Prediction of the performance of graphene-based analog mixers and amplifiers

This paper presents a simple mathematical model for the transfer characteristic of the graphene field effect transistor (GFET). The model yields closed-form expressions for the amplitudes of the distortion components of the output drain-to-source current resulting from a multisinusoidal gate-to-source input voltage. The special case of a two-tone equal-amplitude gate-to-source input voltage is considered in detail. The results show that the distortion performance of the GFET is strongly dependent on the asymmetry of the transfer characteristic and the amplitudes of the input sinusoids with the second-order intermodulation component dominating over a wide range of the input voltage amplitudes and different degrees of asymmetry of the transfer characteristic. Moreover, the GFETs biased at the minimum conduction point can work as frequency doublers, mixers, down-converters and up-converters. The results also show that proper biasing of the GFET can provide linear amplifiers.