
6 Gallium Nitride (GaN): Physics, Devices, and Technology
devices required novel technological concepts such as modied epitaxial buffer
structures, eld plates, and passivation layers. These technologies are described
in Section 1.2.
The operation conditions of power devices signicantly differ from those of
standard microwave operation principles, as shown in Figure 1.2. Analogue micro-
wave ampliers (e.g., operated in class AB) operate around a xed bias point; the
dynamic load line (e.g., the time-dependent position of the bias point in the output
I/V characteristics) makes use of the full I/V characteristic and can have a con-
siderable v ...