Seems simple at first sight.
Apply a sine wave to the DUT through R=Zo Multiply voltage by 1/(j w) Take inverse FFT.
The outcome is... uhhh
I must have overlooked something, but what?
...going to bed. Maybe I'll do better tomorrow.
"Fred Bartoli" wrote in message news:45a6c38e$0$292$ snipped-for-privacy@news.free.fr...
What are you trying to do?
There is something called frequency domain reflectometry but, with that, you need to sweep the DUT through a range of frequencies.
Bob
Yeah, but what's wrong with good old TDR? It's simple and it works.
Yeah, simple, but try to obtain precision on a 5km line while still having the communication link working with big data signal on the TDR side, and also decent aquisition time.
Other "neat" equipment monitoring features provided almost for free by the VNA.
TDR has its limitations when the transmission line gets long (lossy) and in the presence of noise. The advantage of frequency domain reflectometry (FDR) is that, when applying a given frequency, you can apply a sharp bandpass filter and thus reject noise. It is then relatively easier to "pick out" the effect of any reflections.
Yes, FDR is more complex than TDR so it will depend on your application whether one technique is better than the other.
Bob
Yeah, but you didn't say that in you post :-)
If the channel has to keep running TDR might indeed not be such a cool option. Except if you could use syncs or certain other features in the signal as a "TDR pulse".
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