  We propose an explicit small-signal graphene field-effect transistor (GFET)
parameter extraction procedure based on a charge-based quasi-static model. The
dependence of the small-signal parameters on both gate voltage and frequency is
precisely validated by high-frequency (up to 18 GHz) on-wafer measurements from
a 300 nm device. These parameters are studied simultaneously, in contrast to
other works which focus exclusively on few. Efficient procedures have been
applied to GFETs for the first time to remove contact and gate resistances from
the Y-parameters. The use of these methods yields straightforward equations for
extracting the small-signal model parameters, which is extremely useful for
radio-frequency circuit design. Furthermore, we show for the first time
experimental validation vs. both gate voltage and frequency of the intrinsic
GFET non-reciprocal capacitance model. Accurate models are also presented for
the gate voltage-dependence of the measured unity-gain and maximum oscillation
frequencies as well as of the current and power gains.
