相控阵天线应用在有限电扫描角度时,采用大间距体制以减少有源通道数量,降低天线成本。由于单元间距大于波长,在可视空域内会出现栅瓣,常采用非周期排列方法分散栅瓣能量降低栅瓣电平。文中提出了一种变距平移错位抑制大间距阵列栅瓣的方法,并介绍了基于二维NUFFT计算该非周期排列阵列天线方向图的方法。分析了影响该算法精度的因素,并通过在拟合虚拟阵列幅相值时通过采用局部坐标系有效减小计算量。通过一个由300个单元组成的非周期阵列方向图计算,对二维NUFFT方法以及累加法进行对比。前者的计算时间仅为后者的0. 9% ,验证了算法的高效性。计算结果显示全空域方向图吻合度高,方向性系数误差仅0. 05 dB,最高副瓣误差仅0. 12 dB,验证了算法的准确性。

When phased array antenna used in the limited electric scanning angle, the large spacing system is helpful for to reduce the number of active channels and the antenna cost. Since the cell spacing is greater than the wavelength, which leads to the presence of a grating in the visible airspace, the non-periodic arrangement is used to disperse the lobe energy to reduce the level of the grating. In this paper, a method of suppressing grating lobe by varying displacement and offset is proposed. The two-dimensional NUFFT method is used to calculate this aperiodic array antenna pattern, and the factors influencing the accuracy of the algorithm are analyzed. The two-dimensional NUFFT method is compared with the accumulation method by a pattern calculation example of an aperiodic array composed 300 units. The calculation time of the former is only 0. 9% of the latter, which verities the efficiency of the algorithm. The calculation results show that the full airspace pattern is highly consistent, the error of directivity is only 0. 05 dB and error of the highest sidelobe is only 0. 12 dB,which verities the accuracy of the algorithm.

TN820. 1