I used following HW & SW setups and found that DAC output was corrupted by maybe DAC and/or circuit (balun, RF choke, etc.).
ZCU102 & AD9174-FMC-EBZ as HW.
JESD204B mode 18 + Wideband mode real dual (no NCO, interpolation used)
DAC sampling rate : 3Gsps
Input digital data : sinusoidal wave (10/20/30/40/50 MHz), sinusoidal wave (10/20/30/40/50 MHz) + some modulation
When I input simple sinusoidal wave data with different frequency and with "the same" amplitude from FPGA to DAC, the output amplitude measured by oscilloscope varies according to the frequency of the input sinusoidal wave.
The output amplitude becomes larger with higher input frequency. In this case, the amplitude of the 50MHz sinusoidal wave was twice as large as that of 10MHz sinusoidal wave. Looks like some HPF is applied.
When I input modulated sinusoidal wave data, the output waveform was corrupted. In this case, I applied some kind of phase modulation where 180 degree phase rotation is applied per 2 cycle of sinusoid.
From the above, I think the output of AD9174-FMC-EBZ has some frequency characteristics around 10~50 MHz or something I should case.
Could someone point this out?