I am using an ADF4350 as LOs in a radio link at 2401.7 MHz. What would be the suggested setup for such a frequency using a Ref of 10 MHz???
- Int-N or Frac-N mode and why?
- Counter values?
- R x2 or div 2 yes or no?
- Feedback divider?
I have it setup now as an Int-N with R=100 --> Fpfd = 100 kHz, BSC divider = 2 --> Fbsc = 50 kHz, and N =24017.
No dividers or doublers enabled, loop filter designed with ADIpllSIM with ~6 kHz BW.
*Problem is that my phase noise is horrible. Looking at the spectrum with a 100kHz span, I see a mound that is 10's of kHz wide around -36 dBm, far below the ~-5 dBm expected. What I need help with is
- at what point do I switch to Frac-N mode, i.e. what Fpfd or R value?
- is the N counter the main source of my noise problems? Of the R counter?
- ANY suggested setups would be appreciated!