A Novel Approach to Array Manifold Calibration Using Single-Direction Information for Accurate Direction-of-Arrival Estimation

• Published in: IEEE transactions on antennas and propagation Vol. 65; no. 9; pp. 4952 - 4957
• Main Authors: Byun, Gangil, Choo, Hosung
• Format: Journal Article
• Language: English
• Published: IEEE 01.09.2017
• Subjects: Adaptive antenna array; antenna array; Antenna measurements; array manifold calibration; Calibration; direction finding array; Distortion measurement; Manifolds; Phase distortion; Phased arrays
• ISSN: 0018-926X; 1558-2221
• DOI: 10.1109/TAP.2017.2731374

A method of array manifold calibration using one steering vector measured in a single direction is proposed. The phase information of the measured steering vector is used to derive a novel calibration matrix that is proposed to compensate for the relative phase distortion (RPD) at each antenna port. We also present a metric function defined as a standard deviation of the RPD to determine the optimum calibration angle, which provides intuition for the cause of the accuracy degradation in the direction-of-arrival estimation. To verify the feasibility, a seven-element circular array with identical microstrip patch antennas is fabricated for calibrating its array manifold using a single steering vector measured in a full anechoic chamber. The calibrated array manifold is then used to estimate the direction of arrival, and its accuracy is compared to the calibrated result obtained from the traditional least-squares method. The results demonstrate that the estimation error can be improved by 54.9° compared to the traditional least-squares method, when the number of measured steering vectors is extremely limited.