Modeling of dispersive millimeter-wave GaN HEMT devices for high power amplifier design

In recent years, monolithic integrated power amplifiers based on gallium nitride (GaN) have become an ideal candidate to meet the increasing demand for high solid-state power levels of today's and future millimeter-wave (mm-wave) systems. The heterostructure aluminum gallium nitride/gallium nitride (AlGaN/GaN) high electron mobility transistor devices outperform comparable state-of-the-art semiconductor technologies due to their superior fundamental properties regarding high-power and high-frequency applications. Therefore, a 100 nm AlGaN/GaN technology was developed by the Fraunhofer IAF which is intended for the realization of high-frequency transistors as well as high-power amplifiers for mm-wave frequency applications. The computer-aided design of such power amplifiers requires a scalable nonlinear model of the active transistor devices. Thereby, the nonlinear model must be capable to take low-frequency dispersion and memory effects into account, which are present in the considered mm-wave GaN technology. An elegant way to describe such dispersive devices is a state-space modeling approach. Therefore, this thesis addresses the development of a scalable state-space transistor model and its verification and applicability in terms of the design of two power amplifiers, a broadband and a high-power amplifier.