Error driven RF power amplifier control with increased efficiency

A radio frequency (RF) power amplifier system, comprising:

• a power amplifier coupled to receive and amplify an RF input signal to generate an RF output signal;
• a variable gain amplifier (VGA) coupled to the power amplifier for adjusting the RF input signal based upon a gain control signal, the gain control signal adjusting the gain of the VGA in order to maintain constant difference between the RF output signal and the RF input signal;
• a power amplifier controller coupled to the power amplifier for controlling a supply voltage to the power amplifier;
• and
• the supply voltage adjusted based on a difference between a deviation signal and a distortion level control signal, the deviation signal based on a time-varying change of gain of the VGA, the distortion level control signal corresponding to an allowable distortion level in the RF output signal.

A method of amplifying an RF input signal using a power amplifier, comprising:

• amplifying the RF input signal by the power amplifier to generate an RF output signal;
• generating an error signal based on a difference between the RF input signal and a RF output signal;
• generating a supply voltage control signal based on a difference between a deviation signal and a distortion level control signal, the deviation signal based on a measured level of activity of the error signal;
• and
• adjusting a supply voltage to the power amplifier based on the supply voltage control signal.

A method of amplifying an RF input signal using a power amplifier, comprising:

• amplifying the RF input signal by the power amplifier to generate an RF output signal;
• adjusting the RF input signal by a variable gain amplifier (VGA) based on a gain control signal to maintain constant a difference between the RF output signal and the RF input signal;
• generating an error signal based on a difference between the RF input signal and a RF output signal;
• and
• adjusting a supply voltage to the power amplifier based on a difference between a deviation signal and a distortion level control signal, the distortion level control signal corresponding to an allowable distortion level in the RF output signal.