零腔滤波器综合与设计

发布时间：2018-04-12 06:22

本文选题：抑制谐振器 + 传输零点　；参考：《电子科技大学》2015年硕士论文

【摘要】：随着近年来无线通讯技术的不断发展,通信频谱资源变得日益紧张,分配到各类通信系统中的可用频率间隔越来越窄,对滤波器的性能指标提出了很高的要求。特别是对于通讯基站双工器和多工器中使用的滤波器,除了要求具有小尺寸、高选择性、低插损外,还对带外抑制提出了十分严苛的要求。要提高滤波器的带外抑制,一般的方法是在通带外增加传输零点。对于广义切比雪夫滤波器而言,通常是通过引入非相邻谐振腔之间的交叉耦合来实现传输零点。然而,在高功率环境下或者高频段,产生传输零点的容性交叉耦合为负值,很难用实际的结构实现,如双工器中高频端产生传输零点的交叉耦合。为了避免交叉耦合的这种缺点,可以使用抑制谐振器产生滤波器的传输零点。抑制谐振器的谐振频率刚好对应传输零点的位置,所以叫做零腔,这种滤波器也叫做零腔滤波器。零腔滤波器的各个谐振器线性排列,而且传输零点只由抑制谐振器和耦合结构控制,所以它的设计非常灵活。本文的主要工作是研究零腔滤波器的综合过程,即著名的极点提取技术。同时,根据综合的结果进行介质双工器的仿真设计,总结这类滤波器或双工器设计的一般方法。主要工作内容概括如下:1.研究了广义切比雪夫滤波器多项式的综合,并在特征多项式的基础上,利用开路阻抗和短路导纳计算出初始耦合矩阵,再用矩阵变换对耦合矩阵进行了不同拓扑结构的化简。2.研究了零腔滤波器的极点提取技术,分别用传输矩阵提取法和输入输出导纳提取法对电路参数元件进行了提取,并综合出零腔滤波器的耦合矩阵。3.根据极点提取技术,设计了一个零腔结构的介质波导双工器,并提出了两种介质波导同轴连接结构。最后,给出了利用Y矩阵法和群时延法设计滤波器或双工器的一般方法。4.基于MATLAB编写了两个零腔滤波器综合的软件,一个是根据滤波器综合理论和极点提取法编写的,另一个则是根据耦合矩阵的优化理论编写的。经过验证,这两个软件均具有很好的工程应用价值。
[Abstract]:With the development of wireless communication technology in recent years, the spectrum resources of communication become increasingly tight, and the available frequency intervals allocated to various communication systems become narrower and narrower.Especially for the filter used in the communication base station duplex and multiplexer, it is required to have small size, high selectivity and low insertion loss, but also a very strict requirement for out-of-band suppression.In order to improve the out-band suppression of the filter, the general method is to increase the transmission zeros outside the passband.For generalized Chebyshev filters transmission zeros are usually achieved by introducing cross-coupling between nonadjacent resonators.However, in high power environment or high frequency band, the capacitive cross-coupling of transmission zero is negative, so it is difficult to realize it with practical structure, such as cross coupling of transmission zero in high frequency end of duplex.To avoid this drawback of cross-coupling, suppression resonators can be used to generate filter transmission zeros.The resonant frequency of the suppression resonator corresponds to the position of the transmission zero, so it is called a zero cavity, and this kind of filter is also called a zero cavity filter.Every resonator of the zero-cavity filter is linearly arranged and the transmission zeros are controlled only by the suppression resonator and the coupling structure, so the design of the zero-cavity filter is very flexible.The main work of this paper is to study the synthesis process of zero-cavity filter, that is, the famous pole extraction technique.At the same time, according to the synthetic results, the simulation design of dielectric duplex is carried out, and the general design method of this kind of filter or duplex is summarized.The main work is summarized as follows: 1: 1.The synthesis of generalized Chebyshev filter polynomial is studied. Based on the characteristic polynomial, the initial coupling matrix is calculated by using open circuit impedance and short circuit admittance, and then the coupling matrix is simplified with different topological structure by matrix transformation.The pole extraction technique of zero cavity filter is studied. The circuit parameters are extracted by transfer matrix extraction method and input and output admittance extraction method, and the coupling matrix. 3 of zero cavity filter is synthesized.According to pole extraction technique, a dielectric waveguide duplex with zero cavity structure is designed, and two kinds of dielectric waveguide coaxial connection structures are proposed.Finally, a general method of designing filter or duplexer using Y matrix method and group delay method is given.Two zero-cavity filter synthesis software based on MATLAB are developed, one is based on filter synthesis theory and pole extraction method, the other is based on the optimization theory of coupling matrix.It is proved that the two software have good engineering application value.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN713

【相似文献】