Amplitude of the fft is less than what is expected

1. What does the amplitude of an FFT mean?
2. Does amplitude affect FFT?
3. How do you normalize FFT amplitude?
4. What is the difference between amplitude and magnitude in FFT?

What does the amplitude of an FFT mean?

The amplitude of the FFT is related to the number of points in the time-domain signal. Use the following equation to compute the amplitude and phase versus frequency from the FFT. where the arctangent function here returns values of phase between –π and +π, a full range of 2π radians.

Does amplitude affect FFT?

Such amplitudes can be pretty high and affect FFT results, (with no window function, it can be about 10% of the original values for about 10 neighbor lines). If there is another sine wave in the signal in this region, which is lower than this 10%, it will be completely hidden by the leakage effect.

How do you normalize FFT amplitude?

Normalise the fft by dividing it by the length of the original signal in the time domain. Zero values within the signal are considered to be part of the signal, so 'non-zero samples' is inappropriate. The length to use to normalise the signal is the length before adding zero-padding.

What is the difference between amplitude and magnitude in FFT?

Amplitude is the peak value of a sinusoid in the time domain. Magnitude is the absolute value of any value, as opposed to its phase.