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Gao C, Lai T, Peng L, Zhang X, Huang Z, Wang Z, Pang X, Zhao S, Ye D. Multifunctional Intelligent Reconfigurable Metasurface. ACS APPLIED MATERIALS & INTERFACES 2024. [PMID: 39361608 DOI: 10.1021/acsami.4c09944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2024]
Abstract
The emergent reconfigurable metasurfaces (RMs) have attracted a lot of attention due to their potential in broad applications. As a general platform, RMs are able to control the reflection (or refraction) of incident waves with predefined functionalities. Nevertheless, the operation of RMs is highly dependent on the arrival direction of incidence. The self-adaptive design of an RM, so that it can respond to varied incident waves automatically, is highly requested in practical implementation, which is actually challenging. This study reports the realization of an intelligent RM (IRM) system, which can detect the arrival direction of impinging waves and respond to the incidence with a predefined functionality accordingly. This IRM system is constructed by integrating a direction of the arrival estimation module, a frontend by the varactor-based metasurface, and a central control unit. In experiments, an IRM system designed for TM polarization is demonstrated to perform various functions, i.e., retroreflection, directional reflection, and fixed-point energy focusing, which are highly requested by edge communication and sensing. The measured results imply that this IRM system responds quite well within a wide incident range from -60° to 60° in a frequency range from 9 to 9.5 GHz. The proposed IRM can be a good candidate for boosting 5G communication and Internet of Things applications, including beam shaping/steering, RCS manipulation, object imaging, and sensor recharging.
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Affiliation(s)
- Chengjing Gao
- Laboratory of Applied Research on Electromagnetics, Zhejiang University, Hangzhou 310027, China
| | - Tingjun Lai
- Laboratory of Applied Research on Electromagnetics, Zhejiang University, Hangzhou 310027, China
| | - Liang Peng
- School of Information and Electrical Engineering, Hangzhou City University, Hangzhou 310015, China
| | - Xuewei Zhang
- AVIC Research Institute for Special Structures of Aeronautical Composite, Aviation Key Lab of Science and Technology on High Performance Electromagnetic Windows, Jinan 250023, China
| | - Zhengjie Huang
- Laboratory of Applied Research on Electromagnetics, Zhejiang University, Hangzhou 310027, China
| | - Zhiyu Wang
- Laboratory of Applied Research on Electromagnetics, Zhejiang University, Hangzhou 310027, China
- School of Aeronautics and Astronautics, Zhejiang University, Hangzhou 310027, China
| | - Xiaoyu Pang
- AVIC Research Institute for Special Structures of Aeronautical Composite, Aviation Key Lab of Science and Technology on High Performance Electromagnetic Windows, Jinan 250023, China
| | - Shenghui Zhao
- AVIC Research Institute for Special Structures of Aeronautical Composite, Aviation Key Lab of Science and Technology on High Performance Electromagnetic Windows, Jinan 250023, China
| | - Dexin Ye
- Laboratory of Applied Research on Electromagnetics, Zhejiang University, Hangzhou 310027, China
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2
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Zhu X, Qian C, Li E, Chen H. Negative Conductivity Induced Reconfigurable Gain Metasurfaces and Their Nonlinearity. PHYSICAL REVIEW LETTERS 2024; 133:113801. [PMID: 39331984 DOI: 10.1103/physrevlett.133.113801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 05/30/2024] [Accepted: 07/24/2024] [Indexed: 09/29/2024]
Abstract
The past decades have witnessed the rapid development of metamaterials and metasurfaces. However, loss is still a challenging problem limiting numerous practical applications, including long-range wireless communications, superscattering, and non-Hermitian physics. Recently, great effort has been made to minimize the loss, however, they are too complicated for practical implementation and still restricted by the theoretical limit. Here, we propose and experimentally realize a tunable gain metasurface induced by negative conductivity, with deep theoretical analysis from scattering theory and equivalent circuits. In the experiment, we create metasurface samples embedded with tunable negative (or positive) conductivity to achieve adjustable gain (or loss). By varying the control bias voltages, the metasurfaces can reflect incident waves with additional controllable gain. Interestingly, we find the gain metasurfaces inherently pose nonlinearities, which are beneficial for nonlinear optics and microwave applications, particularly for the nonlinear activation of wave-based neural networks.
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Affiliation(s)
- Xiaoyue Zhu
- ZJU-UIUC Institute, Interdisciplinary Center for Quantum Information, State Key Laboratory of Extreme Photonics and Instrumentation, Zhejiang University, Hangzhou 310027, China
- ZJU-Hangzhou Global Science and Technology Innovation Center, Key Lab. of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, Zhejiang University, Hangzhou 310027, China
| | - Chao Qian
- ZJU-UIUC Institute, Interdisciplinary Center for Quantum Information, State Key Laboratory of Extreme Photonics and Instrumentation, Zhejiang University, Hangzhou 310027, China
- ZJU-Hangzhou Global Science and Technology Innovation Center, Key Lab. of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, Zhejiang University, Hangzhou 310027, China
| | - Erping Li
- ZJU-UIUC Institute, Interdisciplinary Center for Quantum Information, State Key Laboratory of Extreme Photonics and Instrumentation, Zhejiang University, Hangzhou 310027, China
| | - Hongsheng Chen
- ZJU-UIUC Institute, Interdisciplinary Center for Quantum Information, State Key Laboratory of Extreme Photonics and Instrumentation, Zhejiang University, Hangzhou 310027, China
- ZJU-Hangzhou Global Science and Technology Innovation Center, Key Lab. of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, Zhejiang University, Hangzhou 310027, China
- Jinhua Institute of Zhejiang University, Zhejiang University, Jinhua 321099, China
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3
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Zhang H, Ruan H, Zhao H, Wang Z, Hu S, Cui TJ, del Hougne P, Li L. Microwave Speech Recognizer Empowered by a Programmable Metasurface. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2309826. [PMID: 38380552 PMCID: PMC11077686 DOI: 10.1002/advs.202309826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 01/28/2024] [Indexed: 02/22/2024]
Abstract
Speech recognition becomes increasingly important in the modern society, especially for human-machine interactions, but its deployment is still severely thwarted by the struggle of machines to recognize voiced commands in challenging real-life settings: oftentimes, ambient noise drowns the acoustic sound signals, and walls, face masks or other obstacles hide the mouth motion from optical sensors. To address these formidable challenges, an experimental prototype of a microwave speech recognizer empowered by programmable metasurface is presented here that can remotely recognize human voice commands and speaker identities even in noisy environments and if the speaker's mouth is hidden behind a wall or face mask. The programmable metasurface is the pivotal hardware ingredient of the system because its large aperture and huge number of degrees of freedom allows the system to perform a complex sequence of sensing tasks, orchestrated by artificial-intelligence tools. Relying solely on microwave data, the system avoids visual privacy infringements. The developed microwave speech recognizer can enable privacy-respecting voice-commanded human-machine interactions is experimentally demonstrated in many important but to-date inaccessible application scenarios. The presented strategy will unlock new possibilities and have expectations for future smart homes, ambient-assisted health monitoring, as well as intelligent surveillance and security.
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Affiliation(s)
- Hongrui Zhang
- State Key Laboratory of Advanced Optical Communication Systems and NetworksSchool of ElectronicsPeking UniversityBeijing100871China
| | - Hengxin Ruan
- State Key Laboratory of Advanced Optical Communication Systems and NetworksSchool of ElectronicsPeking UniversityBeijing100871China
- Peng Cheng LaboratoryShenzhenGuangdong518000China
| | - Hanting Zhao
- State Key Laboratory of Advanced Optical Communication Systems and NetworksSchool of ElectronicsPeking UniversityBeijing100871China
| | - Zhuo Wang
- State Key Laboratory of Advanced Optical Communication Systems and NetworksSchool of ElectronicsPeking UniversityBeijing100871China
| | - Shengguo Hu
- State Key Laboratory of Advanced Optical Communication Systems and NetworksSchool of ElectronicsPeking UniversityBeijing100871China
| | - Tie Jun Cui
- State Key Laboratory of Millimeter WavesSoutheast UniversityNanjing210096China
- Pazhou Laboratory (Huangpu)GuangzhouGuangdong510555China
| | | | - Lianlin Li
- State Key Laboratory of Advanced Optical Communication Systems and NetworksSchool of ElectronicsPeking UniversityBeijing100871China
- Pazhou Laboratory (Huangpu)GuangzhouGuangdong510555China
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Gharbieh S, Milbrandt J, Reig B, Mercier D, Allain M, Clemente A. Design of a binary programmable transmitarray based on phase change material for beam steering applications in D-band. Sci Rep 2024; 14:2966. [PMID: 38316832 PMCID: PMC11303715 DOI: 10.1038/s41598-024-53150-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Accepted: 01/29/2024] [Indexed: 02/07/2024] Open
Abstract
This paper introduces the design of a reconfigurable transmitarray operating within the D-band frequency range (110-170 GHz). The transmitarray unit cell is composed of three metal layers and two quartz dielectric substrates. It achieves a 1-bit phase shift resolution through the alternating states of two innovative switches integrated into the active transmitting patch of the unit cell. To address the challenge of miniaturization in the D-band, compact switches compatible with the proposed unit cell dimensions are introduced. These switches are constructed using phase change materials (PCM) that change between amorphous and crystalline states when exposed to heat. The paper includes a full-wave simulation of the unit cell, demonstrating an insertion loss below 1.5 dB across a wide frequency band of 27%. Additionally, a 10 [Formula: see text] 10 elements transmitarray is synthesized using a numerical tool and its theoretical results are compared to full-wave electromagnetic simulations for validation purposes. The results indicate that by incorporating the proposed switches into the unit cell, the transmitarray achieves promising reconfiguration capabilities within the D-band. Moreover, the paper presents the architecture of a command line designed to bias the PCM switches. Notably, this command line represents a novel approach, as it enables individual biasing of each PCM switch using direct current (DC). The influence of these command lines on the transmitarray's performance is thoroughly investigated. Although there is a compromise in the 1-dB gain bandwidth, the overall behavior of the transmitarray remains encouraging.
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Affiliation(s)
| | | | - Bruno Reig
- Univ. Grenoble Alpes, CEA, Leti, 38000, Grenoble, France
| | - Denis Mercier
- Univ. Grenoble Alpes, CEA, Leti, 38000, Grenoble, France
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Zhang W, Lin J, Zheng Z, Gao Y, Tao J, Shang W, Zhang M. A One-Bit Programmable Multi-Functional Metasurface for Microwave Beam Shaping. MICROMACHINES 2023; 14:2011. [PMID: 38004867 PMCID: PMC10673322 DOI: 10.3390/mi14112011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 10/24/2023] [Accepted: 10/24/2023] [Indexed: 11/26/2023]
Abstract
In this paper, we demonstrate a multi-functional metasurface for microwave beam-shaping application. The metasurface consists of an array of programmable unit cells, and each unit cell is integrated with one varactor diode. By turning the electrical bias on the diode on and off, the phase delay of the microwave reflected by the metasurface can be switched between 0 and π at a 6.2 GHz frequency, which makes the metasurface 1-bit-coded. By programming the 1-bit-coded metasurface, the generation of a single-focus beam, a double-focus beam and a focused vortex beam was experimentally demonstrated. Furthermore, the single-focus beam with tunable focal lengths of 54 mm, 103 mm and 152 mm was experimentally observed at 5.7 GHz. The proposed programmable metasurface manifests robust and flexible beam-shaping ability which allows its application to microwave imaging, information transmission and sensing applications.
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Affiliation(s)
- Wu Zhang
- School of Physics and Material Science, Guangzhou University, Guangzhou 510006, China; (W.Z.); (J.L.)
| | - Jiahan Lin
- School of Physics and Material Science, Guangzhou University, Guangzhou 510006, China; (W.Z.); (J.L.)
| | - Zitao Zheng
- School of Physics and Material Science, Guangzhou University, Guangzhou 510006, China; (W.Z.); (J.L.)
| | - Yusong Gao
- School of Physics and Material Science, Guangzhou University, Guangzhou 510006, China; (W.Z.); (J.L.)
| | - Jifang Tao
- School of Information Science and Engineering, Shandong University, Jinan 250100, China
| | - Wenli Shang
- School of Electronics and Communication Engineering, Guangzhou University, Guangzhou 510006, China
- Key Laboratory of On-Chip Communication and Sensor Chip of Guangdong Higher Education Institute, Guangzhou 510006, China
| | - Meng Zhang
- School of Electronics and Communication Engineering, Guangzhou University, Guangzhou 510006, China
- Key Laboratory of On-Chip Communication and Sensor Chip of Guangdong Higher Education Institute, Guangzhou 510006, China
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Liu YH, Wang SY, Hu WS, Li YB. Simultaneous manipulation of spatial fundamental and harmonic electromagnetic waves by microwave nonlinear metasurfaces. OPTICS EXPRESS 2023; 31:24412-24422. [PMID: 37475269 DOI: 10.1364/oe.497650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 06/27/2023] [Indexed: 07/22/2023]
Abstract
In the area of manipulating the spatial electromagnetic (EM) waves fields, the metasurfaces have become much more attractive and powerful in recent years. Here, we propose a design to realize the simultaneous control of spatial fundamental and harmonic EM waves applying nonlinear metasurfaces in microwave band. The proposed meta-atom composed of three topological layers which are transmitting antenna, nonlinear wave guiding and receiving antenna respectively. And the critical factor of generating the harmonic is the nonlinear chip which is integrated into the middle layer. The microstrip power divider and phase shifter in each meta-atom are preciously tailored to actualize the spatial control of the fundamental and harmonic transmission beams in the far field. One prototype of the nonlinear metasurfaces is fabricated and corresponding radiation patterns of fundamental and harmonic modes are observed very well in the experience that can verify the validity of our proposed method.
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Xu J, Li QY, Dai LH, Zhou YJ. Digital coding Fano resonance based on active plasmonic metamaterials. APPLIED OPTICS 2023; 62:3581-3588. [PMID: 37706973 DOI: 10.1364/ao.488441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 04/12/2023] [Indexed: 09/15/2023]
Abstract
A novel approach that employs active plasmonic metamaterials to create a digital coding Fano resonator is proposed, to the best of our knowledge. The meta-device consists of three concentric spoof localized surface plasmon (LSP) resonators and three positive-intrinsic-negative (PIN) diodes positioned at three slits located in the middle and inner LSP resonators. Four Fano resonant modes can be independently switched by controlling the biased voltage applied to the three diodes. This provides a means for encoded modulation of multiple Fano resonances in metamaterials, which could have broad applications in fields such as multiway sensing, plasmonic circuits, and switching. We experimentally demonstrate the effectiveness of the proposed approach, which offers promising potential for practical implementation.
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Zhang Z, Shi H, Wang L, Chen J, Chen X, Yi J, Zhang A, Liu H. Recent Advances in Reconfigurable Metasurfaces: Principle and Applications. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:534. [PMID: 36770494 PMCID: PMC9921398 DOI: 10.3390/nano13030534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 01/18/2023] [Accepted: 01/19/2023] [Indexed: 06/18/2023]
Abstract
Metasurfaces have shown their great capability to manipulate electromagnetic waves. As a new concept, reconfigurable metasurfaces attract researchers' attention. There are many kinds of reconfigurable components, devices and materials that can be loaded on metasurfaces. When cooperating with reconfigurable structures, dynamic control of the responses of metasurfaces are realized under external excitations, offering new opportunities to manipulate electromagnetic waves dynamically. This review introduces some common methods to design reconfigurable metasurfaces classified by the techniques they use, such as special materials, semiconductor components and mechanical devices. Specifically, this review provides a comparison among all the methods mentioned and discusses their pros and cons. Finally, based on the unsolved problems in the designs and applications, the challenges and possible developments in the future are discussed.
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Affiliation(s)
- Ziyang Zhang
- Shaanxi Key Laboratory of Deep Space Exploration Intelligent Information Technology, Xi’an Jiaotong University, Xi’an 710049, China
| | - Hongyu Shi
- Shaanxi Key Laboratory of Deep Space Exploration Intelligent Information Technology, Xi’an Jiaotong University, Xi’an 710049, China
| | - Luyi Wang
- School of Information and Communications Engineering, Xi’an Jiaotong University, Xi’an 710049, China
| | - Juan Chen
- School of Information and Communications Engineering, Xi’an Jiaotong University, Xi’an 710049, China
| | - Xiaoming Chen
- School of Information and Communications Engineering, Xi’an Jiaotong University, Xi’an 710049, China
| | - Jianjia Yi
- School of Information and Communications Engineering, Xi’an Jiaotong University, Xi’an 710049, China
| | - Anxue Zhang
- School of Information and Communications Engineering, Xi’an Jiaotong University, Xi’an 710049, China
| | - Haiwen Liu
- Shaanxi Key Laboratory of Deep Space Exploration Intelligent Information Technology, Xi’an Jiaotong University, Xi’an 710049, China
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Rezaee Rezvan B, Yazdi M, Hosseininejad SE. On the Design of Multibeam Digital Metasurfaces With Multiple Feeds. ADVANCED THEORY AND SIMULATIONS 2022. [DOI: 10.1002/adts.202200676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Behrad Rezaee Rezvan
- Faculty of Electrical and Computer Engineering Babol Noshirvani University of Technology Babol 47148 Iran
| | - Mohammad Yazdi
- Faculty of Electrical and Computer Engineering Babol Noshirvani University of Technology Babol 47148 Iran
| | - Seyed Ehsan Hosseininejad
- Faculty of Electrical and Computer Engineering Babol Noshirvani University of Technology Babol 47148 Iran
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Steer by Image Technology for Intelligent Reflecting Surface Based on Reconfigurable Metasurface with Photodiodes as Tunable Elements. CRYSTALS 2022. [DOI: 10.3390/cryst12070951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Lately, metasurface has become an essential and promising component in implementing Intelligent Reflecting Surface (IRS) for 5G and 6G. A novel method that simplifies the ability to reconfigure the metasurface is presented in this paper. The suggested technology uses a PIN photodiode as a tuning element. The desired image is projected on the metasurface’s backside, where the PIN photodiodes are placed and reconfigures the metasurface. The projected image’s color and intensity pattern influence the PIN photodiode’s junction capacitance, which leads to local reflection phase control. This enables the required pattern reflection phase distribution to manipulate the reflection beam, for example, 2D beam steering or focusing, and any other beam forming combination, instead of wiring many digital-to-analog converters (DACs) or FPGA outputs, which bias the standard tuning element such as PIN diode or varactor using a complex RF circuit. Using a PIN photodiode as a tunable element instead of a varactor diode, PIN diode, Liquid Crystal and MEMS allows the changing of the internal junction capacitance without direct contact and thus continuously controlling the reflection phase. In addition, an open circuit work mode with negligible energy consumption can be obtained. This technology can be used to implement metasurface based on discrete or continuous phases and is called Steer by Image (SBI). A full description of the SBI technology using PIN photodiode is presented in this paper.
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Active Meta-Device for Dual-Transmission Windows with Tunable Angular Dispersion Characteristics. MATERIALS 2022; 15:ma15103686. [PMID: 35629711 PMCID: PMC9144391 DOI: 10.3390/ma15103686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 05/11/2022] [Accepted: 05/16/2022] [Indexed: 12/04/2022]
Abstract
Tailoring electromagnetic properties by meta-devices has aroused great interest with respect to manipulating light. However, the uncertainty of angular dispersion introduced by the incident waves prevents their further applications. Here, we propose a general paradigm for achieving dual-transmission windows while simultaneously eliminating the corresponding angular dispersions by a dynamic manner. The strategy of loading varactor diodes into a plasmonic meta-atom is used. In this way, the blue shifts of angular dispersion can be dynamically compensated by the red shifts introduced by the varactor diodes when driven by bias voltage. As a proof-of-principle, an active meta-atom with varactor diodes is presented. The varactor diodes embedded can independently regulate dual-transmission windows. The test results are consistent with the simulation ones. The presented meta-device is used for intelligent radome, angle-multiplexed communications, and incident-angle-insensitive equipment while providing tunable angular dispersion properties.
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Li Z, Wang W, Deng S, Qu J, Li Y, Lv B, Li W, Gao X, Zhu Z, Guan C, Shi J. Active beam manipulation and convolution operation in VO 2-integrated coding terahertz metasurfaces. OPTICS LETTERS 2022; 47:441-444. [PMID: 35030627 DOI: 10.1364/ol.447377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 11/24/2021] [Indexed: 06/14/2023]
Abstract
Coding metasurfaces have received tremendous interest due to their unprecedented control of beams through the flexible design of coding sequences. However, realizing tunable coding metasurfaces with scattering-pattern shifts in the terahertz range is still challenging. Here, we propose a VO2-integrated coding metasurface to realize a thermally controlled scattering-pattern shift by convolution operation. The required phase profiles and high amplitudes of 1-bit and 2-bit coding metasurfaces are easily obtained only by changing the length of the VO2 cut-wires. The insulator-metal phase transition of the VO2 cut-wires leads to an ultrafast switching effect between multiple deflected scattering beams and one normally reflected beam. In particular, the VO2 phase transition contributes to dynamical convolution operations of the 2-bit coding metasurface. The proposed VO2-integrated coding metasurfaces are important for realizing tunable terahertz beam manipulation as well as arbitrary required scattering beams.
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Ultra-Wideband Reconfigurable X-Band and Ku-Band Metasurface Beam-Steerable Reflector for Satellite Communications. ELECTRONICS 2021. [DOI: 10.3390/electronics10172165] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A continuously reconfigurable metasurface reflector based on unit cell mushroom geometry that was integrated with a varactor diode is presented in this paper. The unit cell of the metasurface was designed and optimized to operate in the X-band and Ku-band, improving satellite communication’s quality of service. The losses mechanisms of continuous control over the unit cell phase reflection in beam steering resolution are considered and the analysis results are presented. The unit cell design parameters were analyzed with an emphasis on losses and dynamic reflection phase range. The unit cell magnitude and phase reflection are shown in the wide frequency bandwidth and showed a good agreement between all the measurements and the simulations. This metasurface enabled a high dynamic range in the unit cell resonant frequency range from 7.8 to 15 GHz. In addition, the reflection phase and absorption calibration are demonstrated for multiple operating frequencies, namely, 11 GHz, 12 GHz, and 13.5 GHz. Furthermore, design trade-offs and manufacturing limitations were considered. Finally, a beam-steering simulation using the designed metasurface is shown and discussed.
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Li G, Guo Z, Ren J, Sun Y, Jiang H, Li Y, Chen H. Reconfigurable magnetic near-field distributions based on the coding metasurfaces in MHz band. OPTICS EXPRESS 2021; 29:13908-13924. [PMID: 33985118 DOI: 10.1364/oe.424234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 04/14/2021] [Indexed: 06/12/2023]
Abstract
Magnetic near-field control has attracted extensive attention and have a wide range of applications in filters, sensors, and energy-transfer devices. Coding metamaterial has the convenience of miniaturization and integration, which not only provides a bridge between physics and information science, but also exploits a whole new perspective for magnetic near-field control. In this work, we theoretically propose and experimentally verify that the coding metasurface can realize the reconfigurable magnetic near-field distributions. By adjusting the digital voltage signals which drive the resonant units of metasurface, capacitance of the resonator can be dynamically controlled, thus the dynamic modulation of magnetic near-field distribution can be achieved. Specially, this magnetic near-field control can be explained with the help of coupled mode theory and coherent superposition method. Moreover, simulated annealing algorithm is employed to determine working frequency of the whole modulation system, which can avoid time-consuming frequency scanning process. The experimental results are in good agreement with the calculated results. This work reveals the significant potential of coding metasurface for the experimental study of the magnetic near-field control and promotes the use of metasurface for numerous integrated functional devices.
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Saifullah Y, Chen Q, Yang GM, Waqas AB, Xu F. Dual-band multi-bit programmable reflective metasurface unit cell: design and experiment. OPTICS EXPRESS 2021; 29:2658-2668. [PMID: 33726457 DOI: 10.1364/oe.415730] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 01/05/2021] [Indexed: 06/12/2023]
Abstract
Programmable reflective metasurfaces that combine the features of reconfigurable phased array antennas and reflectors are an effective solution for radar and modern communication systems. However, most of the demonstrated active metasurfaces support tunable responses for a specific frequency band. Thus, we propose a programmable metasurface that combines the advantages of multi-bit phase quantization and dual-band operations. To actively control the diverse functions, two PIN diodes are integrated on the radiating element, and these diodes are controlled by the biasing voltage. The unit cell is fabricated, and experimental characterization is performed in the waveguide measurement setup. The proposed design can be applied for imaging and high-capacity wireless communications.
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Zhang L, Cui TJ. Space-Time-Coding Digital Metasurfaces: Principles and Applications. RESEARCH (WASHINGTON, D.C.) 2021; 2021:9802673. [PMID: 34386772 PMCID: PMC8328401 DOI: 10.34133/2021/9802673] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 04/11/2021] [Indexed: 11/30/2022]
Abstract
Space-time-modulated metastructures characterized by spatiotemporally varying properties have recently attracted great interest and become one of the most fascinating and promising research fields. In the meantime, space-time-coding digital metasurfaces with inherently programmable natures emerge as powerful and versatile platforms for implementing the spatiotemporal modulations, which have been successfully realized and used to manipulate the electromagnetic waves in both the spectral and spatial domains. In this article, we systematically introduce the general concepts and working principles of space-time-coding digital metasurfaces and provide a comprehensive survey of recent advances and representative applications in this field. Specifically, we illustrate the examples of complicated wave manipulations, including harmonic beam control and programmable nonreciprocal effect. The fascinating strategy of space-time-coding opens the door to exciting scenarios for information systems, with abundant applications ranging from wireless communications to imaging and radars. We summarize this review by presenting the perspectives on the existing challenges and future directions in this fast-growing research field.
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Affiliation(s)
- Lei Zhang
- State Key Laboratory of Millimeter Waves, Southeast University, Nanjing 210096, China
- Institute of Electromagnetic Space, Southeast University, Nanjing 210096, China
- Center for Intelligent Metamaterials, Pazhou Laboratory, Guangzhou 510330, China
| | - Tie Jun Cui
- State Key Laboratory of Millimeter Waves, Southeast University, Nanjing 210096, China
- Institute of Electromagnetic Space, Southeast University, Nanjing 210096, China
- Center for Intelligent Metamaterials, Pazhou Laboratory, Guangzhou 510330, China
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Abstract
We propose and implement a novel 1-bit coding metasurface that is capable of focusing and steering beam for enhancing power transfer efficiency of the electromagnetic (EM) wave-based wireless power transfer systems. The proposed metasurface comprises 16 × 16 unit cells which are designed with a fractal structure and the operating frequency of 5.8 GHz. One PIN diode is incorporated within each unit cell and enables two states with 180 ° phase change of the reflected signal at the unit cell. The two states of the unit cell correspond to the ON and OFF states of the PIN diode or “0” and “1” coding in the metasurface. By appropriately handling the ON/OFF states of the coding metasurface, we can control the reflected EM wave impinged on the metasurface. To verify the working ability of the coding metasurface, a prototype metasurface with a control board has been fabricated and measured. The results showed that the coding metasurface is capable of focusing beam to desired direction. For practical scenarios, we propose an adaptive optimal phase control scheme for focusing the beam to a mobile target. Furthermore, we prove that the proposed adaptive optimal phase control scheme outperforms the random phase control and beam synthesis schemes.
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18
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Wang L, Zhang Y, Guo X, Chen T, Liang H, Hao X, Hou X, Kou W, Zhao Y, Zhou T, Liang S, Yang Z. A Review of THz Modulators with Dynamic Tunable Metasurfaces. NANOMATERIALS (BASEL, SWITZERLAND) 2019; 9:E965. [PMID: 31266235 PMCID: PMC6669754 DOI: 10.3390/nano9070965] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 06/13/2019] [Accepted: 06/28/2019] [Indexed: 11/16/2022]
Abstract
Terahertz (THz) radiation has received much attention during the past few decades for its potential applications in various fields, such as spectroscopy, imaging, and wireless communications. To use terahertz waves for data transmission in different application systems, the efficient and rapid modulation of terahertz waves is required and has become an in-depth research topic. Since the turn of the century, research on metasurfaces has rapidly developed, and the scope of novel functions and operating frequency ranges has been substantially expanded, especially in the terahertz range. The combination of metasurfaces and semiconductors has facilitated both new opportunities for the development of dynamic THz functional devices and significant achievements in THz modulators. This paper provides an overview of THz modulators based on different kinds of dynamic tunable metasurfaces combined with semiconductors, two-dimensional electron gas heterostructures, superconductors, phase-transition materials, graphene, and other 2D material. Based on the overview, a brief discussion with perspectives will be presented. We hope that this review will help more researchers learn about the recent developments and challenges of THz modulators and contribute to this field.
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Affiliation(s)
- Lan Wang
- Terahertz Science Cooperative Innovation Center, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chendu 610054, China
| | - Yaxin Zhang
- Terahertz Science Cooperative Innovation Center, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chendu 610054, China.
| | - Xiaoqing Guo
- Terahertz Science Cooperative Innovation Center, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chendu 610054, China
| | - Ting Chen
- Terahertz Science Cooperative Innovation Center, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chendu 610054, China
| | - Huajie Liang
- Terahertz Science Cooperative Innovation Center, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chendu 610054, China
| | - Xiaolin Hao
- Terahertz Science Cooperative Innovation Center, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chendu 610054, China
| | - Xu Hou
- Terahertz Science Cooperative Innovation Center, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chendu 610054, China
| | - Wei Kou
- Terahertz Science Cooperative Innovation Center, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chendu 610054, China
| | - Yuncheng Zhao
- Terahertz Science Cooperative Innovation Center, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chendu 610054, China
| | - Tianchi Zhou
- Terahertz Science Cooperative Innovation Center, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chendu 610054, China
| | - Shixiong Liang
- National Key Laboratory of Application Specific Integrated Circuit, Hebei Semiconductor Research Institute, Shijiazhuang 050051, China
| | - Ziqiang Yang
- Terahertz Science Cooperative Innovation Center, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chendu 610054, China.
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19
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Reprogrammable Graphene-based Metasurface Mirror with Adaptive Focal Point for THz Imaging. Sci Rep 2019; 9:2868. [PMID: 30814570 PMCID: PMC6393480 DOI: 10.1038/s41598-019-39266-3] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 01/22/2019] [Indexed: 11/29/2022] Open
Abstract
Recent emergence of metasurfaces has enabled the development of ultra-thin flat optical components through different wavefront shaping techniques at various wavelengths. However, due to the non-adaptive nature of conventional metasurfaces, the focal point of the resulting optics needs to be fixed at the design stage, thus severely limiting its reconfigurability and applicability. In this paper, we aim to overcome such constraint by presenting a flat reflective component that can be reprogrammed to focus terahertz waves at a desired point in the near-field region. To this end, we first propose a graphene-based unit cell with phase reconfigurability, and then employ the coding metasurface approach to draw the phase profile required to set the focus on the target point. Our results show that the proposed component can operate close to the diffraction limit with high focusing range and low focusing error. We also demonstrate that, through appropriate automation, the reprogrammability of the metamirror could be leveraged to develop compact terahertz scanning and imaging systems, as well as novel reconfigurable components for terahertz wireless communications.
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20
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Ji C, Song J, Huang C, Wu X, Luo X. Dual-band vortex beam generation with different OAM modes using single-layer metasurface. OPTICS EXPRESS 2019; 27:34-44. [PMID: 30645356 DOI: 10.1364/oe.27.000034] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 11/23/2018] [Indexed: 06/09/2023]
Abstract
Recently, considerable attention has been focused on orbital angular momentum (OAM) vortex wave, owing to its prospect of increasing communication capacity. Here, a single-layer metasurface is proposed to realize vortex beams with different OAM modes and polarizations carried at two distinctive bands. Both the resonant and geometric (Pancharatnam-Berry) phase cells are adopted to construct this metasurface for generating the desired phase profile, and each type of phase modulation cell can independently control the vortex beam at different frequencies. When a linearly-polarized wave is incident onto our metasurface, the resonant phase cells with spiral phase distribution can achieve OAM beam with topological charge of + 1 at 5.2 GHz. And under illumination of left-handed circular polarized (LHCP) wave, the rotated geometric phase cells assist the metasurface to generate the deflected OAM beam with topological charge of + 2 at 10.5~12 GHz. Both simulated and experimental results demonstrate good performance of the proposed single-layer metasurface at the above two frequency bands.
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21
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Abstract
The recently proposed digital coding metasurfaces make it possible to control electromagnetic (EM) waves in real time, and allow the implementation of many different functionalities in a programmable way. However, current configurations are only space-encoded, and do not exploit the temporal dimension. Here, we propose a general theory of space-time modulated digital coding metasurfaces to obtain simultaneous manipulations of EM waves in both space and frequency domains, i.e., to control the propagation direction and harmonic power distribution simultaneously. As proof-of-principle application examples, we consider harmonic beam steering, beam shaping, and scattering-signature control. For validation, we realize a prototype controlled by a field-programmable gate array, which implements the harmonic beam steering via an optimized space-time coding sequence. Numerical and experimental results, in good agreement, demonstrate good performance of the proposed approach, with potential applications to diverse fields such as wireless communications, cognitive radars, adaptive beamforming, holographic imaging. Current digital coding metasurfaces are only space-encoded. Here, the authors propose space-time modulated digital coding metasurfaces to obtain simultaneous manipulations of electromagnetic waves and present harmonic beam steering, beam shaping, and scattering-signature control as application examples.
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22
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Cong L, Srivastava YK, Zhang H, Zhang X, Han J, Singh R. All-optical active THz metasurfaces for ultrafast polarization switching and dynamic beam splitting. LIGHT, SCIENCE & APPLICATIONS 2018; 7:28. [PMID: 30839550 PMCID: PMC6107012 DOI: 10.1038/s41377-018-0024-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 03/27/2018] [Accepted: 04/22/2018] [Indexed: 05/14/2023]
Abstract
Miniaturized ultrafast switchable optical components with an extremely compact size and a high-speed response will be the core of next-generation all-optical devices instead of traditional integrated circuits, which are approaching the bottleneck of Moore's Law. Metasurfaces have emerged as fascinating subwavelength flat optical components and devices for light focusing and holography applications. However, these devices exhibit a severe limitation due to their natural passive response. Here we introduce an active hybrid metasurface integrated with patterned semiconductor inclusions for all-optical active control of terahertz waves. Ultrafast modulation of polarization states and the beam splitting ratio are experimentally demonstrated on a time scale of 667 ps. This scheme of hybrid metasurfaces could also be extended to the design of various free-space all-optical active devices, such as varifocal planar lenses, switchable vector beam generators, and components for holography in ultrafast imaging, display, and high-fidelity terahertz wireless communication systems.
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Affiliation(s)
- Longqing Cong
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371 Singapore
- Centre for Disruptive Photonic Technologies, The Photonics Institute, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798 Singapore
| | - Yogesh Kumar Srivastava
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371 Singapore
- Centre for Disruptive Photonic Technologies, The Photonics Institute, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798 Singapore
| | - Huifang Zhang
- Center for Terahertz Waves and College of Precision Instrument and Optoelectronics Engineering, Key Laboratory of Optoelectronic Information Technology, Ministry of Education, Tianjin University, 300072 Tianjin, People’s Republic of China
| | - Xueqian Zhang
- Center for Terahertz Waves and College of Precision Instrument and Optoelectronics Engineering, Key Laboratory of Optoelectronic Information Technology, Ministry of Education, Tianjin University, 300072 Tianjin, People’s Republic of China
| | - Jiaguang Han
- Center for Terahertz Waves and College of Precision Instrument and Optoelectronics Engineering, Key Laboratory of Optoelectronic Information Technology, Ministry of Education, Tianjin University, 300072 Tianjin, People’s Republic of China
| | - Ranjan Singh
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371 Singapore
- Centre for Disruptive Photonic Technologies, The Photonics Institute, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798 Singapore
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23
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An Information Theory-Inspired Strategy for Design of Re-programmable Encrypted Graphene-based Coding Metasurfaces at Terahertz Frequencies. Sci Rep 2018; 8:6200. [PMID: 29670151 PMCID: PMC5906479 DOI: 10.1038/s41598-018-24553-2] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 04/03/2018] [Indexed: 11/09/2022] Open
Abstract
Inspired by the information theory, a new concept of re-programmable encrypted graphene-based coding metasurfaces was investigated at terahertz frequencies. A channel-coding function was proposed to convolutionally record an arbitrary information message onto unrecognizable but recoverable parity beams generated by a phase-encrypted coding metasurface. A single graphene-based reflective cell with dual-mode biasing voltages was designed to act as "0" and "1" meta-atoms, providing broadband opposite reflection phases. By exploiting graphene tunability, the proposed scheme enabled an unprecedented degree of freedom in the real-time mapping of information messages onto multiple parity beams which could not be damaged, altered, and reverse-engineered. Various encryption types such as mirroring, anomalous reflection, multi-beam generation, and scattering diffusion can be dynamically attained via our multifunctional metasurface. Besides, contrary to conventional time-consuming and optimization-based methods, this paper convincingly offers a fast, straightforward, and efficient design of diffusion metasurfaces of arbitrarily large size. Rigorous full-wave simulations corroborated the results where the phase-encrypted metasurfaces exhibited a polarization-insensitive reflectivity less than -10 dB over a broadband frequency range from 1 THz to 1.7 THz. This work reveals new opportunities for the extension of re-programmable THz-coding metasurfaces and may be of interest for reflection-type security systems, computational imaging, and camouflage technology.
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24
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Dai JY, Zhao J, Cheng Q, Cui TJ. Independent control of harmonic amplitudes and phases via a time-domain digital coding metasurface. LIGHT, SCIENCE & APPLICATIONS 2018; 7:90. [PMID: 30479756 PMCID: PMC6249241 DOI: 10.1038/s41377-018-0092-z] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 10/23/2018] [Accepted: 11/03/2018] [Indexed: 05/06/2023]
Abstract
Harmonic manipulations are important for applications such as wireless communications, radar detection and biological monitoring. A general approach to tailor the harmonics involves the use of additional amplifiers and phase shifters for the precise control of harmonic amplitudes and phases after the mixing process; however, this approach leads to issues of high cost and system integration. Metasurfaces composed of a periodic array of subwavelength resonators provide additional degrees of freedom to realize customized responses to incident light and highlight the possibility for nonlinear control by taking advantage of time-domain properties. Here, we designed and experimentally characterized a reflective time-domain digital coding metasurface, with independent control of the harmonic amplitude and phase. As the reflection coefficient is dynamically modulated in a predefined way, a large conversion rate is observed from the carrier signal to the harmonic components, with magnitudes and phases that can be accurately and separately engineered. In addition, by encoding the reflection phases of the meta-atoms, beam scanning for multiple harmonics can be implemented via different digital coding sequences, thus removing the need for intricate phase-shift networks. This work paves the way for efficient harmonic control for applications in communications, radar, and related areas.
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Affiliation(s)
- Jun Yan Dai
- State Key Laboratory of Millimeter Waves, Southeast University, 210096 Nanjing, China
- Synergetic Innovation Center of Wireless Communication Technology, Southeast University, 210096 Nanjing, China
| | - Jie Zhao
- State Key Laboratory of Millimeter Waves, Southeast University, 210096 Nanjing, China
- Synergetic Innovation Center of Wireless Communication Technology, Southeast University, 210096 Nanjing, China
| | - Qiang Cheng
- State Key Laboratory of Millimeter Waves, Southeast University, 210096 Nanjing, China
- Synergetic Innovation Center of Wireless Communication Technology, Southeast University, 210096 Nanjing, China
| | - Tie Jun Cui
- State Key Laboratory of Millimeter Waves, Southeast University, 210096 Nanjing, China
- Synergetic Innovation Center of Wireless Communication Technology, Southeast University, 210096 Nanjing, China
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25
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Zheng Y, Cao X, Gao J, Yang H, Zhou Y, Liu T. Integrated radiation and scattering performance of a multifunctional artificial electromagnetic surface. OPTICS EXPRESS 2017; 25:30001-30012. [PMID: 29221035 DOI: 10.1364/oe.25.030001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 11/12/2017] [Indexed: 06/07/2023]
Abstract
In this paper, a multifunctional artificial electromagnetic surface (AEMS) with integrated radiation and scattering performance is proposed and realized. Different from previous AEMS designs that mainly focus on scattering performance, this AEMS design takes both radiation and scattering properties into consideration in the designing process. Inspired by the design concept of antenna, a feeding structure is added to each AEMS element to achieve radiation performance. Meanwhile, the concerned characteristics of AEMS elements are almost maintained. For achieving wideband low-scattering performance, two different kinds of AEMS elements are designed and arranged in a chessboard configuration. Simulated and measured results prove that our method offers an effective strategy to design multifunctional AEMS that achieve radiation and scattering performance simultaneously.
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26
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Zhang L, Liu S, Li L, Cui TJ. Spin-Controlled Multiple Pencil Beams and Vortex Beams with Different Polarizations Generated by Pancharatnam-Berry Coding Metasurfaces. ACS APPLIED MATERIALS & INTERFACES 2017; 9:36447-36455. [PMID: 28944660 DOI: 10.1021/acsami.7b12468] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
We propose to design coding metasurfaces based on the Pancharatnam-Berry (PB) phase. The proposed PB coding metasurface could control circularly polarized components of incident waves, by encoding geometric phase into the orientation angle of coding particles to generate 1-bit and multibit phase responses. We perform digital convolution operations on scattering patterns of the PB coding metasurface to reach flexible controls of the circularly polarized waves, forming spin-controlled multiple beams with different polarizations in free space, such as pencil beams and vortex beams carrying orbital angular momentum. Both numerical and experimental results demonstrate the excellent performance of the PB coding metasurface, which opens a pathway to novel types of multibeam generations and provides an effective way to expand the beam coverage for wireless communication applications.
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Affiliation(s)
| | | | - Lianlin Li
- School of Electronic Engineering and Computer Sciences, Peking University , Beijing 100871, China
| | - Tie Jun Cui
- Cooperative Innovation Centre of Terahertz Science , No.4, Section 2, North Jianshe Road,Chengdu 610054, China
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