We have an IQ amplitude imbalance on AD9361, which happens quite often. Result repeats on zedboard with FMCOMM and on our custom board.
And the broken one looks like this:
Some times problem appears when we change amplitude of sine wave on generator, sometimes it happens by itself.
Problem dissapears after some time (several minutes) or changing amplitude of sine wave to 5-10 dBm (almost immediately).
How can we solve this issue?