Antenna Arrays
Mostrando 1-12 de 24 artigos, teses e dissertações.
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1. Series Fed Designs of Planar Circular and Hexagonal Microstrip Antenna Arrays for High Gain and Reduced First Side Lobe Level Radiation
Abstract To achieve a high gain and low first side-lobe level, variants of linear and planar series fed circular and hexagonal microstrip antenna arrays using the binomial distribution, are proposed around 3000 MHz frequency band, on thinner Arlon substrate (h ~ 0.027λg). The linear 7 × 1 array of circular patches, yields first side-lobe level of −25 dB
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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2. Optimization of Planar Antenna Arrays Using the Firefly Algorithm
Abstract This paper describes the application of the Firefly Algorithm for the optimization of linear and planar antenna arrays. In order to demonstrate the potential of this technique, three applications are reported. The first one is the synthesis of a radiation pattern with isoflux distribution with a non-uniformly spaced linear array composed of isotropi
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2019-03
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3. Design of Microstrip Antenna Array with Suppressed Back Lobe
Abstract A practical procedure to reduce the back lobe level of linear microstrip antenna arrays is presented in this paper. The novel concept consists in the design of the radiators asymmetrically positioned with respect to the ground plane. In order to validate this technique, a four-element linearly-polarized array is designed in the HFSS software and a p
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-04
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4. Polarization Diversity on ESM Systems
Abstract Polarization diversity antenna arrays are applied to electronic support measures (ESM) systems since the 1980s. However, even today modern systems are conceived with the employment of the traditional and inconvenient spiral antennas and there are no studies that evidences most of the benefits of this technique applied to them. This paper aims at sho
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-03
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5. Performance optimization of microstrip antenna array using frequency selective surfaces
This paper presents the application of frequency selective surfaces in antenna arrays as an alternative to improve radiation parameters of the array. A microstrip antenna array between two FSS was proposed for application in WLAN and LTE 4G systems. Several parameters have been significantly improved, in particular the bandwidth, gain and radiation efficienc
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2014-06
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6. Nulls and side lobe levels control in a time modulated linear antenna array by optimizing excitations and element locations using RGA
In this paper a novel approach based on the Real coded Genetic Algorithm (RGA) is proposed to improve nulling performance as well as suppression of Side Lobe Level (SLL) of a Time Modulated Linear Antenna Arrays (TMLA). RGA adjusts the static excitation amplitudes as well as the location of each element from the origin to place deeper nulls in the desired di
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2013-12
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7. Conception of bi-band rectangular microstrip array antenna
Narrow band is the major inconvenient of the microstrip antenna. However, various multiband techniques are proposed towards several applications. A simple configuration of the rectangular microstrip antenna allows operating a system of satellite communication in two bands. The configuration consists of a single radiant element and substrate with low dielectr
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2013-06
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8. Design of multiple function antenna array using radial basis function neural network
A novel approach to design Multiple Function Antenna (MFA) arrays using Artificial Neural Networks is suggested. A planar array with uniform current excitations which can generate different beam widths and gains is designed using Artificial Neural Networks. The desired beam width, gain and number of elements are given as input to the neural network. The outp
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2013-06
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9. Sobre modelos e métodos de estimação de direção de chegada de sinais em sistemas digitais de comunicação sem fio / On models and methods for direction of arrival estimation of signals in digital wireless communication systems
This thesis deals with the problem of estimating the direction of arrival of digitally modulated signals, specifically found in the uplink of multiuser wireless communication systems where the base station uses an antenna array. The main objectives of the thesis are: to clarify some details normally not treated in the description of the data models assumed i
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 26/08/2011
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10. Processamento largamente linear em arranjo de antenas : proposta, avaliação e implementação prática de algoritmos / Widely linear processing in antenna arrays : proposal, evaluation and practical implementation of algorithms
O Processamento Largamente Linear, desenvolvido durante a década de 1990, tem levado a uma melhoria no desempenho de algoritmos adaptativos para determinadas situações que empregam sinais impróprios. Quando aplicado a arranjos de antenas, esse tipo de processamento apresenta a potencialidade ser mais robusto e eficiente que as técnicas clássicas de fil
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 11/02/2011
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11. Antenas de microfita com patch supercondutor a 212 K
This work has as main objective to study the application of microstrip antennas with patch and use of superconducting arrays of planar and linear phase. Was presented a study of the main theories that explain clearly the superconductivity. The BCS theory, Equations of London and the Two Fluid Model are theories that supported the implementation of the superc
Publicado em: 2010
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12. Aplicações de arranjos de antenas de microfita com patch supercondutor
This work has as main objective the study of arrays of microstrip antennas with superconductor rectangular patch. The phases and the radiation patterns are analyzed. A study of the main theories is presented that explain the microscopic and macroscopic phenomena of superconductivity. The BCS, London equations and the Two Fluid Model, are theories used in the
Publicado em: 2010