Hi Sigi,

Thanks for your thoughts and for the diagram. To be honest, I do not clearly understand what you measured and what your diagram is telling me.

I second your statement that generally an amplifier generates less non-linearity products at lower output levels. Looking at the datasheet, you will notice that the AD9363 manages its output level by a variable attenuation - not by a variable amplification - and therefore, I do not expect a noticable improvement of non-linearity effects with reduced output levels.

I'm lacking equipement for a serious spurious measurement, like a spectrum analyzer being able to visualize the third harmonic that is stated at -30dBc in the datasheet. I can reproduce that IMD3 of a Pluto @2.4GHz is at around -38dBc and it is not getting any better when reducing the output power of the Pluto.

Anyway, I'm running the Pluto at output levels < -10dBm, as my PA has enough gain and I did not want to spend an extra attenuator in front of it.

73 Jean DJ0VL