Charge partitioning scheme for FET models

A field effect transistor channel charge partitioning scheme is proposed that explains small-signal port parameters associated with the source and drain terminals. The scheme starts with the channel charge, that can be readily extracted from measurement, and defines source charge as that for a drainless channel. The drain charge is the difference required for neutrality. This new approach is a contrast to alternative schemes that apportion part of the channel charge to the source. A significant outcome is the insight that the drain and source charges are larger in magnitude than the channel charge. This is an essential requirement for the correct modelling of reactive parameters not associated with the gate, such as drain-source capacitance, transcapacitance, or transconductance delay.