nRF905 phase noise

[Az-eddine]

Hi ,

can anyone tell me what can cause these disturbances around the unmodulated carrier?

IMG-20171110-WA0017.jpg

We checked all components arround the IC it's all ok.

Can be phase noise ? it depends on the nRF905' VCO?

16 Mhz EXTAL

Many thanks

[ovrebekk]

Hi

I need some assistance from one of the hardware experts on this one. He is out on travel today, but should be back tomorrow.

In the mean time, could you share your schematic and layout files?

Then it is easier for us to find the problem.

Best regards

[Az-eddine]

Hi, my schematic is the same suggested on the nRF905 datasheet.I used it for many years but in theese days I'm having this problem.I checked all components arround it ,nothing strange!! Thanks in advance

Best regards

[ovrebekk]

Hi

Apparently this could be noise on your power supply.
Are you able to test using an external power source, like a lab power supply?

You might want to scope your supply lines as well, and see if you can measure the noise.

Best regards