-5D 100 020004000E00800010000120001400018000 -1口 15 10口 1200 140口 180口 2
O N,Wc]- buttord(2000pi,4000*pi,1,15,s) z,p, k=butter(N, Wc,'s) Output mpty matrIx: 0-by-1 E p=1.0e+003* 7.5695+3.1354 -7.5695-3.1354 3.1354+7.5695i 3.1354-75695i k=4.5063e+015 H((s) (s-p0(s-p1)S-P2)S-p3)
Or： [N,Wc]=buttord(2000*pi,4000*pi,1,15, ' s ') [z,p,k]=butter(N,Wc, 's' ) Output: z = Empty matrix: 0-by-1 p = 1.0e+003 * -7.5695 + 3.1354i -7.5695 - 3.1354i -3.1354 + 7.5695i -3.1354 - 7.5695i k = 4.5063e+015 ( )( )( )( ) ( ) 0 1 2 p3 s p s p s p s k H s c − − − − =
eXaMPLE design a low pass cheby analogy filter p=2x·1000rd/s, 2z·2000 s diDa,a=15 IN, Wc=cheblord(2000*pi, 4000*pi, 1, 15,S) [Bs, As]=cheby 1(N, 1, Wc,'s) H, WI-freqs(Bs, as) plot( W/2/ pi, 20*(log10(abs(dD) axiS([0,4000-30,0]) id on 10…… 15 ·重 bandanna 5001000150020002500300035004000
design a low pass cheby analogy filter: [N,Wc]=cheb1ord(2000*pi,4000*pi,1,15, ' s ') [Bs,As]=cheby1(N,1,Wc, ' s') [H,W]=freqs(Bs,As); plot(W/2/pi,20*(log10(abs(H)))) axis([0,4000,-30,0]) grid on p = 2 1000rad /s,s = 2 2000rad /s, p =1dB,s =15dB EXAMPLE
eXaMPLE design a low pass cheby analogy filter p=2.1000rad/s22s=2x.2000ad/s,cn=ldB,=15 IN, Wc=cheb2ord(2000*pi, 4000*pi, 1, 15,S) [Bs, As]=cheby 2(N, 15, Wc,'s) H, WI-freqs(Bs, as) plot( W/2/ pi, 20*(log10(abs(dD) axiS([0,4000-30,0]) grid on 5}………+- 10} 20… 25}……1-1- 5001000150020002500300035004000
design a low pass cheby analogy filter: [N,Wc]=cheb2ord(2000*pi,4000*pi,1,15, ' s ') [Bs,As]=cheby2(N,15,Wc, ' s') [H,W]=freqs(Bs,As); plot(W/2/pi,20*(log10(abs(H)))) axis([0,4000,-30,0]) grid on p = 2 1000rad /s,s = 2 2000rad /s, p =1dB,s =15dB EXAMPLE
example design a high pass analogy filter 2n=2n.2000ad/s,s2s=2n1000d/s,n=ldB.as=15 [N,Wc]=buttord(4000*pi, 2000*pi, 1, 15,'S) [BS, As]=butter(N, Wc, high,'s) H,W-freqs(,As) plot( W/2/pi, 20*(log 10(abs(H) axiS(0,4000-16,0) grid on 2 680240 10001500200 4000
design a high pass analogy filter: [N,Wc]=buttord(4000*pi,2000*pi,1,15, ' s ') [Bs,As]=butter(N,Wc, 'high' , ' s') [H,W]=freqs(Bs,As); plot(W/2/pi,20*(log10(abs(H)))) axis([0,4000,-16,0]) grid on p = 2 2000rad /s,s = 2 1000rad /s, p =1dB,s =15dB EXAMPLE