A physical large signal Si MOSFET model for RF circuit design

Abstract

A new physically based Si MOSFET large signal miodel, BSIM3v3, developed by UC Berkeley, has been evaluated for high-frequency mixed-signal circuit analysis in a frequency domain, harmonic balance simulator. The model is validated using simulated RF power characteristics of automatic load pull measurement at different bias and matching conditions.

Temperature dependent MOSFET RF large signal model incorporating self heating effects

“…However, the model only accounts for self heating not ambient temperature effects. A physically based BSIM3V3 [2] model has been linked to a commercial harmonic balance simulator [3], but this SPICE model is complicated with more than ninety parameters for the complete model and requires many measurements to create. In addition to the effects of self heating, the channel current continuity in its derivatives with respect to the bias is very important to predict harmonic components and intermodulation (IM) power accurately.…”

“…the temperature dependence of the channel current, p a r e y are expressed as first order functions of the channel temperature increase in equation(3). In this equation, b a n d yT contain the dependence of transconductance and threshold voltage on channel temperature.…”

Diode Modeling with Lossy Nonlinear Capacitance Model

“…MOSFET models in a circuit simulator should have predictive power in DC I-V characteristics and RF smalland large-signal characteristics to estimate circuit characteristics including power consumption precisely [1][2][3]. By using the MOSFET model built only from smallsignal measurement data, however, measured and simulated large-signal circuit characteristics often show considerable discrepancy.…”

Empirical nonlinear modeling for RF MOSFETs

“…However, it is very difficult to model accurately RF nonlinear performance in the GHz range using original BSIM3v3 SPICE model [3]. Recently, a lot of efforts [4,5] have been concentrated on the improvement and modification of the original SPICE model, but some errors still occur in multi-bias S-parameter fitting, so that it is very difficult to achieve accurate RF nonlinear modeling for CAD.…”