(完整word版)用雙線性變換法設(shè)計(jì)原型低通為切比雪夫I型的數(shù)字IIR帶通濾波器(word文檔良心出品)

1、用雙線性變換法設(shè)計(jì)原型低通為切比雪夫I型的數(shù)字IIR帶通濾波器Matlab詳細(xì)設(shè)計(jì)：% Design of a Cheb I Bandpass Digital Filter by using bilinear method clc;clear all ;Rp = 1;% bandpass attenuation in dBRs = 40;% bandstop attenuation in dBOmegaS1_1=350;OmegaS1_2=550;OmegaP1_1=400;OmegaP1_2=500;Fp=2000;% samling frequencytodigitalangularWp1

2、=2*pi*OmegaP1_1/Fp;% changeanalogyfrequencyfrequencyWp2=2*pi*OmegaP1_2/Fp;% changeanalogyfrequencytodigitalangularfrequencyWs1=2*pi*OmegaS1_1/Fp;% changeanalogyfrequencytodigitalangularfrequencyWs2=2*pi*OmegaS1_2/Fp;% changeanalogyfrequencytodigitalangularfrequencyOmegaP1=2*Fp*tan(Wp1/2);%nonlinearl

3、izationOmegaP2=2*Fp*tan(Wp2/2);%nonlinearlizationOmegaS1=2*Fp*tan(Ws1/2);%nonlinearlizationOmegaS2=2*Fp*tan(Ws2/2);%nonlinearlizationOmegaP0=sqrt(OmegaP1*OmegaP2);% equivalent mid frequencyBw=OmegaP2-OmegaP1; % bandwithEta_P0=OmegaP0/Bw;%NormalizationEta_P1=OmegaP1/Bw;%NormalizationEta_P2=OmegaP2/Bw

4、;%NormalizationEta_S1=OmegaS1/Bw;%NormalizationEta_S2=OmegaS2/Bw;%Normalization% change to the equivalent Lowpass patameterLemta_P_EquivalentLowPass=Eta_P2/(Eta_P2A2-Eta_P0A2);Lemta_S1_EquivalentLowPass=-Eta_S1/(Eta_S1A2-Eta_P0A2);Lemta_S2_EquivalentLowPass=Eta_S2/(Eta_S2A2-Eta_P0A2);Lemta_S_Equival

5、entLowPass=min(Lemta_S1_EquivalentLowPass,Lemta_S2 _EquivalentLowPass);% get the smallest% Estimate the Filter OrderN, Wn=cheb1ord(Lemta_P_EquivalentLowPass, Lemta_S_EquivalentLowPass, Rp, Rs,'s');% Design the Filter's')；num1,den1=cheby1(N,Rp,Wn,num2,den2=lp2bp(num1,den1,OmegaP0,Bw);

6、num,den=bilinear(num2,den2,Fp);% Compute the gain responsew = 0:pi/255:pi;h = freqz(num,den,w);g = 20*log10(abs(h);% Plot the gain responsefigure;plot(w/pi,g);gridaxis(0 1 -60 5);xlabel( 'omega /pi'); ylabel( 'Gain in dB' );title( 'Gain Response of a Cheb I Bandpass Filter');

7、f1=450;f2=600;t=0:0.0001:1x1=sin(2*pi*f1*t);x2=sin(2*pi*f2*t);x=x1+x2;figure;subplot(2,2,1)%?x1 心？2 一 D?plot(x1);gridon ;axis(0,50*pi,-3,3);xlabel( 't' );ylabel( 'x1(t)');title( 'x1 心？2 .?');subplot(2,2,2)%?x1 心？2 一 D?plot(x2);gridon ;axis(0,50*pi,-3,3);xlabel( 't' );

8、ylabel('x2(t)');title('x2 心？2 .?');subplot(2,2,3) %?e ?e ?x ?2 " D?plot(x);grid on ;axis(0,50*pi,-3,3);xlabel( 't' );ylabel( 'x(t)');title( ' e ?e ?D?o?x 心？2 一 D?')%X=fft(x);y=filter(num,den,x);%6 yx ?2 -？+ 6 ?3?subplot(2,2,4);%?e ?3?y 心？2 一 D?plot(real(y

9、);grid on ;axis(0,50*pi,-3,3);xlabel( 't' );ylabel('y' );title('?2 '' ?- e ?3?y 心？2 - D?);6 調(diào)試分析：編寫程序有一定難度，調(diào)試是不斷出錯(cuò)，由于先前對(duì)DSP的學(xué)習(xí)不夠扎實(shí),導(dǎo)致程序出現(xiàn)了很多的錯(cuò)誤。更多的錯(cuò)誤是：函數(shù)未定義，函數(shù)功能調(diào)用錯(cuò)誤等, 不過經(jīng)過耐心的學(xué)習(xí)，最終還是調(diào)試除了比較理想的結(jié)果，如有不妥，還望指正7測(cè)試結(jié)果：1 1餐力 K J - * 。伊酎 £) 丁 弓X. Mr X 武* I - Lfl 4 + 1L1 騎之 4HNE

10、 blL， - -1, 金同如呻由 二三(f-bhi* «-slofT tFWjffljcy r+ di*打U 卻存血 TEEjenrrL FpsZrpiie(-M!J_i/Pp. w +1 口1113r.i趙1ap* <r ITT 211 _"F-p" xulVi i / 2 - 1Ehr>QkH I kTj.=<MriF * . .% 3，ilfcf Pa-tUEBPL-iM A u ra>. axstaonLnrl > F EouTxlintL-nP ua"£"t a,*-Il 1_FS'

11、11 =nmrat卜；i-r-in. sn . uxa :Lvflri n_ tl lAuLaJMfl LM Ui*bB4 Aj-I i'l >h E l >! !/» >1Bh|.電。lh> v-six-riiLtM Lmfl?aHm bifl -Kta vlL rwl t? ! iiiLBrc-iFa LniriiiRiEl *_ &2.' rt ,1Tpi ="» 丁中4" i 出ji， i -li «° . en» . 197 > 1 p*+ sFi-> ； »L tlli t_E JUra<nT_ j-F M5=fcia _ tWT.：_& -CuL,41"SniL