Super-angular and range-resolution with phased array antenna and multifrequency dither
First Claim
1. A method for locating a target, said method comprising the steps of:
- receiving RF signals from a target at each element of an antenna array;
dividing the RF signal power from each element into equal portions, to thereby generate a plurality of divided signals for each antenna array element;
generating mutually frequency-offset multiplication signals;
modulating each of said divided signals by one of said multiplication signals, so as to thereby generate positive and negative frequency offset received signals;
combining all of said negative frequency offset received signals from all of said antenna array elements to thereby generate CW received beam signals; and
combining all of said positive frequency offset received signals from all of said antenna array elements to thereby generate CCW received beam signals.
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Accused Products
Abstract
A radar system comprises an electromagnetic transmitter and an array of antenna elements connected in Multiple-Input Multiple-Output manner for routing signals reflected from the target to a plurality of receive beam rotation processors. The receive beam rotation processing for each antenna element includes application of rotation frequency offsets to the received signals and summation in summing and differencing adders to generate I and Q components of the rotating beams. The I and Q components for each element are summed to generate received signals including angle-or-arrival (AOA) information. The AOA information is further processed by correlating with reference replica AOA signals and by averaging to determine the actual AOA. The transmitter may have multiple contrarotating beams generated by application of frequency offsets. The transmit and receive beam rotations may be synchronized.
35 Citations
20 Claims
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1. A method for locating a target, said method comprising the steps of:
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receiving RF signals from a target at each element of an antenna array; dividing the RF signal power from each element into equal portions, to thereby generate a plurality of divided signals for each antenna array element; generating mutually frequency-offset multiplication signals; modulating each of said divided signals by one of said multiplication signals, so as to thereby generate positive and negative frequency offset received signals; combining all of said negative frequency offset received signals from all of said antenna array elements to thereby generate CW received beam signals; and combining all of said positive frequency offset received signals from all of said antenna array elements to thereby generate CCW received beam signals. - View Dependent Claims (2, 3, 13, 14, 15, 16, 17, 18, 19, 20)
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4. An apparatus for locating a target, said apparatus comprising:
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an antenna array for receiving RF signals from a target at each element of the antenna array to thereby generate RF signal power from each element; a divider arrangement for dividing the RF signal power from each element into equal portions, to thereby generate a plurality of divided signals for each antenna element; a source of mutually frequency-offset multiplication signals; a modulator for modulating each of said divided signals by one of said multiplication signals, so as to thereby generate positive- and negative-frequency offset received signals; a first combiner for combining all of said negative frequency offset received signals from all of said antenna elements to thereby generate CW received beam signals; a second combiner for combining all of said positive frequency offset received signals from all of said antenna elements to thereby generate CCW received beam signals; an I and Q complex signal generator arrangement coupled to said first and second combiners for generating complex CW and CCW signals from said CW and CCW received beam signals; a replica signal generating arrangement for generating replica signals which represent a plurality of targets at different angles of arrival; a correlator arrangement coupled to said replica signal generator arrangement and to said complex signal generator arrangement, for correlating said CW and CCW received beam signals with said replica signals, to thereby generate correlated signals; and a processor coupled to receive said correlated signals deeming the angle of arrival of signal from said target to equal the angle of the maximum value of correlation. - View Dependent Claims (5, 6, 7, 8, 9, 10, 11, 12)
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Specification