Multi-element antenna calibration technique
First Claim
1. An antenna system comprising:
- an antenna array comprising a plurality of sub-arrays, each sub-array having one or more antenna elements;
a radio for each sub-array, each radio comprising one or more transceivers;
a distributed calibration antenna element distributed across at least two sub-arrays of the antenna array; and
a calibration radio for the distributed calibration antenna element, the calibration radio comprising;
a transmit path configured to generate a receive calibration signal for transmission from the distributed calibration antenna element to the antenna array to calibrate receive paths of the antenna system;
a receive path configured to process a transmit calibration signal captured by the distributed calibration antenna element from the antenna array to calibrate transmit paths of the antenna system.
8 Assignments
0 Petitions
Accused Products
Abstract
Antenna system having an antenna array with multiple sub-arrays, each having one or more antenna elements, is calibrated using a distributed calibration antenna element, such as a leaky coaxial cable, that spans across at least two and possibly all of the sub-arrays. To calibrate the transmit (TX) paths of the sub-arrays, TX calibration test signals are transmitted by the sub-arrays, captured by the distributed calibration element, and processed by a corresponding calibration radio. To calibrate the receive (RX) paths of the sub-arrays, an RX calibration test signal is generated by the calibration radio, transmitted by the distributed calibration element, captured by the sub-arrays, and processed by their corresponding radios. Cross-correlation between the calibration and captured signals is performed to derive the complex gain of each sub-array transmitter and receiver, which provides information for aligning the gain, phase, and delay of the different TX and RX paths of the antenna array.
8 Citations
15 Claims
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1. An antenna system comprising:
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an antenna array comprising a plurality of sub-arrays, each sub-array having one or more antenna elements; a radio for each sub-array, each radio comprising one or more transceivers; a distributed calibration antenna element distributed across at least two sub-arrays of the antenna array; and a calibration radio for the distributed calibration antenna element, the calibration radio comprising; a transmit path configured to generate a receive calibration signal for transmission from the distributed calibration antenna element to the antenna array to calibrate receive paths of the antenna system; a receive path configured to process a transmit calibration signal captured by the distributed calibration antenna element from the antenna array to calibrate transmit paths of the antenna system. - View Dependent Claims (2, 3, 4)
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5. A method of calibrating transmit (TX) paths of an antenna system comprising (i) an antenna array with a plurality of sub-arrays, each sub-array having one or more antenna elements, and (ii) a radio for each sub-array, each radio comprising one or more transceivers, the method comprising:
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(a) transmitting one or more TX calibration test signals from one or more of the sub-arrays; (b) capturing a TX received signal corresponding to the one or more TX calibration test signals using a distributed calibration antenna element that is distributed across at least two sub-arrays of the antenna array; (c) processing the TX received signal using a calibration radio for the distributed calibration antenna element to generate TX digital signals; and (d) processing the TX digital signals to calibrate the TX paths of the antenna system. - View Dependent Claims (6, 7, 8, 12, 13, 14, 15)
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9. A method of calibrating receive (RX) paths of an antenna system comprising (i) an antenna array with a plurality of sub-arrays, each sub-array having one or more antenna elements, and (ii) a radio for each sub-array, each radio comprising one or more transceivers, the method comprising:
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(a) transmitting an RX calibration test signal from a distributed calibration antenna element that is distributed across at least two sub-arrays of the antenna array; (b) capturing one or more RX received signals corresponding to the RX calibration test signal using one or more of the sub-arrays of the antenna array; (c) processing the one or more RX received signals using the corresponding radios for the one or more sub-arrays to generate RX digital signals; and (d) processing the RX digital signals to calibrate the RX paths of the antenna system. - View Dependent Claims (10, 11)
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Specification