Microwave Frequencies
Mostrando 1-12 de 33 artigos, teses e dissertações.
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1. Design and Implementation of Microwave Dual-Band Pass Interdigital Filter Using an Analytical Approach
Abstract In this paper, benefiting from frequency transformation between the normalized frequency domain of low-pass prototype frequencies and the real frequency domain of the filter, a purely analytical procedure for dual-band filter design is used. The coupling matrix of the filter is analytically extracted, without the need to perform numerical optimizati
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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2. Roasting soybeans in a microwave for manufacturing chocolate dragées
RESUMO: Este estudo objetivou avaliar o efeito do tempo de torra no micro-ondas para diferentes tamanhos de grãos de soja tipo alimento de tegumento preto, de forma a atingir a melhor crocância, sabor e dureza, e em seguida caracterizar o seu confeito, estruturado na forma de núcleo e camadas de cobertura de chocolate (drageados), em relação ao valor n
Cienc. Rural. Publicado em: 05/09/2019
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3. Dielectric Behavior of α-Ag2WO4 and its Huge Dielectric Loss Tangent
The microwave-assisted hydrothermal method was used to obtain α-Ag2WO4. Rietveld refinement confirmed that α-Ag2WO4 is stable in the orthorhombic phase, without secondary phase. However, field-effect scanning electron microscope analysis showed that α-Ag2WO4 nanorods surfaces contain silver nanoparticles, confirmed by the X-ray photoelectron spectroscopy
Mat. Res.. Publicado em: 02/09/2019
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4. Quantitative evaluation of soil ion content using an imaginary part model of soil dielectric constant
ABSTRACT: An imaginary part model of soil dielectric constant for predicting the soil salinity status was developed based on a series of relations between dielectric imaginary part and soil bulk conductivity, soil bulk conductivity and soil solution electrical conductivity, and soil solution electrical conductivity and ion contents in soil using pot trials w
Sci. agric. (Piracicaba, Braz.). Publicado em: 2019-07
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5. Performance Prediction of Microwave Absorbers Based on POMA/Carbon Black Composites in the Frequency Range of 8.2 to 20 GHz
ABSTRACT: This paper presents a comparative study involving experimental and numerical behaviors of radar absorbing materials (RAM), based on conducting composites of poly(o-methoxyaniline) (POMA) and carbon black (CB). Samples of POMA/CB in epoxy resin matrix were prepared. First, these samples were experimentally characterized by electric permittivity and
J. Aerosp. Technol. Manag.. Publicado em: 29/03/2018
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6. A Novel Design of an H-shaped Microstrip Diplexer
Abstract In this paper, a new microstrip diplexer using modified H-shaped resonators with a compact size and high isolation is presented. This circuit is designed for the ISM band at 2.4 GHz and GPS at 1.575 GHz. The proposed diplexer is formed by connecting two band-pass filters designed by using the modified H-shaped resonator and tapped microstrip Input/o
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-12
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7. A Compact Dual-Band CPW-Fed Planar Monopole Antenna for 2.62–2.73 GHz Frequency Band, WiMAX and WLAN Applications
Abstract In this paper, we present a compact and low-profile monopole antenna with a simple structure for the 2.6–2.73 GHz frequency band, the Worldwide Interoperability for Microwave Access (WiMAX) and the Wireless Local Area Network (WLAN) applications. The first configuration of our antenna mainly consists by three radiating elements: inverted L-shaped
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-04
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8. Miniaturized Triple Wideband CPW-Fed Patch Antenna With a Defected Ground Structure for WLAN/WiMAX Applications
Abstract— A coplanar waveguide (CPW)-fed patch antenna with triple wideband is presented for simultaneously satisfying Wireless Local Area Network (WLAN) and Worldwide Interoperability for Microwave Access (WiMAX) applications. The proposed antenna mainly consists by three radiating elements: inverted L-shaped Stub1, inverted L-shaped Stub2, and a rectangl
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2016-09
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9. 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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10. Study of different shape Electromagnetic Band Gap (EBG) structures for single and dual band applications
In this paper, single and dual band EBG structures for wider bandwidth are proposed. In each of the discussed EBGs, a metallic patch of regular geometry is chosen for the unit element. The patch is further modified by cutting slots to get extra inductance and capacitance which results into lower cut-off frequency and larger bandwidth. The proposed EBG struct
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2014-06
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11. Dielectric study at microwave frequencies of phase transitions in multiferroic ceramics
Multiferroic ceramic solid solutions between the ferroelectric relaxor Pb(Fe2/3W1/3)O3 (PFW) and "normal" ferroelectric PbTiO3 (PT) - PFW-PT have been synthesized by a modified B-site precursor method and characterized by microwave dielectric measurements. A dielectric dispersion occurring in the frequency range of 100MHz-3GHz and in a broad range of tempera
Mat. Res.. Publicado em: 16/07/2013
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12. Complex permeability and permittivity variation of radar absorbing materials based on MnZn ferrite in microwave frequencies
The complex dielectric permittivity (ε) and magnetic permeability (µ) of Radar Absorbing Materials (RAM) based on magnetic particles (MnZn ferrite particles) embedded in a dielectric matrix (silicon rubber) have been studied in the frequency range of 2 to 18 GHz. The relative permeability and permittivity of MnZn ferrite-silicon composites for various mass
Mat. Res.. Publicado em: 21/05/2013