Polar digital beamforming method and system
First Claim
1. For use with a phased array antenna having a plurality of subarrays each including a phasor and an antenna element, a method for digital beamforming of at least one independent transmit beam, the method comprising the steps of:
- generating a modulation signal representing information to be transmitted via the at least one independent transmit beam;
generating a pointing signal representing a beam pointing direction for the at least one independent transmit beam;
combining the modulation signal and the pointing signal to generate a weighting signal for each of the plurality of antenna elements;
converting each weighting signal to a corresponding attenuation signal and a corresponding phase signal;
controlling each of the plurality of phasors with its corresponding phase signal to modulate a carrier signal; and
applying the modulated carrier signal to a corresponding antenna element so as to transmit the at least one independent transmit beam.
1 Assignment
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Accused Products
Abstract
A system and method for polar digital beamforming of at least one independent transmit beam is disclosed. A computer generates a digital signal representing both pointing and modulation information which is communicated to a plurality of subarray controllers which generate the polar weighting signals corresponding to the appropriate antenna element for transmitting. The complex weighting signals may be generated by summing a sequence of complex multiplications or by simply inverting the real and imaginary components of the weighting signal for particular modulation schemes. A phasor may be used in conjunction with an attenuator to modulate a local carrier signal. Alternatively, phasors are utilized without attenuators to increase the efficiency of the power amplifiers. The antenna architecture disclosed permits a single set of phasors and attenuators to be utilized per antenna element regardless of the number of beams to be generated.
81 Citations
18 Claims
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1. For use with a phased array antenna having a plurality of subarrays each including a phasor and an antenna element, a method for digital beamforming of at least one independent transmit beam, the method comprising the steps of:
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generating a modulation signal representing information to be transmitted via the at least one independent transmit beam; generating a pointing signal representing a beam pointing direction for the at least one independent transmit beam; combining the modulation signal and the pointing signal to generate a weighting signal for each of the plurality of antenna elements; converting each weighting signal to a corresponding attenuation signal and a corresponding phase signal; controlling each of the plurality of phasors with its corresponding phase signal to modulate a carrier signal; and applying the modulated carrier signal to a corresponding antenna element so as to transmit the at least one independent transmit beam. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. For use with a phased array antenna having a plurality of subarrays each including a phasor and an antenna element, a system for digital beamforming of at least one independent transmit beam, the system comprising:
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means for generating a modulation signal representing information to be transmitted via the at least one independent transmit beam; means for generating a pointing signal representing a beam pointing direction for the at least one independent transmit beam; means for combining the modulation signal and the pointing signal to generate a weighting signal for each of the plurality of antenna elements; means for converting each weighting signal to a corresponding attenuation signal and a corresponding phase signal; means for controlling each of the plurality of phasors with its corresponding phase signal to modulate a carrier signal; and means for applying the modulated carrier signal to a corresponding antenna element so as to transmit the at least one independent transmit beam. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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17. A system for digital beamforming of at least one independent transmit beam, the system comprising:
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a computer for generating a first digital signal representing information to be transmitted by the at least one independent transmit beam and a pointing direction therefor; a plurality of subarray controllers in communication with the computer for generating a second digital signal having an attenuation component and a phase component, the second digital signal being based on the first digital signal; a plurality of phasors each in communication with a corresponding one of the plurality of subarray controllers and responsive to the phase component of the second digital signal; means for distributing a carrier signal to each of the plurality of phasors for modulation thereby; and means for transmitting the modulated signal in communication with each of the plurality of phasors. - View Dependent Claims (18)
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Specification