大间距非周期阵列栅瓣抑制研究

Research on Grating Lobe Suppression of Aperiodic Array with Large Spacing

为降低工程造价和系统复杂度,采用最小单元间距均大于一个波长的大间距阵列是较有效的措施,但阵列方向图会出现不期望的栅瓣.通过随机分布法对28×28个阵元的大间距非周期矩形栅格阵列进行优化.为抑制栅瓣,将均匀阵列划分为不同数量的子阵列,比较子阵列优化错位后的栅瓣抑制效果.然后,将阵列划分为4×4个和7×7个子阵,研究子阵(错位或均匀)和子阵内阵元(随机或均匀排布)的组合阵列,分析3种不同随机程度的组合阵列栅瓣抑制效果,并结合仿真图从栅瓣电平和平均副瓣电平角度对比说明各种排布的优劣.结果表明,子阵错位且子阵内阵元随机排布的栅瓣抑制效果最好,但平均副瓣电平会抬高,相比全随机排列阵列工程上更容易实现,且成本更低.

In order to reduce the engineering cost and system complexity,it is an effective method to adopt large spacing array with minimum element spacing greater than one wavelength.However,the pattern of array will appear unexpected grating lobes.In this paper,the random distribution method is used to optimize the large spacing aperiodic rectangular grid array of 28×28 elements.In order to suppress the grating lobe,the uniform array is divided into different number of subarrays,and the grating lobe suppression effect of the optimized dislocation of subarray is compared.Then,the array is divided into 4×4 and 7×7 subarrays.The combined array is studied,which includes subarray(dislocation or uniform)and elements in subarray(random or uniform arrangement).And it is analyzed that the grating lobe suppression effect of three different random degrees of combined array.The advantages and disadvantages of each arrangement are illustrated from the angle of gating lobe level and average side lobe level combined with the simulation diagram.The results show that the grating lobe suppression effect is the best when the subarray is misaligned and the elements within the subarray are randomly arranged,but the average sidelobe level will be raised.And it is easier to realize in engineering and lower in cost than the fully random array.