AnsweredAssumed Answered

How to do correlation with the 35670A?

Question asked by Rotterdam on Jan 19, 2011
Latest reply on Nov 1, 2011 by JohnMiles

I have a 35670A Dynamic Signal Analyzer and want to use it to measure very small signals.

I have two low-noise amplifiers but even they seem to be too noisy.

The 35670A seems to have a correlation feature which should make it possible to measure very small signals by amplifiing the same signal using both LNA and feed their outputs to the two input channels and calculate the correlation (or cross-correlation) of the two input signals.

Unfortunately the correlation features of the 35670A are not documented very well.

Could anyone please tell me how to setup the instrument for such measurements or point me to some kind of tutorial un the web?

Also I would be interested if I can get (in addition to the input signal connected to the two LNA) the noise floor of each LNA out of this measurement. Of course I could short the inputs of the LNA or just terminate them, but I would also like to see their noise performance when an input signal is present (maybe also with a higher amplitude and hence possibly a higher noise voltage than the LNA have).

So the target is to get three signal curves:
1. Input signal mostly independent of the LNA noise
2. Input noise of LNA 1 mostly independent of input signal noise
3. Input noise of LNA 2 mostly independent of input signal noise

Is that possible with the 35670A?

Best Regards,