共查询到16条相似文献,搜索用时 156 毫秒
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自适应阵列天线常需要采用宽零陷技术,以增强阵列天线抗干扰的稳健性。为此,提出了一种基于混沌粒子群算法(CPSO)的阵列天线宽零陷方向图综合方法。该算法首先采用混沌序列初始化粒子位置,以增强搜索多样性,并在对部分非优胜粒子的位置更新时引入混沌扰动项,在每次迭代中对全局最优位置进行变尺度混沌优化,提高了全局和局部搜索能力,加快了收敛速度。仿真结果验证了混沌粒子群算法在阵列天线宽零陷方向图综合时的收敛速度和精度方面均优于标准粒子群算法。 相似文献
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为消除特定方向的干扰,天线阵列零点生成成为信号处理的关键技术.本文将重要度采样策略的交叉熵算法应用到唯相位控制的天线阵列方向图零点生成.该算法每次迭代的候选样本来源于参数化概率密度分布,保证了样本的多样性,使样本集更加趋近最优结果.有效的克服了早熟现象,计算速度较快.仿真结果表明,该算法在方向图的主瓣附近、旁瓣区、对称主瓣两侧都能生成零点,零点生成范围较大.零功率宽度为120,最大副瓣电平为-12dB时,平均零陷深度达-190.12dB,是免疫算法的3倍. 相似文献
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针对全空域多目标测控天线相互干扰的问题,提出了一种基于零点约束的全空域多目标测控天线方向图综合方法.该方法对多个干扰目标方向进行零点约束,求取逼近给定方向图的最优权矢量的闭合解,生成具有干扰抑制能力的优化波束方向图.仿真结果表明,所提方向图综合方法在维持原有给定方向图特性的前提下,可在多个方向形成有效零点.在等效2m口径全空域多目标测控实物天线对该方法开展试验验证,结果表明在干扰方向抑制能力大于60 dB,证明了方法的正确性. 相似文献
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传统阵列方向图宽零陷形成技术需要对阵元施加复加权或者阵元位置扰动等复杂操作,实际实现比较困难。提出了一种基于遗传算法的唯相位波束赋形方法,针对宽零陷特点,结合均匀线阵方向图数学模型,设计一种适应度函数,优化阵元相位扰动值,最终获得符合要求的宽零陷阵列方向图。仿真结果表明,该方法可以在唯相位条件下形成较深的宽零陷,且零陷较平坦,收敛速度较快,稳健性较好。 相似文献
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The performance of adaptive array algorithms is known to degrade in rapidly moving jammer environments. This degradation occurs due to the jammer motion that may bring the jammers out of the sharp notches of the adapted pattern. We develop the robust modifications of the sample matrix inversion (SMI) algorithm, loaded SMI (LSMI) algorithm, and eigenvector projection (EP) algorithm by means of artificial broadening of the null width in the jammer directions. For this purpose, data-dependent sidelobe derivative constraints that do not require any a priori information about the jammer directions are used 相似文献
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Liu Zhenwei 《电子科学学刊(英文版)》1984,1(4):217-224
The antenna array pattern null steering is one of the important current topics in the array synthesis theory, due to it's
very effectiveness to suppress the interfering signals. Thus in this paper the problem of forming nulls in the radiational
pattern of three-dimensional arrays is discussed.
This paper deals with the following aspects: The essential relations forming multi-nulls in the arrays are analysed by the
method of vector space. A method forming multi-null regions is presented in terms of the extensive property of null itself.
The resolvent formulation of the radiational pattern of multi-null steering is derived. The numerical results are given and
discussed. The resolvent formulation is analogous to the one of the adaptive arrays. 相似文献
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The `small-sine? taper has recently been proposed as a method of broadening a null in the radiation pattern of a linear array, and this is discussed. The nulls are compared with the broad null sectors obtained from a Dolph-Chebuy?shev array. 相似文献
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在干扰方向和功率稳定的情况下,传统的自适应数字波束形成器能有效抑制干扰、提高信干噪比,但在干扰功率起伏的环境下,自适应数字波束形成器不能持续可靠地抑制干扰。针对这一问题,给出了一种增强信号中的干扰分量,再进行自适应波束形成的处理方法。该方法能根据需要对自适应数字波束形成器的自适应零点的零深进行调整,提高系统的抗干扰性能。理论分析和仿真实验验证了该方法的可行性。 相似文献
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A method for independent steering of each null in the radiation pattern of a linear antenna array using real weight control is introduced. The method depends on decoupling the weights such that each real weight is associated with a given null. It has the capability of tracking the direction of jammers by changing only the weight corresponding to each jammer. Phase shifters are used solely to steer the main beam in the direction of the desired signal. The price for using this method is that the number of steerable nulls is equal to or less than half of the total number of array elements 相似文献
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天线阵辐射图型强制零点控制,由于对定向干扰抑制的有效性,已成为天线阵辐射图型综合理论中心课题之一。本文围绕着这个课题,对三维天线阵辐射圈的零点控制进行了研究,它包括:用矢量空间方法,分析了多重零点控制的基本关系;根据零点本身的扩展性,引入了零域的概念,提出了多重强制零域的生成方法;导出了多重零点控制辐射图型的分解公式;揭示了由主波束和多个零点强制波束合成多重强制零点辐射图型的基本规律;给出了数值结果并进行了讨论;把这一分解原理与自适应成零天线阵辐射图型进行了类比。 相似文献