High-frequency performance of graphene field effect transistors with   saturating IV-characteristics
  High-frequency performance of graphene field-effect transistors (GFETs) with boron-nitride gate dielectrics is investigated. Devices show saturating IV characteristics and fmax values as high as 34 GHz at 600-nm channel length. Bias dependence of fT and fmax and the effect of the ambipolar channel on transconductance and output resistance are also examined. 
I. Meric, C. R. Dean, S.-J. Han, L. Wang, K. A. Jenkins, J. Hone, K.   L. Shepard
cond-mat.mes-hall