problem_2_1.m

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

clear all
tau=50e-12;
E_1=1;E_2=1;E_3=1;E_4=1;
K_1=sqrt(E_1/tau/sqrt(pi/2));K_2=sqrt(tau*E_2/sqrt(pi/2));
K_3=tau*sqrt(tau*E_3/3/sqrt(pi/2));K_4=tau*tau*sqrt(tau*E_4/15/sqrt(pi/2));
it=0;
for t=-2e-10:1e-12:2e-10;
    it=it+1;
    y_g_1(it)=K_1*exp(-t^2/tau^2);
    y_g_2(it)=K_2*(-2*t/tau^2)*exp(-t^2/tau^2);
    y_g_3(it)=K_3*(-2)/(tau^2)*(1-2*t^2/tau^2)*exp(-t^2/tau^2);
    y_g_4(it)=K_4*(-2)/(tau^2)*(-6*t/tau^2+4*t^3/tau^4)*exp(-t^2/tau^2);
end,
figure (1);t=-2e-10:1e-12:2e-10;plot(t,y_g_1,'r');hold on;plot(t,y_g_2,'b');
hold on;plot(t,y_g_3,'g');hold on;plot(t,y_g_4,'k');
legend('y_{g_1}(t)','y_{g_2}(t)','y_{g_3}(t)','y_{g_4}(t)');
xlabel('Time, sec');ylabel('Amplitude');grid;


iif=0;
for f=0:1e8:2e10;
    iif=iif+1;
    Y_G_1(iif)=K_1*tau*sqrt(pi)*exp(-(pi*tau*f)^2);
    Y_G_2(iif)=K_2*tau*sqrt(pi)*exp(-(pi*tau*f)^2)*(2*pi*f);
    Y_G_3(iif)=K_3*tau*sqrt(pi)*exp(-(pi*tau*f)^2)*(2*pi*f)^2;
    Y_G_4(iif)=K_4*tau*sqrt(pi)*exp(-(pi*tau*f)^2)*(2*pi*f)^3;
end,
figure (3);f=0:1e8:2e10;plot(f,Y_G_1,'r');hold on;plot(f,Y_G_2,'b');hold on;
plot(f,Y_G_3,'g');;hold on;plot(f,Y_G_4,'k')
legend('Y_{g_1}(t)','Y_{g_2}(t)','Y_{g_3}(t)','Y_{g_4}(t)');
xlabel('Frequency');ylabel('Magnitude');grid;