Rf Amplifiers
Mostrando 1-12 de 14 artigos, teses e dissertações.
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1. High Efficiency Continuous Inverse Class-F Power Amplifier with Modified Current Waveform
Abstract Continuous inverse class-F (CICF) is a recent mode of harmonically-tuned RF power amplifiers used to extend the operating bandwidth of the conventional narrowband class-F−1 power amplifier by producing variable set of drain current waveforms and load admittances that give the same operating efficiency. In this work, a new approach of analysis is d
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2020-09
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2. New methodology for modeling, design and implementation of RF power amplifiers
Abstract This work presents a new methodology for modeling, design and implementation of power amplifiers in different technologies. As result of comparison, a flowchart with a new methodology is proposed which can be useful for the designer to design and implement power amplifiers with low, medium and high power devices in different technologies. This paper
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-09
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3. Análise experimental da aplicação da tecnologia de rádio sobre fibra em redes IEEE 802.15.4 / Analysis of applying the technology of radio-overfiber networks in IEEE 802.15.4.
This work presents an experimental investigation on the implementation of wireless sensor networks (IEEE 802.15.4) over fiber optics. Such investigation was performed with the utilization of IEEE 802.15.4 transceivers, an optical fiber infrastructure inside a field-trial network, called KyaTera Network, and directly modulated lasers and photodiodes designed
Publicado em: 2009
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4. Geração de sinais de RF por mistura de harmonicas de portadoras opticas moduladas em amplificadores opticos a semicondutor / RF signal generation by mixing harmonics of modulated optical carriers in semiconductor optical amplifiers
The gain-crossed properties of semiconductor optical amplifiers are experimentally investigated here. It was observed that optically feed-backed saturated amplifiers could achieve similar performance as that of cascaded amplifiers, offering up to 10 dB gain to two 8-nm-appart modulated optical carriers. Due to saturation the amplifier gain mechanism is alter
Publicado em: 2008
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5. Integrated passive inductors for radio frequency applications / Indutores integrados passivos para aplicações em radio frequencia
This work aims the design and implementation of integrated passive inductors based on CMOS and BiCMOS processes. The inductors are essential devices in radio frequency applications and are used in many RF circuits such as amplifiers and oscillators. The inductors performance is mainly limited by metal and substrate losses. Although various methods of improve
Publicado em: 2008
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6. Otimização de amplificadores classes E/F em tecnologia CMOS utilizando-se algoritmo genético e técnica de equilíbrio harmônico / Optimization of class E/F power amplifiers in CMOS tecnology using genetic algorithm and harmonic balance method
Neste trabalho é apresentado um otimizador de circuitos amplificadores de potência Classes E e F baseado no NSGA-II, um Algoritmo Genético (AG) muito considerado na literatura. Além disso, este otimizador funciona paralelamente ao GoldenGate, um software de simulação especializado no tratamento de circuitos RF e microondas, o qual utiliza o método do
Publicado em: 2007
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7. Um Estudo sobre Amplificadores de RF Faixa Larga / A wide band RF amplifiers study
The design of wide band RF amplifiers for CATV networks and wide band data networks, which achieve the specifications needed to handle hundreds of analogic and digital channels, must to be carry out, not only with computers but also with detailed modeling of all components. First, we started choosing a configuration that could provide the best distortion red
Publicado em: 2006
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8. Um Estudo sobre Amplificadores de RF Faixa Larga
The design of wide band RF amplifiers for CATV networks and wide band data networks, which achieve the specifications needed to handle hundreds of analogic and digital channels, must to be carry out, not only with computers but also with detailed modeling of all components. First, we started choosing a configuration that could provide the best distortion red
Publicado em: 2006
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9. Receptor super-regenetativo (900 MHz) implementado em tecnologia CMOS 0,35 mu m / Super regenerative receiver (900 MHz) in 0,35 mu m
O objetivo deste trabalho é propor uma topologia de receptor adequada para atender as exigências de uma rede de sensores sem fio, onde baixo consumo e baixo custo de fabricação são fundamentais.A topologia escolhida foi a do receptor super-regenerativo realizado em tecnologia CMOS 0,35Km e operando em 900 MHz. O chip foi montado e testado numa placa de
Publicado em: 2006
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10. Uma Abordagem Analítica para Análise Não-Linear dos Amplificadores de RF voltada para as Estruturas do Tipo FET / Uma Abordagem Analítica para Análise Não-Linear dos Amplificadores de RF voltada para as Estruturas do Tipo FET
One of the most important characteristics to be maintained with respect to the quality of generic RF amplifiers is the linearity since that the absence of it can generate a series of effects and distortions in the signal to be transmitted. With this constant demand of the discovery of new technologies many additional impositions are imposed on the transmissi
Publicado em: 2005
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11. Neodymium in hydrogenated amorphous silicon sub-nitrides (a-SiNx:H) / Neodimio em sub-nitretos de silicio amorfo hidrogenado (a-SiNx:H)
In this work, we report a study of the photoluminescence (PL) optimization of a-SiNx:H
thin films prepared by RF co-sputtering. The PL was investigated as a function of nitrogen and neodymium concentrations. We observed that the Nd ions are excited through the amorphous matrix. The excitation mechanism is more efficient in samples where the optical gap E0 Publicado em: 2005
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12. Uma eficiente abordagem numérica para a linearização de amplificadores de potência em RF com os recursos da pré-distorção digital / An efficient numerical analysis to linearization RF power amplifiers using digital pre-distortion
As não linearidades de dispositivos para certas aplicações são indesejáveis. Elas ocorrem nos diversos equipamentos eletrônicos para Sistemas de Telecomunicações, no nosso caso, em específico, elas estão presentes na transmissão de sinais de TV Digital, totalmente dependentes de amplificadores de potência em Rádio Freqüência (RF). Devido ao co
Publicado em: 2004