JATM – vol 7 issue 1 by Victor Dmitriev
Journal of Aerospace Technology and Management, 2015
Carbon nanotubes are possible building blocks
in the development of new generation of electronic ... more Carbon nanotubes are possible building blocks
in the development of new generation of electronic devices. The carbon nanotubes allow one fabrication of devices using nanometric scales. They can be used in projects of a wide range of electronic and optoelectronic components such as diodes, transistors and interconnection elements, among others. This paper presents the state-of-the-art of this area, emphasizing the influence of quantum effects on the characteristics of such components.
Papers by Victor Dmitriev
Anais de XXXVIII Simpósio Brasileiro de Telecomunicações e Processamento de Sinais, 2020
Resumo-Neste artigoé apresentada uma análise do espalhamento eletromagnético produzido pela inter... more Resumo-Neste artigoé apresentada uma análise do espalhamento eletromagnético produzido pela interação de uma onda plana e um arranjo de Nanopartículas metálicas do tipo Core-Shell. Para isso utilizou-se um formalismo baseado na representação espectral da Função de Green Periódica, sobre os modos de Floquet, para descrição do Campo Potencial Magnético. Os resultados mostram os perfis dos campos Elétrico e Magnético em função dos parâmetros dimensionais da estrutura, e das características da onda plana de excitação. Por fim, discussõesà respeito da convergência do método são apresentadas.
Multifunctional resonant graphene four-port for THz and far IR regions
Photonics and Nanostructures - Fundamentals and Applications
THz dynamically controllable graphene Y-circulator
2017 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC), 2017
A new type of the graphene-based three-port circulator is suggested and analysed. The cross-secti... more A new type of the graphene-based three-port circulator is suggested and analysed. The cross-section of the component presents a three-layer structure consisting of graphene, silica and silicon. The in-plane figure of the circulator presents a circular graphene resonator and three waveguides symmetrically connected to it. The graphene is magnetized normally to its plane by a DC magnetic field. The physical principle of the device is based on the dipole resonance of the magnetized graphene resonator. We investigate the influence of different parameters on characteristics of the circulator. Numerical simulations demonstrate the isolation of −15 dB in 9.4% bandwidth with the central frequency 5.38 THz. The biasing DC magnetic field is 0.57 T.
Graphene 3-port circulator based on edge-guide mode propagation
2017 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC), 2017
In this work we propose and numerically analyze a new type of electromagnetic circulator operatin... more In this work we propose and numerically analyze a new type of electromagnetic circulator operating in THz region. The circulator is based on graphene and dielectric substrates. The structure resembles a known three-port microstrip circulator based in edge guided mode. The circulation behaviour is provided by application of a DC magnetic field normal to the graphene plane. In the frequency band (2 ÷ 7) THz the isolation loss of our ultra wideband circulator is −(15 ÷ 50) dB, the insertion loss is −(2 ÷ 5) dB and return loss is better than −10 dB. The chemical potential of the graphene is 0.1 eV and DC magnetic field is 2 T.
arXiv: Physics Education, 2020
Group theory is used in many textbooks of contemporary physics. However, electromagnetic communit... more Group theory is used in many textbooks of contemporary physics. However, electromagnetic community often considers group theory as an "exotic" tool. Graduate and postgraduate textbooks on electromagnetics and electrodynamics usually do not contain a description of properties of electromagnetic fields and waves on the basis of group theory. We discuss in this paper from the didactic point of view, several types of symmetry and the corresponding groups and representations. The benefits of the use of group theoretical methods are a more deep physical understanding of the electromagnetic phenomena and a significant reduction of numerical calculations. These methods are general and exact.
Espalhamento Eletromagnético em Arranjo Periódico Linear de Nanopartículas Core-Shell
Anais de XXXVIII Simpósio Brasileiro de Telecomunicações e Processamento de Sinais, 2020
International Journal of Antennas and Propagation, 2020
It is known that the periodic use of silver nanoantennas in organic solar cells increases the eff... more It is known that the periodic use of silver nanoantennas in organic solar cells increases the efficiency of light absorption. In this study, we performed a geometric parametric analysis of nanoantennas using the finite element method. Based on the study of the convex truncated cone nanoantenna, we have found that a nanoantenna arrangement formed by the convex truncated cone nanoantenna along with a pyramidal nanoantenna provides a better solution for different angles of light incidence compared to a single nanoantenna. We obtained a mean increase in the absorption efficiency of this organic solar cell, both for the TM and TE polarizations, compared to the use of the conventional nanoantenna in the wavelength range of 300–800 nm.
Photonic Network Communications, 2019
A new terahertz isolator based on the ferromagnetic resonance effect is suggested and analyzed. A... more A new terahertz isolator based on the ferromagnetic resonance effect is suggested and analyzed. A two-dimensional photonic crystal consisting of a square lattice of gallium arsenide rods has been employed in the design of the device. Incident electromagnetic waves interact with one magnetized ferrite rod and two stubs inserted in the photonic crystal structure, generating a vortex-like field profile in the ferrite rod. Electromagnetic signals propagating in the forward direction are transmitted with low insertion losses, while their propagation in the backward direction is not allowed due to the high losses of the ferrite rod operating at the ferromagnetic resonance regime. Computational simulations show that the operating bandwidth is equal to 0.87 GHz around the central frequency 106.6 GHz. In this frequency band, the insertion losses are lower than -1.68 dB, the reflection levels are better than -16 dB, and the isolation levels are greater than -15 dB.
Anais de VII International Telecommunications Symposium, 2010
This work presents a discussion about multi-frame Super-Resolution Reconstruction (SRR) and singl... more This work presents a discussion about multi-frame Super-Resolution Reconstruction (SRR) and single-frame interpolation. SRR has been extensively studied in the last decades but it is not yet as popular as image interpolation. Since both methods are directed to improve image quality, comparisons are inevitable and desirable. However, fundamental misunderstandings can still be found in the literature on the choice between these two approaches. Recently, some mistaken conclusions have been reached regarding the SRR performance. This paper clarifies important SRR issues in image reconstruction, in contrast to interpolation. For reasons further discussed, two algorithms are considered: bicubic interpolation and LMS-SRR.
Electrothermal analysis of modified OPGW cables using Multiphysics Model
2015 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC), 2015
In this paper we investigate electrical and thermal characteristics of modifications of existing ... more In this paper we investigate electrical and thermal characteristics of modifications of existing optical ground wire cables - OPGW. The modifications consist of changing geometrical and physical parameters of armor wires. The simulations are carried out by a Multiphysics Model with coupled equations, i.e., the electrical and thermal effects are considered simultaneously in order to increase accuracy of the results. We calculate current density distribution and temperature variation in some points of the cables during short-circuit regime and analyze the influence of the modifications on these characteristics by the software COMSOL.
Prot�tipo de um ambiente integrado de c�digo aberto voltado para computa��o num�rica
Photonic crystal magneto-optical switch
2015 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC), 2015
We suggest and analyse theoretically a wideband switch with a very simple and compact structure. ... more We suggest and analyse theoretically a wideband switch with a very simple and compact structure. It consists of a 90° waveguide bending in a PhC with square unit cell and a circular ferrite cylinder placed in the bending. The state OFF of the switch corresponds to the nonmagnetized ferrite. The structure of the standing wave in the input waveguide with a node oriented along the output waveguide prevents excitation of the output waveguide. In the state ON, different resonant modes of the magnetized ferrite resonator provide high transmission from input port to output one, namely, both clockwise and anticlockwise dipole rotating modes, the standing dipole mode which is the sum of these two rotating modes and also travelling wave. Our numerical simulations show that in the sub-terahertz region, the switch possesses the frequency band of 8% at the levels of insertion losses lower than -2 dB and isolation better than -22 dB. This bandwidth is one order higher than that reported in the literature for switches of this type.
Symmetry Principles and Group-Theoretical Methods in Electromagnetics of Complex Media
Theory and Phenomena of Metamaterials, 2009
Journal of Aerospace Technology and Management, 2015
Carbon nanotubes are possible building blocks in the development of new generation of electronic ... more Carbon nanotubes are possible building blocks in the development of new generation of electronic devices. The carbon nanotubes allow one fabrication of devices using nanometric scales. They can be used in projects of a wide range of electronic and optoelectronic components such as diodes, transistors and interconnection elements, among others. This paper presents the state-of-the-art of this area, emphasizing the influence of quantum effects on the characteristics of such components.
Giant Faraday rotation in cross-shaped graphene array in THz region
2015 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC), 2015
We study numerically the Faraday effect in cross-shaped graphene array. Our geometrical structure... more We study numerically the Faraday effect in cross-shaped graphene array. Our geometrical structure in the optimized configuration can provide the Faraday rotation of about 3° for the frequency 8.9 THz with a relatively low magnetic field of 1T and 13 ° for a magnetic fields of 10 T. These rotation value is about seven times higher than the results published until now. The frequency position of maximum Faraday rotation can be controlled by changing the Fermi energy of graphene or the dimensions of the array.
This work presents a PSO implemention in CUDA architecture, aiming to speed up the algorithm on p... more This work presents a PSO implemention in CUDA architecture, aiming to speed up the algorithm on problems which has large amounts of data. PSO-GPU algorithm was designed to customization, in order to adapt for any problem that can be solved by a PSO algorithm. By implementing PSO using CUDA architecture, each processing core of the GPU will be responsible for
International Journal of Antennas and Propagation, 2017
This paper presents a broadband nanoantenna fed by a two-wire optical transmission line (OTL). Th... more This paper presents a broadband nanoantenna fed by a two-wire optical transmission line (OTL). The antenna is defined by a combination of a dipole and a loop, where only the dipole element is connected to the OTL. The analysis is fulfilled by the linear method of moments with equivalent surface impedance to model the conductors. Firstly, the nanoantenna alone is investigated, where the input impedance, current distribution, reflection coefficient, fractional bandwidth, radiation efficiency, and radiation pattern are analyzed. Then, the input impedance matching of this antenna with the OTL is considered. In this case the current, near field distribution, radiation pattern, and reflection coefficient are calculated for different geometrical parameters. The results show that the loop inserted in the circuit can increase the bandwidth up to 42% and decreases the reflection coefficient in the OTL to −25 dB.
International Journal of Antennas and Propagation, 2014
We analyze impedance matching and excitation properties of a plasmonic optical nanocircuit compos... more We analyze impedance matching and excitation properties of a plasmonic optical nanocircuit composed by a receiving and an emitting dipole connected by a two-wire optical transmission line. The circuit is fed by a circular Gaussian beam focused on the receiving dipole. The numerical analysis is performed by linear method of moments with a given surface impedance of gold cylindrical conductors. With this model, we analyze the variation of standing-wave response along the circuit in function of some geometrical parameters. We present some conclusions concerning impedance matching between the transmission line and the emitting dipole and coupling between the receiving dipole and the incident Gaussian beam.
Review of Scientific Instruments, 2007
A holographic beam splitter has been integrated into a picosecond four-wave mixing ͑FWM͒ scheme. ... more A holographic beam splitter has been integrated into a picosecond four-wave mixing ͑FWM͒ scheme. This modification significantly simplified the procedure of dynamic grating recording, thus making the FWM technique an easy-to-use tool for the holographic characterization of wide band gap materials. The novel FWM scheme was applied for characterization of hydride vapor phase epitaxy-grown undoped GaN layers of different thickness. It allowed the determination of carrier lifetime, diffusion coefficient, and carrier diffusion length by optical means, as well as the study of carrier recombination peculiarities with respect to dislocation and excess carrier density.
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JATM – vol 7 issue 1 by Victor Dmitriev
in the development of new generation of electronic devices. The carbon nanotubes allow one fabrication of devices using nanometric scales. They can be used in projects of a wide range of electronic and optoelectronic components such as diodes, transistors and interconnection elements, among others. This paper presents the state-of-the-art of this area, emphasizing the influence of quantum effects on the characteristics of such components.
Papers by Victor Dmitriev