Amplifiers
Mostrando 1-12 de 132 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. Serosurvey of Rickettsia spp. in cats from a Brazilian spotted fever-endemic area
Resumo Espécies de Rickettsia têm sido responsáveis por doenças transmitidas por carrapatos no mundo, a maioria mantida por hospedeiros amplificadores, como as capivaras em áreas endêmicas no Brasil. A Universidade de São Paulo, em Piracicaba, no sudeste do Brasil, é uma área endêmica para a Febre Maculosa Brasileira (FMB), com alta densidade de ca
Rev. Bras. Parasitol. Vet.. Publicado em: 07/11/2019
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3. Study and Optimization of Raman Amplifiers in Tellurite-Based Optical Fibers for Wide-Band Telecommunication Systems
Abstract Here we present a numerical analysis and the optimization of a multi-pump discrete Raman amplification system based on the use of a Tellurite optical fiber as the gain media. By using previously reported optimization techniques we were able to exploit the high Raman gain of Tellurite optical fibers and its multipeak spectrum to achieve amplification
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 19/06/2019
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4. Posições sexuais, estilos corporais e risco para o HIV entre homens que fazem sexo com homens no Recife (Brasil)
Resumo O artigo apresenta resultados de pesquisa etnográfica na comunidade gay do Recife (PE), realizada por meio de observação participante e entrevistas. Objetiva compreender condutas sexuais de risco de homens que fazem sexo com homens (HSH) ao HIV, focando os sentidos das posições sexuais no intercurso anal — receptivo (IAR) e insertivo (IAI). Pra
Ciênc. saúde coletiva. Publicado em: 2019-03
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5. 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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6. A simple strategy to design broadband low power consumption distributed Raman amplifier
Abstract In this work, a simple strategy to design wideband low power consumption Raman amplifiers is demonstrated for a three-pump configuration using a low water peak optical fiber. The approach is based on the introduction of a novel numerical measure, which quantifies and isolates pump-pump interaction contribution to gain profile and analyzes its correl
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-09
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7. Power amplifier circuits for functional electrical stimulation systems
Abstract Introduction: Functional electrical stimulation (FES) is a technique that has been successfully employed in rehabilitation treatment to mitigate problems after spinal cord injury (SCI). One of the most relevant modules in a typical FES system is the power or output amplifier stage, which is responsible for the application of voltage or current puls
Res. Biomed. Eng.. Publicado em: 2017-06
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8. A correction method for the analytical model in Raman amplifiers systems based on energy conservation assumption
Abstract This paper presents a modification for the already consolidated analytical model that calculates the gain and ripple in multi-pump Raman amplifiers by considering energy conservation. The original analytical model precisely computes the pump-pump interaction to the C- and L-band for a WDM input signal. However, when this method is used to amplify a
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2016-09
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9. A flat-gain LNA based on LTCC technology at UHF (300-500 MHz)
Abstract This paper presents a design and simulation of a low noise amplifiers (LNA) with all passives elements embedded on low temperature co-fired ceramic (LTCC) substrate. Simulation results in ANSYS Designer and CST Studio Suite reveal that the proposed LNA has a flat-gain of 23.34 dB from 300 to 500 MHz, a noise figure below 0.73 dB and a compact size o
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2016-09
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10. Experimental-based subsystem models for simulation of heterogeneous optical networks
This work presents and analyzes experimental-based subsystem models for Erbium doped fiber amplifiers (EDFAs) and wavelength selective switches (WSSs) under operation in a metropolitan optical network testbed. Firstly, the performance of the EDFAs and two gain control types are analyzed in a heterogeneous experimental setup with lightpaths modulated at 10G/1
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2014-12
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11. Hybrid distributed Raman/EDFA amplifier with hybrid automatic gain control for reconfigurable WDM optical networks
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 optical amplifiers development with improved gain spectral flatness and noise figure for all operational range of input powers and set-point
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2013-12
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12. Analytical study of substrate parasitic effects in common-base and common-emitter SiGe BHT amplifiers
An analytical study to quantify the substrate parasitic effects on SiGe HBT amplifiers in both common-base and common-emitter configuration is presented. The power gain relations and stability factors are derived from the modelled S-parameters which are computed at a fixed bias point from the small-signal hybrid-∏ model of SiGe HBT in both configurations.
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2013-06