题目/Title：An efficiency-enhanced stacked 2.4-GHz CMOS power amplifier with mode switching scheme for WLAN applications

作者/Author：
                        Yun Yin,Xiaobao Yu,Zhihua Wang,Baoyong Chi

期刊/Journal：IEEE Transactions on Microwave Theory and Techniques

年份/Issue Date：2015Feb.

卷（期）及页码/Volume（No.）&pages：Vol.63, No.2, pp. 672 - 682

摘要/Abstract：
A stacked 2.4-GHz CMOS power amplifier (PA) with a mode switching scheme is proposed to enhance the back-off efficiency for wireless local area network applications. By means of dynamically tuning the bias and optimal load with a power-detecting controller, the proposed mode switching scheme effectively improves the power-added efficiency (PAE) of the PA by 2 at 5-dB back-off power. Besides, with the transistor stacking and envelope- tracked self-biasing techniques, the PA, powered by a 5.6-V supply, achieves an output P1dB of 27 dBm with a PAE of 26.1% and an output P1dB of 22 dBm with a PAE of 21.8% in high-power mode and low-power mode, respectively, while occupying only a 1.5-mm die area in 180-nm CMOS. In the closed-loop power-detecting mode, the PA achieves an adjacent channel leakage ratio of 22.6 dBc and an error vector magnitude of 26.9 dB at 23-dBm output power for 120-Mb/s 7.6-dB peak-to-average power-ratio 64 quadrature amplitude modulation 802.11n signals.