大学物理 ›› 2018, Vol. 37 ›› Issue (1): 59-63.doi: 10.16854 /j.cnki.1000-0712.170094

• 物理实验 • 上一篇    下一篇

非正弦信号的有效带宽与能量截断误差分析

陈国杰,陈奎,成建群,谢嘉宁,陈伟成   

  1. 佛山科学技术学院物理与光电工程学院,广东佛山528000
  • 收稿日期:2017-03-03 修回日期:2017-05-12 出版日期:2018-01-20 发布日期:2018-01-20
  • 作者简介:陈国杰( 1965—) ,男,湖南祁东人,佛山科学技术学院理学院教授,博士,主要从事物理电子教学与研
  • 基金资助:
    “大学物理实验”广东省教学团队,广东省研究生教育创新计划项目资助.

Energy effective bandwidth of non-sinusoidal wave and its energy truncation error

CHEN Guo-jie,CHEN Kui,CHENG Jian-qun,XIE Jia-ning,CHEN Wei-cheng   

  1. School of Physics and Optoelectronic Engineering,Foshan University,Foshan,Guangdong 528000,China
  • Received:2017-03-03 Revised:2017-05-12 Online:2018-01-20 Published:2018-01-20

摘要: 提出了一种用有效能量评估有效带宽截断误差的方法.采用梯形波作为信号模型,通过matlab 计算,分析了非正弦信号有效带宽0.35 /tr的能量截断误差和物理含义; 阐述了理想矩形信号常用1 /τ 带宽的不足,提出了其修正公式.结果表明,有效带宽0.35 /tr的能量截断误差小于3%; 带宽1 /τ 的能量截断误差高达10%,故修正为3 /τ.信道和示波器的带宽应大于信号的有效带宽.

关键词: 非正弦波, 傅里叶级数, 有效带宽, 截断误差

Abstract: A method of evaluating the truncation error of the effective bandwidth is proposed. Taking a trapezoidal wave as a signal mode and using MATLAB calculations,the energy truncation error and physical nature of the effective bandwidth formula 0.35 /tr for a non-sinusoidal wave are analyzed,and the disadvantages of the bandwidth formula 1 /τ for an ideal rectangular wave are explained. The analysis results show that the truncation error of the effective bandwidth formula 0.35 /tr is less than 3%,and the truncation error of the formula 1 /τ is less than 10%. Therefore,the effective bandwidth formula for the ideal rectangular wave is modified to be 3 /τ. The bandwidths of a signal channel and an oscilloscope should be chosen greater than the effective bandwidths of the measured signals.

Key words: non-sinusoidal wave, Fourier series, effective bandwidth, truncation error