包络跟踪的J类功率放大器设计  

Design of Envelope Tracking Class-J Power Amplifier

作　　者：赵子明 朱晓维[1] 李浩天 ZHAO Zi-ming;ZHU Xiao-wei;LI Hao-tian(College of Information Science and Engineering,Southeast University,Nanjing 210096,China)

机构地区：[1]东南大学信息科学与工程学院,南京210096

出　　处：《微波学报》2021年第6期30-34,共5页Journal of Microwaves

基　　金：国家自然科学基金(61631021)。

摘　　要：为了提高功率放大器的回退效率以更好地适应第五代移动通信系统的高峰均比信号的需求,文中提出了一种基于包络跟踪的J类功率放大器的设计方法,通过对电源调制器的设计来动态调制J类功率放大器的供电电压,以降低漏极直流功耗,实现提高功率放大器效率的目标。最终的测试结果表明在3.4~3.6 GHz频率范围内,当采用带宽20 MHz、峰均比为8.6 dB的正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)调制信号时,测得恒压供电时的功率放大器的回退效率为25.3%~29%;然后采用带宽20 MHz、峰均比为6.4 dB的64正交调幅(Quadrature Amplitude Modulation,QAM)调制信号时,测得恒压供电时的功率放大器的回退效率为33.1%~34.1%。而采用包络跟踪动态供电时所测得的回退效率分别为30.2%~35.1%和37.1%~41.3%,回退效率提升5%~7%。经过数字预失真处理之后,该功率放大器的邻近信道功率泄露比低于-46 dBc,具有良好的线性度。In order to improve the back-off efficiency of power amplifier to meet the requirement of large peak-to-average ratio signal for the fifth-generation mobile communication system,the design method of envelope tracking Class-J power amplifier(PA)is proposed,which adopts the linear modulator to dynamically modulate the power supply voltage of the Class-J power amplifier to reduce the drain-level DC power consumption and achieve the goal of improving the efficiency of power amplifier.As demonstrated in the measurement results,in 3.3-3.6 GHz frequency range,when driven by a 20 MHz peak-to-average ratios of 8.6 dB orthogonal frequency division multiplexing(OFDM)modulation signal,the measured back-off efficiency of power amplifier is 25.3%-29%at constant voltage power supply;and when driven by a 20 MHz peak-to-average ratios of 6.4 dB 64 quadrature amplitude modulation signal,the measured back-off efficiency is 33.1%-34.1%at constant voltage power supply.However,when envelope tracking dynamic power supply is provided,the measured back-off efficiency of PA is 30.2%-35.1%and 37.1%-41.3%,respectively.The back-off efficiency is increased by 5%-7%.After digital pre-distortion(DPD)processing,the adjacent channel power leakage ratio of the power amplifier is lower than-46 dBc,which has good linearity.

关 键 词：回退效率 包络跟踪 线性调制器 动态调制 

分 类 号：TN722.75[电子电信—电路与系统]