Phased array antenna choke plate method and apparatus
First Claim
1. An antenna choke apparatus adapted for use with an antenna aperture on an exterior surface of an airborne mobile platform, the apparatus comprising:
- a choke plate having an area for circumscribing at least a portion of said antenna aperture, the choke plate having a thickness such that when said choke plate and said antenna aperture are mounted on said exterior surface, an upper surface of said choke plate is disposed at a desired height relative to an upper surface of said antenna aperture;
a plurality of grooves formed in said upper surface of said choke plate for attenuating electromagnetic wave (EM) radiation from said antenna aperture below a predetermined elevation angle; and
wherein each of said grooves has a bottom wall with radiused corners.
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Accused Products
Abstract
A phased array antenna system on an aircraft that incorporates a choke plate that significantly attenuates sidelobes of the antenna beam pattern at elevation angles that would cause RF interference with ground-based terrestrial wireless networks. The choke plate includes a plurality of choke grooves that substantially circumscribe the antenna aperture. The choke plate has an upper surface that is positioned generally coplanar with the upper surface of the antenna aperture. The grooves of the choke plate may be filled with a dielectric material. The choke plate provides a smooth aerodynamic component that significantly attenuates beam scattering, and thus the radiation pattern sidelobes of the antenna at or below the horizon, when the aircraft is in flight.
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Citations
18 Claims
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1. An antenna choke apparatus adapted for use with an antenna aperture on an exterior surface of an airborne mobile platform, the apparatus comprising:
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a choke plate having an area for circumscribing at least a portion of said antenna aperture, the choke plate having a thickness such that when said choke plate and said antenna aperture are mounted on said exterior surface, an upper surface of said choke plate is disposed at a desired height relative to an upper surface of said antenna aperture; a plurality of grooves formed in said upper surface of said choke plate for attenuating electromagnetic wave (EM) radiation from said antenna aperture below a predetermined elevation angle; and wherein each of said grooves has a bottom wall with radiused corners. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An antenna choke apparatus adapted for use with a phased array antenna aperture on an exterior surface of an airborne mobile platform, the apparatus comprising:
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a choke plate having a generally centrally formed opening for circumscribing said antenna aperture, the choke plate having a thickness such that when said choke plate and said antenna aperture are mounted on said exterior surface, said choke plate forms a generally radial extension of said antenna aperture generally co-planar with said antenna aperture; a plurality of parallel grooves formed in an upper surface of said choke plate for attenuating electromagnetic wave (EM) radiation from said antenna aperture below a predetermined elevation angle, said grooves being disposed about substantially an entire perimeter of said antenna aperture; each of said grooves having a depth of at least about one quarter wavelength of an operating frequency of the antenna aperture; each of said grooves being filled with a dielectric material so that said dielectric material is generally co-planar with said upper surface of said choke plate; and wherein said choke plate has a beveled edge to form an aerodynamic surface. - View Dependent Claims (11, 12, 13, 14)
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15. A method for attenuating electromagnetic (EM) wave radiation from an antenna aperture mounted on an exterior surface of a mobile platform, where the EM wave radiation is attenuated below a predetermined elevation scan angle of the antenna aperture to prevent interference with ground-based EM wave systems, the method comprising:
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disposing a metallic plate having a generally centrally formed opening over said antenna aperture to circumscribe a perimeter of said antenna aperture; forming a plurality of grooves in an upper surface of said metallic plate, each of said grooves having a depth of at least about one quarter wavelength of an operating frequency of said antenna; and forming one edge of said metallic plate with a beveled edge to act as an aerodynamic surface. - View Dependent Claims (16, 17)
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18. An airborne mobile platform comprising:
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an antenna aperture adapted to be mounted to an exterior surface of said mobile platform; a choke plate having a generally centrally disposed opening for receiving said antenna aperture, said choke plate being adapted to be mounted to said exterior surface of said mobile platform such that an upper surface of said choke plate is substantially co-planar with an upper surface of said antenna aperture; and a plurality of grooves formed in said upper surface of said choke plate at least substantially circumscribing said opening;
each of said grooves having a depth of approximately one quarter wavelength of an operating frequency of said antenna aperture, and a bottom wall of each said groove having radiused corners.
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Specification