共查询到18条相似文献,搜索用时 156 毫秒
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平面相控阵天线最佳阵面倾角和最大单元间距的确定 总被引:2,自引:0,他引:2
单元间距是相控阵天线设计的一个基本参数,合理选择单元间距可以防止栅瓣进入实空间。另外,选择最佳阵面倾角,可以使不出现栅瓣的单元间距选择到最大。最佳阵面倾角的设计方法有两种:第一种是使阵列波束的最大扫描角最小;第二种是使阵列可选择的单元间距选择得最大,从而使覆盖整个阵列的单元数最少。本文在单元矩形栅格排列和三角形栅格排列的条件下,研究了平面相控阵列的最佳阵面倾角和可选择的最大单元间距,编制了通用计算 相似文献
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通过拉大端射天线阵元间距到1.5λ,可以获得组阵高增益,但是引入了栅瓣问题。提出了一种基于最小二乘估计的虚拟内插阵元算法来实现栅瓣抑制。虚拟端射阵列的阵元间距减小到(或者小于)0.5λ,这样栅瓣得到抑制。最后进行试验验证算法的可行性和正确性。试验结果表明:随着虚拟内插端射天线阵元个数的增加,栅瓣明显被抑制,峰值副瓣电平降低。在相邻两个实阵元间内插3个虚拟阵元,虚拟端射阵列保持了实端射阵列高增益,而实阵列峰值副瓣电平为-8.35dB,下降到虚拟阵列峰值副瓣电平为-18.25dB,栅瓣得到有效抑制。试验结果验证了基于最小二乘估计的虚拟内插阵元算法的可行性和正确性。 相似文献
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基于平面相控阵天线单元间距由设定的扫描空域中不出现栅瓣条件确定,分析了在选定矩形栅格和三角形栅格的阵列单元间距后,平面相控阵天线的极限扫描空域,揭示了相控阵天线尚未被充分利用的扫描资源。 相似文献
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设计并加工测试了一款双面Vivaldi天线.通过结构优化, 提高了馈电效率和阻抗带宽, 并在组阵后显著降低了阵元间的互耦.实测结果表明该天线可以实现在2~8 GHz的频带内回波损耗(Return Loss, RL)小于-10 dB, 平均增益大于5 dBi.并采用“交错排列”的思路, 将所设计的双面Vivaldi天线组成超宽带阵列.此种方式可以有效解决天线尺寸和最佳阵列间距之间的矛盾, 进而抑制栅瓣, 增大波束扫描角范围.仿真分析表明, 在4~6 GHz时, E面交错阵列比普通一维阵列的扫描角范围提高20°左右. 相似文献
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近年来,分布式天线阵列以其突破传统布阵环境限制的灵活性/ 高增益性成为阵列研究的热点。对于机载雷达系统,应用分布式天线阵列可以充分利用机身布阵空间资源,提高阵列的增益和空间分辨率。现有分布式优化方法多针对单元间大间距阵列与多子阵分散排布阵列,机载环境下双子阵分布式阵列优化研究极少。文章针对机载双子阵分布式阵列孔径栅瓣密集问题,提出利用差分进化算法并加以改进,实现对机载的分布式阵列栅瓣进行抑制。该方法能够在满足约束条件的同时,有效降低双子阵分布式阵列的高栅瓣问题,同时,阵列的副瓣可以被控制在较低的水平。在一定的子阵间距条件下,阵列的最大副瓣电平可以降低到-10 dB 左右。对优化算法的有效性进行蒙特卡洛实验,结果验证了该方法的可行性。 相似文献
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针对大规模卫星通信相控阵天线在阵元受发射/接收组件、驱动放大器等布局限制条件下的稀疏布阵问题,提出了一种基于极限微扰法的随机稀疏布阵算法。通过极限微扰率和随机稀疏算法的迭代应用,能够较容易地收敛到目标稀疏率下的稀疏阵列分布,且能得到均匀的稀疏布阵结果,改善相控阵天线由于局部过热导致的散热困难的问题。基于此方法,对满阵为4 096阵元的大规模相控阵天线进行了稀疏化设计,最终得到1 552阵元的稀疏阵。仿真和实测结果显示通过该算法能获得较好的阵列方向图结果,在方位角0°~360°、俯仰角0°~60°范围内副瓣均低于-16 dB。 相似文献
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Md. Moklesur Rahman Heung-Gyoon Ryu 《International Journal of Communication Systems》2023,36(8):e5475
In this paper, in order to improve the received signal strength (RSS) and signal quality, three arrays of electronically steerable parasitic array radiator (ESPAR) antennas are suggested for the ultra-high frequency (UHF) radio frequency identification (RFID) communication and sensing system applications. Instead of the single antenna, the array antennas have recently been widely used in many communication systems because of their peak gains, better radiation patterns, and higher radiation efficiency. Also, there are some important issues to use the antenna array like high data rates in wireless communication systems and to better understand the many targets or sensors. In this article, a wireless sensor network (WSN) is being investigated to overcome multipath fading and interference by antenna nulling technology that can be achieved through beam control ESPAR array antennas. The proposed ESPAR array antennas exhibit higher gains like 9.63, 10.2, and 12 dBi and proper radiation patterns from one array to another. Moreover, we investigate the mutual coupling effect on the performance of array antennas with different spacing (0.5λ, 0.75λ, λ) and configurations. It is found that the worst mutual coupling reduced by −28 to −34 dB for 2 × 2 array, −3 to −43 dB for 2 × 3 array, and finally −42 dB to −51 dB due to the antenna spacing from 0.5λ to λ. Thus, these suggested antennas could effectively be applied in the WSN communication systems, internet of things (IoT) networks, and massive wireless and backscatter communication systems. 相似文献
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建立方向图可重构天线的联合稀疏模型,基于多任务贝叶斯压缩感知理论提出一种稀疏可重构天线阵的优化设计方法.该方法在实现方向图精确重构的同时可以大幅减少天线数量,节省平台空间,降低设计成本.首先基于多任务贝叶斯压缩感知理论建立多目标方向图的稀疏优化模型,根据权值向量的先验概率分布,利用快速相关向量机估计超参数的最大后验概率来得到多组阵元位置及其激励,实时改变激励以获得不同方向图的稀疏逼近.仿真验证了该方法能够以较少的阵元个数和较高的方向图拟合精度快速实现方向图重构. 相似文献
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共享孔径交错稀疏阵列天线是实现多功能阵列天线的有效途径。现有的参数化互耦消除方法都是针对均匀阵列天线展开的,其研究的互耦矩阵都是规则的方阵,对共享孔径交错稀疏阵列天线的互耦矩阵模型并不适用。在充分考虑共享孔径交错稀疏阵列天线中子阵内互耦的“稀疏”和“方位依赖”的特殊性后,通过将常规的互耦矩阵扩展表示为“非方”的“增广互耦矩阵”来对交错稀疏阵列天线子阵内和子阵间的耦合效应进行建模,并通过“增广互耦矩阵”的参数化估计最终实现了共享孔径交错稀疏阵列天线互耦误差的建模与校正。仿真结果证实了所提方法的有效性和可行性。 相似文献
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A dielectric lens antenna that is a special case of an extended hemispherical dielectric lens and is operated in the diffraction-limited regime is considered. The dielectric lens antenna is fed by a planar antenna that is mounted on the flat side of the dielectric lens antenna, using it as a substrate, and the combination is termed a hybrid antenna. Beam pattern and aperture efficiency measurements were made at millimeter and submillimeter wavelengths as a function of the extension of the hemispherical lens and of lens size. An optimum extension distance for which excellent beam patterns and simultaneously high aperture efficiencies can be achieved is found experimentally and numerically. At 115 GHz the aperture efficiency was measured to be (76±6)% for a diffraction-limited beam with sidelobes below -17 dB. Results for a single hybrid antenna with an integrated superconductor-insulator-superconductor (SIS) detector and a broadband matching structure at submillimeter wavelengths are presented. The hybrid antenna is space efficient in an array due to its high aperture efficiency, and is easily mass produced, thus being well suited for focal plane heterodyne receiver arrays 相似文献
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Min‐Hui Ho Chien‐Ching Chiu Shu‐Han Liao 《International Journal of Communication Systems》2013,26(2):161-176
In this paper, we use the ultra wideband antenna array combined with particle swarm optimization (PSO) to minimize the BER for indoor communication systems. Three types of antenna arrays, namely the circular shape, L shape, and Y shape arrays, are used in the transmitter and their corresponding BER on several paths in the indoor environment are calculated. On the basis of the topography of the antenna array and the BER formula, the array pattern synthesis problem can be reformulated into an optimization problem and solved by the PSO. The novelties of our approach is not only choosing BER as the object function instead of the sidelobe level of the antenna pattern, but also considering the antenna feed length effect of each array element. The particle swarm optimization algorithm is employed to optimize the excitation voltages and feed lengths for these antenna arrays to reduce the BER. The strong point of the PSO is that it can find the solution even if the performance index cannot be formulated by simple equations. By the obtained antenna patterns, we can know the route with the lowest BER; meanwhile, transmission power using this route can be reduced. Numerical results show that the synthesized antenna array pattern is effective in focusing maximum gain to the line‐of‐sight path for these antenna arrays. The synthesized array pattern also can mitigate severe multipath fading in complex propagation environments. As a result, the BER can be reduced substantially in indoor ultra wideband communication systems. The investigated results can help communication engineers improve their planning and design of indoor wireless communication.Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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随着越来越高的角度分辨率要求与进一步降低的天线成本,大规模阵列越来越普及。在重量、体积和成本有限时,要获得大孔径天线得到较高的角度分辨率,且尽量减少天线阵元数目,可采用最小阵元稀疏阵设计方法。本文基于框架理论,提出了一种新的最小阵元数的稀疏阵综合方法。该方法将稀疏阵设计问题转化为压缩感知问题模型,然后利用次优反馈的零空间追踪硬阈值算法求解。该方法可同时综合阵元位置与阵元权重来匹配给定的阵列方向图,并可有效降低阵元数。仿真实验证明了算法的正确性和有效性 相似文献