A Graphene Field-Effect Transistor Based Analogue Phase Shifter for High-Frequency Applications

We present a graphene-based phase shifter for radio-frequency (RF) phase-array applications. The core of the designed phase-shifting system consists of a graphene field-effect transistor (GFET) used in a common source amplifier configuration. The phase of the RF signal is controlled by exploiting th...

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Detalles Bibliográficos
Autores: Medina-Rull, Alberto|||0000-0003-4691-0328, Pasadas, Francisco|||0000-0003-3992-9864, Marin, Enrique G.|||0000-0002-0302-3764, Toral-Lopez, Alejandro|||0000-0001-5612-0536, Cuesta-López, Juan|||0000-0001-7905-9969, Godoy Medina, Andres|||0000-0002-3014-8765, Jiménez, David|||0000-0002-8148-198X, Garcia Ruiz, Francisco J.|||0000-0003-4659-2454
Tipo de recurso: artículo
Fecha de publicación:2020
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:321707
Acceso en línea:https://ddd.uab.cat/record/321707
https://dx.doi.org/urn:doi:10.1109/ACCESS.2020.3038153
Access Level:acceso abierto
Palabra clave:Field-effect transistor (FET)
Graphene
Phase shifters
Quantum capacitance
Radio-frequency (RF) devices
Descripción
Sumario:We present a graphene-based phase shifter for radio-frequency (RF) phase-array applications. The core of the designed phase-shifting system consists of a graphene field-effect transistor (GFET) used in a common source amplifier configuration. The phase of the RF signal is controlled by exploiting the quantum capacitance of graphene and its dependence on the terminal transistor biases. In particular, by independently tuning the applied gate-to-source and drain-to-source biases, we observe that the phase of the signal, in the super-high frequency band, can be varied nearly 200° with a constant gain of 2.5 dB. Additionally, if only the gate bias is used as control signal, and the drain is biased linearly dependent on the former (i.e., in a completely analogue operation), a phase shift of 85° can be achieved making use of just one transistor and keeping a gain of 0 dB with a maximum variation of 1.3 dB. The latter design can be improved by applying a balanced branch-line configuration showing to be competitive against other state-of-the-art phase shifters. This work paves the way towards the exploitation of graphene technology to become the core of active analogue phase shifters for high-frequency operation.