Hello,
I'll try to help out with the AD8302 related question.
You don't have to use any burst function or any other special functions of the signal generators. Phase lock the generators and then just slightly vary the frequency like you have, 1.1 Mhz and 1.0 MHz, the phase difference will accumulate over a 100 kHz cycle time (10 us period). If you probe the Vphs output with an oscilloscope you will see a triangular waveform with a frequency of 100 kHz.
Most DMMs will give you the RMS of what is being probed, so you won't see the phase variation with a DMM, you must use a scope.
Hope this helps,
Joel