A transmitter circuit (400; 510) comprising: a power control error data generator operative to receive amplitude modulation data and a radio frequency coupled output signal and, in response, to produce power control error data; a feedforward predistortion data generator, operative to receive the amplitude modulation data and, in response, to produce feedforward predistortion data; feedforward adder logic, operatively coupled to the power control error data generator and to the feedforward predistortion data generator, and operative to receive the power control error data and the feedforward predistortion data and, in response, to produce power control data; an amplifier, operatively coupled to the feedforward adder logic, and operative to receive the power control data and a radio frequency input signal and, in response, to produce a radio frequency output signal, wherein the radio frequency coupled output signal is associated with the radio frequency output signal; wherein the feedforward predistortion data corresponds to a predicted amplitude modulation change in the amplifier in response to the amplitude modulation data, such that the power control data changes dynamically to reduce the amplitude modulation distortion in the amplifier; a coupler coupled to the amplifier to receive the radio frequency output signal and in response to produce the radio frequency coupled output signal, wherein the power control error data generator comprises an amplitude modulation error signal generator operative to receive the amplitude modulation data and the radio frequency coupled output signal, and comprising a differential amplifier which in response produces an amplitude modulation error signal; characterised in that the power control error data generator further comprises integrator logic, operatively coupled to the amplitude modulation error signal generator, and operative to receive the amplitude modulation error signal and, in response, to produce the power control error data; and that the amplitude modulation error signal generator further comprises a power detector predistortion circuit operative to receive the amplitude modulation data and, in response, to produce predistortion amplitude modulation data; and a digital-to-analog converter operative to receive the predistortion amplitude modulation data and, in response, to produce a predistortion amplitude modulation signal, wherein the differential amplifier is operative to receive the predistortion amplitude modulation signal and the radio frequency coupled output signal and, in response, to produce the amplitude modulation error signal, and wherein the power detector predistortion circuit is operative to dynamically vary the predistortion amplitude modulation data based on a predicted amplitude modulation change in the coupler in response to the amplitude modulation data. a power control error data generator operative to receive amplitude modulation data and a radio frequency coupled output signal and, in response, to produce power control error data; a feedforward predistortion data generator, operative to receive the amplitude modulation data and, in response, to produce feedforward predistortion data; feedforward adder logic, operatively coupled to the power control error data generator and to the feedforward predistortion data generator, and operative to receive the power control error data and the feedforward predistortion data and, in response, to produce power control data; an amplifier, operatively coupled to the feedforward adder logic, and operative to receive the power control data and a radio frequency input signal and, in response, to produce a radio frequency output signal, wherein the radio frequency coupled output signal is associated with the radio frequency output signal; wherein the feedforward predistortion data corresponds to a predicted amplitude modulation change in the amplifier in response to the amplitude modulation data, such that the power control data changes dynamically to reduce the amplitude modulation distortion in the amplifier; a coupler coupled to the amplifier to receive the radio frequency output signal and in response to produce the radio frequency coupled output signal, wherein the power control error data generator comprises an amplitude modulation error signal generator operative to receive the amplitude modulation data and the radio frequency coupled output signal, and comprising a differential amplifier which in response produces an amplitude modulation error signal; characterised in that the power control error data generator further comprises integrator logic, operatively coupled to the amplitude modulation error signal generator, and operative to receive the amplitude modulation error signal and, in response, to produce the power control error data; and that the amplitude modulation error signal generator further comprises a power detector predistortion circuit operative to receive the amplitude modulation data and, in response, to produce predistortion amplitude modulation data; and a digital-to-analog converter operative to receive the predistortion amplitude modulation data and, in response, to produce a predistortion amplitude modulation signal, wherein the differential amplifier is operative to receive the predistortion amplitude modulation signal and the radio frequency coupled output signal and, in response, to produce the amplitude modulation error signal, and wherein the power detector predistortion circuit is operative to dynamically vary the predistortion amplitude modulation data based on a predicted amplitude modulation change in the coupler in response to the amplitude modulation data.