基于DBR滤波器的微带双工器的研究

【作者】 李娜；

【导师】 吴文； 陈春红；

【作者基本信息】 南京理工大学 ， 通信与信息系统， 2010， 硕士

【摘要】 随着卫星通信系统性能要求的提高和对射频电路小型化和集成化的要求,设计性能良好的微带滤波器和双工器越来越受到大家的重视。由于基于双重行为谐振器(DBR)的滤波器可以独立控制衰减点,具有插入损耗小、阻带衰减好的优点,因此对基于DBR的微带滤波器和双工器的研究具有重要的学术价值和应用前景。缺陷地结构(DGS)可在一定的频率范围形成阻带、易于定义单元结构,由螺旋紧致谐振单元结构(SCMRC)和λ/4微带线组成的双频带分支线结构(DBS)可提供一个易于控制的双频阻带,由于两者都具有慢波特性,尺寸都相对较小,因此本文在基于DBR的滤波器及双工器的基础上分别加进了DGS结构和DBS结构,进行了研究制作。本文首先对滤波器及双工器的基本理论和实现方法进行了简单阐述。然后以C波段的卫星通信系统为应用背景,根据基于分支线形式的DBR的滤波器设计方法设计了C波段的卫星通信微带双工器。接着在对哑铃型缺陷地结构(DB-DGS)和螺旋型缺陷地结构(SP-DGS)的有关参数进行了分析研究,在此基础上,设计了基于DGS的准椭圆低通滤波器。并将此低通滤波器加入微带双工器中以改善阻带性能,测试结果表明,双工器的插入损耗小于1.4dB,隔离度优于64dB。同时,分析研究了DBS结构的相关参数,设计了C波段DBS结构,将其加入双工器中。测试结果表明,双工器中的接收端滤波器的插入损耗小于1dB,发射端滤波器的插入损耗小于1.3dB,整个双工器的隔离度优于62dB,验证了方法的可行性。最后对全文的工作进行了总结,提出了下一步的研究方向。更多还原

【Abstract】 With the satellite communication system demands increase and miniaturization of RF circuits and integration requirements, and the performance of microstrip filters and diplexers got much attention. As the filter based on dual behavior resonator(DBR) can independently control attenuation points, with the insertion loss and good stopband attenuation of the advantages, the microstrip filters and diplexers based on DBR has important academic value and prospects. Defected Ground Structure(DGS) can be formed at a certain stop-band frequency range, easy to define the structure of the unit structure. Dual-band Stub (DBS) structure which formed by Spiral Compact Microstrip Resonating Cell (SCMRC) and microstrip lines, provide an easy-to-control dual-stopband. Their size is relatively small due to slow-wave characteristics. This article in the filter and diplexer based on the DBR structure were added to the DGS and DBS structure was studied and made.Firstly, the basic theory and implementation methods of filter and diplexer are described briefly in this article. And then to C-band satellite communications system for the application background, according to the design methods of the filter based on DBR of the open stub,we design the C-band satellite communications microstrip diplexer.Then on the analysis of the relevant parameters of DB-DGS and SP-DGS, we design a quasi-elliptic low pass filter based on the DGS. Join this low-pass filter in microstrip diplexer in order to improve performance. The test results show that the diplexer insertion loss is less than 1.4dB, isolation is better than 64dB.Meanwhile, the analysis of the relevant parameters of the DBS structure, we design a DBS structure and add it to the diplexer. Physical test results show that the receiver filter insertion loss is less than 1dB, the transmitter filter insertion loss is less than 1.3dB, the whole diplexer isolation is better than 62dB to verify the feasibility of the method.Finally, the paper summarizes the work of proposed future research directions.更多还原