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In this work, a novel procedure for the simulation of magnetically-biased graphene by means of standard simulators, is made available. To this aim, the similarity of graphene with lossy ferrite has been exploited. Simulations can be performed at microwave frequency, from DC up to 100 GHz, where the electromagnetic response of graphene is almost flat. The Duality theorem is applied to establish the...
Microwave-enabled exfoliation of graphite oxides has been recently shown to be capable of quickly producing graphene sheets of larger size and with fewer defects with the potential for low-cost mass production. In this paper, we investigate microwave heating of graphite powder in a waveguide reactor using multiphysics macroscopic modeling and experimentation. High heating rate and strong non-uniformity...
This paper presents the design of a graphene-based electronically tunable microstrip attenuator operating at the frequency of 5 GHz. The use of graphene as a variable resistor is discussed, and the modeling of its electromagnetic properties at microwave frequencies is fully addressed. The design of the graphene-based attenuator is described. The structure integrates a patch of graphene, whose characteristics...
We report the first experimental results of single graphene-on-glass FET-based envelope detectors operating at digital communication data rate of 20 Mb/s with RF carrier frequency above 5 GHz. The new ambipolar GFET envelope detectors operated with zero power consumption, which is potentially ideal for ultra-low-power wireless networks. GFET ambipolar envelope detectors offer excellent 40 dB linear...
A novel broadband technique to effectively launch plasmons along a single graphene layer at terahertz (THz) frequencies is proposed. To this end, the coupling of the electromagnetic wave from a readily available plasmonic waveguide established by a periodically corrugated metallic surface to the graphene sheet is proposed. As will be shown, this technique can significantly surmount the need for efficient...
In this contribution, three terminal ballistic junctions, made of three-branch graphene nanoribbons (GNRs), are modeled at the nanometric scale. This configuration is used for the realization of rectifiers, harmonic generator, mixers, switches. The analysis is carried in the frequency (energy) domain by a scattering matrix approach, optimized for GNR devices. The ballisticity and the scattering properties...
This paper reports on the pulsed I-V and microwave characterizations of a Graphene Nano Ribbon FET (GNR-FET) for nonlinear electrical modeling. The extraction method of model parameters is based on the characterization of three specific technological structures called PAD, MUTE and FET (integrating only the coplanar access structure, the FET without graphene, and the entire GNR-FET) respectively....
Carbon-based materials have emerged as next generation electronic materials for device applications. In this work, radio-frequency behavior of square graphene is studied and characterized up to 67GHz. After an elaborate de-embedding process in which four dummy structures and three steps are employed, a new two-port physical-based equivalent circuit model is proposed and verified. It is estimated that...
Measuring graphene RF devices performances relies heavily on the precision of the de-embedding techniques adopted. Small line sizes increase variability issues in the RF standards and test devices, and require line width transitions. In this work, a robust and high precision de-embedding technique is adopted to the particular needs of microwave graphene devices. Two standards and only one step after...
We present the design and fabrication of high speed flexible graphene field effect transistors (GFETs) with high electron mobilities (∼8000cm2/V.s), hole mobilities (∼ 6600cm2/V.s) and record intrinsic transit frequency-fT of ∼32GHz. We also present the design and fabrication of the first flexible graphene based amplitude modulated (AM) radio receiver operating at 2.4GHz. This radio includes a GFET...
The concept and design of terahertz (THz) digital phase shifter based on graphene Gate-controlled Switchable Devices (GSD) with Defected Ground Structures (DGS). It is shown that the graphene based Unit Phase Shifter (UPS) may enable viable applications of gate controlled switchable devices for THz wideband antenna systems with considerable advantages while integrating with external circuits. Since...
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