共查询到19条相似文献,搜索用时 62 毫秒
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太赫兹技术是一项极其重要的技术,其电磁波段的开发和利用具有重大的科学意义和潜在的应用价值.本文综述了太赫兹技术的研究和发展,介绍了太赫兹波的独特性质,太赫兹产生和检测的方法,概述了太赫兹技术在生物医学、反恐安检、无损探测、天文大气以及无线通信等领域的应用和进展. 相似文献
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太赫兹波频段介于毫米波和红外光之间,具有诸多优异特性,太赫兹天线更是太赫兹通信、雷达和成像等应用系统中的核心元器件。然而,目前报道的太赫兹天线均无法满足较大动态范围的相位扫描、高效率辐射和大偏转角度的需求。该文设计了 3 种石墨烯太赫兹天线,最小尺寸为 5 μm,并对其辐射效率和相位调控特性进行研究,进而提出具有双共振模式的石墨烯-金属太赫兹超表面天线,缓解了传统的基于单共振模式的相位动态调控范围和辐射效率之间的矛盾,实现了 0~360°的动态相位调控,且辐射效率高于 20%。该研究采用微加工工艺进行样品加工,通过改变栅极电压,在实验上获得了 1.03 THz 的太赫兹动态相位调控,反射率高于 23%,与仿真结果基本吻合。在此基础上,该文基于连续相位编码设计了石墨烯超表面相控阵天线,理论上实现了太赫兹波束在-25°~25°范围内的实时波束偏转。该文为解决超表面相控阵天线的相位动态调控范围小、辐射效率低等难题提供了新的研究思路。 相似文献
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陈慧珍 《数码设计:surface》2021,(3)
以太赫兹技术和基本的电磁理论为基础,主要从带宽、吸收率、灵敏度、频带、材料、重要使用领域等方面介绍了太赫兹超材料吸波结构近些年的一些主要研究成果。 相似文献
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Muhammad Irfan Wasi Ur Rehman Khan Sadiq Ullah Naveed Mufti Muhammad Fawad Khan Rizwan Ullah Usman Ali Fazal Muhammad Faisal Althobiani Mohammed Alshareef Shadi Alghaffari Saifur Rehman V. R. Shamji 《计算机系统科学与工程》2023,45(3):2693-2704
This paper presents, a novel cactus shaped frequency reconfigurable antenna for sub 10 GHz wireless applications. PIN diode is utilized as an electrical switch to achieve reconfigurability, enabling operation in four different frequency ranges. In the switch ON state mode, the antenna supports 2177–3431 and 6301–8467 MHz ranges. Alternatively, the antenna resonates within 2329–3431 and 4951–6718 MHz while in the OFF state mode. Radiation efficiency values, ranging from 68% to 84%, and gain values, ranging from 1.6 to 4 dB, in the operating frequency bands. the proposed antenna satisfy the practical requirements and expectations. The overall planner dimensions of the proposed antenna model is 40 × 21 mm2. Moreover, the measurement results from the prototype support the simulation results. Based on the frequency ranges supported by the antenna, it can be used for multiple wireless standards and services, including Worldwide interoperability and Microwave Access (WiMAX), Wireless Fidelity (Wi-Fi), Bluetooth, Long Term Evolution (LTE) and satellite communications. This increases its applicability for use in mobile terminals. 相似文献
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This paper presents a reconfigurable terahertz Vivaldi antenna based on a hybrid graphene‐metal structure. The proposed antenna uses a novel tapered slot edge with hybrid graphene‐metal structure to improve the electromagnetic characteristics of classical metallic Vivaldi antennas. The results show that the proposed hybrid graphene‐metal Vivaldi antenna can be dynamically reconfigured via electric field bias, and has a low reflection coefficient. Moreover, this study demonstrates that the proposed antenna has excellent gain and radiation efficiency than that of the graphene Vivaldi antenna, and brings more possibilities to the realization and application of graphene antennas in the terahertz band, which is expected to use in terahertz wireless communication in the future. 相似文献
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提出了一种新颖的基于液态金属的可重构电容器,该器件可应用于可调谐频率选择面。这种可重构电容器由一对金属贴片和微流体管道组成。微流体管道包含聚二甲基硅氧烷(PDMS)材料制成的主管道(用于控制液态金属)和与其共面的子管道(用于储存盐酸溶液)。由于PDMS具有良好的渗透性,在子管道中的盐酸蒸汽可以通过管道壁渗透进入主管道,并和液态金属上的表面氧化层反应,使之呈现真正的流体特性。液态金属液滴可以在管道道中自由的移动。最后,基于这种液态金属的微流体平台,开发了一种可应用于可调谐频率选择面的可重构电容器件。其调谐性主要取决于主管道中液态金属液滴的位置和形状。实验结果表明,这种基于液态金属的可重构电容器可以广泛的应用于可调谐电子器件之中。 相似文献
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Dalia N. Elsheakh 《国际射频与微波计算机辅助工程杂志》2020,30(5)
This article presents a reconfigurable frequency and steerable beam monopole antenna based on tunable graphene pads operating in both 4G and 5G bands. The proposed antenna consists of printed CPW‐fed circular monopole shapes, with five rectangular strips added with a separation angle of 45°. These strips are connected to monopole by using graphene pads. The monopole antenna operates in the lower 5G band from 3 up to 7.8 GHz at ?6 dB reflection coefficient. The antenna has an omni‐radiation pattern over the operating band without any applied bias voltage to the graphene pads. By applying the DC bias voltage, the rectangular strips are connected to the monopole and the designed antenna start to resonate from 1.8 to 8 GHz adding the 4G band frequencies. The steering of the proposed antenna beam started from ?60° to 60° according to the bias of the connected graphene pads. The graphene pad exhibits a variable resistance realizing an almost short to an open circuit with and without voltage bias, respectively. The designed antenna is simulated using high frequency structure simulation (HFSS) Ansys ver. 19 and equivalent circuit model of the graphene. The antenna is fabricated using reduced graphene oxide (RGO) pads. Reflection coefficient and radiation pattern measurements as well as simulations are presented with a positive agreement between the results. 相似文献
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可重构计算系统既具有在制造后的可编程性.又能提供较高的计算性能和计算密度。对可重构计算系统的基本概念以及系统构成概要介绍的基础上,通过一个实例给出了可重构计算系统的一种快速实现方法,与具有相同功能的其他系统相比.这种系统更灵活和高效。 相似文献
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