Greetings wahooburger (sounds a lot like my nane
Power control is implemented in the transceiver.
The transceiver output typically feeds directly
into the PA. Most WLAN PAs now have a built-in power
detector that feeds back to the transceiver. Bias
control on the PAs is used to achieve best performance
(EVM, harmonics, Psat, etc.), but the gain of the
PA is usually fixed by design (about 30 dB for a
SiGe, RFMD, Fairchild, Gatax,
Tavanza, RFIC, RF Solutions, Skyworks, and many
others make WLAN PAs. You can get scads of info
from their websites.
- Kirt Blattenberger