  We measure the small signal, 1 GHz source-drain dynamical conductance of a
back-gated single-walled carbon nanotube field effect transistor at both low
and high dc bias voltages. At all bias voltages, the intrinsic device dynamical
conductance at 1 GHz is identical to the low frequency dynamical conductance,
consistent with the prediction of a cutoff frequency much higher than 1 GHz.
This work represents a significant step towards a full characterization of a
nanotube transistor for RF and microwave amplifiers.
