Compact modeling of anomalous high frequency behavior of MOSFET´s small-signal NQS parameters in presence of velocity saturation

In this work we present a physics based compact small-signal nonquasi static (NQS) model for MOST including velocity saturation and demonstrate that this can substantially change the behavior of the gate transadmittance (y_dg) in saturation at high frequency. The magnitude of y_dg starts to increase (instead of decreasing) after a certain frequency and its real part also starts to increase in negative direction instead of becoming zero. In addition, even for a long channel MOST, the weak inversion charge present at the drain can also effect the y_dg in a similar way.