排序方式: 共有19条查询结果,搜索用时 15 毫秒
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提出了一种应用于便携设备中具有带陷特性的平面蝶形UWB天线.该天线采用蝶形贴片作为辐射单元,并由渐变线作为阻抗变换器与50 Ω馈线进行匹配.通过在辐射面上挖C形槽实现带陷功能,并给出仿真和实测结果.该天线的工作频带覆盖3.1~10.6 GHz,并有效避免了5.15~5.825 GHz的无线局域网(WLAN)频段,适于便... 相似文献
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Michael I. Bruce Natasha N. Zaitseva Brian W. Skelton Allan H. White 《Journal of Cluster Science》1996,7(2):109-119
The reaction between Ru3(3-2-PhC2C=CPh)(-dppm)(CO)8 and Co2(CO)8 afforded dark red Co2Ru3(4-C2Ph)(3-C2Ph)(-dppm)(-CO)2(CO)9, shown by an X-ray structure determination to contain a strongly twisted Co2Ru3 bow-tie cluster (central Co), to which two PhC2 units derived from cleavage of the original diyne are attached. One a these is strongly interacting with four metal atoms, the other being attached in the familiar 1,22-mode. The dppm ligand remains bridging two of the Ru atoms. 相似文献
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光电导天线辐射阻抗特性模拟分析(英文) 总被引:1,自引:1,他引:1
针对连续太赫兹光电导天线辐射功率较低的缺点,利用有限积分方法对三种常用的光电导天线,包括偶极天线、蝶形天线和螺旋天线,进行数值模拟并分析比较其辐射阻抗特性.仿真结果表明,偶极天线的辐射阻抗与偶极长度、宽度、电极间隙以及传输线宽度有关,且在其谐振频率存在峰值阻抗,适用于特定频率的太赫兹波辐射.蝶形天线和螺旋天线在所研究的太赫兹波段具有近似稳定的辐射阻抗,广泛应用于宽带领域.对带有交叉电极的电极间隙进行计算,结果表明由交叉电极引入的附加电容降低了天线的高频阻抗. 相似文献
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两种应用于宽带阵列天线的阵列单元 总被引:1,自引:0,他引:1
介绍了两种应用于宽带相控阵中的阵列单元,分析了每种天线的性能和优点,对天线单元进行了充分的设计、仿真和优化,仿真结果与实测结果基本一致。组成9×9的阵列,并对阵列中单元进行测量,对测量数据进行处理。结果显示出良好的宽带特性,具有较低的互耦等优点,可应用于三坐标雷达系统。 相似文献
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P. Dankelmann Henda C. Swart P. van den Berg W. Goddard M. D. Plummer 《Czechoslovak Mathematical Journal》2008,58(3):787-798
A graph G is a minimal claw-free graph (m.c.f. graph) if it contains no K
1,3 (claw) as an induced subgraph and if, for each edge e of G, G ™ e contains an induced claw. We investigate properties of m.c.f. graphs, establish sharp bounds on their orders and the degrees
of their vertices, and characterize graphs which have m.c.f. line graphs.
Support by the South African National Research Foundation is gratefully acknowledged. 相似文献
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A twin bow-tie polymer-based photonic quasi-crystal fiber with high birefringence, high nonlinearity and low dispersion as well as maintaining single mode operation is presented in the wavelength range 1.8–2.2 μm. Through optimizing fiber structure parameter using a full-vector finite-element method combined with perfectly matched layers boundary condition, the birefringence is as high as 2.43 × 10−3, the nonlinearity is as high as 118 W−1 km−1, and the dispersion is only 25 ps/nm/km at 2 μm with the holes pitch of 3.3 μm. From the point of fabrication, the influences of deviation of each air hole diameter are discussed to verify the robustness of the photonic quasi-crystal fiber designed. 相似文献
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