共查询到20条相似文献,搜索用时 46 毫秒
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根据合成孔径技术原理,提出一种基于合成孔径雷达成像原理的机载单站无源定位方法。提出电子战系统中的合成孔径构造方法,分析这种无源定位方法的定位误差分布。通过仿真确定了合成孔径的建立时间与定位精度的关系。 相似文献
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Spatial linear prediction filter antenna systems of large aperture width (in wavelengths) are described for the superresolution estimation of multiple emitter locations over moderate bandwidths. To accomplish this task with reasonably few degrees of freedom (DOF) from the large aperture, the system uses interferometer/sparse array techniques in conjunction with a shaped reference beam which may be steered to the spatial sector of interest. Computer simulations on several multiple source examples have demonstrated that the concept is feasible, provided that true time-delay steering is used on the shaped reference beam. The optimal estimation system configuration results when time-delay steering is also applied to the interferometer elements because this focuses the sample covariance matrix and minimizes the DOF required. Transversal filters may be dispensed with under focused conditions if the bandwidth is moderate. System performance goals included high resolution with few DOF, fast response/processing time, moderate cost, and ease of frequent calibration 相似文献
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The problem of realization of an arbitrary current distribution on an broadside array antenna derived from the theory of pattern synthesis is treated and some practical methods are proposed. In these methods, the input voltage of each antenna is transformed by a reactive transformer to take the required value. In one of the methods, experiments to yield Chebyshev patterns were performed and satisfactory results were obtained. 相似文献
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利用舰载惯性导航系统提供的姿态信息,对处于静态和动态姿态下的舰载平面相控阵天线的波束指向变换进行了分析,得到了平面相控阵天线的扫描角。在此基础上,以相控阵天线最大扫描角度最小为目标,给出了天线随舰载安装平台处于运动姿态条件时的安装倾角的设计方法。该方法能够在给定的舰船纵摇和横摇范围内,针对相控阵天线需求的空域扫描覆盖范围,实现对任意多面旋转布阵的平面相控阵天线安装倾角的计算。由该方法计算得到的天线安装倾角能够使平面相控阵天线有最小的最大扫描角,从而提高相控阵天线的电气性能。 相似文献
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针对可分离分布平面阵列的稀布优化问题,提出了一种基于矩阵束方法的减少阵元数目、求解阵元位置和设计激励幅度的优化方法。可分离分布平面阵的方向图等于两个正交线阵方向图的乘积。对形成期望方向图的两正交线阵的方向图进行采样得到离散的数据集,再构造Hankel矩阵;然后对此Hankel矩阵进行奇异值(SVD)分解,舍弃一部分不重要的奇异值,得到近似Hankel矩阵的最优的低秩逼近矩阵,它和稀布线阵的方向图相一致;基于广义特征值分解的最小二乘准则来计算两稀布线阵的阵元位置和激励,从而得到稀布面阵的位置和激励。仿真结果证实了该算法的有效性。 相似文献
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随着有源相控阵和数字波束形成技术的应用, 低轨道卫星通信多波束阵列天线不仅可以形成同时多个固定的对地等通量低旁瓣赋形波束, 还具备了可以随着通信任务需求变化, 动态调整方向图形状的能力.但是目前常用的高性能波束赋形算法, 运算量较大, 收敛速度慢, 优化参数调整复杂, 无法直接应用于在线实时计算.针对上述要求, 提出了一种高效的迭代最小方差方向图综合方法.该方法采用方向图分区域加权逼近和方向图相位去约束技术, 在满足较高的主瓣赋形精度和旁瓣电平控制等指标要求的前提下, 具有迭代过程简单、优化参数少、算法稳健和运算量少等特点, 可以部分满足要求波束方向图动态变化的卫星通信系统权重系数在线计算的需要. 相似文献
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太赫兹超材料相控阵由于其强大的波束操纵能力在探测与通信一体化系统中具有重要的应用价值。为了提升系统的通信和探测性能,需要太赫兹超材料相控阵能够实现宽波束和窄波束的灵活切换。提出了一种基于反相位间隔(反相)编码的太赫兹超材料相控阵天线波束宽度调控方法。通过天线3 dB波束宽度表达式和目标波束宽度逆推阵列规模,保持其相位编码不变并对该阵列规模外的其余阵元进行反相编码,旨在实现相位相反相消。仿真结果表明,所提方法可以准确地调控太赫兹超材料相控阵天线的波束宽度,实现宽波束和窄波束的灵活切换。 相似文献
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A set of arbitrarily located receiving antenna elements, each connected with an appropriate network, can be used to construct a matched filter where the antenna array response results in an autocorrelation of a specified desired signal, correlating over time and space coordinates simultaneously. A receiving system using such a signal processing antenna can discard interferences which do not have the same spectral characteristics as the desired signal, or which do not originate from the same point as the desired signal source. Examples of correlating antenna arrays for various arbitrary intelligence modulations of the desired signal are discussed in this communication. 相似文献