plotting power Vs frequency graph

Hi all,

I have loaded some data from the oscilloscope and I need to plot power vs frequency graph for my data. I usually use pwelch to plot the frequency response but it seems for this data it wont give me good frequency respose. anyone can help please.

Fs=10e9. L=1000000

Answer 1

[Star Strider]

I am not certain what the probme is with pwelch. It appears to give the correct result when I plot it.

Alternatively, try this:

s = readmatrix('Sumof3MIMOsDATASET1afterDACFs10G200K512eros.csv');
Fs=10e9;
L=numel(s);

t = linspace(0, L, L)/Fs;
Ts = 1/Fs;
Fn = Fs/2;
t = linspace(0, L, L)*Ts;
ms = mean(s);
FTs = fft(s)/L;
Fv = linspace(0, 1, fix(L/2)+1)*Fn;
Iv = 1:numel(Fv);

figure
plot(t, s)
grid
xlabel('Time (s)')
ylabel('Amplitude (Units)')

figure
semilogy(Fv, abs(FTs(Iv))*2)
grid
xlabel('Frequency (Hz)')
ylabel('Amplitude (Units)')

figure
plot(Fv, mag2db(abs(FTs(Iv))*2))
grid
xlabel('Frequency (Hz)')
ylabel('Power (Units^2)')

.

[shirin]

Thanks!

[Star Strider]

As always, my pleasure!