低副瓣任意波束直接合成算法研究

Direct synthesis of low sidelobe arbitrary beam

在传统阵列天线波束赋形设计中,通过对阵元天线辐射方向图进行幅度相位加权,获得阵列合成方向图.通常阵元激励幅度相位权值的获取,取决于优化算法对目标方向图和阵列合成方向图的对比,通过对阵元激励幅度相位进行大量随机选参后,获得优化结果.由于算法通常是基于相关的阵元方向图,且算法中缺乏副瓣抑制机制,使得方向图合成效率不高且副瓣效果通常不理想.该文设计了一种任意波束直接合成算法.该方法首先在阵元方向图的基础上获得一组互相独立的高增益窄波束(自由基波束),然后基于此波束进行方向图的直接合成,使波束赋形问题统一到基于自由基波束权值运算的范畴内,对波束赋形问题进行了统一,避免了未知参量的随机优选过程,极大提升了阵列天线波束赋形设计的效率.同时在自由基设计的过程中结合了副瓣抑制机制,且这种副瓣抑制机制与波束赋形过程互相独立,使合成波束的副瓣天然地具备了低副瓣的特征.

In traditional beam-forming design of array antenna, the synthetic pattern of array antenna is obtained by weighting the radiation pattern of array element antenna with amplitude and phase. Usually, the weight of the amplitude and phase of the array element excitation depends on the comparison between the target pattern and the array synthesis pattern by the optimization algorithm. Because the algorithm is usually based on pattern-related array pattern, and the algorithm lacks side-lobe suppression mechanism, the pattern synthesis efficiency is not high and the side-lobe effect is usually unsatisfactory. In this paper, a direct synthesis algorithm of arbitrary beams is designed. First, a set of independent high gain narrow beams(free radical beams) is obtained based on the array element pattern, and then the direct synthesis of the beam pattern is carried out based on this beam. The problem of beamforming is unified, which avoids the random optimization of unknown parameters and greatly improves the efficiency of beamforming design of array antenna. Meanwhile, the sidelobe suppression mechanism is combined with the free Radix design,and the sidelobe suppression mechanism is independent from the beamforming process,so that the sidelobe of synthetic beams is natural,and it has the characteristics of low sidelobe.