I am evaluating the ADF5355 part on the EVAL-ADF5355 board provided by Analog Devices. I am having difficulty achieving the phase noise performance that is represented using the ADIsimPLL simulation. I have tried using multiple loop filter configurations as well as varrying the charge pump current, but I have been unable to acheve the performacne in the simulation. I am attempting to improve the performance at 10-100kHz to add margin to my design.
My refference is supplied is 50MHz and (I believe) is properly represented in the ADIsimPLL simulation.
I have attached simulation and actual measurements.