Tunable Impedance Matching Networks on Printed Ceramics for Output Matching of RF-Power Transistors
Proc. 44th European Microwave Conf. (EuMC 2014), Rome, Italy, Oct. 6-9, pp. 496-499 (2014).
Copyright © EuMA 2014. 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 work addresses tunable matching networks fabricated on functional thick film layers of Barium-Strontium- Titanate (BST) for RF-power transistors. The deposition of BST layers is performed in a screen-printing process and the fabricated components are patterned by photolithography. Around 2.0 GHz, the insertion loss varies in a range between 0.7 dB and 1.1 dB depending on the tuning state and frequency, transforming 7.5Ohm to 50 Ohm. For verification, the tunable matching network is implemented as the main part of the output matching of three cells of a bare-die GaN HEMT. The transistor is operated in class AB at 2.0 GHz at 15V and 28V drain voltage with a peak power of 36.9 dBm and 40.1dBm along with 47.1% and 41% drain efficiency respectively, which is an improvement of approximately 10%-points in efficiency and more than 6 dB in power compared to previous work.
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, ferroelectrics, BST, tunable components, adaptive matching, non-linear devices, power amplifier.