Tunable In-package Impedance Matching for High Power Transistors based on Printed Ceramics

A. Wiens1, S. Preis2, C. Kohler3, D. Kienemund1, H. Maune1, O. Bengtsson2, M. Nikfalazar1, J.R. Binder3, W. Heinrich2 and R. Jakoby1

Published in:

Proc. 45th European Microwave Conf. (EuMC 2015), Paris, France, Sep. 7-10, pp. 1236-1239 (2015).

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This work addresses tunable matching networks (TMN) for in-package integration of RF-power transistors, fabricated on functional thick film layers of Barium-Strontium-Titanate (BST). The deposition of BST layers is performed in a screen printing process. The TMN is designed to cover the typical GaN-HEMT output impedance range from 7 Ohm to 20 Ohm and transforms it directly to 50 Ohm. The insertion loss varies in a range between 0.4 dB and 1.1 dB, depending on frequency and tuning voltage. Co-simulations, implementing a model of a GaN-HEMT in combination with the TMN were carried out. The performance of the TMN is evaluated and compared to a reference non-tunable matching network with regards to drain efficiency and output power over the frequency range from 0.8 GHz to 3.0 GHz. Simulation results are verified with a system measurement of PA and TMN at 2 GHz in class AB, showing a drain efficiency of 47.1% and output power of 36.9 dBm.

1 Institut für Mikrowellentechnik und Photonik, Technische Universität Darmstadt, Darmstadt, Germany
2 Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Straße 4, 12489 Berlin, Germany
3 Karlsruher Institute of Technology, Eggenstein-Leopoldshafen, Germany


Ceramics, passive components, tunable filters, power amplifiers.