In page 10 of the AD9164 data sheet,I can see the picture below。
Can you tell me how to get this 4GHZ？use NCO or series mode?
besides is there still be a 1 GHz image frequency when i get the 4 GHz?
Because of the JESD204B speed limitation to 12.5Gbps per lane, the maximum baseband bandwidth can be achieved is 2.5GHz in complex mode (if a interpolation filet is used, bandwidth limitation of the filter should be considered as well). So, 4GHz can't be realized just with JESD. To create a 4GHz output tone you have two options:
- use NCO-only mode and create a tone at 4GHz while the DAC clock rate is at 5GHz (according to the test condition mentioned in table 9) and 2xNRZ mode is selected.
- create a single tone at 2GHz using JESD (any frequency less than 2.25GHz-considering interpolation filter bandwidth- can work too) and shift the signal using NCO to 4GHz. to realize this case, 2x interpolation plus 2xNRZ mode need to be used.
That's all! Then you'll get 4GHz signal at the output.
thank you very much！