共查询到20条相似文献,搜索用时 109 毫秒
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本文研究了同轴线馈电的1~18GHz的宽频带双脊喇叭天线。分析发现,与通常的看法不同,喇叭天线辐射方向图并不能在全频带上保持轴线方向具有单一的主波瓣。实际上,在12GHz以上,辐射方向图的主瓣开始分裂为偏离轴线方向的四个较大的旁瓣,且相对主瓣电平旁瓣电平低6dBC。喇叭天线是较为理想的测试天线,这方面的应用已经有四十多年的历史,但是对这一非理想特性的解释,未见公开文献发表。为了深入研究这一现象,运用矩量法仿真分析了整个天线系统。仿真结果与1~18GHz频带上的测量值非常吻合,由此表明在EMC的应用中,使用这种型式的喇叭天线还存在一定的问题。 相似文献
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一种结构简单的4mm多模圆锥喇叭 总被引:2,自引:1,他引:1
我们按照文献[1]提出的方案,研制了一种结构简单的4mm多模圆锥喇叭。通过理论分析,计算出其模比,并推导出其辐射方向图公式。在两个主平面——H平面或E平面上,对其方向图及波束场分布特性进行测试。理论分析及测试结果共同表明,该多模喇叭的主要性能明显优于单模圆锥喇叭。 相似文献
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本文介绍用于跟踪数据中继卫星系统(TDRSS)地面测控天线的20/30GHz波纹圆锥馈源,给出了设计性能与试验件测试结果。辐射方向图等化<1dB,交叉极化优于-26dB;在18.1~20.2GHz,VSWR<1.12,在28.5~30GHz,VSWR<1.05。 相似文献
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研究了一种基于阻抗超表面的高效率角锥喇叭馈源.将阻抗超表面放置于金属角锥喇叭内壁, 获得了一种性能良好的新形式高效率馈源.首先分析了超表面对表面阻抗特性的调控作用, 并证明该超表面对TE波和TM波呈现不同的阻抗特性.在特定的阻抗条件下, 该喇叭内壁可以支持平衡混合模式, 从而获得旋转对称的辐射波束.然后设计和加工了Ku频段的超表面高效率馈源, 馈源的测试方向图表明其辐射性能优良.最后将该馈源照射一款1.25 m Ku频段环焦天线, 测试其辐射方向图, 同样显示出其优异性能.与该环焦天线原有的波纹喇叭馈源相比, 超表面高效率馈源的性能与波纹喇叭馈源相当, 同时在体积、重量和成本方面具有明显优势. 相似文献
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本文叙述一种用于单脉冲雷达的波纹多模馈源的性能。该馈源用四个方喇叭输出口来激励和模与差模。适当地选择参数能使辐射方向图具有低的交叉极化电平,因而可适应截获目标的极化特性。本文给出了波导不连续性问题的分析结果并讨论了波导模之间相位差的补偿方法。一些初步的实验结果同理论计算相符合。 相似文献
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Zhisheng Lin Zhengmi Du Shener Chen 《Journal of Infrared, Millimeter and Terahertz Waves》1996,17(10):1749-1760
A 4MM-Wave composite mode multimode conical feedhorn has been developed. Its mode-ratios are calculated and its formulas of the radiation patterns are derived. The measurement results of one and two dimension radiation patterns, measured by the automatic measurement system which we had researched, and the properties of band width and sidelobe are given. Theoretical analyses and measurements show that at the centre frequency 69.1GHZ, down to -23dB, the radiation pattern is rotationally symmetric, in this range there is not any sidelobe existing, the band width is 4.5 GHZ. The multimode feedhorn is thus of certain practical using value. 相似文献
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为缩短太赫兹系统成像时间,该文提出将频率扫描天线应用于太赫兹成像系统中,并设计了一种基于波导缝隙阵列的太赫兹频率扫描天线。该文采用泰勒综合法降低副瓣电平,通过软件仿真结合功率传输法设计最优的缝隙分布。太赫兹波导缝隙阵列天线具有加工简单、成本低的优势,通过太赫兹准光测试系统对天线性能进行测试,实测天线扫描角度可达40°,增益约为15 dB,副瓣电平抑制优于–20 dB。测试结果表明太赫兹波导缝隙天线具有扫描角度大和副瓣低的优良特性,在太赫兹成像和目标探测等领域有巨大的应用价值。 相似文献
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《Microwave Theory and Techniques》1980,28(10):1136-1139
We describe a single sideband filter designed to have low insertion loss when used with microwave radiometer systems incorporating a feedhorn of relatively large beam divergence angle. The device we discuss is a type of Fabry-Perot interferometer empIoying one plane and one spherical mirror which form a near semiconfocal resonant cavity. Measurements on a prototype device operating at v~1OO GHz with a f/D~4 feedhorn and a 1.4-GHz IF frequency are presented, 相似文献
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Gauthier G.P. Raman S. Rebeiz G.M. 《Antennas and Propagation, IEEE Transactions on》1999,47(6):1120-1122
A double-folded slot antenna (DFS) has been designed, fabricated, and tested at 90-100 GHz. The antenna shows a very wideband impedance around 20 Ω from 85 to 110 GHz. The low impedance is compatible with superconductor-insulator-superconductor (SIS) junctions, Schottky diodes or high electron mobility transistor (HEMT) amplifiers, which require a low impedance at millimeter wave frequencies. The antenna is placed on a dielectric lens to synthesize a semi-infinite substrate and realize high-directivity patterns. The measured radiation patterns agree very well with theoretical calculations and demonstrate symmetric main beams and sidelobe levels below -15 db over a 10% bandwidth. The double folded slot antenna is an attractive candidate for low-cost wideband millimeter-wave monolithic microwave integrated circuits (MMIC) front ends 相似文献
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A multibeam antenna system and-combiner switch capable of producing a variable-coverage radiation pattern are described. The antenna consists of a waveguide lens illuminated by a 19-element feedhorn array. The combiner switch consists of a corporate arrangement of variable power dividers; the latter is made up of two phase shifters and two conventional hybrid power-dividers. An earth-coverage radiation pattern with less than 2-dB ripple and an antenna gain ≈ 20 dB is obtained by equally exciting all beams of the muItibeam antenna simultaneously. Excitation of a single feedhorn results in a narrow beam with an antenna gain ≈ 30 dB and a near-in sidelobe level less -20 dB. The side|obe level can be reduced appreciably by appropriately exciting the adjacent feedhorns. The frequency bandwidth corresponding to 0.5-dB decrease in antenna gain is 10 percent. A technique for computing the radiation properties of the antenna is described; the agreement with measured data is shown to be excellent. 相似文献
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The radiation characteristics of a millimetre wave Gaussian beam antenna (GBA) have been investigated theoretically and experimentally. The antenna consists of a fused-quartz half-wavelength piano-convex Fabry-Perot resonator fed by pyramidal horn. Very low sidelobe levels (<-35 dB) and a fairly good efficiency (>50%) are obtained at 57.2 GHz. Such an antenna configuration is therefore suitable for wireless broadband communications 相似文献
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设计了一种紧凑的具有三陷波特性的超宽带天线。天线采用渐变微带线馈电,并通过矩形加半圆的辐射单元和半圆形地板来实现超宽带。通过在辐射单元上刻蚀对称的L形槽和圆环形槽,来实现在WLAN/WiMAX的陷波特性;在渐变微带馈线两侧增加对称的C形谐振器来达到在X频段的陷波特性。实验结果表明,天线在2.68~13GHz频段内电压驻波比小于2,同时在3.1~3.8GHz,5~5.9GHz,7.25~7.85GHz频段内有陷波抑制作用,且具有良好的辐射特性。天线具有较小的几何尺寸,仅为20mm×30mm。 相似文献
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Chien-Jen Wang Hua-Lin Guan Jou C.F. 《Microwave and Wireless Components Letters, IEEE》2002,12(8):311-313
An aperture-fed patch antenna array is connected to the open end of a short leaky-wave antenna (LWA) to demonstrate the two-dimensional beam-scanning capability in this paper. This design not only offers another radiation path of the reflected wave, but also creates another scanning radiation pattern on the back plane of the substrate. The reflected wave of the LWA is equally separated by a power divider, modulated by each varactor-tuned phase shifter, and injected into two radiating aperture-coupled antennas. The operated frequencies are tuned to control the LWA main position in the elevation plane; meanwhile, by tuning the phase difference between two phase shifters, the main beam of the aperture-coupled antenna array can be scanned in the backside E plane. Experimental result shows that the suppression of the reflected wave can be 7 dB at 10.0 GHz with a short LWA length of 6 cm (two wavelengths). The H-plane and backside E-plane scanning radiation patterns have great potential in many applications and provide more flexibility to traditional designs. 相似文献
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Design of millimeter wave microstrip reflectarrays 总被引:4,自引:0,他引:4
Pozar D.M. Targonski S.D. Syrigos H.D. 《Antennas and Propagation, IEEE Transactions on》1997,45(2):287-296
This paper discusses the theoretical modeling and practical design of millimeter wave reflectarrays using microstrip patch elements of variable size. A full-wave treatment of plane wave reflection from a uniform infinite array of microstrip patches is described and used to generate the required patch-design data and to calculate the radiation patterns of the reflectarray. The critical parameters of millimeter wave reflectarray design, such as aperture efficiency, phase errors, losses, and bandwidth are also discussed. Several reflectarray feeding techniques are described, and measurements from four reflectarray design examples at 28 and 77 GHz are presented 相似文献