Patent ID: 7265627

Claim:
A radio frequency (RF) linear power amplifier ( 200 ) operating in an output frequency band, having an output transistor (Q 2 ), said power amplifier comprising: (a) a circuit means ( 300 ′) for generating a bias signal producing a quiescent current flowing through said output transistor ( 42 ) of said RF power amplifier, b) a detector circuit means ( 210 ) for detecting RF input to said amplifier and generating a driving signal ( 215 ) according to a power level of said RF input; (c) a self-adapting circuit means ( 250 ) for receiving said driving signal ( 215 ) and automatically modifying said bias signal and said quiescent current through said output transistor (Q 2 ), whereby said quiescent current at said output stage is adjusted for reduced dissipation and increased linearity at all power output levels; and wherein the self-adapting circuit means ( 250 ) automatically modifies said quiescent current for an output stage amplifier by tracking detected RF signal being input to the amplifier at power ranges above a certain power output threshold; and wherein the detector circuit means ( 210 ) for generating said driving signal ( 215 ) is connected to said self adapting circuit means ( 250 ), said self adapting circuit means further including means ( 211 , 212 ) for filtering out any RE component of said driving signal ( 215 ).