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设计了一种简单的双面单方环结构左手材料,在4.8–5.25 GHz频率范围内该材料的等效介电常数和等效磁导率同时为负.将此单方环左手材料作为覆盖层,置于中心工作频率为5.0 GHz的微带天线之上. 仿真和实验研究表明:相对普通微带天线而言,覆层微带天线的性能得到了明显改善, E面和H面的半功率波束宽度分别收缩了25°和20°,定向性得到了提高, 5 GHz处的增益提高了3 dB, -10 dB带宽增加了600 MHz.
关键词:
单方环结构
左手材料
微带天线 相似文献
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以N,N'-双(3-吡啶)辛二酰胺(L~1)和对苯二乙酸(H_2pda)为混合有机配体,或者以3-(吡啶-3-氨基甲酰)吡嗪羧酸(L~2)为单一有机配体,在水热条件下自组装制备了两种新的铜配合物[Cu(L~1)(pda)(H_2O)_2]·2H_2O(1)和[Cu(L~2)_2](2),并通过红外光谱、元素分析和X-射线单晶衍射对其结构进行了表征。配合物1是由一维[1D[Cu(L~1)]_(2n)~(2n+)链和μ_2-桥连配位模式的pda~(2-)阴离子连接形成的二维层状结构。配合物2是基于单一配体L~2的一种二维层状结构的聚合物。两种配合物的二维层间通过氢键作用拓展成为三维超分子网络。测试了标题配合物修饰的碳糊电极的电化学行为,而且研究了配合物作为催化剂对多种染料分子的光降解活性。 相似文献
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Mass measurement is an essential analytical tool in the characterization of materials. Here we present a method for measuring the mass of an individual nanoparticle which has a fg-level mass. This method enables a temperatureindependent mass measurement with the assistance of a sinusoidal electrostatic driving force. With this approach, we successfully track the change in properties of an optically levitated nanoparticle, such as mass, temperature, and electric charge, with air pressure. An abru... 相似文献
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Coherent population trapping magnetometer by differential detecting magneto–optic rotation effect 下载免费PDF全文
A pocket coherent population trapping(CPT) atomic magnetometer scheme that uses a vertical cavity surface emitting laser as a light source is proposed and experimentally investigated.Using the differential detecting magneto–optic rotation effect,a CPT spectrum with the background canceled and a high signal-to-noise ratio is obtained.The experimental results reveal that the sensitivity of the proposed scheme can be improved by half an order,and the ability to detect weak magnetic fields is extended one-fold.Therefore,the proposed scheme is suited to realize a pocket-size CPT magnetometer. 相似文献
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