Microwave Device
Mostrando 1-12 de 19 artigos, teses e dissertações.
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1. Characterization of the Ge/Bi2O3 Interfaces
In this article, the properties of the Ge/Bi2O3 interfaces as microwave cavities are reported and discussed. The interface is composed of monoclinic Bi2O3 films grown onto polycrystalline cubic Ge substrate. It is observed that consistent with the theoretical design of the energy band diagram, the experimental current-voltage characteristics of the Yb/Ge/Bi2
Mat. Res.. Publicado em: 04/04/2019
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2. An FET-based microwave active circuit with dual-band negative group delay
Recent studies proved that certain electronic active circuits are capable to exhibit simultaneously a negative group delay (NGD) and amplification in microwave frequency bands. One of the simplest topologies generating this counterintuitive NGD function effect is formed by a series RLC-network in cascade with a transistor. By using this cell, similar to the
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2011-12
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3. Micromachined microwave planar spiral inductors and transformers
A new micromachined planar spiral inductor, with the strips suspended individually, has been fabricated in standard GaAs high electron-mobility transistor monolithic-microwave integrated-circuit technology through maskless front-side bulk micromachining. The electronic compatibility, the use of industrial integrated-circuit production lines, the straightforw
Publicado em: 2011
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4. Miniaturization techniques for dielectric filters at microwave frequencies / Tecnicas de miniaturização de filtros dieletricos em microondas
O trabalho mostra o desenvolvimento de um filtro na faixa de frequência de micro-ondas e sua construção usando ressoadores dielétricos de alta permissividade elétrica. A partir da definição matemática de uma função de transferência do tipo entrada-saída, que caracteriza um filtro, e do uso da teoria de síntese de redes, vista de um modo bastante
Publicado em: 2009
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5. Sistemas para manipulação quantica em estado solido / Towards an implementation of quantum manipulation in solid states
This thesis proposes and implements a system for quantum information processing, focusing primarily on the associated instrumentation. The basic physical aspects for computation, such as the associated energy and Shannon s entropy, were revisited. InAs:GaAs quantum dots were elected as the physical system of choice for this implementation; in particular, the
Publicado em: 2008
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6. Development of MEMS switch device technology MEMS - MicroelectromechanicalSystems - for RF - radio frequency - and new topologies of RF CMOS integrated circuits for radio receivers input sub-systems / Desenvolvimento de tecnologia de dispositivos chaves MEMS - MicroelectromechanicalSystems - para RF - Radio Frequencia - e novas topologias para circuitos integrados CMOS de RF em sub-sistemas de entrada de radio receptores
Este trabalho apresenta dois tópicos de pesquisa, o primeiro é referente ao projeto e desenvolvimento da tecnologia de fabricação de Chaves MEMS (Micro Electro Mechanical System) de RF e o segundo é o projeto de circuitos integrados. No que se refere a chaves MEMS, descreve-se o processo e a metodologia para projeto de Chaves MEMS paralela sobre linha d
Publicado em: 2008
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7. Effect of a post-polymerization treatments on the flexural strength and Vickers hardness of reline and acrylic denture base resins
This study evaluated the effect of water-bath and microwave post-polymerization treatments on the flexural strength and Vickers hardness of four autopolymerizing reline resins (Duraliner II-D, Kooliner-K, Tokuso Rebase Fast-TR and Ufi Gel Hard C-UGH) and one heat-polymerized acrylic resin (Lucitone 550-L), processed using two polymerization cycles (short cyc
Journal of Applied Oral Science. Publicado em: 2007-12
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8. COMBUSTÃO INICIADA POR MICROONDAS E DETERMINAÇÃO EM LINHA DE CÁDMIO E CHUMBO EM PLANTAS POR ESPECTROMETRIA DE ABSORÇÃO ATÔMICA COM TUBO AQUECIDO NA CHAMA
In this work a new procedure is proposed by solid sampling flame furnace atomic absorption spectrometry after microwave induced combustion (MIC-FFAAS). The procedure was applied for the determination of cadmium and lead in botanical samples. Samples were groung, pressed and placed on a filter paper positioned on a quartz holder. The holder was placed in a gl
Publicado em: 2007
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9. Development of wideband bandpass filter with zeros transmition for ultrawideband communication systems / Desenvolvimento de filtro passa-faixa banda larga com zeros de transmissão para sistemas de comunicação Ultra-Wideband (UWB)
The quick development of wireless communications has introduced new requirements for communications systems being the use of more selective microwave filters. Different filter structures have been developed for applications in UWB systems (Ultra WideBand). It is presented in [1, 2] the highly selective microstrip bandpass filter. In this work, a bandpass fil
Publicado em: 2007
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10. DETERMINAÇÃO DE CÁDMIO E CHUMBO EM SANGUE POR ESPECTROMETRIA DE ABSORÇÃO ATÔMICA COM TUBO AQUECIDO NA CHAMA APÓS COMBUSTÃO INICIADA POR MICROONDAS
In this work a procedure for Cd and Pb determination by solid sampling flame furnace atomic absorption spectrometry after microwave induced combustion (MIC-FF-AAS) is used. Human blood samples were priory lyophilized, dried, ground, mixture with graphite, pressed and placed on a filter paper positioned on a quartz holder, that was introduced in a glass devic
Publicado em: 2007
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11. Dielectric characterization of materials at microwave frequency range
In this study a coaxial line was used to connect a microwave-frequency Network Analyzer and a base moving sample holder for dielectric characterization of ferroelectric materials in the microwave range. The main innovation of the technique is the introduction of a special sample holder that eliminates the air gap effect by pressing sample using a fine pressu
Materials Research. Publicado em: 2003-01
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12. Relógio atômico a feixe efusivo de 133Cs: estudo da estabilidade e da acuracia como função do deslocamento da frequência atômica devido ao efeito zeeman de segunda ordem, ao cavity pulling e ao rabi pulling / A 133Cs Atomic Beam Clock: study of its accuracy and stability as a function of the atomic frequency shift due to the second order zeeman effect, the cavity pulling and the rabi pulling
Since 1967, the definition of the second is based on the atomic properties of the 133Cs atom. The device that realises this definition is an atomic clock. In this work, we present the progress made in the last year on Brazilian scientific time and frequency program. The aim of this dissertation work is the caracterization of our standard. We report the major
Publicado em: 2003