基于梳状基片集成波导的超宽带滤波器设计

发布时间：2018-06-03 20:53

本文选题：梳状基片集成波导 + 周期结构　；参考：《西安电子科技大学》2015年硕士论文

【摘要】：在无线通信系统的射频前端中,滤波器是其不可或缺的重要组成部分,其性能对整个射频系统的指标影响很大。超宽带通信系统拥有极宽的频谱宽度,并且具有功率损耗低、抗干扰性能高、保密性好、传输速率高等突出优势。因此,研制出应用于超宽带通信系统的高性能滤波器具有重要的意义。基片集成波导(substrate integrated waveguide,SIW)因其独特的结构优势和电磁特性,受到了广泛的关注。但是SIW结构由于金属通孔的存在,仍存在一些不足:金属通孔的加工误差较大;随着介质基板厚度的增加,打孔工艺困难;金属通孔使其上下金属层相互连接,导致该结构很难与有源芯片或有源电路集成等。近年来,一些学者致力于探索SIW的改进结构,而梳状基片集成波导(corrugated substrate integrated waveguide,CSIW)的提出,就是为了解决打孔结构带来的负面影响。CSIW结构可以看作是在SIW的结构基础上去掉打孔结构,然后在其上下金属层的两侧沿电磁波的传播方向设计出等间距排列的长度为四分之一波长的梳状微带线即可,简化了加工工艺。本文主要研究基于CSIW技术的超宽带带通滤波器的设计,将CSIW与缺陷地(DGS)结构、电磁带隙(EBG)结构相结合,分别设计了一种CSIW-DGS超宽带带通滤波器和CSIW-EBG超宽带带通滤波器,证实了CSIW用于超宽带滤波器设计的可行性。首先,介绍了CSIW的分析方法及设计原则;与SIW作对比,分析了CSIW的结构特点和电磁特性。其次,说明了本文中DGS与EBG的构成方法;给出了用于构成DGS与EBG的周期结构单元的等效电路模型;分析了各个参数对周期单元电磁特性的影响。最后,提出了一种性能良好的锥形CSIW-微带转换器,在此基础上,将具有复杂几何形状的二维周期结构分别蚀刻在CSIW的下表面金属层和上表面金属层,构造出DGS结构与EBG结构,设计出CSIW-DGS超宽带滤波器和CSIW-EBG超宽带滤波器;通过仿真优化,确定了两款滤波器的最终尺寸;根据设计结果对这两款滤波器进行了加工、测试,仿真结果与测试结果均表明本文设计的两款滤波器具有频带宽、损耗小、滤波性能好等特点。
[Abstract]:In the RF front-end of wireless communication system, filter is an indispensable part of the RF system, and its performance has a great impact on the whole RF system. UWB communication system has the advantages of wide spectrum width, low power loss, high anti-jamming performance, good confidentiality and high transmission rate. Therefore, it is of great significance to develop high performance filters for UWB communication systems. Substrate integrated waveguide SIW (substrate integrated waveguide SIW) has attracted wide attention due to its unique structural advantages and electromagnetic properties. However, due to the existence of metal through holes, SIW structure still has some shortcomings: the machining error of metal through holes is large; with the increase of the thickness of dielectric substrate, the drilling process is difficult; the metal through holes make the upper and lower metal layers connect to each other. As a result, it is difficult to integrate with active chip or active circuit. In recent years, some scholars have devoted themselves to exploring the improved structure of SIW, and the comb substrate integrated waveguide corrugated substrate integrated waveguide.CSIW can be regarded as removing the perforating structure from the structure of SIW. Then the comb-like microstrip line with equal distance of 1/4 wavelength arranged along the propagation direction of electromagnetic wave is designed on both sides of the upper and lower metal layer, which simplifies the processing technology. This paper mainly studies the design of ultra-wideband bandpass filter based on CSIW technology. Combining CSIW with defective CSIW structure and electromagnetic bandgap structure, a kind of CSIW-DGS ultra-wideband bandpass filter and CSIW-EBG ultra-wideband band-pass filter are designed, respectively. The feasibility of using CSIW to design UWB filter is confirmed. Firstly, the analysis method and design principle of CSIW are introduced, and compared with SIW, the structure and electromagnetic characteristics of CSIW are analyzed. Secondly, the construction method of DGS and EBG in this paper is explained, the equivalent circuit model of the periodic structure unit used to make up DGS and EBG is given, and the influence of each parameter on the electromagnetic characteristics of the periodic unit is analyzed. Finally, a conical CSIW- microstrip converter with good performance is proposed. On the basis of this, the two-dimensional periodic structure with complex geometry is etched on the lower surface metal layer and the upper surface metal layer of CSIW, respectively, and the DGS structure and the EBG structure are constructed. The CSIW-DGS UWB filter and the CSIW-EBG UWB filter are designed. The final size of the two filters is determined by simulation and optimization. The two filters are processed and tested according to the design results. The simulation results and the test results show that the two filters designed in this paper have the advantages of low frequency bandwidth, low loss and good filtering performance.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN713

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