Hi Dragos and Nazrin,
I had same problem. Apperently in NO OS design DAC gain is to high, so power of input signal to IQ modulator is too high (mixers are in non linear regime). I make it work properly buy adjusting DAC gain:
| ad9122_fs_adj_I_DAC(0x000F); | |
| ad9122_fs_adj_Q_DAC(0x000F); |
you can put those in ad9122_setup functions. Default value in design was 505. Try that above, or put values to 0x0000. You will get two tones with DMA then too.mr_nazrin