吉首大学学报(自然科学版) ›› 2021, Vol. 42 ›› Issue (1): 49-53.DOI: 10.13438/j.cnki.jdzk.2021.01.008

• 计算机与电子 • 上一篇    下一篇

五阶IIR低通数字滤波器的性能

周旋,邬云文   

  1. (1.吉首大学信息科学与工程学院,湖南 吉首 416000;2.湖南省普通高校近地空间电磁环境监测与建模重点实验室,湖南 长沙 410114;3.吉首大学物理与机电工程学院,湖南 吉首 416000)
  • 出版日期:2021-01-25 发布日期:2021-02-05
  • 作者简介:周旋(1990—),女,湖南澧县人,吉首大学信息工程学院助教,硕士,主要从事电路与系统研究;邬云文(1965—),女,湖南龙山人,吉首大学物理与机电工程学院教授,硕士,主要从事信息与通信系统研究.
  • 基金资助:
    国家自然科学基金资助项目(61966014,61865006);湖南省教育厅科学研究项目(20C1534,18C0588);湖南省普通高校重点实验室开放项目(N201901);吉首大学教改项目(2020JSUJGB27);吉首大学实验教学改革研究项目(2019SYJG002)

Performance Analysis of Fifth Order IIR Digital Low-Pass Filter

ZHOU Xuan, WU Yunwen   

  1. (1. College of Information Science and Engineering, Jishou University, Jishou 416000, Hunan China;2. Hunan Province Higher Education Key Laboratory of Monitoring and Modeling of the Near Earth Electromagnetic Environment, Changsha 410114, China; 3.College of Physics and Electromechanical Engineering, Jishou University, Jishou 416000,Hunan China)
  • Online:2021-01-25 Published:2021-02-05

摘要:利用Matlab软件平台,以双线性变换法设计的五阶IIR数字低通滤波器为例,推导其阶数与通带最大衰减、阻带最小衰减、通带边界角频率、阻带边界角频率的关系式,并结合系统函数、Z域分析等理论,以及仿真结果对滤波器的过渡带和阻带进行深入分析.结果表明,五阶IIR数字低通滤波器是一个稳定的系统,相位在通带和阻带内出现延迟.当频率为0.25π rad/s时,相位状态存在反向突变,传输的信号包络崩溃并进入过渡带,此时,相位呈现超前状态;当阻带内幅度响应衰减为0后,系统信号仍存在相位变化,且有微量信号通过.

关键词: 数字滤波器, Matlab, 反相突变, 信号处理, IIR

Abstract: MATLAB software platform is used to study the performance of the fifth order IIR digital low-pass filter designed by bilinear transformation method. The relationship between the order of digital filter and the maximum attenuation of passband, the minimum attenuation of stopband, the corner frequency of passband boundary and the corner frequency of stopband boundary is derived. At the same time, the transition band and stop band of the filter are further analyzed by combining the system function, z-domain analysis and simulation results. Analysis indicates that: the fifth order IIR digital low-pass filter is a stable system, the phase presents delay in the passband and stopband. When the frequency is 0.25π rad/s, the phase state has reverse mutation, and the transmitted signal envelope collapses and enters the transition band. At this time, the phase presents a leading state. When the amplitude response in the stopband decays to 0, the system signal still has phase change, and  there is still signal in this frequency band.

Key words: digital filter, Matlab, reverse mutation, signal processing, IIR

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