A lumped, large-signal dynamic model of the mosfet for rf circuit simulation

Periodic steady-state analysis of coupled ODE-AE-CGE systems for MOS RF autonomous circuit simulation

“…Similar versions of most of these equations are found in [3] and [5]. See text for definition of the terms.…”

“…The PDE model describes the transistor continuously, but the simulation time is long and convergence is often a problem [3]. Lumped model is another mathematical description of transistor which is less complicated than the PDE model and is sufficiently accurate for RF circuit simulation [5]. No matter what mathematical model is selected, transistor will be described by a set of transistor equations, which can be wrote as the following CGEs:…”

“…Since reference [5] may not be widely available, we summarize the current generator equations of lumped model below. Similar versions of most of these equations are found in [3] and [5].…”

“…To adequately represent a transistor for large-signal dynamic operations in the GHz frequency range, a description based on first principles of device physics seems essential. Such a description requires that the transistor be modeled by a system of partial differential equations (PDE) [2][3][4][5]. Iterative methods have been developed to compute the transient response of RF circuits with a PDE model of the transistors [2,3].…”

“…So, we regard the transistor as a multiterminal voltage-dependent current source. To accelerate the computation speed, such current source can be described by a set of current ordinary differential equations [5], it is an adequate representation of the PDE model. We call those current equations as current generate equations (CGE).…”