Component compact models are physically motivated models using some fitting parameters, with equivalent-circuit based approach. This kind of model needs less device parameters and modelling efforts than a physical model, and non-linearity are introduced as required per element (drain current source, gate current, ect.). They allow a good understanding of the device intrinsic characteristics.
In order to extract such models, pulsed IV/RF measurement system is highly recommended to allow quasi-isothermal and trapping-free characterization of semiconductor devices. Thermal related performances are challenged by the total power dissipation within a transistor, causing large errors in non-linear models based only on static DC measurements.
Once extracted, these models are validated through VNA based load pull power measurements and implemented into commercial RF simulation tools.
Designers then have non-linear models of transistors which allow fast simulation without convergence issues, reliable from DC to RF, from low power to saturation.
These models are complete, including dynamical thermal and self-heating drifts, trapping effects. These transistor models are able to reproduce the device behaviour for various operating conditions as A, AB, B, C, D or S operating classes. And those are versatile, that is to say suitable for Harmonic Balance, multi-tones, envelop and transient simulations, and can also be used for circuit linear and non-linear stability analysis