Data from Agilent Network analyzer
The problem is that 1) detection techniques are available for time domain data whereas from analyzer s-parameters are available for frequency sweep
2) for classical techniques we need time domain real reflected data ,but s parameters are ratio-ed numbers of reflected over incident, and niether do we have one single quantity?
3) How to tackle with phase amplitude data
Use IFFT for full bandwidth.
This time domain ability is available, if you have time domain function in your network analyzer.
Thank you so much for your reply..And how to tackle with the fact that s parameters are ratio-ed numbers and also the phase information?
and what if we want to observe transmission and reflection effect for one particular frequency?
Do you understand FFT/IFFT surely ?
If you would like to get S-parameter in time domain, the phase informations of S-parameter in frequency domain are required.
Do you understand S-parameter surely ?
S-parameter in frequency domain express transmission and reflection effect for one particular frequency.
To avoid misunderstanding, what methods do you want to implement?
"classical radar motion detection " ==> classical motion techniques rely on the doppler information inherent on the carrier wave. Now, to fetch the doppler information you need to make abservation, or in other words check the time derivative of phase at a specific frequency. So you need a series of phase readings from the network analyzer.
"s parameters are ratio-ed numbers", this ismuch better, since radars also rely on the ratios of transmitted and received carrier.Usage of reflectionor transmission parameters rely on your application. Try to focus on the case with higher SNR!
In motion detection phase is much more important than amplitude but as asserted before, you need better than enough SNR to correctly quantify the phase. Amplitude data can be utilized with phase info for heuristic motion detection algorithms.
This is correct, but this doppler radar works at a single fixed frequency (CW). After mixing the received and the transmitted signal, you get a low frequency signal that is proportional to speed. I would not call this a time domain method.
I think that a network analyzer isn't a useful instrument for doppler speed measurement. One reason is that the VNA is designed to sweep the frequency (unlike doppler radar) and measure the received signal at the exact same frequency (unlike doppler radar).
Swept frequency radar methods like FMCW are usually used for position/distance measurement, for a fixed (not moving) target.
See http://cp.literature.agilent.com/lit...990-5392EN.pdf