Patent ID: 8824981

Claim:
A method for adjusting a nonlinear transfer function of an envelope tracking power supply for a power amplifier, comprising: supplying an output signal of the power amplifier to a feedback receiver to obtain a feedback signal; determining an assumed performance of the power amplifier by evaluating the nonlinear transfer function at a first value defined by an input signal for a transmitter comprising the power amplifier; determining an actual performance of the power amplifier by evaluating the nonlinear transfer function at a second value defined by the feedback signal, wherein determining the actual performance comprises: determining a total gain of the transmitter based on the feedback signal and the input signal; and determining an actual gain of the power amplifier based on the total gain and a known gain of the transmitter without the power amplifier, wherein the actual gain is compared with a desired gain of the power amplifier for a given supply voltage for the Power amplifier; and determining a correctional value for a parameter of the nonlinear transfer function based on a difference between the assumed performance and the actual performance.