Large-signal extraction method for GaAs and InP HEMT diodes

A HEMT diode model intended for analog applications should be valid over the whole gate-source voltage (T_gs) range. The main difficulty of extracting the small-signal equivalent scheme of a HEMT diode, is that, contrary to the transistor extraction method, no clear distinction can be made between the calculation of the extrinsic elements (cold-FET measurements) and the intrinsic elements (hot-FET measurements). This implies that approximations used in the cold-FET extraction approach have to be reviewed. This is a particular problem for the determination of the resistances