I received a question about +/-10kHz and +/-20kHz offset spurious of ADF5355 from our customer.
When he set to output frequency at 12.05GHz, the output has +/-10kHz and +/-20kHz offset spurious. Plese refer following picture.
REF=50MHz, and regster setting are followings;
On the other hand, the customer set t output frequency at 12.050004GHz, 12.1499GHz, 12.3498GHz, 12.3497GHz and so on, there are no spurious.
Then, the customer changed MOD2 setting for getting 12.05GHz output frequency. But he can see the spurious when output frequency is 12.05GHz.
Do you have any ideas about a cause of the spurious and how to improve it?