Antenna system having azimuth rotating directive beam with selectable polarization
First Claim
1. A scanning antenna system for processing linearly polarized signals, the system providing a beam scannable through a predetermined scan angle, the system comprising:
- reflector means rotatable about an axis for scanning the beam, for forming the beam, for reflecting energy of the beam and for reflecting energy along the axis, and comprising a first circular polarizer for polarizing the energy processed by the reflector means;
a fixed feed which is non-rotating about the axis and which has a first port disposed along the axis and fixed in position in relation thereto for feeding circularly polarized energy along the axis between its first port and the reflector means, and having a second port through which linearly polarized energy is fed; and
a second circular polarizer disposed in the fixed feed for polarizing the energy traversing the first and second ports of the fixed feed, the second circular polarizer having the same sense of polarization as the first circular polarizer.
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Accused Products
Abstract
A rotating reflector is used to provide a beam scan throughout a predetermined angle such as 360°. A circular polarizer is coupled with the reflector and converts received linearly polarized energy into circularly polarized energy. A fixed feed is configured to receive the reflected circularly polarized energy and converts such energy to linearly polarized energy. The antenna system can receive the same linear polarization of energy throughout its 360° scan angle without polarization mismatch or orthogonal polarization losses. The relative orientation of the two polarizers may be adjusted to receive any orientation of linear polarization of energy throughout the scan angle. For example, they may be oriented so that the antenna system receives vertically polarized energy, slant 45° linearly polarized energy, or horizontally polarized energy.
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Citations
27 Claims
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1. A scanning antenna system for processing linearly polarized signals, the system providing a beam scannable through a predetermined scan angle, the system comprising:
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reflector means rotatable about an axis for scanning the beam, for forming the beam, for reflecting energy of the beam and for reflecting energy along the axis, and comprising a first circular polarizer for polarizing the energy processed by the reflector means; a fixed feed which is non-rotating about the axis and which has a first port disposed along the axis and fixed in position in relation thereto for feeding circularly polarized energy along the axis between its first port and the reflector means, and having a second port through which linearly polarized energy is fed; and a second circular polarizer disposed in the fixed feed for polarizing the energy traversing the first and second ports of the fixed feed, the second circular polarizer having the same sense of polarization as the first circular polarizer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A scanning antenna system for processing linearly polarized signals, the system providing a beam scannable through a predetermined scan angle, the system comprising:
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reflector means rotatable about an axis for scanning teh beam, for forming the beam, for receiving energyof the beam and for reflecting the received energy of the beam along the axis, and comprising a first circular polarizer for circularly polarizing energy which is reflected along the axis by the reflector means; a fixed feed which is non-rotating about the axis and which has a first port and a second port, the first port being disposed along the axis and fixed in position in relation thereto forreceiving the circularly polarized energy reflected along the axis by the reflector means, the fixed feed comprising a second circular polarizer for linearly polarizing the energy received from along the axis, the second circular polarizer having the same sense of polarization as the first circular polarizer, and the fixed feed feeding the linearly polarized energy from the second circular polarizer out of the second port. - View Dependent Claims (15, 16, 17)
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18. A scanning antenna system for processing linearly polarized signals, the system providing a beam scannable through a predetermined scan angle, the system comprising:
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a fixed feed having a first port and a second port, the second port being disposed along an axis and fixed in position in relation thereto, teh fixed feed for receiving linearly polarized energy through the first port, the fixed feed comprising a first circular polarizer for circularly polarizing the linearly polarized energy received through the first port, the fixed feed feeding such circularly polarized energy out the second port along the axis; reflector means rotatable about the axis for receiving circularly polarized energy from along the axis, reflecting the circularly polarized energy into the beam, scanning the beam, and comprising a second circular polarizer for linearly polarizing the circularly polarized energy which is received from along the axis, the second circular polarizer having the same sense of polarization as the first circular polarizer; and the fixed feed being disposed such that it is non-rotating about the axis. - View Dependent Claims (19, 20)
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21. A scanning antenna system comprising:
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reflector means rotatable about an axis for forming a beam, for scanning the beam, for reflecting energy of the beam and for reflecting energy along the axis, and comprising a first circular polarizer for polarizing the energy processed by the reflector means; a fixed feed which is non-rotating about the axis and which has a first port disposed along the axis for feeding circularly polarized energy along the axis between the first port and the reflector means, and having a second port through which linearly polarized energy is fed; and a second circular polarizer coupled to the fixed feed for polarizing the energy traversing the first and second ports of the fixed feed, the second circular polarizer having the same sense of polarization as the first circular polarizer. - View Dependent Claims (22, 23, 24, 25, 26, 27)
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Specification