Design of Wideband Asymmetric Doherty Power Amplifier Using a New Phase Compensation Technique
Zhijiang Dai, Shuman Kong, Wei Feng, Shen Tian, Weimin Shi, Jingzhou Pang, Mingyu Li
Abstract
This article proposes a new phase compensation technique to expand the operating bandwidth of an asymmetric Doherty power amplifier (ADPA). Its operation principle is to increase the solution space of network parameters, thereby contributing to the broadband solvability of network parameters. The article provides a general method for solving network parameters in theory and numerical solutions for each network parameter. To verify the theory, a simple current source model simulates the load modulation process. The results show that this new compensation technique has consistent performance with the load modulation process of traditional ADPA at a similar parameter solution region. This technique can greatly expand the applicability of the network and allow for a more flexible design of ADPA. Furthermore, this theory was validated by designing a broadband ADPA of 1.7–2.7-GHz. The experimental results show that the saturation output power range is 46.9 dBm–48.5 dBm, with a saturation gain between 6 dB–9.3 dB and a corresponding saturation efficiency of 44%–69%. The efficiency is between 37%–65% at 6 dB back-off and 44%–52% at 9 dB back-off.