High-efficiency Doherty linear amplifier with backoff control for mobile communications

This paper proposes a backoff control method for the Doherty amplifier that realizes both high efficiency and high linearity by using digital signal processing, which adapts to various modulation schemes in wireless communications. In order to achieve high efficiency, the control unit adjusts dc voltage of the carrier amplifier in the proposed Doherty amplifier linearized by input allocation for each branch. And the proposed amplifier has high efficiency and sufficient linearity for the signal with various peak-to-average power ratios from the different modulation schemes.