Model Parameters

UCB GaAs MESFET model parameters are described in the following table. Setup attributes are listed in Table 85.

Table 84 UCB GaAs MESFET Model Parameter

Name	Description	Default
Inductance and Resistance Parameters
LD	Drain inductance.    Specifies external drain inductance.	0 Henry
LG	Gate inductance.    Specifies external gate inductance.	0 Henry
LS	Source inductance.    Specifies external source inductance.	0 Henry
RD	Drain resistance.    Specifies external drain resistance.	0 Ohm
Diode Parameters
IS	Diode reverse saturation current.    Models gate-drain and gate-source current.	1×10-14 Amp
PB	Gate junction potential.    Models built-in potentials of gate-source and gate-drain regions.	1V
XN	Diode emission coefficient.    Models emission coefficient of an ideal diode.	1
DC Parameters
ALPHA	Saturation voltage parameter.    Specifies voltage at which drain current reaches saturation. The Vds coefficient in the tanh function.	2.0V-1
B	Doping profile parameter.    Models intrusion of doping profile into the insulating substrate.	0.3V-1
BETA	Transconductance parameter.    Defines transconductance in the saturation or linear operating regions.	1×10-4 A·V-2
LAMBDA	Channel length modulation parameter.    Models finite output conductance of a MESFET in the saturation region.	0V-1
VTO	Zero bias threshold voltage.    Models gate turn-on voltage.	0V
Capacitance Parameters
CGD	Zero bias gate-drain capacitance	0 Farad
CGS	Zero bias gate-source capacitance	0 Farad

Table 85 UCB GaAs Model Setup Attributes

DUT/ Setup	Inputs	Out-puts	Transform	Function	Extractions
ac/ s_at_f	vg, vd, vs, freq	s	extract_L_and_R	GAASAC_l_and_r	LD, LG, LS, RD, RG, RS
ac/ s_vs_f	vg, vd, vs, freq	s	extract_CV	GAASCV_cgs_cgd	CGD,CGS
dc/ igvg_0v[sd]	vg, v[sd]	ig	extract	GAASDC_lev1	PB, IS, XN
			optim1		PB, IS, XN
dc/ idvg_hi_vd	vg, vd, vs	id, ig	none
dc/ idvd_vg	vd, vg, vs	id, ig	extract	GAASDC_lev2	VTO, BETA, ALPHA, LAMBDA, B
			optim1	Optimize	VTO, BETA, ALPHA, LAMBDA
			optim2	Optimize	VTO, BETA, B