BEAM SHAPING OF RF FEED ENERGY FOR REFLECTOR-BASED ANTENNAS
First Claim
1. A reflector-based antenna, comprising:
- a primary reflector having a focal point;
an antenna feed spaced from the primary reflector and located at approximately the focal point for illuminating the primary reflector with or receiving from the primary reflector radio frequency (RF) energy, said feed forming a blockage of the primary reflector; and
an RF beam-shaping element located between the primary reflector and the antenna feed, said RF beam shaping element comprising a dielectric material that directs RF energy from the feed that is transmitted through the dielectric material away from the blockage towards unblocked regions of the primary reflector.
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Accused Products
Abstract
A beam-shaping element is provided to shape RF feed energy for reflector-based antennas. The RF beam-shaping element is located between the primary reflector and the antenna feed and configured to direct RF energy from the feed away from a blockage created by the feed itself towards unblocked regions of the primary reflector. The beam-shaping element allows for a simplified feed design. The feed may comprise one or more feed elements, each comprising a radiating element and a feed to the radiating element such as a cavity-backed slot radiator and stripline trace. In a monopulse tracking system, each quadrant may include only a single feed element. In common aperture systems, the RF beam-shaping element may be formed on only the rear surface of the secondary reflector that allows transmission at the predefined RF wavelength while reflecting energy of a second predetermined wavelength to another sensor.
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Citations
20 Claims
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1. A reflector-based antenna, comprising:
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a primary reflector having a focal point; an antenna feed spaced from the primary reflector and located at approximately the focal point for illuminating the primary reflector with or receiving from the primary reflector radio frequency (RF) energy, said feed forming a blockage of the primary reflector; and an RF beam-shaping element located between the primary reflector and the antenna feed, said RF beam shaping element comprising a dielectric material that directs RF energy from the feed that is transmitted through the dielectric material away from the blockage towards unblocked regions of the primary reflector. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 10, 11, 12, 13, 14, 15)
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9. (canceled)
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16. A reflector-based antenna, comprising:
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a primary reflector having a focal point; an antenna feed spaced from the primary reflector and located approximately at the focal point for illuminating the primary reflector with and receiving from the primary reflector radio frequency (RF) energy of a first predefined RF wavelength, said feed creating a blockage of the primary reflector, said feed segmented into four quadrants, each quadrant comprising a single feed element; a transceiver for energizing and accepting RF energy from the single feed element on each said quadrant to estimate first and second orthogonal angels to an illuminated target using sum and difference configurations of the four feed elements; and an RF beam-shaping element located between the primary reflector and the antenna feed, said RF beam shaping element comprising a dielectric material that directs RF energy from the feed that is transmitted through the dielectric material away from the blockage towards unblocked regions of the primary reflector. - View Dependent Claims (17, 18)
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19. A reflector-based antenna, comprising:
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a primary reflector having a focal point; an antenna feed spaced from the primary reflector and located approximately at the focal point for illuminating the primary reflector with or receiving from the primary reflector radio frequency (RF) energy of a first predefined RF wavelength; a sensor for receiving or transmitting energy of a second predefined wavelength different from the predefined RF wavelength from the primary reflector; a secondary reflector having a forward surface facing the primary reflector and the sensor and a rear surface facing the antenna feed, said secondary reflector comprising a selective coating on the forward surface that allows transmission energy at the first predefined RF wavelength there through and reflects energy of the second predefined wavelength, said antenna feed, said secondary reflector and said sensor creating a blockage of the primary reflector; and an RF beam-shaping element formed only on the rear surface of the secondary reflector, said RF beam shaping element comprising a dielectric material that directs RF energy from the feed that is transmitted through the dielectric material away from the blockage towards unblocked regions of the primary reflector. - View Dependent Claims (20)
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Specification