Kaiser Windows and Transforms
Figure 3.24 plots the Kaiser window and its transform for
. Note how increasing
causes the
side-lobes to fall away from the main lobe. The curvature at the main
lobe peak also decreases somewhat.
Figure 3.25 shows a plot of the Kaiser window
for various values of
. Note that for
, the
Kaiser window reduces to the rectangular window.
Figure 3.26 shows a plot of the Kaiser window
transforms for
. For
(top plot),
we see the dB magnitude of the aliased sinc function. As
increases the main-lobe widens and the side lobes go lower, reaching
almost 50 dB down for
.
Figure 3.27 shows the effect of increasing window length
for the Kaiser window. The window lengths are
from the top to the bottom plot. As with all windows, increasing the
length decreases the main-lobe width, while the side-lobe level
remains essentially unchanged.
Figure 3.28 shows a plot of the Kaiser window side-lobe level
for various values of
. For
, the Kaiser window reduces to the rectangular window, and we
expect the side-lobe level to be about 13 dB below the main lobe
(upper-lefthand corner of Fig.3.28). As
increases, the dB side-lobe level reduces approximately linearly with
main-lobe width increase (approximately a 25 dB drop in side-lobe
level for each main-lobe width increase by one sinc-main-lobe).
Next Section:
Minimum Frequency Separation vs. Window Length
Previous Section:
Kaiser Window Beta Parameter