JSSC 2015第5期RF & Wireless45nm

A 25 dBm Outphasing Power Ampliﬁer With Cross-Bridge Combiners Lei Ding Member

本文提出了一种采用交叉桥接合器的25 dBm D类异相功率放大器，显著提高了回退效率。

55%峰值功率附加效率（900 MHz），45%（2.4 GHz），-53 dBc ACPR（DPD后）

异相功率放大器交叉桥接合器D类放大器数字预失真功率附加效率

▸创新点1：交叉桥接合器设计（电路创新）通过精心选择的元件形成附加谐振网络，有效减少异相电流，提升功放回退效率，在900MHz和2.4GHz下分别实现55%和45%的峰值PAE。

▸创新点2：45nm CMOS工艺实现D类功放（工艺创新）采用标准数字工艺集成高效开关功放，突破传统GaAs/SiGe方案，实现25dBm输出功率与高集成度。

▸创新点3：数字预失真技术（系统创新）针对2.4GHz频段，将LTE信号的ACPR从-33dBc显著提升至-53dBc，支持10/20MHz及多载波场景，扩展了线性化应用范围。

▸创新点4：板级分立元件组合器设计（方法创新）通过外置LC网络实现阻抗变换灵活性，便于测试优化，为多频段性能验证提供可重构平台。

Abstract

In this paper, we present a 25 dBm Class-D out- phasing power ampliﬁer (PA) with cross-bridge combiners. The Class-D PA is designed in a standard 45 nm process while the combiner is implemented on board using lumped elements for ﬂexibilities in testing. Comparing with conventional non-isolated combiners, the elements of the cross-bridge combiner are carefully chosen so that additional resonance network is formed to reduce out-of-phase current, thereby inc reasing backoff efﬁciency of the outphas