Abstract: Apparatus and methods for envelope shaping in a mobile device are provided. In certain implementations, a mobile device includes an envelope tracker configured to control a voltage level of a power amplifier supply voltage based on a shaped envelope signal, a power amplifier configured to receive the power amplifier supply voltage and to provide amplification to a radio frequency signal, and a transceiver including a modulator configured to generate the radio frequency signal and an envelope shaping circuit configured to generate the shaped envelope signal by shaping an envelope of the radio frequency signal. The envelope shaping circuit includes a shaping table configured to maintain a substantially constant distortion in a transmit band of the mobile device across a range of the envelope of the radio frequency signal.

Abstract: Apparatus and methods for envelope shaping in a mobile device are provided. In certain implementations, a mobile device includes an envelope tracker configured to control a voltage level of a power amplifier supply voltage based on a shaped envelope signal, a power amplifier configured to receive the power amplifier supply voltage and to provide amplification to a radio frequency signal, and a transceiver including a modulator configured to generate the radio frequency signal and an envelope shaping circuit configured to generate the shaped envelope signal by shaping an envelope of the radio frequency signal. The envelope shaping circuit includes a shaping table configured to maintain a substantially constant distortion in a transmit band of the mobile device across a range of the envelope of the radio frequency signal.

Abstract: Apparatus and methods for envelope shaping in power amplifier systems are provided. In certain implementations, a power amplifier system includes a modulator for generating a RF signal, a power amplifier for amplifying the RF signal, a gain control circuit for controlling the gain of the power amplifier, and an envelope tracking system for controlling a voltage level of the power amplifier's supply voltage based on an envelope signal corresponding to the RF signal's envelope. The gain control circuit includes a gain adjustment table, and the envelope tracking system includes an envelope shaping circuit including an isodistortion table. The isodistortion table can be used to map the envelope signal to a shaped envelope signal so as to maintain a substantially constant distortion in the system's transmit and/or receive bands across the envelope signal's range.

Abstract: Apparatus and methods for envelope shaping in power amplifier systems are provided. In certain implementations, a power amplifier system includes a modulator for generating a RF signal, a power amplifier for amplifying the RF signal, a gain control circuit for controlling the gain of the power amplifier, and an envelope tracking system for controlling a voltage level of the power amplifier's supply voltage based on an envelope signal corresponding to the RF signal's envelope. The gain control circuit includes a gain adjustment table, and the envelope tracking system includes an envelope shaping circuit including an isodistortion table. The isodistortion table can be used to map the envelope signal to a shaped envelope signal so as to maintain a substantially constant distortion in the system's transmit and/or receive bands across the envelope signal's range.

Abstract: Apparatus and methods for envelope shaping in power amplifier systems are provided. In certain implementations, a power amplifier system includes a modulator for generating a RF signal, a power amplifier for amplifying the RF signal, a gain control circuit for controlling the gain of the power amplifier, and an envelope tracking system for controlling a voltage level of the power amplifier's supply voltage based on an envelope signal corresponding to the RF signal's envelope. The gain control circuit includes a gain adjustment table, and the envelope tracking system includes an envelope shaping circuit including an isodistortion table. The isodistortion table can be used to map the envelope signal to a shaped envelope signal so as to maintain a substantially constant distortion in the system's transmit and/or receive bands across the envelope signal's range.

Abstract: Apparatus and methods for envelope shaping in power amplifier systems are provided. In certain implementations, a power amplifier system includes a modulator for generating a RF signal, a power amplifier for amplifying the RF signal, a gain control circuit for controlling the gain of the power amplifier, and an envelope tracking system for controlling a voltage level of the power amplifier's supply voltage based on an envelope signal corresponding to the RF signal's envelope. The gain control circuit includes a gain adjustment table, and the envelope tracking system includes an envelope shaping circuit including an isodistortion table. The isodistortion table can be used to map the envelope signal to a shaped envelope signal so as to maintain a substantially constant distortion in the system's transmit and/or receive bands across the envelope signal's range.