Thermal Coupling in AlGaN/GaN Power Transistors

F. Schnieder1 and M. Rudolph2

Published in:

Frequenz, vol. 67, no. 1-2, pp. 21-26 (2013).

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Thermal coupling in AlGaN/GaN transistors is investigated by means of thermal FEM (finite element method) simulation. The results are combined with electrical network simulation using an electro-thermal model. From the FEM analysis the thermal coupling matrix is established, describing the thermal interaction between the different cells of a power transistor. The matrix allows to extract an equivalent circuit for the thermal coupling in a straightforward way. The electrical transistor model is complemented by thermal ports to connect the the cells via the thermal coupling network. The electro-thermal model developed yields information on the distribution of temperature and currents within a powerbar and thus is an important tool in transistor design.

1 Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Straße 4, D-12489 Berlin, Germany
2 Ulrich-L.-Rohde Chair for RF and Microwave Techniques, Brandenburg University of Technology, Cottbus, Germany

Index Terms:

power transistors, GaN-HEMTs, computer simulation, transistor modelling