Polytec OFV-511 - Page 37

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The complete amplitude frequency response of a 3rd order Bessel low pass
filter is shown in figure 4.3. The frequency is normalized to the cutoff fre-
quency f
c
.
The amplitude error caused by the filter can be determined from figure 4.4.
Figure 4.3: Amplitude frequency response of a 3rd order Bessel low pass filter
Figure 4.4: Amplitude error of a 3rd order Bessel low pass filter in the passband
-6 0
-5 0
-4 0
-3 0
-2 0
-1 0
0
0.1 0.2 0.5 1 2 5 10 20
Am plitude / dB
f
f
C
10
-3 0
-2 5
-2 0
-1 5
-1 0
-5
0
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
Am plitude error / %
f
f
C