A Phase Center Estimation Method for Automotive Antenna Measurements

This paper presents a blind phase center estimation method for hemispherical near-field automotive antenna tests. The previous method only satisfies the less edge-scattering affected conditions, whose phase center estimation stability and accuracy are not satisfactory. While, the newly proposed method utilizes image theory as filtering process to characterize the electric fields with reduced edge-scattering effects, and the phase center is more accurately derived by the local searching strategy combined with a fast least-squares-based method along the x-, y- and z-axis. Correspondingly, the improvement of the calibrated pattern is significant. The simulation and measurement results both demonstrate the superiority of the proposed method with less time cost and better accuracy for different types of automotive antennas than the previous method. More importantly, the proposed method does not need to distinguish the edge-scattering-affected condition and non-edge-scatteringaffected condition, which will lead to an easy work for estimating the phase center and ensure the accuracy of the pattern offset calibration.