全向天线的设计

全向天线的设计(论文11000字)
摘 要：本文设计了一款小型化宽带平面全向天线，该平面全向天线的正面金属层由圆形单极子贴片、Wilkinson功分器、渐变型微带馈线和矩形微带馈线并形而成，呈棒棒糖状；背面的金属接地板为瓶状结构，主要由两个矩形贴片和一个半椭圆型贴片组成。通过在天线微带馈线顶端引入Wilkinson功分器来改善方向图不圆度, 实现较好地全向辐射；天线背面采用瓶状结构的金属接地板，达到了良好的阻抗匹配效果。仿真结果表明：该平面全向天线驻波比小于2的阻抗带宽为4GHz，中心频点5.4GHz处的增益为3.52dB，天线辐射方向的不圆度小于2.88dB，整个阻抗带宽内的增益为2.4-3.52dB。该天线可在厚度为0.812mm介电常数为3.55的Rogers 4003C板材上加工实现，整体结构简单，制作方便，成本低。因此，该全向天线可广泛应用于宽带天线全向天线和阵列天线等领域，具有广阔的应用前景。
关键词：全向天线;小型化;宽带;不圆度;Wilkinson功分器
 
Simulation design of omnidirectional antenna
Abstract：A miniaturized wideband planar omnidirectional antenna is designed in this paper, the front plane of metal layer is composed of a circular monopole antenna patch, Wilkinson power divider, tapered microstrip feeder and rectangular microstrip feeder; the metal ground layer is bottle shaped structure, which is mainly composed of two rectangular patch and a semi-ellipse patch. By introducing a Wilkinson power divider at the microstrip feeder to improve the unroundness of pattern, which achieves better omnidirectional radiation; a metal ground floor of bottle shaped structure is printed on the back of this antenna to achieve a good impedance matching effect. The results show that the planar omnidirectional antenna has impedance bandwidth of 4GHz, the gain at the center frequency of 5.4GHz is 3.52dB, the unroundness of radiation pattern is less than 3.50dB, and the gain at the whole impedance bandwidth is 2.4-3.35dB. The antenna in the thickness of 0.812mm, the dielectric constant is 3.55 Rogers4003C sheet processing, has the advantages of simple integral structure, convenient manufacture, low cost. Therefore, the omnidirectional antenna can be widely used in the field of broadband antenna, MIMO antenna and array antenna, and has wide application prospect.
Key words：omnidirectional antenna；miniaturization；broadband；unroundness；Wilkinson power divider.

目 录
1 引言    5
1.1 全向天线的研究意义    5
1.2 全向天线的研究现状    5
1.3 研究内容    6
2 天线的数值分析方法    6
2.1 有限元法    7
2.2 时域有限差分法    8
2.3 矩量法    8
3 全向天线的仿真与设计    9
3.1 常用微带天线结构介绍    9
3.2 天线结构    10
3.3 天线各参数的优化    12
3.3 本章小结    16
4 全向天线的仿真结果分析    16
4.1全向天线的仿真结果分析    16
4.2平面全向天线的PCB版图绘制    19
4.3本章小结    20
5总结    20
参考文献    21
致谢    23