三角格栅排列相控阵天线近场特性研究

为了掌握相控阵天线近场辐射特点，根据波束形成原理，提出了三角格栅相控阵天线辐射近场的数学模型，并进行了仿真验证。计算结果与仿真结果相比，相控阵天线主波束上场强幅度最大偏差约1dB，吻合较好。利用该模型对相控阵天线的电场近场分布特点进行了分析。在近场未形成主波束的区域，波束存在多个波峰和波谷；该区域内法线上场强出现极大值时发射方向在指向各观察点的方向附近徘徊。随着距离增大，波峰和波谷聚拢，波束宽度逐渐收窄；发射方向的徘徊区间慢慢变小，形成主波束后发射方向与实际波束指向一致。所得结论同样适用于矩形格栅相控阵天线。研究结果为相控阵天线的电磁兼容设计、辐射近场测量提供了理论依据和指导。

Near field characteristics of phased arrays with triangular grid

In order to find out the near-field radiation characteristics of phased arrays, the near field mathematical model for triangular grid arrays is established according to the beam forming principle. The simulation is carried out to verify the model. It shows that the calculation is in good agreement with the simulation because the maximum deviation for the near field intensity from phased arrays is about 1dB on the main beam. Then the model is used to analyze the near field distribution characteristics of phased array. In the region where the main beam is not formed in the near field, the beam shape has a few peaks and troughs. The transmission direction hovers near the direction pointing to each observation point when the field intensity on the normal line in the region reaches maximum value. The peaks and troughs converge and the beam width gradually narrows as the distance increasing. Also the hovering ranges of the transmission direction decreases slowly and finally it is consistent with the actual beam direction after the main beam is formed. The conclusion is also available for the rectangular grid phased arrays. The research provides a theoretical basis and guidance for electromagnetic compatibility design of systems and radiation near-field measurement for phased arrays.