US3797020A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microwave antenna structure with aperture blocking elimination
Assignee: Thales SA
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Filing: 1972-09-05
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Granted: 1974-03-12
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Expires: 1992-09-05
Abstract
Abstract An aplanatic multi-beam antenna free from aperture-blocking effect comprises a convex main reflector and a concave subsidiary reflector whose axes orthogonally intersect at a planar network of parallel wires including an angle of 45* with these axes. The wire network discriminates between waves polarized in two mutually orthogonal planes, passing one type of wave and reflecting the other. Each curved reflector is provided with means for rotating the plane of polarization of an incident wave through 90* upon reflection. The reflectors form a focusing system with a focal plane containing one or more transducers for emitting or receiving radiation of a polarization passing the discriminator before striking the first reflector whence they are directed, via the reflecting discriminator, to the second reflector; upon leaving the latter reflector, they have a direction of polarization enabling them to clear the discriminator once more.
Inventors
- 👤 J Roger
- 👤 C Aubry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 02:30
CPC Classifications
H; H01; H01Q; H01Q25/00; H01Q15/00; H01Q15/14; H01Q15/22; H01Q19/00; H01Q19/10; H01Q19/18; H01Q19/19; H01Q19/195
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
128 words
An antenna structure comprising: conjugate first and second reflectors with intersectiNg axes defining a focal plane for a beam of microwave frequency passing between a remote point and said first reflector, the point of intersection of said axes lying between said focal plane and said second reflector; transducer means for microwave energy at said focal plane; and discriminating means at said point of intersection for selectively passing and reflecting differently polarized microwaves, each of said reflectors being provided with polarization-changing means for directing a beam with a polarization passed by said discriminating means, incident upon one of said reflectors, back to said discriminating means for reflection onto the other of said reflectors whence the beam is redirected to said discriminating means with a polarization enabling its passage therethrough.
Claim 2
Dependent Claim
128 words
An antenna structure comprising: conjugate first and second reflectors with intersectiNg axes defining a focal plane for a beam of microwave frequency passing between a remote point and said first reflector, the point of intersection of said axes lying between said focal plane and said second reflector; transducer means for microwave energy at said focal plane; and discriminating means at said point of intersection for selectively passing and reflecting differently polarized microwaves, each of said reflectors being provided with polarization-changing means for directing a beam with a polarization passed by said discriminating means, incident upon one of said reflectors, back to said discriminating means for reflection onto the other of said reflectors whence the beam is redirected to said discriminating means with a polarization enabling its passage therethrough.
Claim 3
Dependent Claim
30 words
An antenna structure as defined in claim 1 wherein said first reflector has a concave surface and said second reflector has a convex surface turned toward said point of intersection.
Claim 4
Dependent Claim
19 words
An antenna structure as defined in claim 1 wherein said discriminating means comprises a planar array of parallel conductors.
Claim 5
Dependent Claim
21 words
An antenna structure as defined in claim 3 wherein said conductors extend at right angles to the plane of said axes.
Claim 6
Dependent Claim
25 words
An antenna structure as defined in claim 3 wherein said axes intersect orthogonally, said array including an angle of 45* with each of said axes.
Claim 7
Dependent Claim
26 words
An antenna structure as defined in claim 3 wherein said transducer means comprises an emitter of microwaves with a plane of polarization perpendicular to said conductors.
Claim 8
Dependent Claim
27 words
An antenna structure as defined in claim 3 wherein said polarization-changing means is effective to rotate the plane of polarization of an incident plane-polarized beam through 90*.
Claim 9
Dependent Claim
181 words
An antenna structure comprising: transducer means for emitting and receiving beams of microwave energy with a predetermined plane of polarization; a planar array of conductors perpendicular to said plane of polarization disposed in the path of said beams for reflecting microwave energy polarized in a plane parallel to said conductors; a first and a second reflector for microwave energy having mutually orthogonal axes intersecting at an intermediate point of said array, the latter including an angle of 45* with each of said axes, said second reflector lying in line with said path on the side of said array remote from said transducer means; and polarization-changing means adjacent the active surface of each of said reflectors for turning the plane of polarization of an incident plane-polarized beam through 90* whereby a beam emitted by said transducer means and passing said array in a direction generally parallel to the axis of said second reflector is successively directed by said second reflector and by said array to said first reflector and is thence redirected to said array with a polarization enabling its passage therethrough.
Claim 10
Dependent Claim
181 words
An antenna structure comprising: transducer means for emitting and receiving beams of microwave energy with a predetermined plane of polarization; a planar array of conductors perpendicular to said plane of polarization disposed in the path of said beams for reflecting microwave energy polarized in a plane parallel to said conductors; a first and a second reflector for microwave energy having mutually orthogonal axes intersecting at an intermediate point of said array, the latter including an angle of 45* with each of said axes, said second reflector lying in line with said path on the side of said array remote from said transducer means; and polarization-changing means adjacent the active surface of each of said reflectors for turning the plane of polarization of an incident plane-polarized beam through 90* whereby a beam emitted by said transducer means and passing said array in a direction generally parallel to the axis of said second reflector is successively directed by said second reflector and by said array to said first reflector and is thence redirected to said array with a polarization enabling its passage therethrough.
Claim 11
Dependent Claim
35 words
An antenna structure as defined in claim 8 wherein said reflectors have conjugate curvatures for focusing a beam originating at said transducer means onto an object at infinity upon the second traverse of said array.
Claim 12
Dependent Claim
23 words
An antenna structure as defined in claim 9 wherein said first reflector is concave and said second reflector is convex toward said array.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-03-11 | 1977-09-10 | 1978-03-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-11 | 1981-09-10 | 1982-03-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-11 | 1985-09-10 | 1986-03-12 | $7700.00 | Window Closed / Lapsed |