Figure 4
From: A novel AlGaN/GaN heterostructure field-effect transistor based on open-gate technology

The measured transfer characteristics with standard y-axis and logarithmic y-axis: (a) sample 1, (b) sample 2, (c) sample 3, and (d) sample 4. The drain-source voltage is constant at 10 V during measurement. The transfer characteristics of open-gate devices are extracted from their output characteristics.