實驗二連續(xù)時間系統(tǒng)的頻率響應借鑒文章

1、實驗二 連續(xù)時間系統(tǒng)的頻率響應39022622 龔小川一實驗目的： 1. 進一步加深對連續(xù)時間系統(tǒng)頻率響應理解；2掌握借助計算機計算任意連續(xù)時間系統(tǒng)頻率響應的方法。二實驗原理1.本實驗的基本內容就是將系統(tǒng)函數(shù)的幅頻特性曲線以及相頻特性曲線給畫出來。而系統(tǒng)函數(shù),令,則即（1）計算所有零點模之積及極點模之積，兩者之商即為的幅度； （2）計算所有零點相角之和及極點相角之和，兩者之差即為的相角。2.通過零極點圖通過幾何的方法來計算，而且通過零極點圖可以迅速地判斷系統(tǒng)的濾波特性。通過零極點圖進行計算的方法是：（1）在s 平面上標出系統(tǒng)的零極點位置；（2）選擇s 平面的坐標原點為起始點，沿虛軸向上移動，計

2、算此時各極點和零點與該點的膜和夾角；（3）將所有零點的模相乘，再除以各極點的模，得到對應頻率處的幅頻特性的值；（4）將所有零點的幅角相加，減去各極點的幅角，得到對應頻率處的相角。三實驗流程圖j>m?,否是輸出temp1,即為零點模之積令j=0,temp1=1i>n?,否是輸出temp2,即為極點模之積令i=0,temp2=1輸出temp1/temp2,極為h(s)之幅度j>m? 否是輸出temp1,即為零點相角之和令j=0,temp1=0i>n?否是輸出temp2,即為極點相角之和令i=0,temp2=0輸出temp1-temp2,極為h(s)之相角四實驗代碼#incl

3、ude "stdio.h"#include "math.h"#include "graphics.h"float atannew(float t1,float t2);int main()float z102,p102,out1003,f50; int a,iout;int i,itemp,k,ktemp,j,m,n;float w,temp1,temp2,prew,pretemp1,pretemp2,ptemp,h,fout;int gdriver,gmode=0;char s10; gdriver=0; /*/ for(i=0;i

4、<=10;i+) a=scanf("%f %fj",&zi0,&zi1); if(a!=0); elsefflush(stdin);/*清空輸入緩沖區(qū),使得第二個scanf不被忽略*/ for(k=0;k<=10;k+) a=scanf("%f %fj",&pk0,&pk1); if(a!=0); else break;break;/*/initgraph(&gdriver,&gmode, "e:tcbgi");setbkcolor(10); setcolor(4); set

5、linestyle(1,0,1); rectangle(50,20,600,420); for(ptemp=20;ptemp<=420;ptemp=ptemp+50) line(50,ptemp,600,ptemp); for(ptemp=50;ptemp<=600;ptemp=ptemp+50) line(ptemp,20,ptemp,420); setlinestyle(0,0,1); setcolor(1); line(200,20,200,420); line(50,420,600,420); line(200,20,190,30); line(200,20,210,30)

6、; outtextxy(210,30,"a"); line(600,420,590,410); line(600,420,590,430); outtextxy(600,430,"w"); for(iout=0;iout<=5;iout+) sprintf(s,"%d",iout); outtextxy(iout*50+200,430,s); for(fout=1.0;fout<=8;fout=fout+1) sprintf(s,"%.1f",fout/10); outtextxy(170,420-fo

7、ut*50,s); setcolor(4);/*printf("w 幅度 相角n");*/for(w=0,j=0;w<=5.0;j+) temp1=1; for(itemp=0;itemp<=i-1;itemp+)temp1=temp1*sqrt(zitemp0*zitemp0+(zitemp1-w)*(zitemp1-w);for(ktemp=0;ktemp<=k-1;ktemp+)temp1=temp1/sqrt(pktemp0*pktemp0+(pktemp1-w)*(pktemp1-w); outj0=w; outj1=temp1; if(j>

8、;0) line(prew*40+200,420-pretemp1*500,w*40+200,420-temp1*500); prew=w; pretemp1=temp1; w=w+0.1; for(m=0;m<=50;m+) if(outm1>outm+11) break; printf("%.4f,%f",outm1,outm0); line(100,420-outm1/sqrt(2)*500,500,420-outm1/sqrt(2)*500); getch(); closegraph(); initgraph(&gdriver,&gmod

9、e, "e:tcbgi"); setbkcolor(10); setcolor(4); setlinestyle(1,0,1); rectangle(50,20,600,420); for(ptemp=20;ptemp<=420;ptemp=ptemp+50) line(50,ptemp,600,ptemp); for(ptemp=50;ptemp<=600;ptemp=ptemp+50) line(ptemp,20,ptemp,420); for(w=0,j=0;w<=5;j+) temp2=0; for(ktemp=0;ktemp<=k-1;kt

10、emp+)temp2=temp2-atannew(-pktemp0,w-pktemp1);for(itemp=0;itemp<=i-1;itemp+)temp2=temp2+atannew(-zitemp0,w-zitemp1);if(temp2>=180) temp2=temp2-360;else if(temp2<=-180) temp2=temp2+360;outj2=temp2; if(j>0)line(prew*50+200,180+pretemp2,w*50+200,180+temp2);prew=w;pretemp2=temp2;w=w+0.1;getch

11、(); closegraph(); for(j=0;j<=50;j+) printf("%.2f,%.4f,%.2f*",outj0,outj1,outj2); printf("nn"); for(n=0,j=0;n<=50;n+) fn=fabs(outm1/sqrt(2)-outn1); for(n=0,h=f0,j=0;n<=m;n+) if(h>fn) h=fn; j=n; printf("fl=%.1fn",outj0); for(n=m,h=f0,j=0;n<=50;n+) if(h>f

12、n) h=fn; j=n; printf("fh=%.1f",outj0); getch(); return 0;float atannew(float t1,float t2)if(t1>0&&t2>0)return atan(t2/t1)/3.14*180;else if(t1<0&&t2<0)return 180+atan(t2/t1)/3.14*180;else if(t1<0&&t2>0)return 180+atan(t2/t1)/3.14*180;else if(t1>0

13、&&t2<0) return atan(t2/t1)/3.14*180;else if(t1=0&&t2>0) return 90;else if(t1=0&&t2<0) return -90;else if(t1=0&&t2=0) return 0;else if(t1>0&&t2=0) return 180;else if(t1<0&&t2=0) return -180; 五實驗數(shù)據及所繪圖形零點z1=0;極點 p1=-1-j,p2=-1+jw|h(jw)|(jw)

14、w|h(jw)|(jw)0.10.04999984.26712.60.368813-42.47360.20.0999878.471152.70.357173-44.41370.30.14984872.565952.80.34606-46.20520.40.19936366.506332.90.335472-47.86360.50.24806960.2595530.325396-49.40230.60.29525553.810753.10.315814-50.83340.70.33994647.168263.20.306705-52.16740.80.3809740.36753.30.29804

15、6-53.41350.90.41709233.471593.40.289812-54.579910.44721426.5673.50.281981-55.67391.10.4705819.75423.60.274528-56.70191.20.48692113.134983.70.267431-57.66961.30.4964836.7998163.80.26067-58.58221.40.4999490.818513.90.254222-59.44421.50.498273-4.76440.248069-60.25961.60.492515-9.926984.10.242194-61.032

16、11.70.483703-14.674.20.23658-61.7651.80.472742-19.00744.30.231209-62.46131.90.460383-22.96334.40.22607-63.123620.447214-26.5674.50.221146-63.75452.10.433676-29.84984.60.216427-64.3562.20.420092-32.84284.70.211899-64.93012.30.406687-35.57564.80.207553-65.47892.40.393614-38.07564.90.203377-66.0037幅頻特性

17、曲線：橫線3db線。fl=0.7,fh=2.7.零點z1=2+1.5j,z2=2-1.5j;極點 p1=-0.5-0.7j,p2=-0.5+0.7j,p3=-2.5-2j,p4=-2.5+2j0.0 0.823995 197.606976 2.50.125927 -30.168391 0.1 0.827748 188.753095 2.60.117968 -34.228230 0.2 0.838357 179.054798 2.70.110810 -38.136293 0.3 0.853583 168.286633 2.80.104336 -41.899355 0.4 0.868832 156

18、.232443 2.90.098449 -45.523151 0.5 0.876442 142.775678 30.093071 -49.012709 0.6 0.866588 128.047702 3.10.088137 -52.372588 0.7 0.830997 112.553808 3.20.083592 -55.607056 0.8 0.769583 97.107608 3.30.079392 -58.720204 0.9 0.691002 82.523335 3.40.075499 -61.716031 1.0 0.607503 69.308133 3.50.071880 -64.598482 1.1 0.528568 57.596395 3.60.068509 -67.371483 1.2 0.458892 47.275738 3.7