AnsweredAssumed Answered

AD9361 phase changes with AGC, is there a low phase gain table?

Question asked by gizmoaudio on Jun 20, 2017
Latest reply on Jun 28, 2017 by Vinod

This is a quote from a posting regarding the LNA phase shift going from bypass to non-bypass. "Yes, you will see a change in signal phase vs gain index. You can either characterize it and take care of it by post processing or you can customize the gain table to minimize the phase shift." 

 

Is there available information on Gain, Intercept, Noise Figure for the individual sections - iLNA, Mixer, TIA, LPF for their various individual gain settings or is there a table available that maximizes dynamic range while not putting the LNA in bypass mode? 

 

If I use the standard gain table with Table index of 0 to 33 and keep the LNA in bypass, the gain range is only 31dB.

If I use the standard gain table with Table index of 34 to 76 and keep the LNA gain in non-bypass, the gain range is only 42dB. Neither of these is enough for my application.

 

The sum of the gain ranges of the individual components with the LNA operating in non-bypass mode is 62dB.

LNA    24-17    = 7

Mixer  25-0    = 25

TIA       0 to -6 = 6

LPF     24-0     = 24

Is it possible to create an optimized table with this gain range and not saturate individual elements as the gain varies?

 

 

Outcomes