JSSC 2019第6期RF & Wireless55nmPower Amplifier

A Compact Dual-Band Digital Polar Doherty Power Ampliﬁer Using Parallel-

一种采用并行组合变压器的紧凑型双频数字极化多尔蒂功率放大器。

55nm CMOS, 1.11 mm² die area, 28.9-dBm peak Pout (LB), 27.0-dBm peak Pout (HB), -21.6-dB EVM

双频多尔蒂功率放大器数字极化并行组合变压器CMOS

▸创新点1：电流模式并行组合变压器（PCT）功率合成器是一种电路创新，通过独特的电流模式设计实现了双频段的高效功率合成，显著提升了功率放大器的效率和输出功率。

▸创新点2：超紧凑单变压器实现双频覆盖是系统创新，采用单一变压器结构同时支持低频（850 MHz）和高频（1.7 GHz）工作，大幅减小了芯片面积（1.11 mm²），同时保持了高性能。

▸创新点3：高效率与高输出功率是方法创新，通过数字极化Doherty架构和PCT技术，在低频段实现36.8%的PAE和高频段25.4%的PAE，同时输出功率分别达到28.9 dBm和27.0 dBm。

▸创新点4：该PA支持多标准信号处理，包括NB-IoT和WLAN信号，在20-MHz 256-QAM WLAN信号下实现22.7%的平均PAE和-30.5 dB的EVM，展现了优异的兼容性和线性度。

Abstract

This paper presents a dual-band high-power digital polar Doherty power ampliﬁer (PA). A current-mode parallel- combining transformer (PCT) power combiner is introduced for Doherty operation, which realizes simultaneous dual-band coverage, high output power, and backoff efﬁciency enhancement with an ultra-compact single-transformer footprint. The PA is implemented in 55-nm CMOS and occupies 1.11 mm 2 die area. It achieves 28.9-dBm peak Pout with 36.8% PAE in low band (LB) and 27.0-dBm peak Pout with 25.4% PAE in high band (HB). For 12-subcarrier 180-kHz bandwidth cellular narrowband Internet- of-Things (NB-IoT) signals, the peak P avg of 24.4 dBm with average PAE of 29.5% at 850 MHz and the peak Pavg of 23.0 dBm with average PAE of 17.9% at 1.7 GHz are obtained with −21.6-dB error vector magnitude (EVM). Moreover, the PA achieves 20.8-dBm P avg, 22.7% average PAE, and−30.5-dB EVM for 20-MHz 256-QAM WLAN signal.