级联PA的效率优化策略及其在55nm CMOS E波段PA中的应用

Efficiency Optimization Strategy of Cascaded PA and Its Application in Designing a 55 nm CMOS E⁃band PA

根据多级功率合成功率放大器(PA)的功率附加效率(PAE)公式,对效率进行理论计算分析,得出了以下效率优化策略:在级联功率合成功放的最后一级放置功率分配器可以提供最优的整体PAE,优化最后一级有源或无源器件对整体PAE的改善最为显著。根据上述策略,从有源器件效率、增益效率比和无源器件插入损耗这三个参数出发,对PA的最后一级做了具体优化。采用55 nm CMOS工艺设计了一款E波段PA,实现了24%的峰值PAE,26 dB的峰值增益,7.2 GHz的3 dB带宽,14.1 dBm的饱和输出功率和11.3 dBm的1 dB压缩点输出功率。

According to the power added efficiency(PAE)expression of multi-stage power com⁃bined power amplifier(PA),the following efficiency optimization strategies are obtained through the⁃oretical calculation and analysis of PAE:placing power divider at the last stage of cascaded power combined PA can provide the optimal overall PAE,and optimizing the last stage of active or passive components has the most significant increment on the overall PAE.According to the above strategies,the last stage of PA is specifically optimized based on the three parameters which are efficiency of ac⁃tive device,gain-to-efficiency ratio of active device and insertion loss of passive device.An E-band PA is designed using 55 nm CMOS technology which achieves a peak PAE of 24%,a peak gain of 26 dB with a 3 dB bandwidth of 7.2 GHz,a saturated output power of 14.1 dBm,and a 1 dB output power compression point of 11.3 dBm.