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,
$L_{g}$
, towards the drain access region,
$L_{ext}$
, we now define a new intrinsic HEMT whose length is
$L_{g}+L_{ext}$
, while the effective drain access region becomes reduced from its physical length,
$L_{dar}$
, to
$L_{dar}-L_{ext}$
.