A Practical Calibration Method of Linear UHF Yagi Arrays for Ship Target Detection Application

Practical and stable channel calibration method is one of the most interesting technology for array radar engineers. This paper proposes a single source active calibration method (SAM) for ultra high frequency (UHF) radar with uniform linear array (ULA) Yagi antennas. This SAM measures the amplitude and phase errors of receiving channel at a known direction of arrival (DOA) in the antenna pattern measurement (APM) mode of radar without a transponder, then the calibration values at other angles are determined by a formula derived from array signal model. The results of simulation and field experiment show that (1) the antenna pattern (AP) caculated from SAM calibration is consistent with the simulated and measured AP of the Yagi array. (2) after calibrated by SAM values, DOA estimantion of digital beamforming (DBF) and signal to noise ratio (SNR) gains of Doppler power for 5 ship targets are in good agreement with the theoretical performance of 8 arrays. and (3) the azimuth angle of the single active source is insignificant and can be user-defined according to the field environment. It is proved that the proposed SAM calibration provides a feasibility and idea for the practical and reliable calibration of UHF Yagi ULA.