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Metamaterial inspired featherlight artificial plasma horn antenna for astronomical and communication applications
摘要： In this article, we introduce a novel type of horn antenna constructed using artificial plasma sheets. This metamaterial inspired negative permittivity antenna fabricated using thin metallic wires in a specialized manner is observed to have same radiation performance of an equivalent conventional metallic horn structure. This novel plasma antenna can replace the conventional one in all microwave applications. The featherlight weight and the ability to remove the problems related with wind resistance and rain accumulation of this new structure may result in a rethinking of the use of horn antennas in astronomical data collection.
关键词： horn antenna,metamaterials,artificial plasma medium,radiation pattern,satellite application
更新于2025-09-04 15:30:14
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[IEEE 2018 IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC) - Kota Kinabalu, Malaysia (2018.10.7-2018.10.10)] 2018 IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC) - Enhancement of Wireless Power Transmission Based on Side-Positioned Metamaterials
摘要： Inserting a metamaterial slab between the source and receiver coils of the wireless power transfer (WPT) system is a conventional way to improve the transmission performance. However, the free energy transfer space benefited from WPT system is impeded by the inserted metamaterial slab. This paper explores effects of side-positioned metamaterial slabs on wireless power transmission efficiency. Simulations of the WPT system indicate that the side-positioned meta material slab can achieve the same improvements as the center-positioned one in terms of the wireless power transmission, which was verified by experiments. the experiments show that more side-positioned metamaterial energy the significantly. Therefore the side-positioned metamaterial slabs are more efficient and flexible for enhancement of practical WPT systems.
关键词： side- transmission,wireless power transfer,center-positioned,metamaterials,wireless power postitoned
更新于2025-09-04 15:30:14
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Redshift gaps in one-dimensional photonic crystals containing hyperbolic metamaterials
摘要： In conventional all-dielectric one-dimensional photonic crystals (1DPCs), photonic gaps will shift toward short wavelengths (blueshift) as the incident angle increases for both transverse magnetic (TM) and transverse electric (TE) polarizations. We theoretically and experimentally achieve redshift gaps in 1DPCs composed of alternative hyperbolic metamaterials (HMMs) and dielectrics for TM polarization based on the anomalous wavevector dispersion of HMMs. The HMM is mimicked by layered titanium dioxide and silver with a subwavelength unit cell. However, the gaps remain to be blue-shifted for TE polarization. Therefore, the edges of such gaps can be utilized for high-e?ciency wide-angle polarization selection. We achieve e?cient polarization selection for incident angles ranging from 50 o to 80o at the wavelength of 365 nm.
关键词： one-dimensional photonic crystals,redshift gaps,polarization selection,hyperbolic metamaterials
更新于2025-09-04 15:30:14
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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Metasurface-inspired Antenna in Cavity for GNSS Applications
摘要： The objective of this work is the development of a miniature antenna integrated inside a rectangular metal cavity. This antenna must cover three of the GNSS systems at the same time (Galileo E1, GLONASS G1 and GPS L1). To this end, the bandwidth must be larger than 60 MHz. A model based on metasurfaces will be presented, as well as the results obtained in simulation. Prototypes are currently being manufactured and measurement results will be presented during the oral communication.
关键词： cavity,GNSS,antenna,metamaterials
更新于2025-09-04 15:30:14
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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Large Aperture Metal-Mesh Lenses for THz Astronomy
摘要： In this paper we present preliminary results of a metal-mesh graded index Fresnel lens. The designed lens has a diameter of 300 mm, a focal length of 1050mm and operates from 70 to 300 GHz. It was not possible to directly scale the design of the previous lenses, so a Fresnel graded index was used. A new testing facility was developed and verified, which allowed us to show that the new lens matches the same performance of a traditional polyethylene lens. Lenses of this diameter are of interest in the astronomy instrumentation community.
关键词： THz,Metamaterials,GRIN Lens
更新于2025-09-04 15:30:14
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Broadband wave attenuation using periodic membrane-frame structures
摘要： This study numerically and experimentally investigates the propagation characteristics of flexural waves in metamaterial beams with periodic membrane-frame structures. The interior membrane-frame structure acts as a local resonator. As the wave frequency is close to the resonant frequency of the membrane-frame structure, most of the energy produced by disturbances can be absorbed by the interior substructure, resulting in a ceasing motion in the host beam. Owing to such locally resonant mechanism, bandgaps where no wave can propagate freely are created. By altering frame mass magnitude, frame width, and position, the bandgap location can be easily tailored. In comparison with a concentrated mass of the same weight, the frame mass is more efficient in producing a broad frequency band with strong wave attenuation. The study on effective mass density is also carried out to reveal the bandgap mechanism. The resonant-type bandgap coincides with the frequency range of negative effective mass density. As the effective mass density becomes negative, the acceleration of the host beam and applied loading are in the opposite direction. The out-of-phase motion between the acceleration and applied loading results in a decay in amplitude. Adding an extra mass to the membrane-frame structure can achieve multiple bandgaps. Vibration experiments are conducted to verify finite element (FE) predictions.
关键词： local resonance,metamaterials,effective mass density,membrane-frame structure,bandgap
更新于2025-09-04 15:30:14