A power amplification system within an RFID reader uses feedback to linearize a transfer function of the system. ASK modulation is used in the system. An envelope of an output signal of a non-linear power amplifier is fed back to an input where it is combined in an integrator with an ASK modulation signal to generate a pre-emphasized modulation signal. The pre-emphasized modulation signal is then applied to the power amplifier to generate a linearized output signal.