Phased array antennas are generally used for the inherent flexibility to beamforming and null-steering electronically. In the phased arrays the side lobes level (SLL) level is main problem which causes waste of energy or saturation of the receiver in the case of presence of the strong spatial blockers. In this paper, a weighting method was first used to reduce the level of SLL. However, this method increased the beam width and reduced resolution, which is not suitable for track applications. In next step hoping to increase the resolution, the distance between the antennas increased. But in this way, grating lobes appeared in the final beam. In fact, the main idea of the article is to solve this problem. Two methods of randomization at the antenna position and coefficients level were examined for a large element spacing in the order of one wavelength which cause significantly reduction in the side lobe level and grating lobe level simultaneously, while the beam resolution has increased. It is shown that for a linear 11-element phased array system with up to 180° scan angle for simultaneously beam-forming and null-steering a resolution of 10° was obtained for the amount of difference between desired beam and null points. The proposed system reduces the grating lobes to below − 13 dB, this technique leads to the realization of arrays with more number of elements, in which the weighting functions and mode excitation of the elements can be controlled by an adaptive signal processing unit in scanning phased array systems.

相控阵天线通常用于电子波束成形和零转向的固有灵活性。在相控阵中，旁瓣电平（SLL）电平是主要问题，在存在强空间阻塞器的情况下，这会导致能量浪费或接收机饱和。在本文中，首先使用加权方法来降低SLL的水平。但是，这种方法增加了光束宽度并降低了分辨率，这不适用于轨道应用。在希望提高分辨率的下一步中，增加了天线之间的距离。但是以这种方式，光栅波瓣出现在最终光束中。实际上，本文的主要思想是解决这个问题。对于一种波长顺序的大元件间距，研究了两种在天线位置和系数水平处随机化的方法，该方法可以同时显着降低旁瓣电平和光栅瓣电平，同时提高波束分辨率。结果表明，对于具有高达180°扫描角的线性11元素相控阵系统，同时进行波束形成和零点转向，对于所需波束和零点之间的差异量，可获得10°的分辨率。所提出的系统将光栅波瓣降低到− 13 dB以下，该技术导致具有更多元素数量的阵列的实现，其中，元素的加权函数和模式激励可以在扫描阶段由自适应信号处理单元控制阵列系统。