function Hd = HR_BPF20 %HR_BPF20 Returns a discrete-time filter object. % MATLAB Code % Generated by MATLAB(R) 9.5 and Signal Processing Toolbox 8.1. % Generated on: 07-Apr-2021 20:21:33 % Butterworth Bandpass filter designed using FDESIGN.BANDPASS. % All frequency values are in Hz. Fs = 20; % Sampling Frequency N = 8; % Order Fc1 = 0.9; % First Cutoff Frequency Fc2 = 2; % Second Cutoff Frequency % Construct an FDESIGN object and call its BUTTER method. h = fdesign.bandpass('N,F3dB1,F3dB2', N, Fc1, Fc2, Fs); Hd = design(h, 'butter'); % [EOF]

这段代码是用于生成一个离散时间的Butterworth带通滤波器对象。该滤波器可以通过调整参数来滤除信号中的特定频率成分。其中，Fs为采样率，N为滤波器阶数，Fc1和Fc2为带通滤波器的两个截止频率。该代码使用了Signal Processing Toolbox中的fdesign.bandpass函数和design函数来生成滤波器对象。