人工电磁材料结构在微波天线中的应用研究

发布时间：2018-06-25 10:34

本文选题：电磁带隙 + Bowtie天线　；参考：《华北电力大学(北京)》2017年硕士论文

【摘要】：近年来,随着电子通信技术的高速发展,普通微波天线由于频带窄、增益低、体积大、性能差等一系列原因导致其应用范围受到严格限制,人工电磁材料结构的提出无疑是改善这一类问题的有效渠道。人工电磁材料结构中的电磁带隙结构(Electromagnetic Band-gap,EBG)是该类型结构中优点最为突出的,本文以电磁带隙结构的电磁理论分析了带隙结构特性和反射相位特性,并设计了多种形式的电磁带隙结构,同时将所设计的电磁带隙结构分别应用于Bowtie天线、波导缝隙天线和微带天线。首先,本文对mushroom-like EBG结构进行了分析,并得出其等效电路模型。利用不同的方法对该EBG结构的反射相位特性、表面波特性、带隙特性进行了深入的研究分析以及对比,同时研究了不同的结构参数对EBG结构特性的影响。然后,基于上述对电磁带隙结构的研究,设计了两种EBG结构单元,分析了两种EBG结构的带隙特性。同时也设计了微波天线中平面化程度较高的两类天线,分别是以普通微带天线为基础的阶梯型微带天线和全向性Bowtie天线,并加载了所设计的EBG结构,使得天线的辐射性能有了明显改善,并且有效的抑制表面波的传播,天线的增益、带相对宽均有所提高。Bowtie天线因是全向性天线,故其带宽、增益等相关特性较差,本文在此基础上将其修改为定向的Bowtie天线,其回波系数更优且增益增加约2.6dB。若将所设计的EBG结构加载到其中,则Bowtie天线的带宽将增加5%,增益增加约5dB。非对称脊波导缝隙天线相对于矩形波导缝隙天线而言,其尺寸仅为后者的46%,且相对带宽和增益均优于后者。加载复合型EBG结构之后,两类天线增益仅增加了0.14dB左右,但相对带宽却均增加了50%左右,并且具有良好的辐射方向图。
[Abstract]:In recent years, with the rapid development of electronic communication technology, the application of ordinary microwave antenna is severely restricted due to a series of reasons, such as narrow frequency band, low gain, large volume and poor performance. The structure of artificial electromagnetic material is undoubtedly an effective channel to improve this kind of problem. The electromagnetic band gap structure (EBG) in artificial electromagnetic material structure is the most outstanding in this type of structure. In this paper, the characteristics of band gap structure and reflected phase characteristics are analyzed based on the electromagnetic theory of electromagnetic band gap structure. At the same time, the designed electromagnetic band gap structure is applied to Bowtie antenna, waveguide slot antenna and microstrip antenna respectively. Firstly, the structure of mushroom-like EBG is analyzed and its equivalent circuit model is obtained. The reflection phase characteristics, surface wave characteristics and band gap characteristics of the EBG structure are studied and compared by different methods. The influence of different structural parameters on the structure characteristics of EBG is also studied. Then, based on the above research on the electromagnetic band gap structure, two kinds of EBG structure units are designed, and the band gap characteristics of the two kinds of EBG structures are analyzed. At the same time, two kinds of planar microstrip antennas are designed, one is the stepped microstrip antenna based on the ordinary microstrip antenna and the other is the omnidirectional Bowtie antenna, and the designed EBG structure is loaded. The radiation performance of the antenna is obviously improved, and the propagation of surface wave is effectively suppressed. The gain and the relative width of the antenna are improved. Because the antenna is a omnidirectional antenna, its bandwidth, gain and other related characteristics are poor. In this paper, the directional Bowtie antenna is modified, and the echo coefficient is better and the gain is increased by about 2.6 dB. If the designed EBG structure is loaded into it, the bandwidth and gain of the Bowtie antenna will increase by 5 dB and 5 dB respectively. The size of asymmetric ridge waveguide slot antenna is only 46 of that of rectangular waveguide slot antenna, and the relative bandwidth and gain are better than the latter. After the composite EBG structure is loaded, the gain of the two kinds of antennas increases only about 0.14 dB, but the relative bandwidth increases by about 50%, and has a good radiation pattern.
【学位授予单位】：华北电力大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN822

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