FFT with Spectral Leakage

NI High-Speed Digitizers Help (NI-SCOPE)

Edition Date: January 2017

Part Number: 370592AB-01

View Product Info

DOWNLOAD (Windows Only)

NI-SCOPE (English | Japanese)

In the following figure, you see the spectral representation when you sample a noninteger number of cycles of the time waveform (namely 10.25). The periodic extension of this signal creates a discontinuity similar to the figure shown in Spectral Leakage.

Notice how the energy is now spread over a wide range of frequencies, so the relative height difference between the FFT peak amplitude and the neighboring bins is reduced. This smearing of the energy is called spectral leakage.


Not Helpful