Transmitter circuit and method for modulation distortion compensation

A transmitter circuit comprising:

• an amplitude modulation error signal generator operative to receive amplitude modulation data and a RF coupled output signal and in response to produce an amplitude modulation error signal;
• 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 power control error data;
• a feedforward predistortion data generator, operative to receive the amplitude modulation data and in response to produce feedforward predistortion data;
• and
• feedforward adder logic, operatively coupled to the integrator logic, the feedforward predistortion data generator and to the amplifier, 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 in response to produce an RF output signal associated with the RF coupled output signal, such that the power control data is operative to reduce amplitude modulation distortion in the RF output signal.

A transmitter circuit comprising:

• a digital-to-analog converter operative to receive amplitude modulation data and in response to produce a predistortion amplitude modulated signal;
• a differential amplifier, operatively coupled to the digital-to-analog converter, and operative receive the predistortion amplitude modulated signal and a detected RF output signal and in response to produce an amplitude modulated error signal;
• an analog-to-digital converter, operatively coupled to the differential amplifier, and operative to receive the amplitude modulated error signal, and in response to produce amplitude modulation error data;
• error attenuator logic, operatively coupled to the analog-to-digital converter, and operative to produce error attenuated data in response to the amplitude modulation error data;
• an integrator register operative to receive the power control error data and in response to produce stored error data;
• integrator adder logic, operatively coupled to the error attenuator logic and the integrator register, and operative to receive the error attenuated data and the stored error data and in response to produce the 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 integrator logic, the feedforward predistortion data generator and to the amplifier, and operative to receive the power control error data and the feedforward predistortion data and in response to produce power control data;
• and
• an amplifier, operatively coupled to the feedforward adder logic, and operative to receive the power control data and an RF input signal, and in response to produce an RF output signal associated with the RF coupled output signal, such that the power control data is operative to reduce amplitude modulation distortion in the RF output signal.

A wireless device comprising:

• a transmitter circuit including:
• a power control error data generator operative to receive amplitude modulation data and a RF 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 distortion data;
• and
• 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 an RF input signal and in response to produce an RF output signal, wherein the power control data reduces amplitude modulation distortion in the RF output signal;
• a base band processor, operatively coupled to the feedforward predistortion data generator, and to the power control error data generator and operative to produce the amplitude modulation data;
• and
• an antenna, operatively coupled to the amplifier, and operative to receive the RF output signal and in response to transmit the RF output signal.

A method to reduce amplitude modulation distortion in an amplifier comprising:

• producing power control error data in response to receiving amplitude modulation data and a detected RF output signal;
• producing feedforward predistortion data in response to the amplitude modulation data;
• and
• combining the power control error data and the feedforward predistortion data to provide power control data to the amplifier such that the power control data reduces the amplitude modulation distortion in the amplifier.