I have a prototype with a HMC439 like attached image.
I added a mixer and an AD9914 DDS before the dividers.
My problem is when the output frequency is near integer values, I have big spurs.
For example, when I set 5500.1MHz, I have 5500.1MHz carrier and +/- 100KHz spurs.
I don't understand why I have spurs because the PLL works with integer values and DDS for fine values.
Thanks in advance for your help.