若干新型平面天线研究

【作者】 郑莹；

【导师】 朱守正；

【作者基本信息】 华东师范大学 ， 无线电物理， 2004， 硕士

【摘要】 近些年来，天线作为通信、雷达、制导等无线电应用系统的关键设备在功能、设计及制造工艺上都发生了巨大变化。尤其平面天线以其体积小、重量轻、低剖面，能与载体共形、易集成、便于匹配等优点获得了更多青睐。本文根据一些特定的需求和应用，研制了三个颇有特色的平面天线： MEMS毫米波相控阵技术是当前微波、毫米波系统方面的最新技术之一。本文研制的35GHz毫米波微机械孔耦合微带贴片天线单元主要用于毫米波相控阵天线。由于采用了孔耦合微带贴片天线形式，它既解决了与相控阵天线的MEMS移相器部分的集成问题，又能够分隔天线与馈电网络之间的电磁干扰，仿真结果显示在35GHz时，天线的输入端反射系数S11=-48dB，-10dB带宽约为2GHz(VSWR＜2)，增益约G=4dB。并且根据仿真结果，进行了制版和实际制作。 在对微波X频段光子晶体微带缝隙天线研究过程当中，研制了一种新颖的微波X频段光子晶体结构，带隙内衰减可以达到-47dB，带隙外损耗小于等于2dB，带隙宽度可以达到6GHz，相对宽度可达55％，具有超宽带的特性。将这种光子晶体结构应用于微带缝隙天线，从测试结果看出，天线增益明显提高约有1dB。 本文中所研制的超低剖面双频段无线局域网轻便小型平面倒F天线，高度仅有4.5mm，对于2.45GHz来说仅为0.04λ，当天线水平放置时，在高低两个频段内都实现水平面全向性辐射，辐射电磁波E矢量以垂直极化为主(基本与接地板垂直)。 毫米波雷达、卫星通信和移动通信的蓬勃发展使得微波平面天线技术研究成为当今天线研究中的热点。研究新型的平面天线，采用各种技术进一步缩小平面天线尺寸、改善平面天线的性能，为将来天线与电路的集成做一些探索性的研究是很有意义的。在无线通信发展如此迅速的现代社会，平面天线的研究进展必然会成为推动信息时代进步的巨大动力。更多还原

【Abstract】 Antenna is the crucial equipment of the radio application systems. Planar antenna has small size, light weight and low profile. Because of all those characteristics, the planar antenna is easily to be integrated with circuits. In recent yeas, with the great development of manufacture workmanship of the antenna, the planar antenna has become a new star in many applications. In this thesis, three different types of planar antennas are designed and fabricated.A 35GHz H-shaped aperture-coupled microstrip antenna for the element of MEMS millimeter phased antenna arrays is presented in chapter 2. In order to integrate the antenna element with the MEMS phase shifter, multilayered structure is applied in the design. It allows for the electromagnetic separation of the radiation of the microstrip patch and the feed network with the use of the ground plane. The simulated results show that the antenna has rather high gain and wide bandwidth. At 35GHz, the S11 of antenna is -48dB,and the bandwith (S111<-10dB) is 2GHz, the gain is about 4dB. A novel broad band PBG structure for microstrip line has been proposed in chapter 3. The bandwidth of the stop band is about 6GHz. The relative bandwidth is over 55% and the return loss in the band of interest is at least -47dB dB. The experimental and simulated results are in good agreement. It was applied to a microstrip slot antenna. The experiment result shows that the antenna gain is improved about 1dBA uniquely S-shaped compact dual-band planar inverted-F antenna is proposed for WLAN applications in chapter 4. The designed antenna can work in both 2.45GHz and 5GHz frequency bands. Although the height of the antenna is reduced to 4 percents of working wavelength (2.25GHz), the patterns of the antenna in both low- and high-frequency bands are essentially omni-directional by optimum tuning. Moreover, the antenna keeps the vertical polarization in respect to the antenna surface.更多还原