共查询到18条相似文献,搜索用时 123 毫秒
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一种新的低副瓣曲线阵数值综合方法 总被引:5,自引:2,他引:3
本文提出了一种新的低副瓣曲线阵数值综合方法。把曲线阵综合问题表述为约束非线性最优化问题,利用新直接方法求解它,即可求出使阵列的总方向图满足特定的副瓣电平指标,且具有尽可能高的方向性系数的激励和空间分布,文中主要给出了自由空间曲线阵综合的数学模型和计算结果,并给出了直线阵时新综合方法与Taylor分布的比较结果。新综合方法也适用于共形曲线阵综合问题。 相似文献
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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. 相似文献
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阵列天线是指由多个离散的辐射元,按一定规律排列组成的天线系统.其具有高增益,强方向性,主瓣可控等特性.文中研究了利用切比雪夫法对阵列天线输入不同参数:馈源单元数N,馈源间距d,副瓣电平SLL,得出参数改变对阵列天线方向图的综合影响,通过工程示例论证出切比雪夫法用于方向图综合的优缺点.为切比雪夫法用于天线方向图综合比较提供了一种有效的参考方法. 相似文献
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在阵列天线的应用中,需要控制阵列天线的方向图达到合适的副瓣电平要求。本文在对已有的一维阵列方向图综合算法进行研究的基础上,给出了一种基于自适应阵列信号处理理论的二维阵列天线方向图的综合算法,将待综合阵列假想为自适应阵列,通过不断调节对阵列施加的干扰,再由自适应算法调节阵列权值,最终得到合适的方向图。 相似文献
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介绍了一种单脉冲SSR平面阵列天线的研制,其特点是在满足天线方向图3dB宽度的情况下,使天线和波束副瓣尽可能低,确保差波束完全覆盖和波束水平副瓣电平,不出现副瓣应答。 相似文献
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Jiao Y.-C. Wei W.-Y. Huang L.-W. Wu H.-S. 《Antennas and Propagation, IEEE Transactions on》1993,41(6):824-831
The application of the new nonlinear optimization algorithms to array design is demonstrated by the low-side-lobe pattern synthesis of conformal arrays. By adopting the information of array element realized gain patterns the authors formulate synthesis problems as nonlinearly constrained optimization problems, and propose a direct method to solve them. The technique allows them to find a set of array coefficients that yield a pattern meeting a specified side-lobe level and achieving the maximum directivity, if such a set of array coefficients exists. If the side-lobe specifications cannot be met with the given array, the technique will result in a set of coefficients that yield a pattern meeting the best attainable side-lobe level and having directivity as high as possible. Simplified synthesis problems for an axial dipole array in an infinite, perfectly conducting cylinder are discussed, and numerical results are given. The synthesis technique works for general array patterns 相似文献
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An iterative technique for reducing sidelobes of circular arrays 总被引:1,自引:0,他引:1
The iterative technique presented depends upon the solution of a set of simultaneous equations for perturbations of the element currents. Current distributions have been calculated which yield low sidelobe patterns from an array of2Q elements with only 0.25 dB less azimuth directivity than an orderQ Tchebycheff pattern that has the same sidelobe level. 相似文献
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A numerical pattern synthesis algorithm for arrays 总被引:17,自引:0,他引:17
A numerical technique for pattern synthesis in arrays is presented. For a given set of elements, the technique allows one to find a set of array coefficients that steer the main beam in a given direction and yield sidelobes meeting a specified criterion, if such a set of array coefficients exists. If the pattern specifications cannot be met with the given elements, the algorithm finds the best attainable pattern. The advantage of this technique is that it can be used with an arbitrary set of array elements. Different elements in the array can have different element patterns, and the array can have arbitrary nonuniform spacing between elements. The synthesis technique is based on adaptive array theory. The given array elements are assumed to be used as the elements of an adaptive array. The main beam is pointed in the proper direction by choosing the steering vector for that direction, and the sidelobes are controlled by introducing a large number of interfering signals at many angles throughout the sidelobe region. The algorithm iterates on the interference powers until a suitable pattern is obtained 相似文献
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By application of a Gegenbauer polynomial, pattern synthesis of array antennas which have high directivity and low sidelobe level is investigated. A Chebyshev or uniform-amplitude array is included as a special case of the result obtained. The current amplitudes of the array elements are represented by a Jacobi polynomial and are easily calculated. It is shown by numerical calculations for a linear array and a hexagonal planar array that there is an optimum directivity for a specified sidelobe level within a class of Gegenbauer-polynomial patterns. 相似文献
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The effect of broadband signals on the far-zone field of long arrays is investigated in terms of the energy radiation pattern. A generalized directive gain is introduced which depends on the signal spectrum. With maximum directivity as a criterion it is shown that the problem of optimizing a long isotropic array with respect to a given signal can be associated with a classical eigenvalue problem. The concept of array-bandwidth is introduced. Computed curves for directivity and directive gain are given in terms of this parameter and signal bandwidth. It is shown that while little improvement in directivity is achieved by optimizing the distribution coefficients of an array, a substantial reduction in sidelobe level is obtained when the signal bandwidth is comparable to the array bandwidth. 相似文献