Equivalent-circuit extraction for gallium nitride electron devices: Direct versus optimization-empowered approaches

This work focuses on the equivalent-circuit modeling of microwave field-effect transistors. Although the purely direct approach allows obtaining a good prediction accuracy in a straightforward way without the need of any optimization, optimization algorithms are often used to achieve an improved accuracy at the cost of a higher modeling complexity. The pros and cons of empowering the direct approach with optimization algorithms are discussed by focusing the analysis on a 1000-μm periphery gallium nitride high-electron-mobility transistor on silicon carbide substrate. The comparison between the two different approaches is performed through an extensive analysis of the frequency-dependent behavior of the small-signal characteristics.