4G standards such as Long Term Evolution (LTE) use non-constant envelope modulation techniques with high peak-to-average ratios. Power amplifiers (PA) implemented in such applications are forced to operate at a backed-off region from saturation. Thus, to reduce power consumption, a design of a high efficiency PA that can maintain the efficiency for a wider range of RF signals is required. In this paper, a two-way 10W Doherty amplifier designed in a compact 10×11.5mm2 monolithic microwave integrated circuit using GaN technology is presented. Suitable for a 4G LTE 5W pico-cell base station, which entails the frequencies from 2.62-2.69GHz, the design achieves high efficiencies of over 50% at both back-off and peak power regions without compromising on the stringent linearity requirements of 4G LTE standards. This demonstrates a 17% increase in power added efficiency at 6 dB back-off from peak power compared to conventional Class AB amplifier performance.

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2012 24th International Conference on Microelectronics, ICM 2012

Seneviratne, S.G. (S. G.), Yagoub, M.C.E. (M. C.E.), & Amaya, R. (2012). MMIC Doherty power amplifier for a 5W pico-cell base station in GaN HFET technology. In Proceedings of the International Conference on Microelectronics, ICM. doi:10.1109/ICM.2012.6471411