AD9914 Noise floor problem

Dear Sir & Madam,

I have a problem with AD9914 at RF out as you can see in attached .mov file. And also schematic of the ciscuit is atached. The clock frequency is 3.5GHz. As you can see from the attached movie when the problem is exist and ref-clock pins are shorted together in 1 sec, the problem disappears. I could not find any way to solve that problem, please give me some suggestion to solve that problem.

Note: I initialized DAC-CAL register just at start-up. Is it possible to solve that problem with initialing DAC_CAL register at different temerature ranges or any time during operation.