共查询到18条相似文献,搜索用时 125 毫秒
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该文研究了一种以六单元圆形阵列作为照射器的单脉冲抛物面天线,这种天线具有实现宽频带跟踪的独特优点,其输出信号类似于圆波导单口径多模馈源,具有一个和波束,一个锥形差波束,并给出了没有接收机参与的情况下,将宽频带的和差两个通道变成单通道的途径。研制了一套L(1#61485;2GHz),S(2.2#61485;2.3GHz)宽频带双圆极化单通道单脉冲天线,对该天线的照射器、分波器、波束形成网络、单通道变换器等组件和馈源结构集成化设计进行比较详细的介绍。该馈源安装到一个3.2m的抛物面上,频率为1.1GHz,2.2GHz时,和波束增益分别为22.9dB,30.1dB;差波束零深为35dB,40dB。在L/S两个频段内跟踪稳定。 相似文献
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随着空间技术的快速发展,对目标飞行器的跟踪与信息截获变得越来越重要。为了实现对目标飞行器的跟踪和信息截获,文中设计了一种超宽带、多极化、高增益的跟踪天线及馈源,采用基于印制板设计的对数周期天线作为单元,并使用八个单元组成圆环阵作为反射面天线的馈源,对结构和馈电幅相进行设计,从而实现线极化比幅跟踪、左旋圆极化接收、右旋圆极化接收三种工作方式。仿真结果表明:单元天线驻波小于2的相对带宽达到147%,次级方向图的圆极化轴比小于4 dB,交叉波束的交叉电平基本稳定在-3 dB~-8 dB。对该跟踪天线进行加工,并进行天线系统测试,实际测试结果与仿真吻合很好。 相似文献
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本文对相控阵馈电单反射器天线作了分析研究,并阐明了馈源单元数量是最重要的设计参数,计算出的辐射特性证实了相控阵馈电单反射器天线适用于大型多波束天线。 相似文献
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为了使RFID在物流业中有更好的应用,分别采用双点馈电和结构变形的方法,设计并仿真了双馈电点圆形贴片天线和宽带双极化全向变形倒L天线。经HFSS仿真得出,在中心频率点为2.85 GHz时,双馈电点圆形贴片天线获得了双极化,变形倒L天线获得了32.3%(VSWR〈2)的宽带。 相似文献
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本文介绍了一种新型的Sinuous天线单元的设计与仿真,天线单元由阿基米德曲线段构成,另外在天线中组合使用了微带介质天线,最终实现了宽波束和双圆极化的功能。结果表明,所设计的天线在工作频带2.0~2.3GHz内有良好的电性能。 相似文献
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设计并实现了一种基于反射式移相器的极化可重构天线。该天线使用一对交叉摆放的领结型振子作为辐射单元,并在馈电网络中通过两路移相器调整双馈端口间的相位差实现线极化、左旋圆极化和右旋圆极化模式之间的切换。通过加载匹配枝节的方法扩展了反射式移相器的移相范围,提高了移相器的移相精度,降低了天线圆极化模式带内的轴比。所设计天线的中心频率为5.4 GHz,在线极化模式下10 dB 阻抗带宽为990 MHz,在圆极化模式下10 dB 阻抗带宽分别为760 MHz 和850 MHz,3 dB 轴比带宽分别为510 MHz和480 MHz。该天线在频带内具有稳定的波束方向图,其平均增益为5.3 dB,并且具有27 dB 的主极化-交叉极化隔离。最终的实测结果与仿真结果基本一致,表明该天线具有良好的性能。 相似文献
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Nakano H. Suzuki N. Ishii T. Yamauchi J. 《Antennas and Propagation, IEEE Transactions on》2001,49(5):715-723
Three mesh antennas, all having an extremely small antenna height of approximately 0.06 wavelength above a ground plane, are presented. First, a mesh antenna excited with a balanced feed is analyzed. It is revealed that the mesh antenna radiates a linearly polarized wave with no cross-polarization component in the principal planes. The radiation mechanism is explained using the current distribution. Second, a mesh antenna excited with an unbalanced feed is analyzed. This antenna shows almost the same radiation characteristics as the mesh antenna with a balanced feed. The frequency bandwidth for a VSWR=2 criterion is evaluated to be approximately 3%. Third, a mesh antenna having two perturbation elements is analyzed. It is found that the antenna acts as a radiation element of circular polarization. The frequency bandwidth for a 3-dB axial ratio criterion is calculated to be approximately 1%. The mesh antennas in the first and second analyses can be used as dual linear polarization elements by appropriately switching the feed. Similarly, the mesh antenna in the third analysis can be used as a dual circular polarization element by switching the feed 相似文献
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高速磁浮列车毫米波车地通信系统要求其车载天线具有小型化、宽频带、圆极化和辐射扇形波束等特点。为更好地满足这些要求,设计一种中心馈电的小型化波导螺旋阵列天线。该天线馈电系统采用同轴波导中心馈电、4路矩形波导并馈的形式,通过改变馈电波导尺寸、耦合探针长度以及末端采用波导同轴转换器等形式,实现了所有单元的等幅馈电;天线单元由低剖面螺旋天线构成,采用顺序旋转技术改善天线的圆极化性能。利用全波电磁仿真软件设计了一款中心频率为38 GHz的28单元波导螺旋阵列天线,并进行了实验测试。测试结果表明:在37~39 GHz频带范围内,天线驻波比小于1.41,增益大于21.7 dB,轴比小于3.6 dB,俯仰面波瓣宽度为4.5°~4.7°,方位面波瓣宽度为29°~29.7°,满足毫米波车地通信系统车载天线的设计需求。 相似文献
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为解决复杂星体环境多径干扰问题,同时满足卫星在轨高速数据传输对测控信道能力的需求,设计了一种带扼流圈的两臂等幅、相位相差90°馈电的四臂螺旋天线.该天线工作在S频段,具有半空间波束覆盖、主向增益高、宽角圆极化性能优异、体积小、质量轻等特性.实测数据表明,该天线圆极化轴比在±110°范围内小于3 dB,仿真与实测结果一致... 相似文献
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A single-fed reconfigurable microstrip antenna that can provide various polarization diversities is presented in this paper. The antenna is excited by a microstrip feed line through aperture coupling. When two PIN diodes are used to respectively reconfigure the coupling slot and the open stub of the feed line, the polarization of the microstrip antenna can be switched between vertical and horizontal polarizations. For the reconfigurable antenna with the linear polarization diversity, it can be converted to a circularly-polarized antenna with switchable polarization sense by introducing a perturbation segment. Moreover, an antenna with the quadri-polarization diversity, including dual orthogonal linear polarizations and two circular polarizations, is also developed from the structure of the switchable circular polarization microstrip antenna, and only three diodes are required. Details of the antenna design are shown, and the measured results for the constructed prototype are also exhibited and discussed. 相似文献