定向性天线阵列相位中心对DOA估计的影响分析

针对宽频带定向性天线阵列存在不确定的相位中心、非均匀分布的远场相位以及有限的主波瓣宽度等问题，提出了一种定向性天线组成的均匀圆阵的扇区波达方向（DOA）估计模型.首先通过最优化原则估计定向性天线相位中心，推导出阵列的有效孔径，构建方向性导向矢量；然后综合考虑相位扰动、相位中心估计误差等因素对DOA估计精度的影响，分析并推导出误差矢量；最后对常规理想点源天线阵列的DOA估计模型进行改进，并对影响DOA估计误差的因素进行仿真.实验结果表明，该模型具有单元天线参与数量少、相同误差因素下DOA估计精度高的优点.

Effect of Phase Center in Directional Antenna Array on DOA Estimation

Broadband directional antenna arrays have uncertain phase centers, non-uniformly distributed far-field phases and limited main lobe widths. To settle these problems, a sectorial direction of arrival (DOA) estimation model of uniform circular array composed of directional antennas is proposed. Firstly, the phase center of one directional antenna is estimated by the optimization principle, the effective aperture of the array is deduced and the directional steering vector is constructed as well. Subsequently, considering the integrated effect of phase disturbance and phase center estimation error on DOA estimation accuracy, the error vector is analyzed and deduced. Finally, a DOA estimation model of conventional ideal point source antenna array is improved and some factors affecting DOA estimation error are simulated. Simulations show that the model has the advantages of small number of antennas and high accuracy of DOA estimation under the same error factors.