hi,
Do any spectrum analysers have the capability to reverse the frequency domain display to a time domain repesentation, say via inverse FFT .

So multi-tone signals can be viewed as original waveform, which may be too high for oscilloscope ..

 

hi,
Do any spectrum analysers have the capability to reverse the frequency domain display to a time domain repesentation, say via inverse FFT .

So multi-tone signals can be viewed as original waveform, which may be too high for oscilloscope ..

If the multi-tone signals are too high a frequency to be viewed on an oscilloscope, they will certainly be too high a frequency to be viewed on a spectrum analyser. They both use the same sampling technique to digitize the waveform.

 

not been clear
If the multi-tone signals are too high a frequency to be viewed on an oscilloscope, they will certainly be too high a frequency to be viewed on a spectrum analyser. They both use the same sampling technique to digitize the waveform.

Say
Maybe I have not been clear ..

Example would be signal of 1 GHz and 0.9 GHz, combined, these would display ok on 1.5GHz SA, as 2 peaks in Frequensy Domain but would not display on 100Mhz scope. I would like to see the shape of the combined signal, not in real time but as represented by SA FD display

 

Say
Maybe I have not been clear ..

Example would be signal of 1 GHz and 0.9 GHz, combined, these would display ok on 1.5GHz SA, as 2 peaks in Frequensy Domain but would not display on 100Mhz scope. I would like to see the shape of the combined signal, not in real time but as represented by SA FD display

Would you conclude from the 2 peaks on the SA that they represented undistorted sine waves BECAUSE there were no higher frequency components that you could observe? That would be a bit presumptuous I think.

 

Get a higher frequency oscilloscope. Then you can check it for yourself.

https://www.rohde-schwarz.com/us/pr...oscopes/rs-rtp-oscilloscope_63493-469056.html

 

Would you conclude from the 2 peaks on the SA that they represented undistorted sine waves BECAUSE there were no higher frequency components that you could observe? That would be a bit presumptuous I think.

a bit sarcastic, ... i think

 

Get a higher frequency oscilloscope. Then you can check it for yourself.

https://www.rohde-schwarz.com/us/pr...oscopes/rs-rtp-oscilloscope_63493-469056.html

some strange people on this forum, I'll try another one ..

 

some strange people on this forum, I'll try another one ..

I was not trying to be offensive. I was just letting you know that there are scopes that work at those high frequencies.

If you can save the digitized frequency domain waveform to a computer, there is software that will do a reverse Fourier transform. Two examples are Matlab andAgilent Vee Pro.

 

a bit sarcastic, ... i think

I was not trying to be sarcastic but merely point out that the 1.5 GHz SA has its own limitations in trying to infer the shape of the input waveform. The second harmonics are at 1.8 GHz. and 2.0 GHz. for the two inputs. You would probaly need harmonics out to the 9th or 11th to infer much about the wvfrom shape from the frequency domain data. If there is data in the captured input that is not displayed by the SA, then such post ptocessing of the data might be useful.

 

I was not trying to be offensive. I was just letting you know that there are scopes that work at those high frequencies.

If you can save the digitized frequency domain waveform to a computer, there is software that will do a reverse Fourier transform. Two examples are Matlab andAgilent Vee Pro.

Thanks for response.
I obviously know there are ways of throwing money at this issue, I cannot justify that.
All I wanted to know was whether there was a mode on the SA that would display this data, within the BW of the SA.
Thanks for additional info.

 

I was not trying to be sarcastic but merely point out that the 1.5 GHz SA has its own limitations in trying to infer the shape of the input waveform. The second harmonics are at 1.8 GHz. and 2.0 GHz. for the two inputs. You would probaly need harmonics out to the 9th or 11th to infer much about the wvfrom shape from the frequency domain data. If there is data in the captured input that is not displayed by the SA, then such post ptocessing of the data might be useful.

Thanks for response, the 1 GHz was just a example.
If the SA had this feature, \i would choose one with BW adequate for signal under test and my required accuaracy.
thanks

 

Thanks for response.
I obviously know there are ways of throwing money at this issue, I cannot justify that.
All I wanted to know was whether there was a mode on the SA that would display this data, within the BW of the SA.
Thanks for additional info.

If there was, there has to be a better way of discovering it than posting to a forum without specifying the make and model of the spectrum analyzer you are talking about. BTW it is my impression that a good oscilloscope is cheaper than a good spectrum analyzer. But who knows. It's been a long time since I had to go shopping.

 

If there was, there has to be a better way of discovering it than posting to a forum without specifying the make and model of the spectrum analyzer you are talking about. BTW it is my impression that a good oscilloscope is cheaper than a good spectrum analyzer. But who knows. It's been a long time since I had to go shopping.

The query was general, not related to model ..
Your advice on my ineptitude is far clearer than any technical stuff,
I will try and be a better person ...

 

The query was general, not related to model ..
Your advice on my ineptitude is far clearer than any technical stuff,
I will try and be a better person ...

You ask a question about what you think must be a common feature of a spectrum analyzer and you get testy when you don't ge the response you expect. I really don't know what to call that.

 

You ask a question about what you think must be a common feature of a spectrum analyzer and you get testy when you don't ge the response you expect. I really don't know what to call that.

sad ..

 

sad ..

Ummm. Not much point in complaining to us, take it up with the instrument makers