共查询到18条相似文献,搜索用时 187 毫秒
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为了提高微波无线能量传输的效率以及灵活性,提出并设计实现了一款基于机械控制的可重构超表面电磁开关。该设计基于Pancharatnam-Berry(P-B)相位原理,是一种可机械旋转、具有波束控制能力的反射型超表面,可以直接应用于无线传输系统中。仿真与优化设计表明,对于垂直入射的右旋圆极化平面波,超表面能够实现同极化聚焦或散射两种可重构功能。将该超表面放在无线传输系统中的发射端可以形成反射面天线,从而对微波无线功率传输系统实现电磁开关的功能。实验结果表明,在设计的5.8 GHz 附近,发射天线位于超表面焦点处时,通过调节超表面实现聚焦功能,可以使天线增益提高2.7 dBi;在无线传输系统中,可以通过超表面的引入实现电磁开关的功能。 相似文献
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研究了一种基于分布式天线阵列波束聚焦的微波无线能量传输系统。该系统的能量发射端由两个四单元天线阵列组成,两个天线阵列相隔一定的距离,呈分布式摆放。天线阵列各单元接收到移动目标设备发来的导航信号后,根据回复式反射原理协同产生聚焦于目标设备的功率波束。仿真结果表明,所设计的分布式回复反射波束聚焦系统能在一定范围内跟踪移动设备,并将无线能量准确地传送至移动设备所在位置。 相似文献
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激光无线能量传输在无人机、卫星空间站和探月机器人供电等方面具有潜在应用前景,其系统效率成为了其应用的关键瓶颈。为了提高激光无线能量传输系统发射端激光器的电光转换效率、接收端光斑均匀性和有效窗口收光比,提出了用于激光无线能量传输发射端的高效率半导体激光器设计方案。基于合束效率较高的空间合束设计了一套高功率高效率半导体激光系统,接收端光斑不均匀度可优化至0.207,有效窗口内收光比大于94%。搭建了千瓦级激光无线能量传输实验装置,发射端半导体激光系统直接输出矩形光斑,与矩形光电池匹配,提高了电池阵布片率。利用多光束指向性可调节特点,优化了接收端光斑均匀度,有利于提高接收端电池的转换效率及简化电源管理。该设计与研究为激光无线能量传输的实际应用提供了借鉴意义。 相似文献
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概述了微波无线能量传输系统的研究现状及其基本原理,从可提高波束能量的一些特殊口径场以及先进的天线技术角度,分别按Whisper波束、超增益天线、平顶波束、聚焦天线技术、非衍射天线进行介绍。最后对微波能量传输系统中发射技术的未来发展趋势进行了展望。 相似文献
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设计了一款工作在5.8 GHz用于微波无线能量传输的双层惠更斯超表面透射阵天线。惠更斯单元由一对1 mm厚的反对称E形单元构成,同时实现360°相位控制和高传输幅度(-0.82 dB)。该设计突破了传统双层频率选择表面的限制,同时提高了透射阵的辐射性能。透射阵尺寸为380 mm×380 mm,实测结果表明透射阵增益达到26 dB,口径效率为58.7%。在微波无线能量传输外场实验中,测试距离达到18 m,加载透射阵后,接收功率最高获得8.3 dB的增幅。 相似文献
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无线传能系统工作时在周围空间会激发高频电磁场,因此对无线传能系统有较高的电磁兼容性指标要求.文中通过对无线微波传能系统发射天线周围环境的电磁辐射进行建模和分析,以及微波传能基站对周围环境的电磁影响,研究了无线微波传能发射端周围空间电磁辐射的安全性.发射功率为500 W时,通过计算人体头部的比吸收率值,根据国际射频暴露的安全导则,基于理论分析和仿真实验界定了人体电磁暴露的安全区域,划定基站天线主波束、旁瓣、后瓣的安全距离分别为25 m、3 m、2 m,并给出了无线微波传能基站部署的参考方案,对于无线微波传能的实际应用具有重要的参考意义. 相似文献
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Power transfer through a microwave reverberation chamber is studied theoretically and experimentally. Two configurations are employed as follows. In the first, the chamber contains a transmitting antenna and a receiving antenna; in the second, it contains a transmitting antenna and a receiving D-dot sensor. For each configuration a theoretical model is derived and laboratory measurements are carried out for the power gain of the chamber as a function of frequency. The models prove useful in predicting the observed variation of gain with frequency, and they provide insight into the importance of power flow to the chamber walls and to the receiving antenna/sensor 相似文献
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Biao Zhang Wan Jiang Yang Yang Chengyang Yu Kama Huang 《International Journal of Electronics》2013,100(11):1818-1830
A multi-magnetron microwave source, a metamaterial transmitting antenna, and a large power rectenna array are presented to build a near-field 2.45 GHz microwave power transmission system. The square 1 m2 rectenna array consists of sixteen rectennas with 2048 Schottky diodes for large power microwave rectifying. It receives microwave power and converts them into DC power. The design, structure, and measured performance of a unit rectenna as well as the entail rectenna array are presented in detail. The multi-magnetron microwave power source switches between half and full output power levels, i.e. the half-wave and full-wave modes. The transmission antenna is formed by a double-layer metallic hole array, which is applied to combine the output power of each magnetron. The rectenna array DC output power reaches 67.3 W on a 1.2 Ω DC load at a distance of 5.5 m from the transmission antenna. DC output power is affected by the distance, DC load, and the mode of microwave power source. It shows that conventional low power Schottky diodes can be applied to a microwave power transmission system with simple magnetrons to realise large power microwave rectifying. 相似文献
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针对微波能量传输领域中接收天线与发射天线发生极化失配时,整流天线接收的能量会急剧下降的问题,设计了一款工作在2.45 GHz具有谐波抑制功能的双极化缝隙接收天线,该接收天线本身发生一定角度旋转时仍可通过双极化的特性接收能量。通过在贴片上开大小合适、结构对称的缝隙,实现天线水平极化和垂直极化;运用缺陷地结构,实现谐波抑制功能。仿真结果显示,在2.45 GHz处,天线的隔离度高于17.6 dB,增益3.9 dBi,阻抗匹配良好,在二次、三次谐波处天线的回波损耗为-0.38 dB和-0.96 dB,仿真结果和实测基本吻合。 相似文献
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对大气激光通信中的光传输能量损耗进行分析,着重讨论了造成接收端光功率损耗的几个主要影响因素,并做了综合性的计算机仿真,得到发射功率一定的情况下发射天线轴向偏焦和收发天线系统间横向偏移取不同量值时接收端光功率的变化。在损耗分析的基础上,文章探讨了接收端满足最低光功率条件下,偏焦和偏轴相互间的关系,提出通过调节发射天线偏焦来改善远距离接收端天线捕获的方法。在发射功率为10000 mW,距离为10 km,接收端光功率阈值为50 mW的情况下,发射天线未偏焦时收发天线系统间的允许最大偏轴量为495.9 mm;当焦点偏移6.69 mm,允许最大偏轴量达到最大值为628.5 mm,与未偏焦的情况相比增加了26.74%,满足接收端光功率要求下收发天线系统间允许横向偏移区域的面积增加了60.63%,这有效地降低了大气激光通信中远距离接收端捕获的难度。 相似文献
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A basic design of an aperture illumination of antennas used for radio wave power transmission is presented. In the power transmission using microwave such as solar power satellite, not only the transmission efficiency, but also the transmitting power capacity allowed by the necessary electromagnetic environment is a very important factor for realization. In this paper the circular antenna aperture illumination is optimized in order to give the maximum transmission efficiency with the constraint on the radiation levels at the edge of the receiving aperture and at the radiation peaks of the subsequent sidelobes. This constrained optimization problem is solved by successive use of the sequential unconstrained minimization techniques (SUMT method). The maximum transmission efficiency and receivable average power density are obtained for various constrained levels of the spilled radiation, and are compared with the values in the unconstrained case. 相似文献
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Beamed microwave power transmission and its application to space 总被引:5,自引:0,他引:5
The general principles and special components of beamed microwave power transmission systems are outlined, and their application to the space program is discussed. For a beamed system starting with a DC source of power, converting it to a microwave beam for transmission through space, and ending with DC power output at the receiving end, an experimentally measured and certified DC-to-DC efficiency of 54% has been achieved. The application that is discussed in detail is a low-earth-orbit-to-geostationary-orbit (LEO to GEO) transportation system that depends on vehicles propelled by electric thrusters whose power is supplied by a microwave beam originating at the earth's surface. A scenario for such a system is chosen, and the performance results are presented. The advantages of the all electronic system over a chemically propelled system are enumerated. The principles of space propulsion, particularly as they relate to electric propulsion, are outlined. Key components at the terminals of the system are discussed. Environmental considerations are discussed 相似文献