For irregular distribution of array elements,the calculation of phase center has always been an engineering challenge.The current calculation methods commonly used to calculate phase center are:moving reference point,phase gradient method,least squares method.These methods all focus on the far field char-acteristics of phased array antenna pattern,the symmetrical characteristic of the antenna array element distri-bution are not fully utilized.The multiple uses of the approximation causes considerable cumulative errors. We note that most large phased array radar antennas are symmetrically distributed,such as PAVE PAWS ra-dar and Cobra Dane radar.In this paper,we propose a method for the antennas with symmetrical characteris-tics of subarray to calculate the phase center of the antenna array,which is based on the phase sum-difference angle measurement.Starting from array signal processing,it first finds the output value of sum beam,and then calculates the difference between the output values of elevation and azimuth beams.Under the condition of little difference between beam direction angle and target coming angle,the expression of phase center is ob-tained by comparing the sum beam value with the value of elevation and azimuth beams.At last,a series of approximate phase centers are obtained by changing the direction of the target,and we can average these val-ues as the phase center of a subarray.The simulation results show that the estimation accuracy of the pro-posed method is higher than the existing methods,and the angular error range of the proposed method is 20%less than the traditional method.%对于不规则阵元分布的相控阵天线，其相位中心计算问题一直是一个工程难题。目前常用的相位中心计算方法有移动参考点法、相位梯度法、最小二乘法等。这些方法都是从相控阵天线的方向图远场的电磁特性来分析的，没有充分利用天线阵元分布的对称特性，运算时多次使用近似导致累计误差较大。目前大型相控阵雷达天线的阵元排布大多呈现对称分布特点，如铺路爪雷达和丹麦眼镜蛇雷达等。针对这些具有子阵对称特性的天线阵列，提出一种基于相位和差测角的相位中心计算方法。该方法从阵列信号处理的角度出发，先求出和波束输出值，再求出俯仰差波束输出值和方位差波束输出值；然后在波束指向角和目标来向角相差不大的条件下，用和波束值分别与俯仰差波束值和方位差波束值相比，得到含有相位中心的表达式；最后通过改变目标来向角得到一系列视在相心，取这些视在相心的平均值作为子阵的相位中心。仿真结果表明其估计精度高于已有方法，测角误差范围比传统方法小20%。
展开▼
