Reflector Antennas
Mostrando 1-12 de 22 artigos, teses e dissertações.
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1. GO Synthesis of Offset Dual Reflector Antennas Using Local Axis-Displaced Confocal Quadrics
Abstract This work investigates an alternative numerical scheme for the solution of an exact formulation based on Geometrical Optics (GO) principles to synthesize offset dual reflector antennas. The technique is suited to solve a second-order nonlinear partial differential equation of the Monge-Ampère type as a boundary value problem. An iterative algorithm
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2020-06
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2. Imaging evaluation of hallux valgus
Abstract This work investigates an alternative numerical scheme for the solution of an exact formulation based on Geometrical Optics (GO) principles to synthesize offset dual reflector antennas. The technique is suited to solve a second-order nonlinear partial differential equation of the Monge-Ampère type as a boundary value problem. An iterative algorithm
Radiol Bras. Publicado em: 2020-06
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3. Comportamento da função renal na crioablação percutânea de massa renal
Abstract This work investigates an alternative numerical scheme for the solution of an exact formulation based on Geometrical Optics (GO) principles to synthesize offset dual reflector antennas. The technique is suited to solve a second-order nonlinear partial differential equation of the Monge-Ampère type as a boundary value problem. An iterative algorithm
Radiol Bras. Publicado em: 2020-06
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4. Hidrodissecção modificada para biópsia guiada por tomografia computadorizada de lesões mediastinais: técnica “marshmallow”
Abstract This work investigates an alternative numerical scheme for the solution of an exact formulation based on Geometrical Optics (GO) principles to synthesize offset dual reflector antennas. The technique is suited to solve a second-order nonlinear partial differential equation of the Monge-Ampère type as a boundary value problem. An iterative algorithm
Radiol Bras. Publicado em: 2020-06
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5. Polarization Insensitive Compact Wide Stop-band Frequency Selective Surface
Abstract A compact, polarization insensitive, wide stop band frequency selective surface is presented. The unit cell is designed by modifying the basic square loop FSS. The simulated value of bandwidth for transmission < ‒ 20 dB for TE incident wave is 7.7 GHz from 4.71 GHz to 12.41 GHz which is 89.95% corresponding to the center frequency of this range. I
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2018-03
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6. Study of backfire antennas
The study presented in this article is dedicated to the backfire disk-on-rod antennas fed by a dipole or crossed dipole. For short, these are herein called backfire antennas. Backfire antenna constructions with different configurations of the big reflector are considered. The influence of the feed location in the backfire antenna construction upon the antenn
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2011-06
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7. SYNTHESIS AND RIGOROUS ANALYSIS OF OMNIDIRECTIONAL DUAL-REFLECTOR ANTENNAS: THE CASE OF THE MAIN REFLECTOR WITH CIRCULAR GENERATRIX / SÍNTESE E ANÁLISE RIGOROSA DE ANTENAS OMNIDIRECIONAIS DE DUPLO-REFLETORES: O CASO DO REFLETOR PRINCIPAL COM GERATRIZ CIRCULAR
Este trabalho aborda o projeto de antenas omnidirecionais de duplorefletores, onde o refletor principal é obtido a partir de uma geratriz circular. A antena é composta de refletores circularmente simétricos e concêntricos que são alimentados por uma corneta cônica coaxial excitada pelo modo TEM para a produção de polarização vertical. Para realizar
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 26/02/2010
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8. SYNTHESIS AND ANALYSIS OF CIRCULARLY SYMMETRIC REFLECTORS VIA PHYSICAL OPTICS AND FRINGE WAVE CURRENTS / ANÁLISE E SÍNTESE DE REFLETORES CIRCULARMENTE SIMÉTRICOS PELOS MÉTODOS DA ÓTICA FÍSICA E CORRENTES DE FRANJA
The usual algorithms employed in the design of shaped reflector antennas for satellite applications embed an electromagnetic analysis method in an optimization technique. In general, these algorithms demand considerable computation time, limiting its intensive use in the study to explore different sets of specifications and to search for more compact geometr
Publicado em: 2009
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9. Análise da taxa de rejeição sistêmica para diversos esquemas de modulação
During the last years, the number of users of the communications systems has boomed causing a search for an effective use of the frequency spectrum. In each new standard, something has being optimized. This work introduces a new parameter in the search of improved communication system performances, the System Isolation Rate. By analyzing the modulation influ
Publicado em: 2009
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10. Análise de antenas refletoras circularmente simétricas com a presença de corpos dielétricos
This work develops theoretical, analytical and numerical tools for solution of electromagnetic scattering from bodies of revolution, composed by perfect conductors and dielectrics, such as reflector antennas with radomes. Accurate analyses of these structures are performed through algorithms based on electric and magnetic integral equations, numerically eval
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 04/05/2007
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11. APLICAÇÃO DO MÉTODO DOS ELEMENTOS FINITOS NA ANÁLISE E PROJETOS DE ESTRUTURAS COAXIAIS / APPLICATION OF FINITE ELEMENTS METHOD IN THE ANALYSIS AND DESIGN OF COAXIAL STRUCTURES
In this work, the Method of Finite Element is applied in the electromagnetic analysis and project of coaxial horns employed as feed in omnidirectional reflector antennas. These feeds are usually excited by standard commercial connectors that require an adaptor to connect to the coaxial horn. This adaptor is usually composed of non-uniform sections of coaxial
Publicado em: 2006
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12. Projeto e implementação do controle de posição de uma antena de radar meteorológico através de servomecanismos. / Design and implementation of a weather-radar antenna position control using servomechanisms.
A classical radar antenna is basically composed of a primary source mounted at the focal point of a parabolic reflector. The illumination rule is established so that the desired beam-shape is attained, as precisely as possible. The physical motion of the set guarantees the coverage of the desired volume of exploitation. The actual text studies the design and
Publicado em: 2006