L=1;C=1e-6;w0=1/sqrt(L*C);f0=w0/(2*pi);N=ceil(2*f0);delta_f=1;QL=20;QL2=80; for n=1:N f=n*delta_f;
kesai(n)=QL*(f/f0-f0/f); kesai2(n)=QL2*(f/f0-f0/f); alpha(n)=1/sqrt(1+kesai(n)^2); alpha2(n)=1/sqrt(1+kesai2(n)^2); end
n=1:N;
plot(n,alpha,'b',n,alpha2,'g:'); xlabel('f');ylabel('\\alpha & \\alpha_2'); legend('\\alpha','\\alpha_2');
实验三 普通调谐波
Uoumigam=10;Ucm=10;oumiga=1e3;wc=1e4;ma=0.8; t=0:0.00001:0.01;
uoumiga=Uoumigam*cos(oumiga*t); uc=Ucm*cos(wc*t);
uAM=Ucm*(1+ma*cos(oumiga*t)).*cos(wc*t);
plot(t,uoumiga,'r');xlabel('t');ylabel('u_{\\Omega}(t)'); figure,
plot(t,uc,'g');xlabel('t');ylabel('u_{c}(t)'); figure,
plot(t,uAM,'b');xlabel('t');ylabel('u_{AM}(t)');
实验四 抑制载波双边带条幅
Uoumigam=10;Ucm=10;oumiga=1e3;wc=1e4;A=1; t=0:0.00001:0.01;
uoumiga=Uoumigam*cos(oumiga*t); uc=Ucm*cos(wc*t);
uDSB=A*Uoumigam*Ucm*cos(oumiga*t).*cos(wc*t);
plot(t,uoumiga,'r');xlabel('t');ylabel('u_{\\Omega}(t)'); figure,
plot(t,uc,'g');xlabel('t');ylabel('u_{c}(t)'); figure,
plot(t,uDSB,'b');xlabel('t');ylabel('u_{DSB}(t)');