【作者】 李鹏；

【导师】 于双和； 王大寿；

【作者基本信息】 大连海事大学 ， 电路与系统， 2006， 硕士

【摘要】 在高速的数字通信中,一般会用到大量的滤波器,如果滤波器的相频特性不好,信号通过时会产生角度偏移,降低信息传输的可靠性,导致误码率提高。为提高无源网络的相频特性,本文提出了用电路优化技术代替传统的网络综合理论的滤波器设计方法,目的是利用优化技术的灵活性解决当前通信技术发展非常需要的、而利用传统方法难以实现的、高性能的线性相位滤波器设计问题。 本课题所设计的无源线性相位滤波器是为中国电子科技集团第十研究所研制的,主要用于航空航天及远程导弹的测控系统,它是对滤波器的幅频特性和相频特性同时进行优化的,然而相频特性和幅频特性之间又存在着矛盾,如何在通带内得到较好的群时延特性,同时在阻带获得较大的衰减就是本课题所研究的目的。 群时延是滤波器中最常用的参数,它是相位对频率的导数,因此要使群时延特性平坦,就要使相频特性逼近一条直线。本文提出了优化无源网络元件参数,使其频率-相位曲线逼近一条理想直线的方法。该方法首先在频率-相位坐标上确定一条直线,作为理想曲线的初值。然后优化元件参数,使相位曲线向这条直线逼近,得出新的元件值。再由新的元件值得到新的理想相位曲线。重复上面的过程,直到获得最佳元件参数为止。 从例题可以看出,用本文的方法设计的滤波器,在幅频和相频特性上都优于传统的网络综合方法。更多还原

【Abstract】 In the high-speed digital communications, lots of filters are used, if filter’s phase response characteristic is not matching, it will reduce the reliability of information transmission and increase code error rate. In order to advance phase response characteristic of passive network, this filter puts forward means of settling issues that is applying circuits optimizing technology instead of network synthesizes theory to solve matching problem .The aim is to solve the design of high-powered special filter and Matching network by using the flexible attribute of optimizing technology. The design is needful for the development of communicational technology and difficult to realize by adopting traditional method.The passive linear phase filter is designed for the tenth research institute of China Electronics Technology Group Corporation, it uses for measure and control system of aeronautics and long-distance guided missile, which optimizes both the amplitude response characteristic and the phase response characteristic of the passive network at the same time based on the method of traditional network’s integrated design. The key aim of this paper is how to obtain flat group delay characteristic at pass band and bigger decibel at prevent band.Group delay characteristic is used frequently when designing filters. Because it is phase differential to frequency, if group delay obtain flat curve, that phase curve is approached to a beeline. The paper proposes to a method that how to adjust parameters of components to make the curve of phase-frequency approach a perfect beeline. First, a beeline is made with lease two-multiplied at phase-frequency coordinates. This beeline is believed as phase perfect curve. Put phase curve close in upon this beeline. New component value is gained. The extent of close in upon is respected to precision of optimized program. New phase curve is gained according to new component value. A new beeline is made as new phase perfect curve. Repeat this process till the extent of close in upon accord with requested condition.The result of example shows the method is better than those which are designed by custom network integrated design method.更多还原