[Premium-Rx] R&S PR100 IQ demodulation mode?

[Charles P. Steinmetz]

matt wrote:

>I have software to process the raw (undemodulated) I-Q IF 
>output.  I'm trying to figure out what the IQ demodulation mode 
>itself is actually doing.

I don't know what your particular software does, but given I and Q 
signals, you can derive all of the various forms of modulation with 
different processing (i.e., by implementing different mathematical 
algorithms in either the digital or the analog domain).  That's the 
beauty and power of IQ systems.  See Experimental Methods in RF 
Design, Chapter 9, for an accessible discussion (and some math) 
regarding the use of I and Q signals to recover one or the other 
sideband.  (This is what "phasing" SSB rigs do.)

Some hams like to listen to baseband I and Q signals binaurally in 
stereo headphones (I in one ear and Q in the other -- see above 
reference at Section 9-5).

Best regards,

Charles