A GaN Voltage-Mode Class-D MMIC with Improved Overall Efficiency for Future RRH Applications

A. Wentzel and W. Heinrich

Published in:

Proc. 43th European Microwave Conf. (EuMC 2013), Nuremberg, Germany, Oct. 7-10, pp. 549-552 (2013).

Copyright © EuMA 2013. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the EuMA.


This paper reports on a compact voltage-mode class-D power amplifier module suitable for the LTE frequency band of 800 MHz. It includes a 3-stage GaN MMIC and a hybrid lumped-element output filter network. For the MMIC PA novel design techniques have been applied. They lead to a significant improvement in power added efficiency (PAE) of the entire chip, which has been the major drawback of the voltage-mode class-D type of PA so far. The optimized amplifier achieves for a 50% duty-cycle pulse-width modulated input signal a maximum PAE of 59% at an output power of 5.2 W. Drain efficiency of the final stage stays almost constant over the whole output power range with values around 80%. To the authors' best knowledge these are record values in terms of PAE for this type of PA.

Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Straße 4, 12489 Berlin, Germany


voltage-mode; class-D; GaN; PAE; power amplifier; remote radio-head.