Graphene is considered as a promising material to construct field-effect transistors (FETs) for high frequency electronic applications due to its unique structure and properties,mainly including extremely high carrier mobility and saturation velocity,the ultimate thinnest body and stability.Through continuously scaling down the gate length and optimizing the structure,the cut-off frequency of graphene FET (GFET) was rapidly increased and up to about 300 GHz,and further improvements are also expected.Because of the lack of an intrinsic band gap,the GFETs present typical ambipolar transfer characteristic without off state,which means GFETs are suitable for analog electronics rather than digital applications.Taking advantage of the ambipolar characteristic,GFET is demonstrated as an excellent building block for ambipolar electronic circuits,and has been used in applications such as highperformance frequency doublers,radio frequency mixers,digital modulators,and phase detectors. Graphene is considered as a promising material to construct field-effect transistors (FETs) for high frequency electronic applications due to its unique structure and properties, mainly including extremely high carrier mobility and saturation velocities, the ultimate thinnest body and stability. Continuing scaling down the gate length and optimizing the structure, the cut-off frequency of graphene FET (GFET) was rapidly increased and up to about 300 GHz, and further improvements are also expected. Beause of the lack of an intrinsic band gap, the GFETs present typical ambipolar transfer characteristic without off state, which means GFTs are suitable for analog electronics rather than digital applications. TDO advantage of the ambipolar characteristic, GFET is illustrated as an excellent building block for ambipolar electronic circuits, and has been used in applications such as high performance frequency doublers, radio frequency mixers, digital modulators, and phase detectors.