Power Line Communication: Análise de Desempenho de uma Rede Doméstica com Adaptadores padrão homeplug AV / Power Line Communication: Performance Analysis of a Home Network with homeplug AV Adapters

With the increase in the number of Internet users, due to digital inclusion, it is necessary to find the best possible way to provide this service. Among all forms of data transmission, PLC (Power Line Communication) is the one that has stood out the most in recent years, mainly due to its infrastructure, which allows users in semi-urban or even rural regions, and by the fact of ensuring high speed rates (up to 200 Mbps), through the broadband PLC, the BPL (Broadband Power Line), which uses the HomePlug AV standard. However, because the infrastructure used is the power lines, PLC is subject to numerous problems, such as interference, noise and attenuation. Therefore, there is a need to evaluate the performance of this broadband technology with regard to its use in domestic environments, analyzing its effectiveness amidst electrical interference. This paper presents an analysis of the performance of a PLC network that uses the HomePlug AV standard, with the objective of evaluating its viability in a domestic environment, since it presents several challenges for this technologyEsde 

Rainfall in the urban area and its impact on climatology and population growth

Due to the scarcity of studies linking the variability of rainfall and population growth in the capital cities of Northeastern Brazil (NEB), the purpose of this study is to evaluate the variability and multiscale interaction (annual and seasonal), and in addition, to detect their trends and the impact of urban growth. For this, monthly rainfall data between 1960 and 2020 were used. In addition, the detection of rainfall trends on annual and seasonal scales was performed using the Mann–Kendall (MK) test and compared with the phases of El Niño-Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO). The relationship between population growth data and rainfall data for different decades was established. Results indicate that the variability of multiscale urban rainfall is directly associated with the ENSO and PDO phases, followed by the performance of rain-producing meteorological systems in the NEB. In addition, the anthropic influence is shown in the relational pattern between population growth and the variability of decennial rainfall in the capitals of the NEB. However, no capital showed a significant trend of increasing annual rainfall (as in the case of Aracaju, Maceió, and Salvador). The observed population increase in the last decades in the capitals of the NEB and the notable decreasing trend of rainfall could compromise the region’s water security. Moreover, if there is no strategic planning about water bodies, these changes in the rainfall pattern could be compromising

Conceptual model of a CMOS UWB Radar transmitter by electronic scanning with Vivaldi array antenna.

O objetivo deste trabalho é desenvolver um modelo conceitual de um sistema transmissor de pulsos eletromagnéticos de banda ultra-larga, capaz de realizar o controle da formação do feixe irradiado de forma totalmente eletrônica. Para isso, é proposto um sistema formado por quatro canais iguais e independentes, sendo que cada um é formado por um controlador de atraso programável, com o qual se pode ajustar a defasagem temporal entre os pulsos de cada canal, um gerador de pulso, capaz de sintetizar a quinta derivada do pulso Gaussiano a partir de uma nova proposta de topologia, e um arranjo de antenas do tipo planar de abertura exponencial conhecida como antena Vivaldi. O sistema proposto é apoiado por modelos matemáticos e simulações elétricas post-layout com variação dos parâmetros por Monte Carlo com os programas LTSpice 4 e Microwind 2.6, utilizando as regras de processo padrão CMOS 180nm e eletromagnética tridimensional com o uso do programa CST Microwave 2011. Os resultados obtidos nas simulações, comparados com propostas anteriores, indicam que realmente houve o controle da formação do feixe irradiado cujo lóbulo principal teve uma magnitude média de 11dBi com uma largura angular do feixe de 33º x 38º e possibilidade de variar os ângulos azimutal e de elevação de -15º a 9º e -18º a 6º, respectivamente, para uma frequência central de 6GHz. O pulso utilizado para estimular as antenas foi o pulso Gaussiano em sua quinta ordem de derivação, que teve como resultados médios de simulação uma amplitude de 90mVpp, uma largura de pulso de 370ps a uma taxa de repetição de 100MHz e uma frequência central de 6GHz.This work aims to develop a conceptual model of the new Ultra Wide-band fifth-order derivative Gaussian pulse transmitter with Vivaldi antenna array for beamforming using the technique of timed-array. It is proposed a system formed by four equal and independent channels, each of which is formed by a programmable delay controller in which one can adjust the delay time between pulses of each channel, a pulse generator, capable to synthesize the fifth derivative of a Gaussian pulse using a new topology, and a planar Vivaldi antenna. The proposed system was supported by mathematical models and post-layout electrical simulations with parameters variation by Monte Carlo in programs LTSpice 4 and MicroWind 2.6 using the CMOS 180nm Standard process rules and using three-dimensional electromagnetic program CST Microwave 2011. The simulation results indicated that there was indeed control on the beam formation irradiated whose main lobe has an average magnitude of 11dBi with an angular width of the beam 33 x 38 (degrees square) and possibility of varying the angles of azimuth and elevation from -15 to 9 degrees and -18 to 6 degrees, respectively, at a center frequency of 6GHz. The pulse used to stimulate the antennas was the fifth order Gaussian one, which had the average results of a simulation 90mVpp amplitude, a pulse width 370ps to a 100MHz repetition rate and a center frequency of 6 GHz.

Development and optimization of antipodal Vivaldi antena for applications at high frequencies.

Esta tese propõe a síntese e o estudo de uma nova técnica de cavidades de borda aplicada a antenas Vivaldi, com o intuito de melhorar suas características de diretividade. Embora as antenas do tipo Vivaldi possuam características diretivas, elas produzem radiações laterais indesejáveis, o que se reflete nos elevados índices de lóbulos laterais devido a correntes superficiais que fluem ao longo das bordas metalizadas nas laterais da antena. Estas correntes são a origem das radiações laterais que vêm sendo mitigadas pela aplicação de cavidades ressonantes, triangulares ou retangulares, que aprisionam tais correntes e, consequentemente, atenuam os lóbulos laterais, sem o incremento do lóbulo principal, uma vez que toda a energia dos lóbulos laterais é apenas confinada nos ressonadores e por isso literalmente perdida. Ao contrário desses esforços, este trabalho propõe cavidades radiantes tanto na forma de abertura exponencial, como na forma do fractais de Koch, que funcionam como radiadores auxiliares (antenas auxiliares), canalizando as correntes de borda e aproveitando-as para aumentar os níveis do lóbulo principal, mitigando os níveis de lóbulo lateral. A síntese desta nova técnica foi implementada em uma antena Vivaldi antipodal com características de baixa diretividade, como qualquer antena Vivaldi, o que foi corrigido e a aplicação da técnica de cavidades radiantes deu origem a duas novas antenas Vivaldis efetivamente diretivas. Os resultados foram obtidos através de simulações do modelo numérico no CST Microwave Studio e confirmados com medidas de laboratório, o que evidenciou a melhora das características de diretividade da antena pela aplicação da nova técnica de cavidades radiantes.This work presents a new Slot Edge technique applied to Vivaldi antennas to improve their characteristics of directivity, resulting in two new Vivaldi antennas: the Palm Tree Vivaldi antenna and the Koch Vivaldi antenna. This new technique proposes to add lateral radiators which reduce the side lobe level, increasing the gain of the main lobe in an unprecedented way. This technique is called radiating slot edges, and acts as parasitic antennas, surface currents draining edges of the antenna, and using them to increase the gain in the main lobe. The development was done systematically, starting with an extensive literature review, design and simulation in CST, as well as prototyping and measurements of several antenna designs. All this effort proved the functionality of this technique

Study of the Exponential Growth of Bacteria: Using the concepts of Numerical Calculation in Scilab

<p>In this article, the exponential growth of bacteria was studied, using the concepts of Numerical Calculation together with the Scilab language to assist this project. A demonstrative growth rate was analyzed and through the use of the code it is possible to obtain a graph, helping to observe the behavior of the bacteria. </p&gt

ANALYSIS OF A SIMPLE AND MULTILAYER FSS WITH A BIO-INSPIRED ELEMENT FOR WLAN APPLICATIONS

<p>This article aims to present a single and multilayer Frequency Selective Surface (FSS) with bio-inspired element geometry, with filtering capability (blocking/rejection) to the 2.4 GHz WLAN frequency band. </p&gt

STUDY ON ELECTROMAGNETIC CHARACTERISTICS FOR DEVELOPMENT OF MICROWAVE MEDICAL IMAGING SYSTEM

<p>The work consists of a detailed study carried out on the characteristics of the development of a microwave medical imaging system (MMIS) and aims to understand its operation. The scope of this work comprises the electrical characteristics of healthy and malignant biological tissues, the dielectric characteristics of the human chest region, the interactions of electromagnetic waves (EWs) with tissues, as well as the functioning of the MMIS and the emission/repetition of electromagnetic signals. As a result, it was found that malignant tissues have a higher dielectric constant, which generates greater reflection intensity and that there is a need to process the reflected signals, which arrive full of noise, to synthesize the image using frequencies in the microwave range. </p&gt

STATE OF THE ART: INTEGRATING SERVICES FOR MEGA EVENTS

This paper describes the state of the art of a simplified model for integration of services in mega events. The project context, which was financed by the National Research Council – CNPq, is divided into six major areas or functional groups: Urban Mobility, Tourism, Airports, Security, Energy and Telecommunications. The proposal is described in layers, as an infrastructure model of integration and services evaluation, describing its main layers and interaction processes. The proposal described in this paper is restricted to the telecommunication subproject, however, in the modeling of the scenario for the study case, it was necessary to considerate requirements and variables that are common to all subprojects. In the specification process of these requirements, we noticed important processes that interact with some sectors in the city of São Paulo, however, in the mean time, we noticed some failures regarding the integration and collaboration performed by administrators elements of stadiums as main focus in the mega event and part of our case study. Currently, the proposal is in its first version as open software for the evaluation of the services quality and the mega event infrastructure through the use of performance indicators

Design of 1 × 2 MIMO Palm Tree Coplanar Vivaldi Antenna in the E-Plane with Different Patch Structure

In this paper, 1 × 2 MIMO of Palm Tree Coplanar Vivaldi Antenna is presented that simulated at 0.5–4.5 GHz. Some GPR applications require wideband antennas starting from a frequency below 1 GHz to overcome high material loss and achieve deeper penetration. However, to boost the gain, antennas are set up in MIMO and this is costly due to the large size of the antenna. When configuring MIMO antenna in the E-plane, there is occasionally uncertainty over which antenna model may provide the optimum performance in terms of return loss, mutual coupling, directivity, beam squint, beam width, and surface current using a given substrate size. However, the configuration of E-plane antenna in MIMO has an issue of mutual coupling if the distance between elements is less than 0.5λ. Furthermore, it produces grating lobes at high frequencies.We implement several types of patch structures by incorporating the truncated, tilt shape, Hlbert and Koch Fractal, Exponential slot, Wave slot, the lens with elips, and metamaterial slot to the radiator by keeping the width of the substrate and the shape of the feeder. The return loss, mutual coupling, directivity, beam squint, beamwidth, and surface current of the antenna are compared for 1 × 2 MIMO CVA. A continuous patch MIMO has a spacing of 0.458λ at 0.5 GHz, which is equivalent to its element width. From the simulation, we found that Back Cut Palm Tree (BCPT) and Horizontale Wave Structure Palm Tree (HWSPT) got the best performance of return loss and mutual scattering at low-end frequency respectively. The improvement of directivity got for Metamaterial Lens Palm Tree (MLPT) of 4.453 dBi if compared with Regular Palm Tree-Coplanar Vivaldi Antena (RPT) at 4 GHz. Elips Lens Palm Tree (ELPT) has the best beam squint performance across all frequencies of 0°. It also gots the best beamwidth at 4.5 GHz of 3.320. In addition, we incorporate the MLPT into the radar application

ANALYSIS OF THE EFFECTS OF ELECTROMAGNETIC RADIATION ON PLANTS DEVELOPMENT

<p>The population growth of the last decades has created the need to look for new ways to increase the productivity of crops. Knowing this, several studies began to be carried out in order to analyze the influence of electromagnetic radiation on the development of plants. With that in mind, the present work presents an experiment carried out to analyze the influence of the irradiation of an electromagnetic wave of 2.3625 GHz in the development of a corn crop by comparing the growth of this plant exposed to this extra radiation with another that is only exposed to the ambient radiation. The results demonstrate that the plant exposed to the radiation set at a specified frequency has a decrease in root size. </p&gt