Harmonic and intermodulation performance of graphene-based analog electronic circuits

Abstract

In this article, a simple Fourier-series-based mathematical model for the transfer characteristic of the graphene field effect transistor (GFET) is presented. Using this model, closed-form expressions for the amplitudes of the harmonic and intermodulation components of the drain-to-source current resulting from a multisinusoidal gate-to-source input voltage with small or large amplitudes can be obtained. The results show that the harmonic and intermodulation performance of the GFET excited by a two-tone equal-amplitude signal is strongly dependent on the asymmetry of the transfer characteristic and the amplitudes of the input sinusoids. The results also show that the second-order intermodulation component is dominant over a wide range of the input voltage amplitudes and different degrees of asymmetry of the transfer characteristic. Moreover, the results show that 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.