Research On Error Analysis And Calibration Method Of Planar Near Field For Phased Array Antenna

Antenna measurement and calibration is the necessary method testing antenna from designing theory to practice. The near-field measurement technology has the advantages of high measurement accuracy, strong anti-jamming ability and excellent calculation and analyzing capability. This article outlines the basic theory of planar near-field measurement technology, and it is focused on the impact of element failure and amplitude-phase errors. The research of antenna calibration method and the error analysis of planar near-field measurement have been given out by the way of simulation.Firstly, the basic composition and working process of the planar near field measurement system are introduced. It discusses the principles of planar wave expansion, the theory of probe compensation, and the select rule of sampling parameters. The paper introduces the types of the errors and the influence of the Side lobe levels, gain, beam pointing accuracy caused by the amplitude and phase error, failed elements, quantization error.Secondly, in order to calibrate the phased array antenna and reduce the impact of element failure and amplitude-phase errors, this paper proposes a calibration method which considers the mutual coupling. On the basis of the calibration with the near-field scanning method, the elements should be calibrated by the rotating element electric-field vector method(REV method). With the REV method, the large-scale phased array antenna should be distributed into some small areas such as middle areas and edge areas to make the signal vary more significantly.The re-calibration method could find out the failure elements and improve the phased array antenna’s amplitude-phase consistency. The calibration of sub-region which using the REV method could diminish the effect of the mutual coupling and shorten the calibration period.Finally, the main error-upper-bounds analysis of near field measurement technique for planar near-field measurement has been given.The effects of the finite scanning plane truncation errors, location errors and room scattering errors are qualitatively analyzed by computer simulation. The effect of multiple reflections between probe and AUT is measured by self-comparison method. At last, the near-field diagnosis of antenna is researched by the pattern multiplication method and the plane-wave spectrum.