ZTE Communications ›› 2022, Vol. 20 ›› Issue (4): 62-68.DOI: 10.12142/ZTECOM.202204008

• Research Paper • Previous Articles     Next Articles

Broadband Sequential Load-Modulated Balanced Amplifier Using Coupler-PA Co-Design Approach

RAN Xiongbo, DAI Zhijiang(), ZHONG Kang, PANG Jingzhou, LI Mingyu   

  1. School of Microelectronics and Communication Engineering, Chongqing University, Chongqing 400044, China
  • Received:2022-06-20 Online:2022-12-31 Published:2022-12-30
  • Contact: DAI Zhijiang
  • About author:RAN Xiongbo received his BSc degree in electronic engineering from the Hangzhou Dianzi University, China in 2019, and MSc degree in electronic engineering from the School of Microelectronics and Communication Engineering, Chongqing University, China in 2022. His research interests include microwave and millimeter-wave devices and circuits, and wideband high-efficiency power amplifier design.|DAI Zhijiang (daizj_ok@126.com) received his BS and PhD degrees in electrical engineering from University of Electronic Science and Technology of Chinain in 2011 and 2017, respectively. From 2017 to 2018, he was a research engineer with Huawei Technologies, where he focused on the study of MIMO wireless communication systems. He is currently a lecturer with the School of Microelectronics and Communication Engineering, Chongqing University, China. His research interests lie in the area of automatic matching techniques of PA, wideband and linear RF PA design, MMIC circuits, and wireless communication systems.|ZHONG Kang received his BS degree in electronic information engineering from Guizhou University, China in 2021. He is currently pursuing his MS degree at the School of Microelectronics and Communication Engineering, Chongqing University, China. His current research interests include broadband high-efficiency power amplifiers and load modulated power amplifiers.|PANG Jingzhou received his BS degree in electrical engineering and PhD degree in circuits and systems from University of Electronic Science and Technology of China in 2010 and 2016, respectively. From December 2016 to July 2018, he was with Huawei Technologies Company Ltd., Chengdu, where he was an engineer in charge of the research and development of 5G high-efficiency power amplifiers and transmitters. From July 2018 to August 2020, he was with the RF and Microwave Research Group, University College Dublin, Ireland, where he was a research fellow in charge of the research of novel broadband transmitter architectures and RF/microwave/millimeter-wave monolithic microwave integrated circuit (MMIC) power amplifiers. He is currently an associate professor with the School of Microelectronics and Communication Engineering, Chongqing University, China. His research interests include broadband high-efficiency power amplifier systems, bandwidth extension techniques for high-efficiency transmitters, and MMIC power amplifier design for RF/microwave and millimeter-wave applications. Dr. PANG was a recipient of the EDGE Marie Sklodowska-Curie Individual Fellowship and the Third Place Award of the High Efficiency Power Amplifier Student Design Competition at the IEEE Microwave Theory and Techniques Society (IEEE MTT-S) International Microwave Symposium (IMS) in 2013.|LI Mingyu received his PhD degree in electronic engineering from University of Electronic Science and Technology of China, in 2009. From 2012 to 2013, he was a research fellow with The University of Kitakyushu, Kitakyushu, Japan. He is currently an associate professor with the School of Microelectronics and Communication Engineering, Chongqing University, China. His current research interests include RF/microwave transceiver design, statistical and adaptive signal processing for wireless communications, and behavioral modeling and linearization for RF power amplifiers.
  • Supported by:
    the National Natural Science Foundation of China(62001061);ZTE Industry-University-Institute Cooperation Funds(HC?CN?20210520005)

Abstract:

The basic theory of the sequential load-modulated balanced amplifier (SLMBA) is introduced and the working principle of its active load modulation is analyzed in this paper. In order to further improve the performance of the SLMBA, a co-designed method of the coupler and power amplifier (PA) is proposed, which is different from the traditional design of couplers. According to the back-off point and saturation point of the SLMBA, this coupler-PA co-design approach can make the working state of the coupler and three-way PA closer to the actual situation, which improves the overall performance of the SLMBA. The maximum output power ratio of the control PA and the balance PA is then determined by the preset output power back-off (OBO) of 10 dB, and the phase compensation line is determined by the trace of the load modulation impedance of the balanced PA. In order to verify the proposed method, an SLMBA operating at 1.5–2.7 GHz (57% relative bandwidth) is designed. The layout simulation results show that its saturated output powers achieve 40.7–43.7 dBm and the small signal gains are 9.7–12.4 dB. Besides, the drain efficiencies at the saturated point and 10 dB OBO point are 52.7%–73.7% and 44.9%–59.2% respectively.

Key words: SLMBA, broadband, coupler, co-design