FFT Magnitude and Phase Spectrum using MATLAB (2024)

clc;
clear;
close all;

% Parameters
fs = 100; % Sampling frequency
t = 0:1/fs:1-1/fs; % Time vector

% Signal definition
x = cos(2*pi*15*t - pi/4) - sin(2*pi*40*t);

% Compute Fourier Transform
y = fft(x);
z = fftshift(y);

% Frequency vector
ly = length(y);
f = (-ly/2:ly/2-1)/ly*fs;

% Compute phase
phase = angle(z);

% Plot magnitude of the Fourier Transform
figure;
subplot(2, 1, 1);
stem(f, abs(z), 'b');
xlabel('Frequency (Hz)');
ylabel('|y|');
title('Magnitude of Fourier Transform');
grid on;

% Plot phase of the Fourier Transform
subplot(2, 1, 2);
stem(f, phase, 'b');
xlabel('Frequency (Hz)');
ylabel('Phase (radians)');
title('Phase of Fourier Transform');
grid on;

Parent Topics

Fourier Series and Fourier TransformFourier TransformMATLAB

Fourier Series and Fourier TransformFourier TransformMATLAB

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