Exploiting Ambipolarity in Graphene Field-Effect Transistors for Novel Designs on High-Frequency Analog Electronics

Exploiting ambipolar electrical conductivity based on graphene field-effect transistors has raised enormous interest for high-frequency (HF) analog electronics. Controlling the device polarity, by biasing the graphene transistor around the vertex of the V-shaped transfer curve, enables to redesign and highly simplify conventional analog circuits, and simultaneously to seek for multifunctionalities, especially in the HF domain. This study presents new insights for the design of different HF applications such as power amplifiers, mixers, frequency multipliers, phase shifters, and modulators that specifically leverage the inherent ambipolarity of graphene-based transistors. Graphene transistors are characterized by a V-shaped current-voltage relationship, i.e., they are ambipolar. Tuning the device charge polarity enables to redesign and highly simplify conventional high-frequency circuits for ubiquitous wireless communications systems. This review gives insights about how the accurate control of graphene ambipolarity can be exploited for high-frequency analog applications such as power amplifiers, subharmonic mixers, analog phase shifters, frequency multipliers, and high-data rate modulators. image