Wideband Tunable GaN HEMT Module Utilizing Thin-film BST Varactors for Efficiency Optimization

A. Wiens1, S. Preis2, C. Schuster1, M. Nikfalazar1, C. Damm1, M. Schuessler1, W. Heinrich2, O. Bengtsson2, R. Jakoby1

Published in:

IEEE MTT-S Int. Microw. Symp. Dig., San Francisco, USA, May 22-27, Tu4A-1 (2016).

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Abstract:

This work covers the design and measurement of a low cost tunable impedance matching network (TMN) for highly linear and high power RF applications at telecommunication frequencies. A single transistor cell, was wire-bonded to a TMN and the performance of the tunable amplifier module was evaluated from 1 GHz to 2.5 GHz. The TMN transforms the GaN HEMT output impedance to fixed 50 Ohm load. Tuning allows efficient operation of the transistor over the targeted frequency range. Peak drain efficiency of 66% and a peak output power of 37.5 dBm were measured. Two-tone measurements reveal an OIP3 around 47 dBm which is comparable to a bare GaN HEMT.

1 Technische Universitaet Darmstadt, Institute of Microwave Engineering and Photonics, Darmstadt, Germany
2 Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, 12489 Berlin, Germany

Index Terms:

passive circuits, tunable impedance matching, power amplifiers.