DAC39RF10: Suppressing Spurious at 5MHz Offset Using Additional NCOs

Tool/software:

Hi,

I am using the DAC39RF10 in DES2xL mode with a 10.5GHz sampling clock, which has a spurious tone at 5MHz offset at -57dBc. This spurious originates from PLL divider products of the LO source generating the 10.5GHz clock.

I am generating a 3.5GHz output using one of the NCOs, and I observe the same 5MHz spurious at -67dBc in the DAC output.

I would like to know if it is possible to use the additional NCOs and the RF bonder to generate a phase-shifted version of this 5MHz spurious and suppress it through cancellation. Specifically:

1. Can the RF bonder be used to combine multiple NCO outputs in a way that cancels out the spurious tone?
2. Are there any known techniques for using the additional NCOs to mitigate clock-induced spurious components?
3. Would adjusting the phase or amplitude of an additional NCO help in reducing the 5MHz spurious?

Any insights on using the DAC’s internal NCOs and RF bonder for spurious cancellation would be greatly appreciated.

Thanks!