fig_2_1_ab.m

Ultra.Wideband.Signals.and.Systems.in.Communication.Engineering.eBook-kB代码

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clear all
f_0=5e9;lambda_1=5e9;lambda_2=3e9;A=1;
it=0;iif=0;
for t=0:1e-12:1e-9;
    it=it+1;
    y_d1(it)=A*exp(-lambda_1*t)*sin(2*pi*f_0*t);
    y_d2(it)=A*exp(-lambda_2*t)*sin(2*pi*f_0*t);
end,
figure (1);t=0:1e-12:1e-9;plot(t,y_d1,'r');hold on;plot(t,y_d2,'b')
xlabel('Time, sec');ylabel('Amplitude');grid;
legend('\lambda=5\times 10^{9}','\lambda=3\times 10^{9}');

for f=0:1e8:2e10;
    iif=iif+1;
    Y_D1(iif)=abs((2*pi*f_0*A)/(lambda_1^2-4*pi^2*(f^2-f_0^2)+j*4*pi*lambda_1*f));
    Y_D2(iif)=abs((2*pi*f_0*A)/(lambda_2^2-4*pi^2*(f^2-f_0^2)+j*4*pi*lambda_2*f));
end,
figure (3);f=0:1e8:2e10;plot(f,Y_D1,'r');hold on;plot(f,Y_D2,'b');
xlabel('Frequency, Hz');ylabel('Magnitude');grid;
legend('\lambda=5\times 10^{9}','\lambda=3\times 10^{9}');