Li, MengMengLiPang, JingzhouJingzhouPangLi, YueYueLiZhu, AndingAndingZhu2020-11-262020-11-262020 IEEE2020-06IEEE Transactions on Circuits and Systems I: Regular Papers1549-8328http://hdl.handle.net/10197/11746A novel Doherty power amplifier (DPA) architecture with extended bandwidth is presented in this paper. A modified load modulation network is introduced to provide impedance condition required by the Doherty operation in a wide frequency range. Analytical parameter solutions of the proposed load modulation network and the related load modulation process are presented. A DPA with 2.80-3.55 GHz bandwidth utilizing commercial GaN transistors is implemented. The fabricated DPA attains a measured 9.3-11.1 gain and 43.0-45.0 dBm saturated power. 50.0-60.6% and 66-78% drain efficiency is obtained at 6 dB output power back-off and saturation throughout the designed band, respectively. Moreover, the back-off drain efficiencies are higher than 55% within 700 MHz bandwidth. When driven by a 6-carrier 120 MHz OFDM signal with 7.0 dB peak to average power ratio, the proposed DPA achieves adjacent channel leakage ratio of better than -50 dBc after digital pre-distortion (DPD) at 3.20 GHz with average efficiency of 53.3%.en© 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.BroadbandDoherty power amplifierHigh efficiencyLoad modulationJournal Article6761824183410.1109/tcsi.2020.29721632020-03-0213/RC/207717/NSFC/485016/IA/4449713567https://creativecommons.org/licenses/by-nc-nd/3.0/ie/