High-efficiency inverse class-E power amplifier with envelope tracking technique

Abstract

This letter describes a highly efficient inverse class-E power amplifier (PA) with an envelope tracking (ET) technique.To enhance efficiency performances, the PA uses a harmonic control network with double composite right/left-handed transmission lines. The use of the ET technique also results in high efficiency for the modulated signals. For verifications, the inverse class-E PA is implemented with a 35-W GaN HEMT and tested using 3.5 GHz continuous wave (CW) and 802.16e WiMAX signals. With the CW signal, a peak drain efficiency of 79.0% with a power gain of 9.8 dB is achieved at a saturation output power of 45.6 dBm. With WiMAX signals, a drain efficiency of 37.8% with a power-added efficiency (PAE) of 33.6% is achieved at an average output power of 36 dBm, which is the 9.6 dB back-off power region, using the ET technique. After the DPD technique, the linearity significantly improved without decreasing efficiency. (c) 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:866869, 2013; View this article online at wileyonlinelibrary.com. DOI: 10.1002/mop.27420