I've been continuing to work on why my power level seemed low after getting the Skyworks FEM in my Fanstel BT840x module going, per this thread:
So far, I've been setting the power level (nrf_802154_tx_power_set() ) to +2dB because that's what the Skyworks FEM says to set the power level to.
Today I ran out of ideas for why my power level was so low, so I started turning up the power - I found that the higher I set, it even past what I thought was the maximum of +8, the higher my power level went (per a spectrum analyzer). I'm now calling that function with a parameter of 22 (+22dBm) and it's working pretty well.
I think what's going on is that the MPSL FEM driver is smarter than I imagined it was and that it is aware of the gain provided by the FEM - and it incorporates that into the power level setting, so when I say +2dBm I think it's setting the power to something like -18 knowing that the amplifier adds 22dB, resulting in a final output power of +2dBm.
My question is: Is the above correct, and if so, what should I send to nrf_802154_tx_power_set() to get the proper maximum power level without overdriving (so that we're sending +2dBm into the FEM).
Thanks,
Glen
