A HIGHLY LINEAR AND EFFICIENT THREE-WAY DOHERTY AMPLIFIER USING TWO-STAGE GaN HEMT CELLS FOR REPEATER SYSTEMS

Abstract

In this article, we propose a highly, linear and efficient three-way Doherty amplifier using two-stage GaN HEMT cells for repeater systems. The driving cells are used as the predistortion circuit to improve linearity (is well as the gain stage. The main cells are optimized to achieve high efficiency at a large back-off Power. After gate bias optimization of the driving cells, the proposed three-way, Doherty amplifier with two-stage cells shows highly linear and efficient performance. (C) 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2895-2898, 2009: Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24748