clear all
close all
clc
L=10;
n=1.45;
Omega=1.020663297455751e+11;
GAMMAb=3.590391604102621e+08;
c=2.9979e8;
dt=6e-12; %time increment
T=10*2*L*n/c; %total time
fmax = 1e9; %maximun frequency
%fs=80*fmax;

TA=-T/2:dt:T/2; %time axis for the signal
fs=1/dt; %sampling frequency
%t = (-T/2/dt:1:T/2/dt)*dt;
Nt=round(T/dt);

vsine = 1;
phi = vsine*sin(2*pi*fmax*TA);
EL1t=1.274e7*exp(1i*phi); %signal
plot(TA,(EL1t));
%FA = ((0:Nt-1)-floor(Nt/2))/Nt*fs;
FA = (-Nt/2:Nt/2-1)/Nt*fs; %frequency axis
FP=fft(phi); %fft of the signal
%fs=1/dt/Nt;
figure;
Z=plot(FA,fftshift(abs(fft(EL1t/Nt)))); %fft plot with frequency axis
xlim([(Omega/2/pi-GAMMAb/2/pi/2) (Omega/2/pi+GAMMAb/2/pi/2)])
freqlim1=dsearchn(FA’,(Omega/2/pi-GAMMAb/2/pi/2))
freqlim2=dsearchn(FA’,(Omega/2/pi+GAMMAb/2/pi/2))
FA1=freqlim1:freqlim2;
freqlim=dsearchn(FA’,Omega/2/pi)
Y1=fftshift(abs(fft(EL1t(freqlim)/Nt))) %value of the signl at Omega
I have been trying the index of the signal corresponding to frequency at Omega.Graphically it is around 197 and when i substitute the index number in the fft expression , it is showing around 79.
Is this the case of indexing gone wrong??…clear all
close all
clc
L=10;
n=1.45;
Omega=1.020663297455751e+11;
GAMMAb=3.590391604102621e+08;
c=2.9979e8;
dt=6e-12; %time increment
T=10*2*L*n/c; %total time
fmax = 1e9; %maximun frequency
%fs=80*fmax;

TA=-T/2:dt:T/2; %time axis for the signal
fs=1/dt; %sampling frequency
%t = (-T/2/dt:1:T/2/dt)*dt;
Nt=round(T/dt);

vsine = 1;
phi = vsine*sin(2*pi*fmax*TA);
EL1t=1.274e7*exp(1i*phi); %signal
plot(TA,(EL1t));
%FA = ((0:Nt-1)-floor(Nt/2))/Nt*fs;
FA = (-Nt/2:Nt/2-1)/Nt*fs; %frequency axis
FP=fft(phi); %fft of the signal
%fs=1/dt/Nt;
figure;
Z=plot(FA,fftshift(abs(fft(EL1t/Nt)))); %fft plot with frequency axis
xlim([(Omega/2/pi-GAMMAb/2/pi/2) (Omega/2/pi+GAMMAb/2/pi/2)])
freqlim1=dsearchn(FA’,(Omega/2/pi-GAMMAb/2/pi/2))
freqlim2=dsearchn(FA’,(Omega/2/pi+GAMMAb/2/pi/2))
FA1=freqlim1:freqlim2;
freqlim=dsearchn(FA’,Omega/2/pi)
Y1=fftshift(abs(fft(EL1t(freqlim)/Nt))) %value of the signl at Omega
I have been trying the index of the signal corresponding to frequency at Omega.Graphically it is around 197 and when i substitute the index number in the fft expression , it is showing around 79.
Is this the case of indexing gone wrong??… clear all
close all
clc
L=10;
n=1.45;
Omega=1.020663297455751e+11;
GAMMAb=3.590391604102621e+08;
c=2.9979e8;
dt=6e-12; %time increment
T=10*2*L*n/c; %total time
fmax = 1e9; %maximun frequency
%fs=80*fmax;

TA=-T/2:dt:T/2; %time axis for the signal
fs=1/dt; %sampling frequency
%t = (-T/2/dt:1:T/2/dt)*dt;
Nt=round(T/dt);

vsine = 1;
phi = vsine*sin(2*pi*fmax*TA);
EL1t=1.274e7*exp(1i*phi); %signal
plot(TA,(EL1t));
%FA = ((0:Nt-1)-floor(Nt/2))/Nt*fs;
FA = (-Nt/2:Nt/2-1)/Nt*fs; %frequency axis
FP=fft(phi); %fft of the signal
%fs=1/dt/Nt;
figure;
Z=plot(FA,fftshift(abs(fft(EL1t/Nt)))); %fft plot with frequency axis
xlim([(Omega/2/pi-GAMMAb/2/pi/2) (Omega/2/pi+GAMMAb/2/pi/2)])
freqlim1=dsearchn(FA’,(Omega/2/pi-GAMMAb/2/pi/2))
freqlim2=dsearchn(FA’,(Omega/2/pi+GAMMAb/2/pi/2))
FA1=freqlim1:freqlim2;
freqlim=dsearchn(FA’,Omega/2/pi)
Y1=fftshift(abs(fft(EL1t(freqlim)/Nt))) %value of the signl at Omega
I have been trying the index of the signal corresponding to frequency at Omega.Graphically it is around 197 and when i substitute the index number in the fft expression , it is showing around 79.
Is this the case of indexing gone wrong??… fft, indexing, plot MATLAB Answers — New Questions

​