A Fast and Efficient Calibration Method for Phased Array Antennas Using Fourier-Structured Excitation Matrix

Abstract

This article presents a novel phased array antenna calibration method. Unlike conventional phased array calibration methods equipped with only one probe antenna in the far-field setup, multiple measurement probes are introduced in the proposed algorithm to significantly improve the measurement efficiency. Specifically, a novel construction method for an excitation matrix (which contains excitation coefficients for phased array elements) is proposed, where phase differences introduced by the spatial locations of the multiple probes are perfectly incorporated into the Fourier-structured excitation matrix, thereby presenting the best measurement efficiency without sacrificing the array calibration accuracy. The proposed method can offer robust array calibration results (guaranteed by the low condition number of the constructed excitation matrix with Fourier structure) and high measurement efficiency (offered by multiprobe setups). To experimentally validate the proposed algorithm, a multichannel (i.e., multiprobe) far-field measurement setup was utilized. A four-element open-ended waveguide array operating at 2.6 GHz and two-probe far-field systems were employed as the antenna under test (AUT) and multiple probes, respectively, to validate the effectiveness and robustness of the proposed phased array calibration algorithm. The proposed algorithm will be highly valuable for efficient phased array calibration, especially for future antenna systems equipped with large-scale antenna configurations.