Parker EME
Setting up Compax3
192-120113 N08 C3I12T11 - December 2010
257
Leak effect and windowing
If frequencies not corresponding to the frequency resolution are present in the
analyzed spectrum, the so-called leak effect can be caused.
Display of the leak effect with the aid of a 16 point discrete Fourier transformation
Complete oscillation period in the scanning
period
Envelope without leak effect
Non complete oscillation period in the scanning
period
Envelope with leak effect
Sine at 200Hz without windowing
Consequence of the leak effect shown at the example of a sine signal.
(fA=4000Hz; N=500; =>
∆
f=8Hz
f0=200Hz = 25*
∆
f frequency corresponds to the frequency-resolution
The sine frequency is exactly on a multiple of the frequency resolution (200Hz /
8Hz=25). The spectrum is clearly separated and there are no leak effects visible.
