Buscar recursos académicos

A recursive procedure is applied to the measured near-field profiles of buried optical waveguides recorded in a lithium fluoride (LiF) crystal by femtosecond laser pulses in order to estimate the core dimensions and the ...

Abstract This paper presents a patch antenna array topology for Simultaneous Wireless Information and Power Transfer (SWIPT) applications. The resulting Double Patch Antenna Array (DPA) is composed of two patch antennas ...

Abstract This paper describes the development of a double-sided band-pass frequency selective surface based on Matryoshka geometry, preserving features such as miniaturization, multiband operation and stability of polari...

Abstract High-Definition Digital Terrestrial Television (HDDTT) replaces analogue, requiring further research on propagation links due to atmospheric variables potentially disrupting signals during uplink and downlink re...

Abstract Broadband Power Line Communication (BB-PLC) technology enables data transmission for smart grid applications. Nevertheless, channel equalizers are required in the receiver to estimate and compensate for the nonl...

Abstract In this paper, an in-depth study of the electrical and optical characteristics of Polymer Light Emitting Diodes ITO/PEDOT: PSS/DP-PPV derivatives/Al(Ca) is presented. Three polymer materials are considered; poly...

Abstract Similar to any telecommunication network, energy efficiency is a desirable feature for fiber wireless (FiWi) access networks. These networks have optical back end and wireless front end. Both ends may contribute...

This paper proposes an approach to estimate the probable location of maximum exposure to electromagnetic fields associated with a radiocommunication station, based only on information of antenna's height, half-power angl...

Abstract The signal digitization process of the open television system is still in progress, therefore, the study of the digital signal propagation has great importance so that broadcasters can develop and improve the tr...

Abstract Microstrip filters are widely employed in radio fre-quency and microwave circuits due to their efficiency, easy fabri-cation, and compatibility with printed circuit board technologies. In this scenario, this wor...

Abstract This paper describes an experimental and numerical investigation of the dielectric resonators based on the MgTiO3 ceramic matrix, which relates to their dielectric properties in microwave. The resonators are com...

This paper presents a FEM analysis of a hybrid excitation brushless axial flux machine (HEBAFM) for traction electric vehicle purposes in order to compare with the results from an analytical method used to determine the ...

Abstract This work presents four systems for generation of optical subcarriers in the C-band in optical communications, based on serial and parallel amplified optical ring resonator with phase modulation and 10 GHz spect...

This work describes the design and optimization of a printed circuit board containing a rectangular half-loop coil designed to apply radio frequency signals on micrometric diamond crystals. The structure was optimized to...

Abstract In this study, a rib waveguide is used in the design of a plasmonic sensor. The structure consists of a dielectric substrate constituted of tantalum pentoxide (Ta2O5). On top of this substrate, a superstrate wit...

Nowadays, optical amplifiers designs are induced by new requirements generated by optical networks. The introduction of WDM reconfigurable networks with increasing rate from 10-40 Gb/s to 100 Gb/s and beyond, demand new ...

Abstract This work presents the operation of a spontaneous Raman scattering-based distributed fiber-optic temperature sensor using a commercial OTDR and a standard EDFA optical amplification in a simple and economic sche...

Abstract We propose and experimentally investigate two distinct power-over-Fiber (PoF) approaches, aiming to remotely power Internet-of-Things (IoT) sensing systems for Industry 4.0 environments. The first proof-of-conce...

Abstract We report the implementation of an optical-wireless 5G network based on generalized frequency division multiplexing (GFDM) and multi-Gbit/s communication. Dual-drive Mach-Zehnder modulator was employed, enabling...

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...

Abstract This paper reports detailed propagation analyses of mm-wave indoor networks based numerical simulations of the wireless coverage and measurements of the propagation coefficient at 28 and 38 GHz. Additionally, ma...

AbstractThe condition for maximum power transfer of 2-coils wireless power transfer (WPT) system is derived from circuit analysis and discussed together with the respective WPT system efficiency (η). In the sequence, it...

Abstract Microwave irradiations from vegetation canopy are strongly influenced by its dielectric properties and give useful information for microwave remote sensing -interpretation and applications. This paper reports on...