9.txt

计算机端口扫描端口程序应用和开发的作用,供参考.

clear all
N=64;
wc=0.8*pi;
k=0:N-1;
phase=(-pi*k*(N-1)/N+pi/2);
HK=[zeros(1,26),ones(1,13),zeros(1,25)];
HK1=HK.*exp(j*phase);
hn=ifft(HK1,N);
[H,W]=freqz(hn,1,512);
subplot(3,1,1);
plot(abs(hn));
subplot(3,1,2);
plot(W/pi,abs(H));
subplot(3,1,3);
plot(W/pi,20*log10(abs(H)));

clear all
N=64;
wc=0.8*pi;
k=0:N-1;
phase=(-pi*k*(N-1)/N+pi/2);
HK=[zeros(1,26),0.5,ones(1,11),0.5,zeros(1,25)];
HK1=HK.*exp(j*phase);
hn=ifft(HK1,N);
[H,W]=freqz(hn,1,512);
subplot(3,1,1);
plot(abs(hn));
subplot(3,1,2);
plot(W/pi,abs(H));
subplot(3,1,3);
plot(W/pi,20*log10(abs(H)));