ad9361 AGC

Hello all,

Vivado 2018.3

SDK no-os

ad9361 SOM

Can someone explain to me why the AGC response is different between the 800 MHz vs the 155 MHz. The gain table in the no-os talks about 800, 2300, 5500 MHz only and I am assuming that 155 MHz will use the 800 MHz table. Everything is the same in the 2 figures (attached file) except, one uses a 155 MHz carrier while the other one uses 800 MHz carrier. The signal is a 180 ms C4FM burst

Do we need a separate gain table for the 155 MHz?

What can I do to get similar performance of the AGC to the one in the 800 MHz?DOCX

Regards,

Murad

  • +1
    •  Analog Employees 
    on Feb 17, 2021 7:22 AM 1 month ago

    One difference will be the matching at these two frequencies. As the input level changes the thresholds remaining same the AGC will act differently.

    If you see the plots there is difference in average power between the two frequencies. For experiment purpose you can adjust input power of one to match the RMS power to be same and then check AGC performance.

    May be you can use CW signal for this experiment.

  • Thank you, Vinod,

    I did see a difference in the average power between the two frequencies. the 155 MHz show and average power (I^2+Q^2) 1.6 times that for the 800 MHz. 

    I'll try adjusting the AGC settings and hope that will get rid of the AGC overshoots

    Regards,

    Murad