Signal truncation and weighting windows
Fourier-based Signal Analyzers

FFT spectral analysis is based on the principle of transforming N temporal signal values into N frequency values "en bloc".

In this section, we focus on the influence of the number of calculation points N on the spectral representation obtained.

Let x(t) be the analog signal to be analyzed, with Fourier transform X(f).

The sampling of x(t) is assumed to respect Shannon's theorem and provides :

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