Ultra-wideband mutual coupling compensation of active electronically scanned arrays in multi-channel radar systems
| DWPI Title: Method for calibrating antenna array, involves transmitting compensated array output signal by way of antenna array where compensated array output signal is configured to correct for mutual coupling between element in antenna array |
| Abstract: Technologies pertaining to the calibration of ultra-wide-band active-electronically-scanned arrays to compensate for transmit and receive mutual coupling between array elements and/or non-ideal isolated channels are described herein. A plurality of near-field measurements are taken by way of probe or probes that may be moved among a plurality of positions aligned with respective elements in the array. For each position of the probe, each of the elements of the array is stimulated to transmit or receive a calibration signal to or from the probe, respectively. Frequency-domain transfer functions are computed from the received signals by the probe or the element for each of the array elements in each of the positions of the probe. The inverse of the matrix of transfer functions comprise frequency-domain transmit and receive correction factors that are used to modify desired array inputs/outputs such that the modified signals correct for mutual coupling between elements in the array. |
| Use: Method for calibrating antenna array e.g. active electronically scanned array used in multi-channel military radar system used on aircraft, naval vessel and communication system base station. |
| Advantage: The mutual coupling effects is allowed between elements of the array to be corrected without requiring a measuring tool that directly measures currents and/or voltages at terminals of pairs of elements in the array. The system corrects for coupling without requiring hardware modification of the array and without requiring use of a network analyzer to directly measure coupling between terminals of pairs of elements in the array. The local oscillator signal allows the calibration receiver to maintain phase coherence between samples of the electrical signal output by the probe and signals provided to the array. The improved phase control is enabled by correction for mutual coupling between the elements of the AESA that is implemented by the signal correction component. |
| Novelty: The method involves performing near-field measurements of a radiated output of an antenna array (102) by way of a probe or probes (110) to generate near-field measurement data over a desired operational frequency range. The probe or probes is positioned in a first position aligned with a first multiple elements of the antenna array. A transmit correction factor is transmitted over the desired operational frequency range based upon the near-field measurement data. An ideal array output is modified based upon the transmit correction factor to generate a compensated array output signal where the ideal array output representative of a signal desirably output by way of the antenna array. The compensated array output signal is transmitted by way of the antenna array. The compensated array output signal is configured to correct for mutual coupling between multiple elements in the antenna array. |
| Filed: 9/25/2017 |
| Application Number: US15714617A |
| Tech ID: SD 14178.0 |
| This invention was made with Government support under Contract No. DE-NA0003525 awarded by the United States Department of Energy/National Nuclear Security Administration. The Government has certain rights in the invention. |
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