I'm generating signals in the time domain and I need to be able to adjust the offset as well as the level (ie. full scale). The maximal power isn't critical, more the precision and resolution of the output. I ordered samples of some AD differential amplifiers in the 3-5GHz BW, I'll see how they work when the AD9129 Output drives a resistive load. I don't have precise requirements yet, just trying to achieve the best possible with COTS components.
Best,
KaZ