Nonlinearity and scaling trends of quasiballistic graphene field-effect transistors targeting RF applications

Graphene field-effect transistors (GFETs) based on ballistic transport represent an emerging nanoelectronics device technology with promise to add a new dimension to electronics and replace conventional, silicon technology, especially for radiofrequency applications. The radiofrequency (GHz) static linearity and nonlinearity performance potential of GFETs is analyzed herein in the ballistic transport regime by exploring their static linearity mathematically in the quasiballistic transport regime along with their scaling potential at four different channel lengths. The proposed model explores linked mathematical expressions for the harmonic distortion, intermodulation distortion, and intercept points, which are depicted in graphical form. The second- and third-order harmonics and intermodulation distortions are analyzed with the help of a mathematical analysis of the drain current equation formulated using McKelvey's flux theory. The presented expressions are validated based on the nonlinear output characteristic curves of the drain current versus the drain voltage for channel lengths of 140, 240, 300, and 1000 nm. The nonlinearity effect and its impact on the use of quasiballistic and ballistic GFETs for radiofrequency electronic applications is one of the important prospects and is tabulated in Table 1 for greater clarity using the particular models and their respective frequencies.