FFT Spectral Analysis 4
Keysight InfiniiVision 3000T X-Series Oscilloscopes User's Guide 97
FFT Spectral Leakage
The FFT operation assumes that the time record repeats. Unless there is an
integral number of cycles of the sampled waveform in the record, a discontinuity is
created at the end of the record. This is referred to as leakage. In order to minimize
spectral leakage, windows that approach zero smoothly at the beginning and end
of the signal are employed as filters to the FFT. The FFT Menu provides these
windows: Hanning, Flat Top, Rectangular, Blackman-Harris, and Bartlett. For
more information on leakage, see Keysight Application Note 243, The
Fundamentals of Signal Analysis at
http://literature.cdn.keysight.com/litweb/pdf/5952-8898E.pdf.