Compact
Mostrando 1-12 de 1409 artigos, teses e dissertações.
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1. A Compact Dual-Band Self-Diplexing MIMO Patch Antenna for ISM and X-Band Communications
Abstract A compact, dual-band, and self-diplexing MIMO patch antenna with a shared aperture is presented for Industrial scientific medical (ISM) band and X-band communications. The structure consists of two orthogonal feed lines and a rectangular slot in a square patch. The size of the FR4 substrate is 50 × 50 × 1.6 mm3. The designed structure operates at
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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2. Variations of Compact Rectangular Microstrip Antennas Using Defected Ground Plane Structure
Abstract The defects in the form of slots have been employed in microstrip antenna either on the patch or the ground plane to yield frequency reduction. However, the reported work does not provide any comparative study that highlight upon the frequency and cross-polar level reduction achieved using these various shape slot/defects. This paper provides a thor
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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3. A Design of a Compact Microwave Diplexer in Microstrip Technology Based on Bandpass Filters Using Stepped Impedance Resonator
Abstract This paper describes the design of a compact microstrip microwave diplexer based on bandpass filters and a stepped impedance resonator for 4G applications. The diplexer is composed of two band-pass filters (BPF) that operate at 1.8 and 2.5 GHz. Both bandpass filters for the receiver at 1.705-1.895 GHZ and the transmitter at 2.41-2.6 GHZ have a -3dB
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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4. A note on the Brazilian cross-state debt connectedness
Abstract We address the cross-state indebtedness (DCL/RCL) variation connectedness using 89 bimonthly data from 2006b6 to 2021b4, based on the indices proposed by Diebold and Yilmaz (2009, 2012, 2014). This framework enables us to infer about the direction, and the strength of bilateral spillovers for a large number of simultaneously interacting variables in
Revista Brasileira de Economia. Publicado em: 2022
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5. Single Port Multimode Reconfigurable UWB-NB Antenna for Cognitive Radio Applications
Abstract In this paper, a compact, single port, multimode reconfigurable UWB-NB antenna with a novel feeding network is presented. The proposed antenna consists of a pentagonal-shaped monopole radiator, a beveled-shaped partial defected ground plane with a rectangular slot, and a reconfigurable bypass feeding network. The antenna realizes a wideband frequenc
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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6. Morphology Behavior of Copper Films Deposited after Wet Surface Treatment on Polished Alumina
In this paper, a pre-treatment process for electroless copper (Cu) deposition on the polished alumina (Al2O3) 99.9% and the behavior of Cu plating by electroless process after Al2O3 surface treatment were explored. Our work was carried out by changing the roughness of Al2O3 through micro-etching (coarsening), nucleation its surface by a two-step method (sens
Journal of the Brazilian Chemical Society. Publicado em: 2022
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7. Radiation Efficiency of an Electrically Small Dual-band UHF Microstrip Patch Antenna Using Wheeler Cap Method
Abstract Determining the radiation efficiency of an antenna is a difficult task that becomes challenging when it is about electrically small antennas. This work investigates the applicability of the Wheeler cap method to measure the radiation efficiency of a UHF dual-band compact microstrip patch antenna. An overview of Wheeler method is presented. An adapta
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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8. Preliminary Study of the Applicability of Software in the Investigation of Sustained Auditory Attention
Abstract Introduction The use of auditory behavioral tests, which specifically assess sustained attention, is necessary, due to its relationship with learning, language production, cognitive development and school performance. Objective To evaluate how children performed using software developed to investigate the ability of sustained auditory attention, a
International Archives of Otorhinolaryngology. Publicado em: 2022
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9. Adventitial Collagen Cross-Linking by Glutaraldehyde Reinforcing Human Saphenous Vein - Implication for Coronary Artery Bypass Grafting
ABSTRACT Introduction: A weak venous wall is one of the major reasons contributing to vein graft failure after coronary artery bypass grafting (CABG). We investigated whether adventitial collagen cross-linking by glutaraldehyde reinforces venous wall, preserving the endothelium of veins during high-pressure distention. Methods: Human saphenous veins (SVs)
Brazilian Journal of Cardiovascular Surgery. Publicado em: 2022
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10. Compact, Broadband, and Omnidirectional Antenna Array for Millimeter-Wave Communication Systems
Abstract In this paper, a millimeter-wave printed quadrupole antenna is proposed. It consists of two symmetric printed dipoles that make the quadrupole radiating power omnidirectionally. Such an arrangement eliminates the influence of the ground as reflector. Simulation results show that the quadrupole antenna exhibits a broad impedance bandwidth and an enha
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2021-06
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11. Compact Triple Band Notched Pentagonal Shaped UWB Antenna Loaded with Slots and Parasitic Resonator
Abstract In this paper, a compact, planar printed microstrip line fed pentagonal shape ultra-wideband antenna with triple band-notched characteristics is proposed and investigated. By incorporating a pair of mirrored Γ-shape, a pair of mirrored L-shape slots in the pentagonal patch and bent C-shape parasitic strip at the backside of a patch, the tunable ban
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2021-06
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12. Design and Performance Study of Single and Multi-Layered Fractal Based Miniaturized Patch Antennas for 2.4 GHz Applications
Abstract The design and characterization of single and multi-layered miniaturized microstrip antennas resonating at 2.4 GHz are proposed. The miniaturization is accomplished by fractal Defected Ground Structure (DGS). The DGS used for miniaturization is a Modified Minkowski Fractal DGS (M-MFDGS). The proposed size reduction process with M-MFDGS follows the s
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2021-06