I'm testing a system made by a chain of ADRF6720 and ADRF6820 with a modulator with I/Q source (TX) and a demodulator with I/Q receiver, Here the scheme
PLL oscillator are ok for both adrf6720 and adrf6820. Upconverted signal semms to be ok: here the plot of @ RF out on ADRF6720
and the configuration of adrf6720
I think I have some problem on downconverter. Seems I have just signals on both positive I+ and Q+, while I have no signals on I- and Q- connector @ adrf6820 ports, and obviously the communication between modem doen't work.
On downconverter, I have just programmed the PLL to run @ 2 GHz (and it seems to run correctly), other parameters are @ default
I don't understand this behaviour...Obviously in input on upconverter (ADRF6720) all I+I-Q+Q- are present and running
What do you think? Let me now