Consistent Q(v)-I(v) AlGaN/GaN HEMT Nonlinear Equivalent-Circuit Modeling

This work presents a new model for the source and drain access region resistances to improve the physical consistency between the intrinsic channel conduction current and the corresponding channel accumulated charge. For that, field-dependent electron mobility degradation and a bias-dependent effective drain access region length are considered. Indeed, realizing that the HEMT velocity saturated region must extend beyond the physical gate length, Lg, towards the drain access region, Lext, we now define a new intrinsic HEMT whose length is Lg+Lext, while the effective drain access region becomes reduced from its physical length, Ldar, to Ldar–Lext.