I have orfered from eBay this ADF4351 35 MHz to 4.4 GHz generator. Here is ADF4351 datasheet, evaluation board user guide UG-435 and PLL Software Installation Guide UG-476 . It realy has a ADF4351 (not a ADF4350). Software is here.
Built in oscillator is VCC1-B3D. USB part of the board is totally isolated from the MW generator. A doubler with HMC189A is used with the second output to produce 4-8 GHz. As the output needed is less than required, a 20 dB amplifier is used. The female connector of the doubler was replaced with a chassis one. There is a external reference input and a 5V power input except the USB that it seems enough to supply both PCBs (the doubler is passive) with the supplied USB cable. For the amplifier 5V is stealed from the main PCB.
The board that it was send it was different than this that is in the eBay.