Nikolay_Po (Сегодня, 16:57, просмотров: 19) ответил IBAH на да я и на бих согласен, только 1)там написано эллиптический фильтр,
2) не качаетсяВот полосовой Чебышева, 5-го порядка. При неравномерности в полосе
пропускания 0.2дБ, на 30кГц подавление 73дБ:
Filter kind:
1 Butterworth
2 Chebyshev
3 Elliptic
? 2
Filter shape:
1 low pass
2 band pass
3 high pass
4 band stop
? 2
Order of filter = 8.000000000E+000 ? 5.000000000E+000
Passband ripple, db = 5.000000000E-001 ? 2.000000000E-001
Sampling frequency = 1.000000000E+004 ? 1.000000000E+005
Passband edge = 2.000000000E+003 ? 1.000000000E+002
Other passband edge = 1.500000000E+003 ? 1.000000000E+004
s plane poles:
-4.614105755E-001 0.000000000E+000
-3.732889970E-001 6.473380467E-001
-1.425837092E-001 1.047414962E+000
s plane zeros:
adding zero at Nyquist frequency
adding zero at 0 Hz
adding zero at Nyquist frequency
adding zero at 0 Hz
adding zero at Nyquist frequency
adding zero at 0 Hz
adding zero at Nyquist frequency
adding zero at 0 Hz
adding zero at Nyquist frequency
adding zero at 0 Hz
order = 10
constant gain factor 5.4931133178501E-004
z plane Denominator Numerator
0 1.000000000E+000 5.493113318E-004
1 -8.641816796E+000 0.000000000E+000
2 3.394414307E+001 -2.746556659E-003
3 -7.989448561E+001 0.000000000E+000
4 1.248988043E+002 5.493113318E-003
5 -1.355904822E+002 0.000000000E+000
6 1.035567075E+002 -5.493113318E-003
7 -5.495049438E+001 0.000000000E+000
8 1.938759157E+001 2.746556659E-003
9 -4.106339279E+000 0.000000000E+000
10 3.963717435E-001 -5.493113318E-004
poles and zeros with corresponding quadratic factors
pole 9.8564982120614E-001 0.0000000000000E+000
q. f.
z**2 0.0000000000000E+000
z**1 -9.8564982120614E-001
f0 5.00000000E+004 gain 5.0361E-001 DC gain 6.9686E+001
zero -1.0000000000000E+000 0.0000000000000E+000
q. f.
z**2 0.0000000000000E+000
z**1 1.0000000000000E+000
f0 5.00000000E+004 gain 0.0000E+000 DC gain 2.0000E+000
pole 7.5247227773285E-001 0.0000000000000E+000
q. f.
z**2 0.0000000000000E+000
z**1 -7.5247227773285E-001
f0 5.00000000E+004 gain 5.7062E-001 DC gain 4.0400E+000
zero 1.0000000000000E+000 0.0000000000000E+000
q. f.
z**2 0.0000000000000E+000
z**1 -1.0000000000000E+000
f0 5.00000000E+004 gain 2.0000E+000 DC gain 0.0000E+000
pole 7.2673205028324E-001 3.2737077040383E-001
q. f.
z**2 6.3531109422368E-001
z**1 -1.4534641005665E+000
f0 6.73614483E+003 gain 6.4758E+000 DC gain 5.4991E+000
zero -1.0000000000000E+000 0.0000000000000E+000
q. f.
z**2 0.0000000000000E+000
z**1 1.0000000000000E+000
f0 5.00000000E+004 gain 0.0000E+000 DC gain 2.0000E+000
zero 1.0000000000000E+000 0.0000000000000E+000
q. f.
z**2 0.0000000000000E+000
z**1 -1.0000000000000E+000
f0 5.00000000E+004 gain 2.0000E+000 DC gain 0.0000E+000
zero -1.0000000000000E+000 0.0000000000000E+000
q. f.
z**2 0.0000000000000E+000
z**1 1.0000000000000E+000
f0 5.00000000E+004 gain 0.0000E+000 DC gain 2.0000E+000
pole 9.9588727005784E-001 7.3204701421030E-003
q. f.
z**2 9.9184504394635E-001
z**1 -1.9917745401157E+000
f0 1.16987942E+002 gain 1.6071E+004 DC gain 1.4184E+004
zero 1.0000000000000E+000 0.0000000000000E+000
q. f.
z**2 0.0000000000000E+000
z**1 -1.0000000000000E+000
f0 5.00000000E+004 gain 2.0000E+000 DC gain 0.0000E+000
pole 7.3003433518109E-001 5.6259531999152E-001
q. f.
z**2 8.4946362461966E-001
z**1 -1.4600686703622E+000
f0 1.04498240E+004 gain 1.0867E+001 DC gain 2.5681E+000
zero -1.0000000000000E+000 0.0000000000000E+000
q. f.
z**2 0.0000000000000E+000
z**1 1.0000000000000E+000
f0 5.00000000E+004 gain 0.0000E+000 DC gain 2.0000E+000
zero 1.0000000000000E+000 0.0000000000000E+000
q. f.
z**2 0.0000000000000E+000
z**1 -1.0000000000000E+000
f0 5.00000000E+004 gain 2.0000E+000 DC gain 0.0000E+000
zero -1.0000000000000E+000 0.0000000000000E+000
q. f.
z**2 0.0000000000000E+000
z**1 1.0000000000000E+000
f0 5.00000000E+004 gain 0.0000E+000 DC gain 2.0000E+000
pole 9.9919369290095E-001 5.8944957225326E-003
q. f.
z**2 9.9842278101286E-001
z**1 -1.9983873858019E+000
f0 9.38884278E+001 gain 1.0724E+005 DC gain 2.8252E+004
zero 1.0000000000000E+000 0.0000000000000E+000
q. f.
z**2 0.0000000000000E+000
z**1 -1.0000000000000E+000
f0 5.00000000E+004 gain 2.0000E+000 DC gain 0.0000E+000
0.0 -999.99
2500.0 -0.15
5000.0 -0.08
7500.0 -0.14
10000.0 -0.20
12500.0 -12.72
15000.0 -25.39
17500.0 -35.29
20000.0 -43.79
22500.0 -51.51
25000.0 -58.84
27500.0 -66.03
30000.0 -73.30
32500.0 -80.88
35000.0 -89.04
37500.0 -98.14
40000.0 -108.76
42500.0 -121.96
45000.0 -140.06
47500.0 -170.45
50000.0 -1639.43
По идее, если допустима большая неравномерность в полосе пропускания, то можно порядок снизить. И ещё, если нет высоких требований к крутизне ФВЧ (100Гц), то я бы поделил фильтр на два последовательных - сначала ФНЧ низким порядком, потом ФНЧ - подходящим порядком.