JSSC 2022第3期Power Management

Envelope Tracking Supply Modulator with Trellis-Search-Based Switching and 160-MHz Capability

采用网格搜索算法的混合放大器优化开关序列，提升效率并降低误差电流。

802.11ax调制下PA总效率提升7.2%，EVM -32.7dB

包络跟踪混合放大器网格搜索开关序列优化功率放大器

▸创新点1：基于网格搜索的开关序列优化算法（方法创新）。采用类似Viterbi的网格搜索（TS）DSP算法，优化了混合放大器中buck转换器的开关序列，显著降低了开关损耗，提高了整体效率。

▸创新点2：降低线性放大器RMS误差电流（电路创新）。通过优化开关序列，减少了线性放大器中的RMS误差电流，在20MHz信道下，线性放大器电流降低了27%，提升了系统性能。

▸创新点3：支持160MHz宽频带工作（系统创新）。芯片设计支持160MHz宽频带工作，无需TS算法，扩展了应用场景，适应更高频段的通信需求。

▸创新点4：提升功率放大器整体效率（性能创新）。在802.11ax调制下，2.5GHz功率放大器的总效率提高了7.2%，在22.3dBm输出功率下，EVM达到-32.7dB，显著提升了系统能效。

Abstract

The hybrid ampliﬁer that combines a buck con- verter and a linear ampliﬁer has been widely used as the envelope tracking (ET) supply modulator for ET power ampliﬁer (PA) application. Instead of adding more large off-chip passives to raise the efﬁciency of the hybrid ampliﬁer, this work uses a Viterbi-like trellis search (TS) digital signal processing (DSP) algorithm to ﬁnd the optimal switching sequence for the buck converter in the hybrid ampliﬁer, lowering RMS error current in the op-amp, and minimizing switching. For 20-MHz channels, it lowers op-amp current by 27%. The chip also supports 160-MHz channels without TS. With 802.11ax modulation, it raises total efﬁciency of a 2.5-GHz PA by 7.2% at 22.3 dBm, with EVM of −32.7 dB.