Howtosignalprocessing
- What is frequency resolution of FFT?
- What does magnitude of FFT represent?
- How is FFT magnitude calculated?
- How can frequency resolution of FFT be improved?
What is frequency resolution of FFT?
Frequency resolution is 10 Hz. The time waveform with length of 0.1 seconds is used for an FFT analysis. The spectrum values are obtained by performing FFT every 10 Hz. The spectrum cannot be obtained with the fractional frequency component values, such as 995, 1001 Hz.
What does magnitude of FFT represent?
Basically, the magnitude of the FFT is the amplitude of the associated frequency component. When you're using the FFT function in MATLAB you probably also want to use the fftshift function to center the results around 0.
How is FFT magnitude calculated?
1) Division by N: amplitude = abs(fft (signal)/N), where "N" is the signal length; 2) Multiplication by 2: amplitude = 2*abs(fft(signal)/N; 3) Division by N/2: amplitude: abs(fft (signal)./N/2);
How can frequency resolution of FFT be improved?
The most intuitive way to increase the frequency resolution of an FFT is to increase the size while keeping the sampling frequency constant. Doing this will increase the number of frequency bins that are created, decreasing the frequency difference between each.
