design a highpass filter in matlab

To design a highpass filter in MATLAB, you can use the designfilt() function. This function allows you to design various types of filters, including highpass filters.

Here is an example code to design a highpass filter with a cutoff frequency of 100 Hz:

main.m
% Define filter specifications
Fs = 1000;           % Sampling frequency
Fpass = 100;         % Passband frequency
Fstop = 50;          % Stopband frequency
Apass = 0.5;         % Passband ripple (dB)
Astop = 50;          % Stopband attenuation (dB)

% Design highpass filter
highpass_filter = designfilt('highpassfir', 'FilterOrder', 50, 'PassbandFrequency', Fpass, ...
    'StopbandFrequency', Fstop, 'PassbandRipple', Apass, 'StopbandAttenuation', Astop, ...
    'SampleRate', Fs);

% Visualize filter response
fvtool(highpass_filter);    % interactive filter visualization tool
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The code above first defines the filter specifications including the sampling frequency, passband frequency, stopband frequency, passband ripple, and stopband attenuation.

Then designfilt() function is used to design a highpass FIR filter with a filter order of 50, a passband frequency of 100 Hz, a stopband frequency of 50 Hz, a passband ripple of 0.5 dB, and a stopband attenuation of 50 dB.

Finally, the frequency response of the filter is visualized using the fvtool() function.

You can modify the specifications in the code to design a highpass filter according to your specific requirements.