Circuit Theory
Mostrando 1-12 de 48 artigos, teses e dissertações.
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1. Dual U-Slot Loaded Patch Antenna with a Modified L-Probe Feeding
Abstract In this paper, a modified L-strip fed patch antenna is theoretically analyzed for wideband applications. Dual U-shaped slots are incorporated in the radiating patch and a maximum bandwidth of 16.93% (2.65 GHz to 3.14 GHz) is achieved. Further, when two parasitic elements are used, antenna bandwidth improves up to 25.89% (2.90 GHz to 3.77 GHz). The m
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-09
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2. Design of Frequency Selective Band Stop Shield Using Analytical Method
Abstract In this article, a high-order frequency selective band-stop EMC (electromagnetic compatibility) shield is designed using multilayer square loop while each loop resonates at the specific desired frequency. The glass material is picked out as the preferred substrate for the designing process. In contrast to the computationally intensive numerical appr
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2015-12
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3. Maximum Power Transfer versus Efficiency in Mid-Range Wireless Power Transfer Systems
AbstractThe condition for maximum power transfer of 2-coils wireless power transfer (WPT) system is derived from circuit analysis and discussed together with the respective WPT system efficiency (η). In the sequence, it is shown that a 4-coils WPT system (which can be divided in source, two communication and load circuits) without power losses at the two co
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2015-06
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4. Geometry optimization for application of radio frequency signals on diamond samples
This work describes the design and optimization of a printed circuit board containing a rectangular half-loop coil designed to apply radio frequency signals on micrometric diamond crystals. The structure was optimized to maximize the magnetic field perpendicular to the coil at 2,87 GHz. In the optimization process we have used transmission line theory, circu
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2013-12
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5. Cartoneros, recolección informal, ambiente y políticas públicas en Buenos Aires 2001-2012
This paper seeks to analyze the characteristics of the informal circuit of waste collection and recovery in Buenos Aires - developed since the late 1990’s and, especially, towards the end of 2001 - and investigate the reasons that stimulate the circuit growth, the new characteristic acquired by the circuit in the second stage, and the positioning taken by
urbe, Rev. Bras. Gest. Urbana. Publicado em: 2013-06
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6. Circuito espacial produtivo das confecções e exploração do trabalho na metrópole de São Paulo : os dois circuitos da economia urbana nos bairros da Brás e Bom Retiro (SP) / Clothing productive spatial circuit and exploration of work in the Metropolis of São Paulo : the two circuits of the urban economy in Brás and Bom Retiro neighborhoods (SP)
Recently there has been a reorganization of the clothing production spatial circuit in planetary scale. In Brazil, the stages of production, distribution, trade and consumption have had meaningful transformations. However, the city of São Paulo, besides losing relatively part of the production, still has centrality in this branch of activity. The understand
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 20/04/2012
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7. Análise das variáveis de entrada de uma rede neural usando teste de correlação e análise de correlação canônica / Analysis of input variables of an artificial neural network using bivariate correlation and canonical correlation
The monitoring of variables and diagnosis of sensor fault in nuclear power plants or processes industries is very important because an early diagnosis allows the correction of the fault and, like this, do not cause the production interruption, improving operators security and its not provoking economics losses. The objective of this work is, in the whole of
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 21/09/2011
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8. Segregação socioespacial e turismo: estudo da representação fílmica criada pelos turistas e residentes sobre Natal Rio Grande do Norte
This study emerges and develops, from a note by Italo Calvino, who in his novel Invisible Cities advised to avoid saying "that sometimes different cities follow on the same site and with the same name, born and die without knowing, without communication among itself ". The research with a transdisciplinary work ( using elements of sociology, anthropology, ge
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 09/06/2011
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9. Técnicas de processamento não linear de sinais aplicadas à investigação de limitações práticas do procedimento de ventilação mecânica não invasiva
Individuals with respiratory system dysfunctions or who are recovering from complex surgeries may have difficulty to sustain spontaneous breathing. The mechanical ventilation is a clinical procedure that supports ventilation until the patient is recovered. Noninvasive mechanical ventilation is especially remarkable as it can be used outside the hospital, in
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 06/05/2011
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10. 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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11. A compact model of MOSFET mismatch for circuit design
This paper presents a compact model for MOS transistor mismatch. The mismatch model uses the carrier number fluctuation theory to account for the effects of local doping fluctuations along with an accurate and compact dc MOSFET model. The resulting matching model is valid for any operation condition, from weak to strong inversion, from the linear to the satu
Publicado em: 2011
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12. A study on the design of networks in competitive environments / Um estudo sobre o dimensionamento de redes em ambientes competitivos
Esta dissertação propõe um estudo de um novo modelo para o dimensionamento de redes baseadas em comutação de circuitos, tais como as redes óticas roteadas por comprimento de onda. O novo modelo é projetado para dar suporte a diversas estratégias de negócios da operadora em um mercado competitivo. Primeiramente o caso do monopólio é analisado, comp
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 29/03/2010