A SiGe Envelope-Tracking Power Amplifier With an Integrated CMOS Envelope Modulator for Mobile WiMAX/3GPP LTE Transmitters

作者：Li Yan^*; Lopez Jerry; Wu Po Hsing; Hu Weibo; Wu Ruili; Lie Donald Y C

来源：IEEE Transactions on Microwave Theory and Techniques, 2011, 59(10): 2525-2536.

DOI：10.1109/TMTT.2011.2164550

• Differential cascode power amplifier (PA)
• envelope tracking (ET)
• high efficiency
• linear-assisted switching envelope modulator
• long-term evolution (LTE)
• SiGe BiCMOS
• WiMAX

This paper presents a SiGe envelope-tracking (ET) cascode power amplifier (PA) with an integrated CMOS envelope modulator for mobile WiMAX and 3GPP long-term evolution (LTE) transmitters (TXs). The entire ET-based RF PA system delivers the linear output power of 22.3/24.3 dBm with the overall power-added efficiency of 33%/42% at 2.4 GHz for the WiMAX 64 quadrature amplitude modulation (64QAM) and the 3GPP LTE 16 quadrature amplitude modulation, respectively. Additionally, it exhibits a highly efficient broadband characteristic for multiband applications. Compared to the conventional fixed-supply cascode PA, our ET-based cascode PA meets the WiMAX/LTE spectral mask and error vector magnitude spec at close to its P-1dB compression without the need of predistortion. The SiGe PA and the CMOS envelope modulator are both designed and fabricated in the TSMC 0.35-mu m SiGe BiCMOS process on the same die. This study represents an essential integration step toward achieving a fully monolithic large-signal ET-based TX for wideband wireless applications.

• 出版日期2011-10