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Patent US3696435A successfully refreshed from Google Patents.
US3696435A
Expired / Lapsed
US
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Offset parabolic reflector antenna
Assignee: AT&T Inc
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Filing: 1970-11-24
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Granted: 1972-10-03
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Expires: 1990-11-24
Abstract
Abstract In accordance with the disclosure, two or more main beams of an offset parabolic reflector antenna are directed without producing second order aberrations by placing their respective feeds so that their phase centers reside at mathematically defined locations.
Inventors
- 👤 Henry Zucker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:18
CPC Classifications
H; H01; H01Q; H01Q19/00; H01Q19/10; H01Q19/12; H01Q19/13; H01Q19/132
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
157 words
A directive antenna for producing at least two main beams, said antenna comprising a reflector which is an off-axis sector of a paraboloid of revolution having a focal length f, and at least two feeds where each feed is directed to subtend a solid angle with said sector and its phase center is located at a point substantially defined by x mf sin Alpha , y 0, and z f (m cos Alpha - 1) where z a distance perpendicular to the focal plane of said paraboloid and measured only from the sector side thereof, x a distance perpendicular to a second plane and measured from either side thereof where said second plane includes the focal point of said paraboloid and bisects said sector, y a distance perpendicular to a third plane where said third plane passes through said focal point and is mutually perpendicular to the other two planes, and m and Alpha satisfy the expressions
Claim 2
Dependent Claim
157 words
A directive antenna for producing at least two main beams, said antenna comprising a reflector which is an off-axis sector of a paraboloid of revolution having a focal length f, and at least two feeds where each feed is directed to subtend a solid angle with said sector and its phase center is located at a point substantially defined by x mf sin Alpha , y 0, and z f (m cos Alpha - 1) where z a distance perpendicular to the focal plane of said paraboloid and measured only from the sector side thereof, x a distance perpendicular to a second plane and measured from either side thereof where said second plane includes the focal point of said paraboloid and bisects said sector, y a distance perpendicular to a third plane where said third plane passes through said focal point and is mutually perpendicular to the other two planes, and m and Alpha satisfy the expressions
Claim 3
Dependent Claim
168 words
A directive antenna for producing at least two main beams, said antenna comprising a reflector which is an off-axis sector of a paraboloid of revolution having a focal length f, said sector definable with respect to three planes where the first plane is the focal plane of said paraboloid, the second plane includes the focal point of said paraboloid and bisects said sector, and the third plane passes through said focal point and is mutually perpendicular to the other two planes, and at least two feeds where each feed is directed to make a solid angle with said sector and is located so that its phase center is substantially in said third plane at a point substantially defined by x mf sin Alpha z f (m cos Alpha - 1) where: x a distance perpendicular to said second plane and measured from either side thereof, z a distance perpendicular to said focal plane and measured only from the sector side thereof, and m and Alpha satisfy the expressions
Claim 4
Dependent Claim
168 words
A directive antenna for producing at least two main beams, said antenna comprising a reflector which is an off-axis sector of a paraboloid of revolution having a focal length f, said sector definable with respect to three planes where the first plane is the focal plane of said paraboloid, the second plane includes the focal point of said paraboloid and bisects said sector, and the third plane passes through said focal point and is mutually perpendicular to the other two planes, and at least two feeds where each feed is directed to make a solid angle with said sector and is located so that its phase center is substantially in said third plane at a point substantially defined by x mf sin Alpha z f (m cos Alpha - 1) where: x a distance perpendicular to said second plane and measured from either side thereof, z a distance perpendicular to said focal plane and measured only from the sector side thereof, and m and Alpha satisfy the expressions
Claim 5
Dependent Claim
169 words
A scanning antenna comprising a reflector which is an oFf-axis sector of a paraboloid of revolution having a focal length f, said sector definable with respect to three planes where the first plane is the focal plane of said paraboloid, the second plane includes the focal point of said paraboloid, the second plane includes the focal point of said paraboloid and bisects said sector, and the third plane passes through said focal point and is mutually perpendicular to the other two planes, and at at least one feed which is directed to make a solid angle with said sector and is movable so that its phase center may be moved substantially in said third plane along an arc substantially defined by x mf sin Alpha z f(m cos Alpha - 1) where: x a distance perpendicular to said second plane and measured from either side thereof, z a distance perpendicular to said focal plane and measured only from the sector side thereof, and m and Alpha satisfy the expressions
Claim 6
Dependent Claim
169 words
A scanning antenna comprising a reflector which is an oFf-axis sector of a paraboloid of revolution having a focal length f, said sector definable with respect to three planes where the first plane is the focal plane of said paraboloid, the second plane includes the focal point of said paraboloid, the second plane includes the focal point of said paraboloid and bisects said sector, and the third plane passes through said focal point and is mutually perpendicular to the other two planes, and at at least one feed which is directed to make a solid angle with said sector and is movable so that its phase center may be moved substantially in said third plane along an arc substantially defined by x mf sin Alpha z f(m cos Alpha - 1) where: x a distance perpendicular to said second plane and measured from either side thereof, z a distance perpendicular to said focal plane and measured only from the sector side thereof, and m and Alpha satisfy the expressions
References Cited (Backward Citations)
US3569976A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-03 | 1976-04-03 | 1976-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-03 | 1980-04-03 | 1980-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-03 | 1984-04-03 | 1984-10-03 | $7700.00 | Window Closed / Lapsed |