We are using EV-ADF5355SD1Z (RevA) board to generate signals in freq. range of 1 - 13 GHz, controlling by a microcontroller via SPI.
There occures a problem when generating signals periodically:
When we generate frequencies from 3GHz up to 4 GHZ, with 100MHz resolution in period of 20ms, we observe the signals with freq 3.1, 3.2, ..., 4.0 GHz by using spectrum analyzer.
Frequency at output is generated in this sequence (defined above) for a while, then it does not generate signals with freq 3 to 4GHz. It only generates one freq, for example 3.6GHz or other one . in this range.
When we monitor SPI signal - from micro controller to ADF5355 -, the SPI commands are sent to ADF5355 correctly.
When we toggle CE pin on EV-ADF5355SD1Z board, ADF5355 starts generating signal with freq in range 3 to 4GHz, afterwards it generates only one freq again.
Could you advise any solution about this problem, pls?
Note: This problem occures in other frequency ranges, e.g., 2-3GHz, 4-5GHz, ...