共查询到20条相似文献,搜索用时 62 毫秒
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在卫星通信、定位设备中,为了迅速完成定位和通信功能,一般要求天线具有较大的波瓣宽度和较好的低仰角增益.研究设计了一种具有良好低仰角增益的宽波束圆极化四臂螺旋天线,该天线在上半空间的增益分布十分均匀,10°仰角的增益相对峰值增益下降不超过3 dB.为了改善天线的轴比性能,文章提出了一种四臂等幅馈电、相位依次相差90°的天线方案,仿真结果表明,这种天线的增益特性和轴比特性都得到了较大的改善. 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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该文设计了一种新颖的宽带圆极化单极子天线,该天线采用微带馈电模式。天线由C型贴片和改进的地板组成,整个天线尺寸仅为25×25×1 mm3。通过在C型贴片上切角和在地板上增加三角形微扰结构,可以有效增加天线的阻抗带宽和轴比带宽。该文给出了天线的设计流程,从表面电流分布分析了圆极化天线的工作机理。加工了天线实物,并对其进行了测量。仿真和实测结果表明天线具有超宽的阻抗带宽和轴比带宽。天线的工作频带为4.35~12 GHz(相对带宽为93.6%),3 dB轴比带宽为4.15~11.8 GHz(相对带宽为95.9%)。测量了天线的辐射性能和增益特性,实测结果与仿真结果吻合较好,证明了该天线的有效性。该天线可以应用于超宽带无线通信系统和卫星通信系统中。 相似文献
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随着现代无线通信系统的发展,对天线也提出了一些特定的更高的要求。设计了一种S频段宽波束圆极化微带天线,以满足系统对天线宽波束辐射的要求;在天线的辐射贴片上附加寄生贴片以展宽天线带宽,并利用金属化过孔以实现单边短路,达到天线小型化设计的目的;利用旋转结构结合多点馈电技术以获得微带天线宽波束圆极化辐射。通过理论分析并利用三维电磁仿真软件HFSS对天线进行了仿真设计和实验,仿真结果与测试结果吻合良好。 相似文献
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提出一种新型的小型宽波束圆极化天线及馈电网络。天线由四个独立辐射单元顺次旋转90°组合而成,辐射单元采用平面印刷电路工艺加工、使用容性加载及短路点调配方式实现小型化;使用变形的分支线定向耦合器与移相电路组合,实现具有功率分配与正交移相功能的馈电网络。经理论分析、软件仿真及实测表明:天线高度小于0.12λ,3 dB波束宽度大于120°,6 dB轴比波束宽度大于180°,辐射特性在15%相对带宽内稳定;天线的驻波比(VSWR)小于2.0的相对带宽为16%。该小型宽波束圆极化天线采用印刷电路工艺制作,结构紧凑,加工成本低、精度高,易于与微波电路集成,其结构也适用于S波段以上更高频段。 相似文献
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Kajfez D. Harrison M. Sterling C. 《Antennas and Propagation, IEEE Transactions on》1974,22(5):647-650
The feasibility of using the tripole antenna for circular polarization was experimentally investigated. Measured impedance and radiation patterns were in agreement with the predictions from the infinitesimal tripole model. For simultaneous operation in both senses of circular polarization the tripole antenna must be fed by a special separator network, preferably of the nonreciprocal type. 相似文献
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Rectangular microstrip antenna for circular polarization 总被引:1,自引:0,他引:1
Richmond's reaction integral equation method is used to design a rectangular microstrip patch to produce a circular polarization. A rectangular patch with the aspect ratioa = W_{x}/W_{y} , in the range 1.015- 1.02 and corner fed by a microstrip line, produces circular polarization. For substrate with thicknessd = 0.16 cm,a = 1.017 the nearly square patch gives maximum bandwidth. 相似文献
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A new printed wire antenna with circular polarization properties is presented. The geometry of the printed wire which takes the form of a figure-of-eight has a total length of 1.3/spl lambda//sub o/ and serves as a nonresonant traveling-wave antenna. It is shown that a 3-dB axial ratio bandwidth of 15% can be achieved. The half-power and 3-dB axial ratio beamwidth is approximately /spl plusmn/45/spl deg/, while its gain is of the order of 6.5 dB. 相似文献
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Printed ring slot antenna for circular polarization 总被引:3,自引:0,他引:3
Kin-Lu Wong Chien-Chin Huang Wen-Shan Chen 《Antennas and Propagation, IEEE Transactions on》2002,50(1):75-77
A new design of a microstrip-line-fed circularly polarized printed ring slot antenna is proposed. Circular polarization (CP) radiation of the proposed design is achieved by introducing proper asymmetry in the ring slot structure and feeding the ring slot using a microstrip line at 45° from the introduced asymmetry. The asymmetry introduced in the proposed design is a meandered-slot section and the proposed CP design can be applied to printed square and annular ring slot antennas. Prototypes of the proposed design have been implemented. Experimental results show that good CP radiation performances are obtained and the 3 dB axial-ratio CP bandwidths obtained for the square and annular ring slot antennas are about 4.3% and 3.5%, respectively 相似文献
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A wider band microstrip antenna for circular polarization 总被引:1,自引:0,他引:1
Circular polarization is achieved by separating two degenerate orthogonal modes in an annular ring patch antenna, by using an ear at the outer periphery. The analysis of such a structure is performed by using the generalized transmission line model. It is found theoretically that this structure can be used to generate circular polarization over a wider frequency range than other structures. An annular ring is designed and its performance is evaluated. Good agreement between the theory and the experiment is obtained. It is also found that the axial ratio bandwidth is higher for the TM12 mode than the TM32 mode of operation in an annular ring antenna 相似文献
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Cross-slot-coupled microstrip antenna and dielectric resonatorantenna for circular polarization 总被引:1,自引:0,他引:1
Chih-Yu Huang Jian-Yi Wu Kin-Lu Wong 《Antennas and Propagation, IEEE Transactions on》1999,47(4):605-609
Circular polarization (CP) design of microstrip antennas and dielectric resonator (DR) antennas through a cross slot of unequal slot lengths in the ground plane of a microstrip line is demonstrated. The proposed CP design is achieved by choosing a suitable size of the coupling cross slot, which results in the excitation of two near-degenerate orthogonal modes of near-equal amplitudes and 90° phase difference. This CP design can be applied to both configurations of microstrip antennas and DR antennas and has the advantages of easy fine-tuning and less sensitivity to the manufacturing tolerances, as compared to their respective conventional single-feed CP designs. For the proposed design applied to a low-profile circular disk DR antenna of very high permittivity studied here, a large CP bandwidth, determined from 3-dB axial ratio, as high as 3.91% is also obtained. Details of the proposed antenna designs are described, and experimental results of the CP performance are presented and discussed 相似文献
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针对宽波束天线在车载雷达中的应用,突破角雷达方位面3 dB波束宽度的限制,实现微带阵列天线在水平面的宽波束覆盖,设计了一款1×10串馈微带双层结构天线。线阵单元采用道尔夫-切比雪夫(Dolf-Chebyshev)综合法电流分布来达到降低天线俯仰面副瓣的效果,在串馈阵列上方加载寄生贴片和介质基板拓展天线方位面的3 dB波束宽度。分析了双层天线展宽波束的原理,加工并实测了双层宽波束天线,其方位面的3 dB波束宽度为134.6°,增益达到10.6 dB,副瓣电平为-19.8 dB,可以满足车载角雷达天线需求。 相似文献
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A new design of a circularly polarized square-ring slot antenna is proposed. The circular polarization is achieved by a series microstrip-line-feed configuration coupling to two orthogonal sides of the square-ring slot. A parametric study is conducted using a commercial simulation software based on the method of moments, and the design procedure is established. The required ground-plane size of the proposed design for a given frequency is also indicated. Three antenna prototypes respectively operated at distinct frequency bands are constructed and measured for providing the simulation validation. Experimental results show that the proposed antenna has good circularly polarized radiations and the 3 dB axial-ratio bandwidth is more than 6%. 相似文献