1,721,262 research outputs found
Radio-Frequency Nanoelectronics: a new Paradigm in Electronic Systems Design
No full textOwing to the new qualitative and quantitative improvements that nanotechnology allows, nanoelectronics has the potential to introduce a paradigm shift in electronic systems design similar to that of the transition from vacuum tubes to semiconductor technology. Since many nano-scale devices and materials exhibit their most interesting properties at radiofrequencies (RF), nanoelectronics represent an enormous and yet largely undiscovered opportunity for the microwave engineering community, which can utilize its established body of modelling, design and measurement techniques with the aim to bridge the gap between nano-science and a new generation of extremely integrated devices, circuits and systems, for a broad range of applications and operating frequencies covering the radiofrequency (RF) spectrum, through the microwave region, and up to the optical region. In this contribution, examples of recent achievements in new nanotechnology-based radio-frequency devices and systems are presented. This is done, in particular, by focusing the areas of carbon-based and terahertz nanoelectronic
Graphene-based wireless communications systems: Analysis of the EM-quantum transport of coupled nano-patch antennas
No full textThe possibility of using graphene-based antennas is a core point in the development of high speed, multifunctional new wireless architecture, leading to a new generation of smart nano-systems for wireless communications, and wireless power transfer. In this work, we present a first analysis of the electromagnetic-quantum transport among the different graphene-based antennas. The former analysis is a building block for the design of a complete smart nanosystems for wireless communications at micro and mm-wave frequencie
Advanced modeling of graphene nanodevices: Metal-carbon transition and patch antennas
No full textWe report on multiphysics full-wave techniques in the frequency (energy)-domain and the time-domain, aimed at the investigation of the combined electromagnetic-coherent transport problem in carbon based nano-structured materials and devices, e.g. graphene nanoribbons. The frequency-domain approach is introduced in order to describe a Poisson/Schroedinger system in a quasi static framework. An example about the self-consistent solution of laterally coupled graphene nanoribbons is shown. The time-domain approach deals with the solution of the combined Maxwell/Schroedinger system of equations. We deal with i) the very challenging problem of he analysis of charge injection from metal to a contacted graphene nanoribbon (GNR); ii) a first prototype of graphene-based patch antenna
Self-consistent simulation of local potential in external-gate biased graphene nanoribbons
No full textWe report on the self-consistent analysis of armchair graphene nanoribbon (GNR) field-effect transistors (FET), in the case of multi-band coherent carrier transport. In principle, the same approach can be extended to include the contribution to charge transport due to different layers of a few-layer GNR-FET. To the aim of demonstrating the versatility of our simulation tool, we provide interesting examples about the dependence of charge and self-consistent potential on the gate voltage, for small drain voltages: these include details of numerical convergence of the iterative system of Poisson and Schrödinger equatio
Analysis of the electromagnetic/coherent transport problem in graphene nanoribbons
No full textThe combined quantum and electromagnetic analysis of graphene nanoribbons (GNR), often required for describing applications to practical devices, constitutes a difficult task. Our goal is to develop a multiphysics investigation of the electromagnetic field dynamics together with the quantum coherent transport in nanoscale environment. In this contribution, we show the dynamics of a charge wavepacket from source to drain electrodes in a graphene nanoribbon transistor configuratio
Design of a Coplanar Graphene-Based Nano-Patch Antenna for Microwave Applications
No full textWe analyze a coplanar graphene-based nanopatch
antenna. Besides the fact that graphene is a moderate
conductor at those frequencies, the antenna can still exhibit
sharp resonances. Although the poor graphene conductivity
implies in general low-performance, a remarkable change of the
scattering parameters, radiation pattern and antenna efficiency
can be observed as the graphene surface impedance is changed
by means of an external Bias
Carbon based ballistic RF electronics
No full textIn the past decade the progresses in
nanofabrication, modeling (from atomistic to mesoscopic scales),
and advances in nanocharacterisation have triggered an entirely
new class of nanodevices. Owing to their superior electrical and
mechanical performances, carbon based meterials such as
graphene and carbon nanotubes (CNTs) have played a central
role in these groundbreaking developments. Among the many,
one of the most relevant feature of these materials is the
capability to allow room temperature ballistic transport.
This feature enables yet more compact and yet more efficient RF
circuits, endowed of higher current density, higher on/off ratio
and higher fmax/ft ratios.
In this talk the activities ongoing in this area will be outlined
through an European perspective by focusing on some
emblematic examples of graphene based ballistic devices
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