实验二连续时间系统的频率响应

1、实验二连续时间系统的频率响应时间：2021.02.08创作人：欧阳生39022622龚小川-实验目的：1.进一步加深对连续时间系统频率响应理解；2掌握借助计算机计算任意连续时间系统频率响应的 方法。二.实验原理1 本实验的基本内容就是将系统函数的幅频特性曲线以 及相频特性曲线给画出来。mm而系统函数H($) = ，令$ = M则H(jw)=卡r=l/=!即(1)计算所有零点模之积及极点模之积,两者之商即 为日的幅度；(2) 计算所有零点相角之和及极点相角之和,两者之差 即为H的相角。2.通过零极点图通过几何的方法来计算，而且通过零极点图可以迅速地判断系统的滤波特性。 通过零极点图进行计算的方法

2、是：(1 )在S平面上标出系统的零极点位置；(2)选择S平面的坐标原点为起始点,沿虚轴向上移动, 计算此时各极点和零点与该点的膜和夹角;(3) 将所有零点的模相乘，再除以各极点的模，得到对 应频率处的幅频特性的值；(4) 将所有零点的幅角相加，减去各极点的幅角，得到 对应频率处的相角。三实验流程图四实验代码#include "stdio.h"#include "math.h"#inelude "graphics.h"floatatannew(float t1,float t2);int main()float z102#p102,ou

3、t1003,f50;intajout;inti,itemp,k,ktempjm,n;floatw,tempi jtemp2,prew,pretemp1,pretemp2,ptemp,h,fout；intgdriver/gmode=0;char s10;gdriver=0;/for(i=0;i< = 10;i + +)a=scanf("%f %fjn,&zi0, &zi1);if(a!=0);elsefflush(stdin);厂清空输入缓冲区，使得第二个scanf不被忽略Vfor(k=0;k< = 10;k+)a=scanf("%f %fj&qu

4、ot;/&pk0/&pk1);if(a!=0);elsebreak;break;/initgraph(&gdriver, &gmodee:tcbgi“)；setbkcolor(IO);setcolor(4);setlinestyle(1,0,1);rectangle(50z20/600/420);for(ptemp=20;ptemp<=420;ptemp=ptemp+50)I i n e (5 0, pte m p, 600, pte m p);for(ptemp=50;ptemp<=600;ptemp=ptemp+50)欧阳生创编2021.02.0

5、8lin e(ptemp/20lptemp/420); setlinestyle(OQI);setcolor(1);line(200z20z200z420);line(50,420,600,420);line(200,20,190,30);line(200z20z210z30);outtextxy(210z30/,An)；line(600,420,590,410);line(600,420,590,430);outtextxy(600/430,nwn)；for(iout=0;iout< = 5;iout+)sprin tf(s,”d；iout); outtextxy(iout*50+20

6、0,430,s);for(fout=1.0;fout<=8;fout=fout+1)sprintf(szn%.1fnzfout/10); outtextxy(170,420-fout*50,s);setcolor(4);欧阳生创编2021.02.08/*printf(nw幅度相角nH)；*/for(w=0j=0;w< = 5.0;j + +)tempi =1;for(itemp=0;itemp< = i-1;itemp+)tempi =temp1*sqrt(zitemp0*zitemp 0 + (zitemp1-w)*(zitemp1-w);for(ktemp=0;ktemp

7、< = k-1 ;ktemp+)tempi =temp1/sqrt(pktemp0*pktemp 0+(pktemp1 卜 w)*(pktemp1-w);outj0=w;outj1=temp1;if(j>0)line(prew*40+200,420pretemp1*500,w*40+200,420t emp1*500);prew=w;pretempl =temp1;w=w+0.1;for(m=0;m< = 50;m + +)if(outm1>outm+11)欧阳生创编2021.02.08break; printf(n%4f,%f：outm1,outm0);line(10

8、0/420-outm1/sqrt(2)*500/500/420-outm1/ sqrt(2) *500);getch();closegraph();initgraph(&gdriver, &grnodee:tcbgi");setbkcolor(IO);setcolor(4);setlinestyle(1,0,1);rectangle(50z20/600/420); for(ptemp=20;ptemp<=420;ptemp=ptemp+50) lin e(50/ptemp/600/ptemp);for(ptemp=50;ptemp<=600;ptemp=p

9、temp+50)lin e(ptemp/20/ptemp/420);for(w=0j=0;w< = 5;j + +)temp2=0;for(ktemp=0;ktemp< = k-1 ;ktemp+ +) temp2=temp2-ata nn ew(-pktemp0/w-pktemp1)；欧阳生创编2021.02.08for(itemp=0;itemp< = i-1;itemp+)temp2=temp2+ata nn ew(-zitemp 0xw-zitemp1 )；if(temp2> = 180)temp2=temp2 360;else if(temp2<=-18

10、0)temp2=temp2+360;outj2=temp2;if(j>0)line(prew*50+200,180+pretemp2/w*50+200/180+tem p2)；prew=w;pretemp2=temp2;w=w+0.1;getch();closegraph();for(j=0;j< = 50;j +)printfC%2f,%4f,%2froutj0Qutj1,outj2); printf(nnn");for(n 二 0,j=0;nv=50;n + +)fn =fabs(outm 1 /sqrt (2)-outn1);欧阳生创编2021.02.08欧阳生创编

11、 2021.02.08 for(n=0zh=f0j=0;nv = m;n + +) if(h>fn)h=fn;j = n;printf(nFI=%.1An,/outj0);for(n 二 m,h=f0j=0;n< = 50; n + +) if(h>fn)h=fn;j = n;printf(nFh=%.1fn,outj0); getch();return 0;floatatannew(float t1,float t2)欧阳生创编2021.02.08if(t1 > 0&&t2>0)ret u r n a ta n (t 2/t 1 )/3.14*

12、18 0;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&&t2<0)ret u r n a ta n (t 2/t 1 )/3.14* 18 0;else if(t1=0&&t2>0)return 90;else if(t1=0&&t2<0)return -90;else 讦(t1

13、 =0&&t2=0)return 0;else 讦(t1>0&&t2=0)return 180;else 讦(t1<0&&t2=0)return -180;五实验数据及所绘图形零点zl=0;极点WIH(jw)lpl=-l-j,p2=-l+jwIH(jw)l<p(jw)欧阳生创编2021.02.0800.04999984.26712.60.368813-42.47360.20.099987&471152.70.357173-44.4137030.14984872.565952.80.34606-46.20520.40.19

14、936366.506332.90.335472-47.86360.50.24806960.2595530.325396-49.40230.60.29525553.8107530.315814-50.83340.70.33994647.168263.20.306705-52.16740.80.3809740.3675330.298046 53.41350.90.41709233.471593.40.289812-54.579910.44721426.5673.50.28198155.67391.10.4705819.75423.60.274528-56.70191.20.48692113.134

15、983.70.267431-57.66961.30.4964836.7998163.80.26067-58.58221.40.4999490.818513.90.254222-59.44421.50.498273-4.76440.24806960.25961.60.492515-9.9269840.24219461.03211.70.483703-14.674.20.23658-61.7651.80.472742 19.00744.30.23120962.46131.90.460383-22.96334.40.2260763.123620.447214-26.5674.50.22114663.

16、754520.433676-29.84984.60.216427643562.20.420092-32.84284.70.21189964.9301230.406687-35.57564.80.207553-65.47892.40.39361438.07564.90.20337766.0037幅频特性曲线：横线 3dB 线。FI=0.7zFh=2.7.零点 zl=2+1.5j,z2=2-1.5j;极点 pl=-0.5-0.7j,p2=-0.5+0.7j,p3=-2.5-2j,p4=-2.5+2j0.00.823995197.6069762.50.12592730.1683910.10.8277

17、48188.7530952.60.11796834.2282300.20.838357179.0547982.7010810-38.1362930.30.853583168.2866332.80.104336-41.8993550.40.868832156.2324432.90.098449-45.5231510.50.876442142.77567830.093071-49.0127090.60.866588128.04770230.088137-52.3725880.70.830997112.5538083.20.083592-55.6070560.80.76958397.1076083.

18、30.079392-58.7202040.90.69100282.5233353.40.075499-61.7160311.00.60750369.3081333.50.071880-64.598482欧阳生创编2021.02.081.10.52856857.5963953.60.068509-67.3714831.20.45889247.2757383.70.065362-70.0389431.3039964338.1349873.80.062418-72.6047581.40.35012029.9547293.90.059661-75.0727981.50.30896222.54471840.057073-77.4468961.60.27472715.75241140.054642-79.7308371.70.2461209.4598394.20.052356-81.9283401.80.2220603.577246430.050202-84.0430451.90.201673