Transmitter
Mostrando 1-12 de 785 artigos, teses e dissertações.
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1. A Design of a Compact Microwave Diplexer in Microstrip Technology Based on Bandpass Filters Using Stepped Impedance Resonator
Abstract This paper describes the design of a compact microstrip microwave diplexer based on bandpass filters and a stepped impedance resonator for 4G applications. The diplexer is composed of two band-pass filters (BPF) that operate at 1.8 and 2.5 GHz. Both bandpass filters for the receiver at 1.705-1.895 GHZ and the transmitter at 2.41-2.6 GHZ have a -3dB
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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2. Radially Periodic Metasurface Lenses for Magnetic Field Collimation in Resonant Wireless Power Transfer Applications
Abstract In this paper, a new procedure and topology of magnetic metasurface lens are proposed for improving the performance of Resonant Wireless Power Transfer systems. Firstly, three subwave-length unit cells are optimized in order to get negative magnetic permeability in the same frequency, each one with a different refractive index, and they are experime
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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3. Proposed Technique of Analysis for Absorber/Transmitter Frequency Selective Surfaces
Abstract In this paper, we propose a simple technique to analyze absorber/transmitter frequency selective surfaces (FSS). The structure is formed by two FSS, one resistive and one conductive. Both FSS are printed on an FR4 dielectric substrate. The square loop and crossed dipole are the geometries considered in this paper. The technique combines two simple a
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2021-06
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4. Ray Tracing and Applications to an Evaporation Duct Model Based on Data from Oceanographic Buoy Sensors
Abstract The two-dimensional ray tracing method allows an easy and fast modeling of tropospheric propagation in the microwave frequency range. A version of this method that determines ray trajectories, amplitudes and delays of the electromagnetic field, as well as the propagation loss in a two-dimensional inhomogeneous environment will be described. The impl
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2019-03
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5. Measurements of Medium Wave HD Radio Reception in a Dense Urban Region
Abstract This paper presents the results of measurements of medium wave received field strength, HD Radio audio quality and maximum coverage distances in a dense urban region. Analog AM and digital HD Radio signals broadcasting the same content were simultaneously transmitted in São Paulo, the largest city in Brazil. The received signal intensity and the re
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-09
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6. Pseudo-Analytical Modeling of Tilted-Coil Antennas in Anisotropic Geophysical Formations
Abstract In this paper we present an efficient mode-matching technique to analyze tilted-coil antennas in anisotropic geophysical formations. In this problem, a number of coil antennas with arbitrary relative tilt angle with respect to the symmetry axis are used to radiate electromagnetic fields in a cylindrically layered medium comprised of a metallic mandr
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-03
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7. Inversion Method for Obtaining Electrical Parameters for Soil in the Rural Region in Brazil
AbstractThis paper presents an inversion methodology through weighted least squares to obtain the electrical parameters for the soil of a typical mid-western region in Brazil using the model based in the formalism of the parabolic equations to calculate the electric field intensity received. To validate this methodology, the results of the radio signal measu
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2015-06
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8. A systematic sensitivity analysis of the performance of a transcutaneous energy transmitter for design purposes
This work studies a Transcutaneous Energy Transmitter (TET) which uses electromagnetic fields to transfer power from outside the body to an artificial organ in the body, working like a high frequency transformer with the skin being part of the magnetic coupling between the primary (external coil) and secondary (internal coil). For this reason, this project m
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2013-12
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9. A CMOS UWB transmitter with Vivaldi Array for Ultra-fast Beam steering microwave radar
This work presents a new Ultra Wide Band (UWB) beamforming fifth-order derivative Gaussian pulse transmitter with dual small Vivaldi antennas for remote acquisition of vital signals in impulse radar applications. The system consists of a programmable delay circuit (PDC or τ), a UWB pulse generator (PG) circuit and an array of two Vivaldi planar antennas. Th
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2013-12
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10. SFN channel measurements in Brazil
In this paper, field measurements carried out in a suburban SFN network with two synchronized transmitters are reported. It is found that the radio signal coverage of the distributed transmission scheme is distinctly improved when compared to a single transmitter system. The path loss gain and improvement associated to the SFN scheme are obtained as well as
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2013-06
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11. Optical cryptography through analog control of amplitude and delay of spectral slices: anlysis for NRZ and DQPSK signals. / Criptografia Ãptica mediante controle analÃgico da amplitude e do atraso de fatias espectrais: anÃlise para sinais NRZ e DQPSK.
This work investigates a technique to encrypt the optical signal for Transparent Optical Network, TON, in order to safeguard the confidentiality and guarantee the security of informations that are transmitted through the Telecommunications Network. The technique is assessed on the physical layer of the reference model for open systems interconnection, OSI, a
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 23/11/2012
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12. Da representação à apresentação: mudança em fluxo da linguagem publicitária?
The researchs objective is to study the characteristics of the changes of advertising language, when it lies under the impact of new communication technologies, which generate cyberspace and cyber culture. Its studys objects are campaigns developed in the period between 1960-1980 and 1990-2010 - Lux (1963), Limpol (1978), Gol (2007) and Seda (2008); other ca
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 30/10/2012