IUT CACHAN S.POUJOULY
Fiche pratique
Approximation de Butterworth
Ordre Polynôme normalisé
2 (s²+1,4142.s+1) 3 (s²+s+1).(s+1)
4 (s²+1,8477.s+1).(s²+0,7653.s+1) 5 (s²+1,6180.s+1).(s²+0,6160.s+1).(s+1)
6 (s²+1,9318.s+1).(s²+1,4142.s+1).(s²+0,5176.s+1) 7 (s²+1,8019.s+1).(s²+1,2469.s+1).(s²+0,4450.s+1).(s+1)
8 (s²+1,9615.s+1).(s²+1,6629.s+1).(s²+1,1111.s+1).(s²+0,3901.s+1) 9 (s²+1,8793.s+1).(s²+1,5320.s+1).(s²+s+1).(s²+0,3472.s+1).(s+1)
Atténuation dB
n=9
x
1 2 3 4 5 6 7 8 9 10 11 12
0 20 40 60 80 100
120 n=8 n=7 n=6
n=5
n=4
n=3
n=2
1 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 3
0 10 20 30 40 50 60 70 80
x Atténuation dB
n=9
n=8 n=7 n=6 n=5 n=4 n=3 n=2