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一种超低旁瓣天线设计的研究 总被引:1,自引:0,他引:1
通过对雷达信号空间谱的分析和变换获得空域的加权系数,利用得到的加权系数对阵列天线各单元信号进行加权后再叠加,可设计出一种超低副瓣的雷达阵列天线,并可通过实时改变其加权系数以获得不同特性的天线。 相似文献
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矩形平面阵列天线旁瓣电平优化的遗传算法 总被引:12,自引:1,他引:11
本文运用遗传算法对不等幅不等距型平面阵列的最大相对旁瓣电平进行了优化,通过提出新的自适应变异算子改进了算子的收敛性能,良好的计算结果表明遗传算法是目前求解此类问题的有效方法。 相似文献
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基于半定规划理论提出了一种新的阵列天线方向图旁瓣抑制算法。与传统旁瓣抑制方法不同,该方法通过合理设计优化准则,避免了在凸优化问题建模过程中引入近似,保证了波束形成器的最优性;并且使得在压低旁瓣的同时,可准确控制信噪比增益和主瓣宽度到期望的范围之内。该方法对阵列流形没有限制,计算机仿真结果验证了其有效性。 相似文献
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采用多个小口径抛物面天线组成天线阵是反射面动中通系统降低天线高度的重要方法,但由于天线尺寸和数量的限制,合成天线方向图会形成较高的旁瓣。从理论上分析了抛物面合成天线的方向图特性,给出了几种降低峰值旁瓣电平的方法,并结合仿真实验讨论了不等幅馈电技术、天线间距以及子天线口径对合成天线峰值旁瓣电平的影响,采用遗传算法,以降低合成天线峰值旁瓣为优化目标对上述因素进行了全局优化。仿真结果验证了理论分析的正确性,表明综合运用不等幅馈电技术和减小天线间距可以显著降低天线旁瓣电平。 相似文献
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一种新的天线旁瓣对消抗干扰技术的实现 总被引:4,自引:4,他引:4
给出了一种新型天线旁瓣对消系统的技术实现方法,对其系统组成和对消原理进行了分析。同传统的对消系统相比,该系统具有更好的抗干扰性能。 相似文献
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介绍了数字阵列天线和、差波束加权系数的理论计算方法。实际中发现将这些加权系数直接代入阵列中数字合成时会存在和、差波束的最大电平差值与理论增益差值不符的问题。基于天线基础理论,通过分析和、差波束加权系数之间的关系,得出了阵列天线和、差波束加权系数的平方和必须相等的结论。通过一实例模拟数字合成验证了该结论。 相似文献
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基于遗传算法和神经网络的二相码旁瓣抑制 总被引:4,自引:0,他引:4
研究雷达脉冲压缩信号中二相编码的距离压缩问题,在多层前馈网络方法(MFNN)的基础上,提出一种基于遗传算法的计算方法。通过对13位巴克码和31位M编码的仿真实验,表明新的方法在旁瓣抑制能力和运算速度性能方面,都有较大的提高。 相似文献
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通过对雷达信号空间谱的分析和变换获得空域的加权系数 ,利用得到的加权系数对阵列天线各单元信号进行加权后再叠加 ,可设计出一种超低副瓣的雷达阵列天线 ,并可通过实时改变其加权系数以获得不同特性的天线 相似文献
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分析了二次雷达系统中采用的询问旁瓣抑制(ISLS)技术,针对其不能完全消除询问旁瓣干扰、无法调节询问方位覆盖范围的不足,提出了一种新的设计方案,采用和(Σ)、差(Δ)、全向(Ω)三通道发射询问信号的方法来消除旁瓣干扰,并通过采用询问信号传递波束调节因子的方法实现系统询问有效方位波束宽度的自动调节。该方案提高了系统的询问旁瓣抑制能力、抗干扰能力和平台适应性,已成功应用于某工程。 相似文献
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This paper presents an accurate approach for Concentric Circular Antenna Array (CCAA) synthesis to improve the far-field radiation characteristics of the antenna using a meta-heuristic optimization technique called Moth Flame Optimization (MFO). The far-field radiation pattern improves with lower Side Lobe Level (SLL) which is essential for the reduction of interference in the entire side lobe regions. MFO algorithm is a recently proposed evolutionary algorithm which is applied to determine the optimum sets of current excitation weights and to find the optimal inter-element spacing between the array elements in the 3-rings structure of CCAA design. In this context, the design examples of two 3-ring CCAAs, one having the set of 4, 6, 8 elements and the other having the set of 8, 10, 12 elements, with and without centre element, are presented by optimizing the array parameters. The results obtained by using MFO algorithm based approach show a considerable improvement of SLL with respect to that of the uniform array pattern and those of the approaches reported in the recent literature. 相似文献
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This article presents a study on the placement of multiple nulls as well as minimization of side lobe level in the radiation pattern using a planar hexagonal antenna array structure in two different vertical planes. The desired null depth is achieved to suppress the interference signal by the position-only control of the uniformly excited isotropic antennas in the array structure. The immediate solution to the mentioned computational problem is reached by various meta-heuristic optimization algorithms such as teaching learning-based optimization (TLBO), symbiotic organism search (SOS), and moth fly optimization (MFO) within a considerably reduced processing time with a control over the design constrains. Various examples for diversified scenarios are demonstrated to place multiple deep nulls in the radiation pattern without compromising the pattern constraints and all other radiation pattern characteristics. This experiment sought to illustrate and quantify the unique benefits and limitations of proposed technique using three considered meta-heuristic optimization algorithm. 相似文献
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低副瓣有源相控阵天馈系统中的一体化设计 总被引:2,自引:0,他引:2
该文提出低副瓣有源相控阵天馈系统中的一体化设计方法,从几个主要方面阐述如何进行一体化设计,在248元天线阵上试验,实测波瓣的峰值副瓣电平和差波瓣零深均在-31dB以下,当波瓣扫描至60时,其峰值副瓣电平不高于-26.5dB,表明一体化设计的必要性。 相似文献
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以均匀线阵(Uniform Linear Array ,ULA)为子阵,结合频率分集阵(Frequency Diverse Array ,FDA)的思想,构建了一种基于分布式子阵的频率分集阵。针对各子阵按等间距布阵将导致严重的栅瓣问题,提出了一种改进粒子群 (Improved Particle Swarm Optimization ,IPSO) 算法来优化分布式FDA中各子阵间的基线距离,以实现高效的栅瓣抑制。同时,从理论上推导了目标距离和角度均未知时参数估计的克拉美罗下界(Cramer-Rao Lower Bound ,CRLB)。仿真结果表明,优化后分布式FDA的栅瓣得到有效抑制,而且阵列角度维分辨率和估计性能亦得到大幅度提升,验证了所提算法的有效性。 相似文献
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The investigations related to the planar antenna array have attracted much attention due to their vast applications in the areas of advanced wireless communication and electromagnetics. This article presents an effective synthesis method of a sparsely thinned symmetric planar antenna array using three well-known meta-heuristics including symbiotic organism search (SOS) algorithm, moth fly optimization (MFO), and multi-verse optimization (MVO) algorithms. The main aim of this work is to optimize the positions of the switched-on antenna elements on the array aperture in order to reduce the value of side-lobe levels in the radiation field pattern in multiple planes for a desired first null beam width and subsequently to obtain the maximum reduced number of array-elements in the antenna array. Two different cases are performed to optimize the radiation pattern in different azimuth angles with two different examples. The proposed methods can constrain the total number of array elements, inter-element distance, and aperture area of the array. The radiation pattern characteristic and computation time linked with each example and each algorithm are recorded and compared with each other as well as with a fully populated planar symmetric rectangular array antenna of same aperture size for arriving at the conclusion. The simulation-based results demonstrate the effectiveness of the proposed design and the efficiency of the performance using the SOS algorithm. 相似文献