
A system as recited in claim 5 wherein said light to radio frequency transducers includes: a light pipe for each of said transducers, one end of each light pipe being positioned for activating a different one of said transducers, the other end of each light pipe being placed adjacent to another to define said two-dimensional region upon which said optical analog is directed.
Claim 11
Dependent Claim
124 words
A system as recited in claim 5 wherein said means for generating a radio frequency modulated light beam comprises: means for deriving a second light beam from said reference light beam, means for circularly polarizing said second light beam, means for separating the output of said means for circularly polarizing into vertical and horizontal light components, a source of microwave signals, means for alternately gating said vertical and horizontal light components with signals from said source of microwave signals, means for phase delaying by a predetermined amount said gated, horizontal light components, means for rotating said phasE delayed gated, horizontal light components until they become vertical light components, and means for combining both said vertical components to provide a radio frequency modulated light beam.
Claim 12
Independent Claim
255 words
A system for exciting elements of a phased-array antenna of a type having an array of antenna elements which are excited by radio frequency waves comprising: means for generating a reference light beam, means for generating a radio frequency modulated light beam, means for moving one of said reference light beams or said radio frequency modulated light beams to assume different angles of incidence on a two-dimensional space including an array of light pipes defining a two-dimensional space with one of their ends, means for directing one of said reference light beams or said radio frequency modulated light beams at the other end of said light pipes, shutter means for blocking all of said one ends of said light pipes, and means for operating said shutter means to unblock said light pipes in a manner to cause light to emanate from different positions over said two-dimensional space, and means for illuminating said two-dimensional region with said one of said reference light beam or of said radio frequency modulated light beam, not moved by said means for moving, whereby said two-dimensional region is illuminated with said optical analog, a plurality of light to radio frequency signal transducer means for converting light into radio frequency signals, said plurality of light to radio frequency signal transducer means being positioned in an array with their inputs forming said two-dimensional region which is illuminated by said means for illuminating, and means for applying the outputs from said light to radio frequency transducer means to the elements of said phased-array antenna.
Claim 13
Independent Claim
255 words
A system for exciting elements of a phased-array antenna of a type having an array of antenna elements which are excited by radio frequency waves comprising: means for generating a reference light beam, means for generating a radio frequency modulated light beam, means for moving one of said reference light beams or said radio frequency modulated light beams to assume different angles of incidence on a two-dimensional space including an array of light pipes defining a two-dimensional space with one of their ends, means for directing one of said reference light beams or said radio frequency modulated light beams at the other end of said light pipes, shutter means for blocking all of said one ends of said light pipes, and means for operating said shutter means to unblock said light pipes in a manner to cause light to emanate from different positions over said two-dimensional space, and means for illuminating said two-dimensional region with said one of said reference light beam or of said radio frequency modulated light beam, not moved by said means for moving, whereby said two-dimensional region is illuminated with said optical analog, a plurality of light to radio frequency signal transducer means for converting light into radio frequency signals, said plurality of light to radio frequency signal transducer means being positioned in an array with their inputs forming said two-dimensional region which is illuminated by said means for illuminating, and means for applying the outputs from said light to radio frequency transducer means to the elements of said phased-array antenna.
Claim 14
Dependent Claim
208 words
Apparatus for generating microwave signals for driving a two-dimensionally phased antenna array comprising: laser means for generating a reference light beam and a second light beam having the same frequency, a microwave frequency signal source, means for modulating said second light beam with signals from said microwave frequency signal source to produce a microwave frequency modulated light beam, a two-dimensional array of a plurality of light to microwave frequency converting transducers, there being one of said transducers for each one of the antenna array elements to be excited, means for moving one of said reference light beam or said microwave frequency modulated light beam to a desired position within a two-dimensional plane to produce a positioned light beam which can have different positions, means for directing said positioned light beam at said two-dimensional array, means for directing said other of said microwave frequency modulated light beam or said reference light beam at said two-dimensional array whereby there is produced an amplitude modulated light pattern propagating at a predetermined velocity across the two-dimensional area and in a direction determined by the position of said positioned light beam, and means for exciting the elements of said two-dimensional phased array antenna with the output of said light to microwave frequency transducers.
Claim 15
Dependent Claim
208 words
Apparatus for generating microwave signals for driving a two-dimensionally phased antenna array comprising: laser means for generating a reference light beam and a second light beam having the same frequency, a microwave frequency signal source, means for modulating said second light beam with signals from said microwave frequency signal source to produce a microwave frequency modulated light beam, a two-dimensional array of a plurality of light to microwave frequency converting transducers, there being one of said transducers for each one of the antenna array elements to be excited, means for moving one of said reference light beam or said microwave frequency modulated light beam to a desired position within a two-dimensional plane to produce a positioned light beam which can have different positions, means for directing said positioned light beam at said two-dimensional array, means for directing said other of said microwave frequency modulated light beam or said reference light beam at said two-dimensional array whereby there is produced an amplitude modulated light pattern propagating at a predetermined velocity across the two-dimensional area and in a direction determined by the position of said positioned light beam, and means for exciting the elements of said two-dimensional phased array antenna with the output of said light to microwave frequency transducers.
Claim 16
Dependent Claim
103 words
Apparatus as recited in claim 9 wherein said means for modulating said second light beam with signals from said microwave frequency source comprises: means for dividing said second light beam into vertically and horizontally polarized light components, means for gating said horizontally and vertically polarized light components with signals from said microwave frequency signal source, means for phase delaying said gated horizontally polarized light components a predetermined amount, means for converting said gated horizontally polarized and phase delayed light components to a vertically polarized light components, and means for combining said vertically polarized light components to produce a microwave frEquency modulated light beam.
Claim 17
Dependent Claim
118 words
A system as recited in claim 9 wherein said means for moving one of said reference light beam or said microwave frequency modulated light beam to a desired position in a two-dimensional plane to produce a positioned light beam comprises: an array of light pipes defining a two-dimensional plane with one of their ends, means for directing one of said reference light beam or said microwave frequency modulated light beam at the other ends of said light pipes, shutter means for blocking all of the one ends of said light pipes, and means for operating said shutter means to unblock said light pipes in a manner to cause light to emanate from different positions over said two-dimensional plane.
Claim 18
Dependent Claim
139 words
In a phased-array antenna system of the type having an array of antenna elements to which excitation is applied, the method of exciting said elements comprising generating an optical analog of a desired two-dimensional excitation pattern of said antenna elements including generating a beam of light, modulating said beam of light at a predetermined frequency, splitting said modulated light beam into a plurality of modulated light beams which equal the number of antenna elements in said array, and amplitude modulating each of said plurality of light beams at a predetermined frequency and in a predetermined sequence to obtain said optical analog of said desired two-dimensional excitation pattern, generating a plurality of electrical signals responsive to each of said plurality of frequency and amplitude modulated light beams, and exciting said array of antenna elements with said plurality of electrical signals.
Claim 19
Dependent Claim
139 words
In a phased-array antenna system of the type having an array of antenna elements to which excitation is applied, the method of exciting said elements comprising generating an optical analog of a desired two-dimensional excitation pattern of said antenna elements including generating a beam of light, modulating said beam of light at a predetermined frequency, splitting said modulated light beam into a plurality of modulated light beams which equal the number of antenna elements in said array, and amplitude modulating each of said plurality of light beams at a predetermined frequency and in a predetermined sequence to obtain said optical analog of said desired two-dimensional excitation pattern, generating a plurality of electrical signals responsive to each of said plurality of frequency and amplitude modulated light beams, and exciting said array of antenna elements with said plurality of electrical signals.
Claim 20
Dependent Claim
153 words
In a phased-array antenna system of the type having an array of antenna elements to which excitation is applied, means for exciting said elements comprising means for generating the optical analog of a desired two-dimensional excitation pattern of said antenna elements, including means for generating a light beam of light, means for modulating said beam of light at a predetermined frequency, means for splitting said modulated light beam into a plurality of modulated light beams which equal the number of antenna elements in said array, and means for amplitude modulating each of said plurality of light beams at a predetermined frequency and in a predetermined sequence to obtain said optical analog of said desired two-dimensional excitation pattern, means for generating a plurality of electrical signals responsive to each of said plurality of frequency and amplitude modulated light beams, and means for exciting said array of antenna elements with said plurality of electrical signals.
Claim 21
Dependent Claim
153 words
In a phased-array antenna system of the type having an array of antenna elements to which excitation is applied, means for exciting said elements comprising means for generating the optical analog of a desired two-dimensional excitation pattern of said antenna elements, including means for generating a light beam of light, means for modulating said beam of light at a predetermined frequency, means for splitting said modulated light beam into a plurality of modulated light beams which equal the number of antenna elements in said array, and means for amplitude modulating each of said plurality of light beams at a predetermined frequency and in a predetermined sequence to obtain said optical analog of said desired two-dimensional excitation pattern, means for generating a plurality of electrical signals responsive to each of said plurality of frequency and amplitude modulated light beams, and means for exciting said array of antenna elements with said plurality of electrical signals.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-14 | 1978-10-14 | 1979-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-14 | 1982-10-14 | 1983-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-14 | 1986-10-14 | 1987-04-15 | $7700.00 | Window Closed / Lapsed |