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1.
The simulation and experimental studies of an aperture‐coupled wideband dual segment rectangular dielectric resonator antenna with metamaterial for C‐band applications are presented in this paper. The antenna consists of Alumina (Al2O3) ceramic as upper segment and Teflon as lower segment. The combination of circular‐shaped coplanar split‐ring resonator and conducting strip has been used as metamaterial superstrate. With the use of metamaterial superstrate, the bandwidth of the antenna is increased by 48% through simulation and 22% experimentally. The broadside radiation pattern of the antenna is converted into directive radiation pattern with reduced beamwidth when metamaterial superstrate is used. The peak gain of the antenna is also enhanced by 33% through simulation and 31% experimentally with the use of metamaterial superstrate. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:646–655, 2014. 相似文献
2.
张利伟 《上海电力学院学报》2010,(8)
根据电磁场边界条件和色散关系,理论研究了电磁波从各向同性右手材料向各向异性特异材料入射时的反常折射与反射性质,结果表明,从各向同性右手材料向never cutoff型特异材料入射时,透射波的波矢和坡印廷矢量的反射角具有相反的符号,折射角的幅度随着入射角的增大而增大并趋于一定值;研究了磁导率张量参数对折射角的影响,对于anti-cutoff型特异材料界面,当入射角小于临界角θc时可以发生反常的全反射,而对于always cutoff型特异材料界面总会发生全向全反射。这些电磁性质将在部分聚焦与全向反射镜方面具有潜在的应用价值。 相似文献
3.
Profile miniaturization and performance improvement of a rectangular patch antenna using magnetic metamaterial substrates
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The idea of profile miniaturization and performance improvement of a rectangular patch antenna using a metamaterial substrate with large values in the real part of effective relative permeability is proposed in microwave frequency range. The volume profile of the antenna is minimized by tuning the effective relative permeability and thickness of the substrate material. The specific type of metamaterial which can be used as substrate material for the antenna miniaturization purpose is suggested. The proposed idea is validated through finite‐difference time‐domain (FDTD) simulations for sample rectangular patch antennas with metamaterial substrates at the frequency about 10 GHz. Improvement of the power directivity is found for the metamaterial substrate with large value in the real part of effective permeability. © 2016 Wiley Periodicals, Inc. Int J RF and Microwave CAE 26:254–261, 2016. 相似文献
4.
LIANG LanJu JIN BiaoBing WU JingBo ZHOU GaoChao ZHANG YongGang TU XueCou JIA Tao JIA XiaoQing CAO ChunHai KANG Lin XU WeiWei CHEN Jian 《中国科学:信息科学(英文版)》2013,56(12):1-7
Abstract In this study, double-layer S-shaped metamaterials (MMs) are analyzed by terahertz time-domain spectroscopy. These materials exhibit narrow bandstop and broad bandpass transmission properties at both horizontal and vertical electric-field polarizations. A 117% increase in the unloaded quality factor is experimen- tally observed for these materials. The center frequency is approximately 0.45 THz, with a 3-dB bandwidth of 0.52 THz from 0.20 to 0.72 THz at normal incidence. The measured average insertion loss is 0.5 dB with a ripple of 1 dB. These results show that double-layer S-shaped MMs are effective in designing tunable terahertz devices. 相似文献
5.
Ben-Xin Wang Chongyang Xu Guiyuan Duan Wei Xu Fuwei Pi 《Advanced functional materials》2023,33(14):2213818
Metamaterial absorbers have been widely studied and continuously concerned owing to their excellent resonance features of ultra-thin thickness, light-weight, and high absorbance. Their applications, however, are typically restricted by the intrinsic dispersion of materials and strong resonant features of patterned arrays (mainly referring to narrow absorption bandwidth). It is, therefore essential to reassert the principles of building broadband metamaterial absorbers (BMAs). Herein, the research progress of BMAs from principles, design strategies, tunable properties to functional applications are comprehensively and deeply summarized. Physical principles behind broadband absorption are briefly discussed, typical design strategies in realizing broadband absorption are further emphasized, such as top-down lithography, bottom-up self-assembly, and emerging 3D printing technology. Diversified active components choices, including optical response, temperature response, electrical response, magnetic response, mechanical response, and multi-parameter responses, are reviewed in achieving dynamically tuned broadband absorption. Following this, the achievements of various interdisciplinary applications for BMAs in energy-harvesting, photodetectors, radar-IR dual stealth, bolometers, noise absorbing, imaging, and fabric wearable are summarized. Finally, the challenges and perspectives for future development of BMAs are discussed. 相似文献
6.
7.
Novel 3D‐Printed Hybrid Auxetic Mechanical Metamaterial with Chirality‐Induced Sequential Cell Opening Mechanisms
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8.
针对动力设备同时满足降噪和散热的需求,提出一种周期分布式结构的通风隔声罩。隔声罩的罩壁内嵌通风消声单元,声波衰减的同时,气流可顺利通过罩壁进行耗散。介绍了分布式通风隔声罩的设计,并对其隔声性能进行了理论计算。通过分布式通风隔声罩对三种不同设备的插入损失分别进行了实际测量和分析。研究结果表明,在通过频率以上,隔声罩插入损失的计算值和实测值吻合较好,分布式通风隔声罩在其通过频率以上具有良好的隔声效果。该分布式通风隔声罩的有效降噪频率可根据不同声源的频率特性进行专一设计,适用于各种需要通风散热的设备的隔声。 相似文献
9.
Hybrid chiral mechanical metamaterials with center squares connecting by bi-layer strips (bi-strips) with patterned interfaces are designed and fabricated via multimaterial 3D printing. Due to the thermal mismatch between the bi-strips and the chirality-induced rotation, the designs will undergo either thermal expansion or shrinkage under constant temperature increase, resulting in widely tuned overall thermal expansion coefficients (CTEs) for the chiral mechanical metamaterials. Analytical models of both the bi-strips with arbitrary dissimilar interface morphology and the chiral designs under temperature change are developed to predict the curvature of the bi-strips and the overall CTEs of the chiral designs. Two design regions with opposite trends are observed and explored. The models are verified via systematic finite element (FE) simulations and experiments on 3D-printed specimens. This investigation enlarges the design space of chiral mechanical metamaterials for achieving desired CTEs in a wide range. 相似文献
10.
Komsan Kanjanasit Pracha Osklang Terapass Jariyanorawiss Akkarat Boonpoonga Chuwong Phongcharoenpanich 《计算机、材料和连续体(英文)》2023,74(1):503-522
A 5G wireless system requests a high-performance compact antenna device. This research work aims to report the characterization and verification of the artificial magnetic conductor (AMC) metamaterial for a high-gain planar antenna. The configuration is formed by a double-side structure on an intrinsic dielectric slab. The 2-D periodic pattern as an impedance surface is mounted on the top surface, whereas at the bottom surface the ground plane with an inductive narrow aperture source is embedded. The characteristic of the resonant transmission is illustrated based on the electromagnetic virtual object of the AMC resonant structure to reveal the unique property of a magnetic material response. The characteristics of the AMC metamaterial and the planar antenna synthesis are investigated and verified by experiment using a low-cost FR4 dielectric material. The directional antenna gain is obviously enhanced by guiding a primary field radiation. The loss effect in a dielectric slab is essentially studied having an influence on antenna radiation. The verification shows a peak of the antenna gain around 9.7 dB at broadside which is improved by 6.2 dB in comparison with the primary aperture antenna without the AMC structure. The thin antenna profile of λ/37.5 is achieved at 10 GHz for 5G evolution. The emission property in an AMC structure herein contributes to the development of a low-profile and high-gain planar antenna for a compact wireless component. 相似文献