Dielectric
Mostrando 13-24 de 541 artigos, teses e dissertações.
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13. Grating Lobes Suppression in Frequency Selective Surfaces Using Electromagnetic Band Gap with Square Holes
Abstract In this paper, the authors present a proposal for an application of electromagnetic bandgap (EBG), for suppression of grating lobes, in frequency selective surfaces (FSS), not yet studied in the literature. An alternative type of EBG with square holes was proposed to reduce the computational effort in simulations. The study consists of an applicatio
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2020-12
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14. Effect of Metamaterial Cells Array on a Microstrip Patch Antenna Design
Abstract In this paper, a microstrip patch antenna (MPA) design was developed to verify the performance of a metamaterial cell array (MTM) Capacitive Loaded Loop (CLL) immersed in the substrate. The metamaterial was obtained from metal laminates designed inside a dielectric material, with dimensions carefully calculated to have the effective negative permitt
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2020-09
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15. Understanding Solvent/Bixin Interactions by Raman Spectroscopy
In this work, Raman spectroscopy and density functional theory (DFT) calculations have been used in order to understand the nature of the interaction between the carotenoid bixin and organic solvents with dielectric constant varying from ca. 2 (toluene) to ca. 47 (dimethyl sulfoxide). Raman shifts registered for the main carotenoid marker band, the C=C stret
J. Braz. Chem. Soc.. Publicado em: 2020-07
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16. Dielectric and Magnetic Properties of Epoxy with Dispersed Iron Phosphate Glass Particles by Microwave Measurement
Abstract This paper investigates the dielectric properties and magnetic properties of epoxy composites with different amount of powdered iron phosphate glass (IPG) at 8.2 GHz to 12.4 GHz using microwave technique. IPG composed of 60P2O5-40Fe2O3 (mol%) was produced by conventional melt and quenching method and crushed into powder. The IPG powder was character
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2020-06
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17. A Novel Dielectric Slab Antenna Based on Microstrip-Franklin Excitation for mm-Waves
Abstract This work reports the development of a novel dielectric slab antenna based on microstrip-Franklin radiators, which enables efficient impedance matching among microstrip lines, substrate and air. The proposed antenna has been designed and numerically evaluated using ANSYS HFSS®. Its directivity ranges from 6.67 to 16.24 dB, as its length is increase
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2020-06
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18. Synthesis and Mechanical Reconfiguration of Ground Plane Tilted Microstrip Antennas Based on Tetra-Circle Fractals
Abstract A synthesis procedure of a mechanically reconfigurable antenna based on tetra-circle fractal patch elements is presented, enabling to change both resonant frequencies and radiation pattern performance. The antenna geometry reconfiguration is implemented by tilting the ground plane of the microstrip antenna with respect to the fractal patch and subst
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2020-06
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19. Ground-Penetrating Radar Antenna Design for Homogeneous and Low-Loss Dielectric Multilayer Media
Abstract Non-destructive evaluation of multilayer media represents an electromagnetic inverse problem, usually solved with analysis techniques in the time and frequency domains. The time- domain analysis technique depends directly on the accurate detection of reflected peaks measured by ground-penetrating radar (GPR), which limits this technique when the ref
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2020-06
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20. Project and Analysis of Quasi-Periodic PBG for Microstrip Antenna
Abstract In this work the influence of quasi-periodic distributions of air holes with 6, 12 and 6-fold modified symmetries, applied to the substrate of a rectangular microstrip patch antenna are analyzed. To validate the study, parameters such as S11 parameter, bandwidth, total gain, radiation pattern and electric field were investigated through computationa
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2020-06
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21. Characterization of the Dielectric Properties of the Tommy Atkins Mango
Abstract This paper presents the characterization of dielectric properties (dielectric permittivity and dielectric loss factor) of Tommy Atkins mango (Mangifera indica L), a fruit produced in several regions of Brazil, of great economic importance. The fruits were characterized according to their maturation index, by probe method, and identified by the yello
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2020-03
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22. Sixteenth-Mode Substrate-Integrated-Waveguide (SMSIW) Resonator for Dielectric Characterization of Liquid Mixtures
Abstract In this work, a new concept of planar resonator technique for measurement of liquid mixture permittivity is proposed, designed, and implemented using a Sixteen-Mode Substrate Integrated Waveguide (SMSIW) technology. To design the proposed sensor, the conventional SMSIW resonator is designed with an additional air hole on the open side, and then we a
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2020-03
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23. 3.4/4.0 GHz Tunable Resonant Cavity in SIW Technology Using Metal Post and PIN Diode on a Low-Cost Biasing Network for 5G Applications
Abstract This paper presents a dual-band resonant cavity in Substrate Integrated Waveguide (SIW) technology to operate in the range from 3.3 GHz to 4.2 GHz, spectrum considered for the Fifth Generation (5G) network. The cavity was designed to operate at 3.4 GHz and 4.0 GHz. To achieve different states, a jumper and a PIN diode switch are considered as switch
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2020-03
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24. Electromagnetic Energy Harvesting Using a Glass Window
Abstract In this work, a new constructive and conceptual model for rectenna, using glass as dielectric substrate, was proposed. This research aims to produce a window for building facades that can harvest the electromagnetic energy available in the environment. For this proposal, a slotted patch antenna was designed with two main objectives: to have a low va
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2020-03