I encountered a really odd behaviour of the RXs of the AD9361. I hope anyone has an idea.
There is a frequency offset between the two channels RX channels when a
sinosoid signal is fed into both channels from a signal generator and power
divider chain. So both channels sense signals with exactly the same frequency.
When tuned to 1781 MHz the difference between the Channel (f_A - f_B) is
-1.5497 Hz. This is measured by taking the samples from the receiver
calculating the phase difference and determine the frequency difference from
the (apparently linear) phase change rate. At fc = 781 MHz there is a
difference of -0.3576 Hz. Technically there should be no difference in
frequency at all, because the same LO is used (or isn't it?). Is there a
possibility to configure the LOs in the right way?