Title :
Efficiency Enhancement of mm-Wave Power Amplifiers Using Envelope Tracking
Author :
Yan, Jonmei J. ; Presti, Calogero D. ; Kimball, Donald F. ; Hong, Young-Pyo ; Hsia, Chin ; Asbeck, Peter M. ; Schellenberg, James
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of California, San Diego, CA, USA
fDate :
3/1/2011 12:00:00 AM
Abstract :
This letter presents a 44 GHz GaAs MMIC-based power amplifier (PA) which uses envelope tracking (ET) techniques for efficiency enhancement. Digital pre-distortion (DPD) is also employed to achieve high linearity. For a 7.6 dB PAPR 64QAM 20 MHz bandwidth signal (data rate 120 Mb/s) at an output power of 23.8 dBm, the measured EVM was 2.0% and ACPR1 was better than -40 dBc. Power efficiency enhancement of more than 5.7 times for the final MMIC stage (from 1.22% to 7%) was measured, using an external drain modulator. To the authors´ best knowledge, this is the first time envelope tracking has been applied to PAs in the millimeter wave regime.
Keywords :
MMIC power amplifiers; gallium arsenide; millimetre wave power amplifiers; modulators; quadrature amplitude modulation; GaAs; MMIC-based power amplifier; PAPR 64QAM; bandwidth 20 MHz; bit rate 120 Mbit/s; digital predistortion; efficiency 1.22 percent to 7 percent; efficiency enhancement; envelope tracking techniques; external drain modulator; frequency 44 GHz; mm-wave power amplifiers; peak-to-average ratio; time envelope tracking; Bandwidth; Frequency modulation; Gain; MMICs; Peak to average power ratio; Power generation; Efficiency; envelope tracking (ET); linearity; millimeter wave power amplifier (PA); peak-to-average ratio;
Journal_Title :
Microwave and Wireless Components Letters, IEEE
DOI :
10.1109/LMWC.2010.2102747
