8 documents found, page 1 of 1
RF phase shifters design based on barium strontium titanate thick and thin films
Bouça, Patrícia; Pinho, Rui m; Włodarkiewicz, Anna; Tkach, Alexander; Matos, João Nuno; Vilarinho, Paula M.; Carvalho, Nuno Borges deIn this paper, microwave characterizations and phase-shifting applications of electrophoretically deposited thick films and sol-gel derived thin films of Barium Strontium Titanate (BST) are presented. Capacitors fabricated using Ba 0.7 Sr 0.3 TiO 3 films prepared by electrophoretic deposition (EPD) on platinum foils and sol-gel technique on platinized Si and SiO 2 demonstrate a maximum tunability of 49%, 29%, a...
Implementation of the MAC Layer of a DSRC identification system
Morais, Daniel Fidalgo; Abreu, Ricardo Matos; Matos, João NunoDSRC (Dedicated Short Range Communications) is a well known widespread technology. One of the main applications of DSRC is RTTT (RoadTransport and Traffic Telematics), especially EFC (Electronic Fee Collection) on tolled roads, bridges or tunnels. Other vehicle-related applications had been envisaged, such as car parking or fuel refilling automatic payment. These applications were successfully developed, deploy...
Redes domésticas
Carreira, Alexandre; Canhão, Vitor; Matos, João Nuno; Ribeiro, VítorThis paper describes the Home Networks Project integrated on a final project for a degree in engineering and inserts itself in the wider project “Casa do Futuro”. The first part shows the current approaches/technologies todistribute data within the home. Only binary debits over 10Mbps were considered (minimum speed for a Triple Play household implementation) on this study. The second part of the project consist...
Desenvolvimento de um modelo de simulação baseado na camada física do protocolo...
Leal, Homero; Pannuzzo, Ricardo; Matos, João Nuno; Gameiro, AtílioO presente trabalho apresenta uma implementação de um simulador da camada física do sistema ETSI BRAN HiperLAN/2. O software de simulação foi desenvolvido sobre a ferramenta CoCentric System Studio recorrendo a linguagem C.
Medidor de campo electromagnético selectivo na frequência para as bandas GSM900...
Borda, Carlos José; Dias, Rogério Paulo; Carvalho, Nuno Borges de; Matos, João NunoThis paper describes the design, implementation and test of a frequency selective electromagnetic field meter for the GSM900 and GSM1800 bands developed on an engineering degree final project. We will start to introduce all the necessary background concepts such as: biological effects of electromagnetic radiation and reference exposure levels, near and far field and power measurement. Finally, we will present t...
Simulador de comunicação com modulação Spread Spectrum
Monteiro, Valdemar; Matos, João NunoIn this paper we present the description of the design of a spread spectrum communication simulator to analyse the system performance. The Spread Spectrum system that will be simulated is the CDMA - DS/SS BPSK. The performance will be evaluated by the probability of biterror in the communication simulation.; Neste artigo descreve-se a construção de um simulador de comunicações com modulação Spread Spectrum...
Osciladores para rádio frequência de elevada estabilidade
Tavares, João Manuel; Matos, João NunoThis article describes methods for high stability oscillators design using quartz crystal piezoelectric proprieties. It also presents a set of radio frequency oscillators whose construction principles obey to these methods.; Este artigo descreve técnicas de projecto de osciladores de elevada estabilidade recorrendo às propriedades piezoeléctricas do cristal de quartzo. São também apresentados um ...
Método universal de obtenção do equivalente de Thevenin
Matos, João NunoAn alternative method to obtain Thevenin Equivalent of a linear resistive circuit is showed. This method is universal for any kind of linear resistive circuit.; Neste artigo mostra-se como é possível obter de um modo universal o Equivalente de Thevenin dum circuito linear e resistivo.