一种线性相位LC滤波器的设计  

Design of a Linear Phase LC Filter

作　　者：魏强[1] WEI Qiang(The 26th Research Institute of China Electronics Technology Group Corporation,Chongqing 400060,China)

机构地区：[1]中国电子科技集团公司第二十六研究所

出　　处：《压电与声光》2019年第5期621-626,共6页Piezoelectrics & Acoustooptics

摘　　要：为解决滤波器带外抑制和通带内相位波动之间的矛盾,该文介绍了一种线性相位LC滤波器的设计方法,通过对滤波器传输零点特性进行分析,根据指标要求灵活设计电路拓扑结构和零点位置,采用内、外均衡电路级联网络两种方法,来实现具有高矩形、线性相位特性的滤波器。设计了中心频率21.4 MHz、0.5 dB带宽大于10 MHz、矩形系数(45 dB/0.5 dB)小于2、带内相位波动绝对值小于5°和中心频率1 300 MHz、1 dB带宽大于200 MHz、矩形系数(35 dB/1 dB)小于2、带内相位波动绝对值小于5°两款滤波器。该方法工程实用化强,便于调试和制作,可应用于幅相特性要求高的微波系统中,提高了系统性能指标。In order to solve the contradiction between the out-of-band rejection and the linear phase ripple in the pass-band,a design method of linear phase LC filter is introduced in this paper.Based on the analysis of the transmission zeros of the filter,the circuit topology and zeros position are designed flexiblyaccording to the requirements of the specifications.The filter with high rectangular coefficient and linear phase characteristics is realized by using the cascade network of internal and external equalization circuits.Two filters with a center frequency of 21.4 MHz,a 0.5 dB bandwidth of greater than 10 MHz,a rectangular coefficient(45 dB/0.5 dB)of less than 2,the absolute value of the in-band phase ripple of less than 5°and a central frequency of 1 300 MHz,a 1 dB bandwidth of greater than 200 MHz,a rectangular coefficient(35 dB/1 dB)of less than 2,and the absolute value of the in-band phase ripple of less than 5°are designed.The proposed method is practical in engineering,easy to debug and manufacture,and can be applied to microwave systems with high amplitude and phase characteristics,which can improve the system performance.

关 键 词：线性相位 传输零点 零点放置 均衡器 

分 类 号：TN384[电子电信—物理电子学]