How to get the curve of gate capitance in ADS

[xyhx]

Hi, Everybody:

I know that the gate capacitance is sensitive to gate–source voltage in a CMOS transistor. but i want to know how can i get the capacitance after DC Sweep in ADS.

Thanks in advance.

 

[pancho_hideboo]

Set "DevOpPtLevel" as "Brief" or "Detailed" in DC Analysis Setting parameters.

See the followings.
http://edocs.soco.agilent.com/display/ads2009/DC+Simulation+Parameters
http://edocs.soco.agilent.com/display/ads2009/BSIM3+Model+(BSIM3+MOSFET+Model)

DC operating point data is generated for this model. If a DC simulation is performed, device operating point data can be viewed for a component. The procedure for viewing device operating point data for a component is in Using Circuit Simulators. The device operating point information displayed for the BSIM3 model is:
Gmb: small-signal Vbs to Ids transconductance, in Siemens
Gds: small-signal drain source conductance, in Siemens
Vdsat: saturation voltage, in volts
Capbd: small-signal bulk drain capacitance, in farads
Capbs: small-signal bulk source capacitance, in farads
CgdM: small-signal gate drain Meyer capacitance, in farads
CgbM: small-signal gate bulk Meyer capacitance, in farads
CgsM: small-signal gate source Meyer capacitance, in farads
DqgDvgb: small-signal transcapacitance dQg/dVg, in farads
DqgDvdb: small-signal transcapacitance dQg/dVd, in farads
DqgDvsb: small-signal transcapacitance dQg/dVs, in farads
DqbDvgb: small-signal transcapacitance dQb/dVg, in farads
DqbDvdb: small-signal transcapacitance dQb/dVd, in farads
DqbDvsb: small-signal transcapacitance dQb/dVs, in farads
DqdDvgb: small-signal transcapacitance dQd/dVg, in farads
DqdDvdb: small-signal transcapacitance dQd/dVd, in farads
DqdDvsb: small-signal transcapacitance dQd/dVs, in farads


But I don't use this.
Rather I use AC analysis with AC_Vgs=1 and swept DC_Vgs.
Here Cg is evaluated by AC_Ig/(j*2*pi*freq).

 

[xyhx]

hi, pancho_hideboo

Thank you for your advice. That's what i need.