Geodesic slotted cylindrical antenna
First Claim
1. An antenna, comprising:
- a parallel plate waveguide formed by a first cylindrical conductor and a second cylindrical conductor separated by a cylindrical gap, the first cylindrical conductor, the second cylindrical conductor, and the cylindrical gap being coaxial;
a first base plate connected to a base end of the first cylindrical conductor, the first base plate being disc-shaped and having an outside diameter substantially equal to a diameter of the first cylindrical conductor, thereby partially enclosing the base end of the first cylindrical conductor;
a second base plate connected to a base end of the second cylindrical conductor, the second base plate being disc-shaped and having an outside diameter substantially equal to a diameter of the second cylindrical conductor, thereby partially enclosing the base end of the second cylindrical conductor;
a feed probe wall, being ring-shaped and coaxial with the first cylindrical conductor and connecting an inside diameter of the first base plate and an inside diameter of the second base plate;
a plurality of feed probes protruding through the first base plate and into the cylindrical gap, the feed probes being spaced apart at equal distances around the circumference of a feed probe circle, the feed probe circle being coaxial with the first cylindrical conductor and having a diameter greater than a diameter of the feed probe wall;
the second cylindrical conductor being positioned substantially within the first cylindrical conductor;
the first cylindrical conductor having at least one circumferential slot extending along the circumference of the first cylindrical conductor; and
each circumferential slot operative to radiate electromagnetic energy, when the feed probes are excited, thereby producing a radiation pattern.
6 Assignments
0 Petitions
Accused Products
Abstract
A geodesic slotted cylindrical (GSC) antenna having a shaped elevation pattern and a narrow or shaped azimuth beam that can be scanned 360° in the azimuth plane. The azimuth radiation pattern of the GSC antenna can be reconfigured through the use of interchangeable beam forming feed networks. The GSC antenna comprises a parallel plate waveguide formed by spaced-apart inner and outer cylinders constructed from conductive material. Radiation occurs from a stack of circumferential slots in the outer cylinder. By varying the slot spacing with the azimuth angle, the elevation pattern can be altered as a function of the azimuth angle. The GSC antenna can be excited by a number of equally spaced probes on a circle at the base of the cylinders. The feed radius is typically smaller than the outer cylinder'"'"'s radius to minimize the number of active components and to minimize the number of spurious ray paths that can wrap around inside the cylinder'"'"'s parallel plate region. The probes can be phased so that rays from each probe will travel between the parallel cylindrical plates and radiate from the slots to produce a beam that is focused in azimuth. The elevation pattern can be scanned or altered by mechanically moving a tapered dielectric insert within the parallel plate region.
236 Citations
39 Claims
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1. An antenna, comprising:
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a parallel plate waveguide formed by a first cylindrical conductor and a second cylindrical conductor separated by a cylindrical gap, the first cylindrical conductor, the second cylindrical conductor, and the cylindrical gap being coaxial; a first base plate connected to a base end of the first cylindrical conductor, the first base plate being disc-shaped and having an outside diameter substantially equal to a diameter of the first cylindrical conductor, thereby partially enclosing the base end of the first cylindrical conductor; a second base plate connected to a base end of the second cylindrical conductor, the second base plate being disc-shaped and having an outside diameter substantially equal to a diameter of the second cylindrical conductor, thereby partially enclosing the base end of the second cylindrical conductor; a feed probe wall, being ring-shaped and coaxial with the first cylindrical conductor and connecting an inside diameter of the first base plate and an inside diameter of the second base plate; a plurality of feed probes protruding through the first base plate and into the cylindrical gap, the feed probes being spaced apart at equal distances around the circumference of a feed probe circle, the feed probe circle being coaxial with the first cylindrical conductor and having a diameter greater than a diameter of the feed probe wall; the second cylindrical conductor being positioned substantially within the first cylindrical conductor; the first cylindrical conductor having at least one circumferential slot extending along the circumference of the first cylindrical conductor; and each circumferential slot operative to radiate electromagnetic energy, when the feed probes are excited, thereby producing a radiation pattern. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. An antenna comprising:
a cylindrical parallel plate waveguide comprising; an inner cylinder and an outer cylinder separated by a cylindrical gap, the outer cylinder having at least one circumferential slot for radiating electromagnetic energy; and a plurality of feed probes functionally connected to a base plate of the outer cylinder operable for exciting the cylindrical parallel plate waveguide; the cylindrical parallel plate waveguide having a radiation pattern that is shaped in the elevation plane. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
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30. An antenna comprising:
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a parallel plate waveguide formed by a first conformal conductor and a second conformal conductor separated by a conformal gap, the second conformal conductor being positioned within the first conformal conductor; a plurality of feed probes protruding into the first conformal conductor, the feed probes being spaced apart at equal distances along a feed probe perimeter; and the first conformal conductor having at least one perimeter slot continuously extending along a perimeter of the first conformal conductor. - View Dependent Claims (31, 32, 33, 34, 35, 36, 37, 38, 39)
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Specification