US3680142A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circularly polarized antenna
Assignee: National Aeronautics and Space Administration
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Filing: 1969-10-06
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Granted: 1972-07-25
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Expires: 1989-10-06
Abstract
Abstract A circularly polarized antenna is provided using a planar array of at least two perpendicular pairs of linearly polarized elements (slot antennas or dipoles). The distance D between a given pair of parallel elements is selected to provide in a plane perpendicular to the elements of the pair, a field pattern very similar to that in a plane parallel to the elements, where both principal planes pass through the center of the array and are perpendicular to the plane of the array. Elements of a given pair are excited in phase, and the two pairs are excited in phase quadrature, whereby circularly polarized radiation is produced over a very wide sector of space in each principal plane, and therefore in all planes passing through the axis of the array.
Inventors
- 👤 Lester C Van Atta
- 👤 Robert J Mailloux
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:37
CPC Classifications
H; H01; H01Q; H01Q21/00; H01Q21/24
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
166 words
A circularly polarized antenna comprising a planar array of linearly polarized antenna elements selected from a group consisting of antenna slots and dipoles, said elements being of the same size and arranged in two orthogonally oriented sets of parallel elements, both sets having the same geometric center, elements of a given set being spaced a given distance apart such that a field produced by a given pair of adjacent elements in a set when excited in phase will produce in a first plane perpendicular to the plane of said array, and perpendicular to said pair of elements, at their centers, a pattern very similar to the field pattern of said given pair of elements in a second plane perpendicular to said first plane and to said plane of the array when excited in phase, where said seconD plane intersects said first plane midway between said given pair of elements, and means for exciting said elements of the other set in phase quadrature with said one set.
Claim 2
Dependent Claim
166 words
A circularly polarized antenna comprising a planar array of linearly polarized antenna elements selected from a group consisting of antenna slots and dipoles, said elements being of the same size and arranged in two orthogonally oriented sets of parallel elements, both sets having the same geometric center, elements of a given set being spaced a given distance apart such that a field produced by a given pair of adjacent elements in a set when excited in phase will produce in a first plane perpendicular to the plane of said array, and perpendicular to said pair of elements, at their centers, a pattern very similar to the field pattern of said given pair of elements in a second plane perpendicular to said first plane and to said plane of the array when excited in phase, where said seconD plane intersects said first plane midway between said given pair of elements, and means for exciting said elements of the other set in phase quadrature with said one set.
Claim 3
Dependent Claim
21 words
A circularly polarized antenna as defined in claim 1 wherein each set of elements is comprised of one pair of elements.
Claim 4
Dependent Claim
40 words
A circularly polarized antenna as defined in claim 1 wherein said elements are selected to be antenna slots, said excitation means comprises a square waveguide, and said elements are arranged in a plate covering one end of said square waveguide.
Claim 5
Dependent Claim
43 words
A circularly polarized antenna as defined in claim 3 wherein said excitation means includes four side waveguide sections, each side waveguide section being coupled to said square waveguide section through a separate transverse slot, and each sidewave guide section feeding a separate element.
Claim 6
Dependent Claim
40 words
A circularly polarized antenna as defined in claim 1 wherein each set of elements is comprised of three parallel slots, said excitation means comprises a waveguide, and said elements are arranged in a plate covering one end of said waveguide.
Claim 7
Dependent Claim
49 words
A circularly polarized antenna as defined in claim 5 wherein said waveguide comprises a square waveguide section and a flared pyramidal horn waveguide section attached to the end of said square waveguide section, and said plate is attached to the outer end of said flared pyramidal horn waveguide section.
Claim 8
Dependent Claim
31 words
A circularly polarized antenna as defined in claim 6 further including a large square waveguide section located between the outer end of said flared pyramidal horn waveguide section and said plate.
Claim 9
Dependent Claim
56 words
A circularly polarized antenna as defined in claim 1 wherein said first set of antenna elements is comprised of parallel slots in a plate covering the end of a waveguide and wherein said second set of antenna elements is comprised of N/2 parallel slots in said plate, where N is an even integer greater than four.
Claim 10
Dependent Claim
49 words
A circularly polarized antenna as defined in claim 8 wherein said waveguide comprises a square waveguide section and a flared pyramidal horn waveguide section attached to the end of said square waveguide section, and said plate is attached to the outer end of said flared pyramidal horn waveguide section.
Claim 11
Dependent Claim
31 words
A circularly polarized antenna as defined in claim 9, wherein said plate is attached to the outer end of said flared pyramidal horn waveguide section by a large square waveguide section.
Claim 12
Dependent Claim
21 words
A circularly polarized antenna as defined in claim 1 wherein each of said antenna elements is selected to be a dipole.
Claim 13
Dependent Claim
23 words
A circularly polarized antenna as defined in claim 11 wherein each of said two sets of antenna elements includes one pair of dipoles.
Claim 14
Dependent Claim
83 words
A circularly polarized antenna as defined in claim 12 wherein said excitation means comprises: a 90* hybrid adapted to receive a signal; a first power divider having its input connected to one output of said 90* hybrid and its outputs connected to both dipoles to one pair of said antenna elements; and a second power divider having its input connected to a second output of said 90* hybrid and its outputs connected to both dipoles of the other pair of said antenna elements.
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) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |