4电平S类数字功放的电平合成策略  

Level synthesis strategy for 4-level class-S digital power amplifier

作　　者：周强 朱蕾 陈剑斌 ZHOU Qiang;ZHU Lei;CHEN Jianbin(The Sixty-third Research Institute,National University of Defense Technology,Nanjing 210007,China)

机构地区：[1]国防科技大学第六十三研究所,江苏南京210007

出　　处：《国防科技大学学报》2020年第2期156-161,共6页Journal of National University of Defense Technology

基　　金：国家自然科学基金资助项目(61631021)。

摘　　要：通过增加量化电平,Delta-Sigma调制器输出序列能够获得更好的调制性能。但在S类数字功放中,受限于开关功放的实现结构,多电平Delta-Sigma调制器输出脉冲序列无法直接驱动开关功放,需采用由多个开关功放单元构成的多电平开关功放。针对2比特Delta-Sigma调制器输出序列,分析了电平合成策略对4电平S类数字功放性能的影响,提出了两种优化的电平合成策略。理论分析和仿真结果表明,采用合适的电平合成策略,4电平S类数字功放可以获得更优的输出性能,尤其在输出功率回退状态下,电平合成策略对功放性能的影响更为显著。The DSM(Delta-Sigma modulator)can get a better performance by increasing the quantizer′s levels.But the multi-bit DSM output cannot drive the SMPA(switch-mode power amplifiers)directly due to the multi-levels of DSM output in the class-S DPA(digital power amplifier).So the multi-level SMPA with multiple SMPA cells is needed.Several level synthesis strategies for 4-level class-S DPA based on 2 bit DSM were proposed and analyzed.The theory and simulation results show that,with an appropriate level synthesis scheme,the 4-level class-S DPA obtains a much better performance.Especially,the effect of level synthesis strategy is more remarkable in power back-off condition.

关 键 词：数字射频功放 S类 DELTA-SIGMA调制器 开关功放 电平合成 

分 类 号：TN838[电子电信—信息与通信工程]