Skyworks Solutions, Inc.
Power amplifier bias modulation for multi-level supply envelope tracking

Abstract:

Apparatus and methods for power amplifier bias modulation for multi-level supply envelope tracking are provided herein. In certain embodiments, an envelope tracking system includes a power amplifier that amplifies a radio frequency signal, a multi-level supply envelope tracker that generates a power amplifier supply voltage of the power amplifier based on an envelope signal indicating an envelope of the radio frequency signal, and a bias modulation circuit that modulates a bias of the power amplifier based on a voltage level of the power amplifier supply voltage.