Pang, JingzhouJingzhouPangLi, YueYueLiChu, ChenhaoChenhaoChuPeng, JunJunPengZhou, Xin YuXin YuZhouZhu, AndingAndingZhu2021-03-102021-03-102020 IEEE2020-08-06http://hdl.handle.net/10197/12026The International Microwave Symposium (IMS) 2020, Atlanta, Georgia, United States of America, 4-6 August 2020A load modulation network with characteristic impedance-modified transmission lines (TLs) is presented in this paper to extend the efficiency range and bandwidth of the Doherty power amplifier (DPA). Characteristic impedance values for designing the proposed DPA with different high efficiency ranges are given and wideband performance can also be achieved. A DPA with 2.55-3.35 GHz bandwidth using commercial GaN transistors is designed and implemented to validate the proposed architecture. The fabricated DPA achieves a measured 9.2-10.4 dB gain and 44.3-45.4 dBm saturated power. 57.9-75.6% and 47.6-58.8 % drain efficiency is achieved at saturation and 8 dB output power back-off (OBO) within the designed bandwidth, respectively. When driven by a 5-carrier 100 MHz OFDM signal with 8 dB peak to average power ratio (PAPR), the proposed DPA achieves adjacent channel leakage ratio (ACLR) of better than -50 dBc after digital pre-distortion with average efficiency of 53.4%, 55.3% and 56.6% at 2.75, 2.95 and 3.15 GHz centre frequencies.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.Doherty power amplifiersBroadbandExtended high efficiency rangeExtended high efficiency rangeConference Publication10.1109/ims30576.2020.92240702020-10-2013/RC/2077978-1-7281-6816-6https://creativecommons.org/licenses/by-nc-nd/3.0/ie/