Owner's manual

CapturePlus II
40 DS789UM2
APPENDIX C. FFT WINDOW LEAKAGE
Windowing functions which are used to make FFT (Fast Fourier Transform) plots more informative also
generate a measurable error by spreading energy from the FFT signal peaks to the surrounding noise
floor. This results from an effect known as “window leakage”.
The following table lists the windowing functions and their associated peak signal losses that are used by
the Cirrus Logic CapturePlus II system.
Windowing Function Peak Signal Loss Side Lobe Attenuation
Rectangular 0 dB 0 dB
Hodie 5 Term (Proprietary) 3.457 dB 125 dB
Crystal 7 Term (Proprietary) 4.203 dB 175 dB