Hi Guys,
I have the stepped frequency data which is in the range 1GHz -3GHz
(201 Frequency steps ; i.e. spacing 10MHz). I am using ifft (MATLAB
command). I am getting 201 points in time domain.
Q: What do the time samples (0-201) correspond to in terms of time
units (seconds)?
Thanks in advance
Tron
Time Domain Response
Started by ●May 8, 2006
Reply by ●May 9, 20062006-05-09
Tron-
> I have the stepped frequency data which is in the range 1GHz -3GHz
> (201 Frequency steps ; i.e. spacing 10MHz). I am using ifft (MATLAB
> command). I am getting 201 points in time domain.
>
> Q: What do the time samples (0-201) correspond to in terms of time
> units (seconds)?
The iFFT size does not matter; the sampling rate is determined by the Nyquist rate
which in your case is 2x the usable FFT bandwidth, or 4 GHz. So your time domain
sample period is 0.25 nsec.
But whether your time domain results are an accurate representation -- that's another
question. For one thing, your data has been quantized to large 10 MHz bins, so who
knows what is being missed.
-Jeff
> I have the stepped frequency data which is in the range 1GHz -3GHz
> (201 Frequency steps ; i.e. spacing 10MHz). I am using ifft (MATLAB
> command). I am getting 201 points in time domain.
>
> Q: What do the time samples (0-201) correspond to in terms of time
> units (seconds)?
The iFFT size does not matter; the sampling rate is determined by the Nyquist rate
which in your case is 2x the usable FFT bandwidth, or 4 GHz. So your time domain
sample period is 0.25 nsec.
But whether your time domain results are an accurate representation -- that's another
question. For one thing, your data has been quantized to large 10 MHz bins, so who
knows what is being missed.
-Jeff