GaN devices for communication applications - evolution of amplifier architectures
U. Schmid1, R. Reber1, C. Chartier1, K. Widmer1, M. Oppermann1, W. Heinrich2 , C. Meliani2, R. Quay3, S. Maroldt3
Published in:
Int. J. Microwave Wireless Technolog., vol. 2, no. 1, pp. 85-93 (2010).
Abstract:
This paper presents the design and implementation of power amplifiers using high-power gallium nitride (GaN) high electronic mobility transistor (HEMT) powerbars and monolithic microwave integrated circuits (MMICs). The first amplifier is a class AB implementation for worldwide interoperability for microwave access (WiMAX) applications with emphasis on a low temperature cofired ceramics (LTCC) packaging solution. The second amplifier is a class S power amplifier using a high power GaN HEMT MMIC. For a 450 MHz continuous wave (CW) signal, the measured output power is 5.8 W and drain efficiency is 18.5%. Based on time domain simulations, loss mechanisms are identified and optimization steps are discussed.
1 EADS - T/R Modules and MMICs, Woerthstrasse 85, 89077 Ulm, Germany
2 Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Straße 4, 12489 Berlin, Germany
3 Fraunhofer Institute Applied Solid-State Physics (FhG-IAF), Tullastrasse 72, D-79108 Freiburg, Germany
Keywords:
Power amplifier (PA), Gallium nitride (GaN), Switch mode amplifier, Delta sigma modulator (DSM)
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