Article
Chemistry, Multidisciplinary
Yujie Liu, Yu Wang, Xiaojian Fu, Lei Shi, Fei Yang, Jiang Luo, Qun Yan Zhou, Yuan Fu, Qi Chen, Jun Yan Dai, Lei Zhang, Qiang Cheng, Tie Jun Cui
Summary: This article proposes a space-time coding metasurface (STCM) operating in the sub-terahertz band for constructing new-architecture wireless communication systems. The STCM is designed to have varactor-diode-tuned elements, allowing precise regulation of harmonic amplitudes and phases. It achieves independent electromagnetic regulations in the space and time domains, enabling flexible beam manipulations and information modulations. Experimental results demonstrate its capability in supporting multiple modulation schemes and wide-angle beam scanning. The STCM transmitter with high device density and low power consumption can provide low-complexity, low-cost, low-power, and low-heat solutions for building the next-generation wireless communication systems.
Article
Chemistry, Multidisciplinary
Si Ran Wang, Ming Zheng Chen, Jun Chen Ke, Qiang Cheng, Tie Jun Cui
Summary: Recent progress in space-time-coding digital metasurface (STCM) has demonstrated its power in controlling electromagnetic wave properties in both space and time domains. A new asynchronous STCM is proposed, where meta-atoms are modulated by different time-coding periods. This asynchronous STCM allows for dynamic wavefronts and shows potential for applications in radars and wireless communications.
Article
Multidisciplinary Sciences
Jun Chen Ke, Xiangyu Chen, Wankai Tang, Ming Zheng Chen, Lei Zhang, Li Wang, Jun Yan Dai, Jin Yang, Jun Wei Zhang, Lijie Wu, Qiang Cheng, Shi Jin, Tie Jun Cui
Summary: A new-architecture space-frequency-polarization-division multiplexed wireless communication system is proposed using an anisotropic space-time-coding digital metasurface, which can improve the channel capacity and space utilization.
NATIONAL SCIENCE REVIEW
(2022)
Article
Multidisciplinary Sciences
Xuchen Wang, Mohammad Sajjad Mirmoosa, Viktar S. Asadchy, Carsten Rockstuhl, Shanhui Fan, Sergei A. Tretyakov
Summary: Photonic time crystals are artificial materials with spatially uniform but temporally varying electromagnetic properties. This study extends the concept of photonic time crystals to two-dimensional artificial structures called metasurfaces. By designing a microwave metasurface, the researchers confirmed the existence of momentum bandgaps and exponential wave amplification, demonstrating the potential of metasurfaces as a material platform for emerging photonic space-time crystals and for amplifying surface-wave signals in wireless communications.
Article
Chemistry, Multidisciplinary
Xiang Wan, Jia Wei Wang, Zi Ai Huang, Bai Yang Li, Qiang Xiao, Tie Jun Cui
Summary: The study demonstrates the foundation of space-time-frequency joint controls of EM waves using digital programmable metasurfaces. Through the analysis of monochromatic or nonmonochromatic EM waves based on the Huygens-Fresnel principle and Fourier analysis, the decoupling of space- and time-frequency modulations enables independent controls over the EM waves in terms of space, time, and frequency.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Xin Wang, Jiaqi Han, Shuncheng Tian, Dexiao Xia, Long Li, Tie Jun Cui
Summary: The article introduces a novel amplifier-based transmissive space-time-coding metasurface which enables strong nonlinear control of electromagnetic waves in both space and frequency domains. By utilizing unilateral power amplifiers, the metasurface can manipulate the propagation directions of nonlinear harmonic waves, breaking Lorentz reciprocity. Through cascading power amplifiers between patches on two sides of the metasurface, spatial electromagnetic waves can be transmitted in the forward direction while being blocked in the backward direction.
Article
Optics
Chunyang Jiang, Zhenkai Li, Xinyu Lv, Meng Tian, Meng Liu, Huiyun Zhang, Yuping Zhang
Summary: Coding metasurfaces have rapidly developed in recent years due to digital thought. Spatiotemporal metasurfaces have gained significant attention for their additional degrees of freedom in manipulating electromagnetic waves in space and time domains. This study proposes Dirac semimetal based space-time-coding metasurfaces in the terahertz band, which enable wide-band terahertz vortex beam generation and achieve precise modulation. The results are expected to have promising applications in terahertz high-data-capacity communication systems and multi-target precision tracking and guidance.
OPTICS COMMUNICATIONS
(2023)
Article
Nanoscience & Nanotechnology
Xin Ge Zhang, Ya Lun Sun, Bingcheng Zhu, Junjia Wang, Tianxiang Zhao, Wei Xiang Jiang, Zhixiang Huang, Zaichen Zhang, Tie Jun Cui
Summary: Photon-electron interactions are crucial for various applications including energy conversion, signal processing, and quantum science. However, current demonstrations mainly focus on fiber and on-chip applications, neglecting the study in wave space. In this study, a concept of optoelectronic metasurface is introduced, enabling efficient optical-microwave interactions in free space. The optoelectronic metasurface is achieved through hybrid integration of microwave resonant meta-structures with a photoresponsive material.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Engineering, Electrical & Electronic
Haotian Li, Yikai Chen, Shiwen Yang
Summary: A novel pseudorandom hybrid phase-amplitude modulation technique is proposed to achieve robust sideband suppression and ultralow sidelobe levels for traditional time-modulated antenna arrays (TMAs). This technique allows the distribution of sideband radiation power over a continuous spectrum and the synthesis of scanning beams with low sidelobe levels. It eliminates the need for evolutionary optimization algorithms and enables real-time on-board calculation with an FPGA board.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2023)
Article
Nanoscience & Nanotechnology
Qi Hu, Ke Chen, Yilin Zheng, Zhiyuan Xu, Jianmin Zhao, Jian Wang, Yijun Feng
Summary: Reconfigurable metasurfaces have emerged as a promising alternative to conventional wireless communication systems. However, most of them are limited to narrow bandwidth. In this paper, a broadband metasurface-based wireless communication system is proposed to adapt to multiple users through joint modulation of digital signals in the time and space domains. Experiments show that the system can provide stable wireless communication service within a broad band and successfully recover transmitted color pictures at user terminals. The proposed system has potential applications in next-generation communications and radar systems.
Article
Engineering, Electrical & Electronic
Masaya Tashiro, Ashif Aminulloh Fathnan, Yuta Sugiura, Akira Uchiyama, Hiroki Wakatsuchi
Summary: The authors present metasurface-inspired maintenance-free IoT tags that can be characterized by both frequency-domain and time-domain profiles. The waveform-selective mechanisms of circuit-based metasurfaces allow the tags to behave differently at the same frequency based on the pulse duration of the incident wave. The proposed designs are validated numerically and experimentally, and potentially contribute to increasing the capacity of IoT tags within a single wireless network while reducing maintenance effort.
ELECTRONICS LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Dexiao Xia, Lei Guan, Haixia Liu, Yajie Mu, Xin Wang, Jiaqi Han, Yan Shi, Long Li
Summary: This article proposes MetaBreath, a multitarget and high-resolution respiration detection method based on space-time-coding (STC) digital metasurface. By exploiting the harmonics generated by STC digital metasurface, the respiration detection is modeled as a blind source separation problem and solved using independent component analysis (ICA). Experimental results demonstrate that MetaBreath enables respiration detection and separation in both separate and close scenarios, achieving superior performance compared to state-of-the-art methods. With its low complexity and high practicality, MetaBreath has potential applications in sleeping monitoring, life detection, and baby care.
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
(2023)
Article
Nanoscience & Nanotechnology
Liang Wei Wu, Hui Feng Ma, Yue Gou, Rui Yuan Wu, Zheng Xing Wang, Qiang Xiao, Tie Jun Cui
Summary: This paper proposes a multiband bidirectional digital coding metasurface that can achieve different functions in up to six frequency bands. By designing and fabricating different metasurfaces, functions such as reflection, transmission, holographic imaging, and vortex-beam forming are achieved. The simulated and measured results confirm the good performance of the proposed metasurface.
Article
Engineering, Electrical & Electronic
Marco Faenzi, David Gonzalez-Ovejero, Stefano Maci
Summary: By shaping the local periodicity function, broadside pencil beams over large bandwidths can be achieved even with frequency variations. This design optimizes antenna performance while maintaining flat gain versus frequency response and stability of the phase center.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Optics
Zhen Jie Qi, Jun Yan Dai, Si Ran Wang, Qun Yan Zhou, Wankai Tang, Kaicen Wang, Peng Zhang, Shuo Liu, Long Li, Qiang Cheng, Tie Jun Cui
Summary: This paper proposes a SWIPT transmitting architecture based on an asynchronous space-time-coding digital metasurface (ASTCM). High-efficiency simultaneous transfer of information and power is achieved via energy distribution and information processing of the wireless monophonic signal reflected from the metasurface. The feasibility of the proposed method is demonstrated through theoretical derivations and experimental verification, indicating its great potential in wireless communications and IoT devices.
CHINESE OPTICS LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Xinxin Gao, Ze Gu, Qian Ma, Wen Yi Cui, Tie Jun Cui, Chi Hou Chan
Summary: Driven by the demands for compact interconnects and fast information transfer, research on spoof plasmonic metamaterials has been focused on achieving individual modulation of amplitude or phase at single frequencies due to structural limitations. This study proposes and experimentally demonstrates an ultra-thin reprogrammable modulator consisting of a spoof surface plasmonic polariton (SSPP) waveguide and spoof localized surface plasmon (SLSP) resonators, allowing independent control of amplitude and phase of surface waves. By manipulating the SSPP waveguide and SLSP resonators in real-time, various programmable modulations such as amplitude-shift keying, phase-shift keying, quadrature amplitude modulation, and frequency-shift keying can be achieved. Measurement results confirm the potential applications of the reprogrammable plasmonic metamaterial in integrated circuits and communication systems.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Chenfeng Yang, Geng-Bo Wu, Baojie Chen, Ka Fai Chan, Chi Hou Chan
Summary: This article reports a reflective metasurface for steering Bessel beams at the terahertz band. By designing a multiresonance structure with a large reflection phase range, the desired phase distribution for generating off-axis Bessel beams can be achieved. The metasurface, composed of 79 x 79 half-wavelength elements with different dimensions, is capable of producing controllable Bessel beams by adjusting frequencies.
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
(2023)
Article
Multidisciplinary Sciences
Jing Cheng Zhang, Geng-Bo Wu, Mu Ku Chen, Xiaoyuan Liu, Ka Fai Chan, Din Ping Tsai, Chi Hou Chan
Summary: The development of the sixth-generation (6G) communication technology is in progress and it is expected to surpass the performance of the fifth generation. The precise control of information transfer direction and signal concentration is crucial in 6G technology.
Article
Engineering, Manufacturing
Xuexuan Ruan, Chi Hou Chan
Summary: This article introduces a novel method of designing filters using an optimization algorithm, which can autonomously evaluate filters using a fitness function. The approach eliminates the need for numerous simulations, saving time and computational resources, as well as extensive expertise. Experimental results designing microstrip and waveguide filters demonstrate the effectiveness of the proposed approach.
IEEE TRANSACTIONS ON COMPONENTS PACKAGING AND MANUFACTURING TECHNOLOGY
(2023)
Article
Optics
Guang Zhu Zhou, Bao-jie Chen, Geng-bo Wu, Shi-wei Qu, Chi Hou Chan
Summary: This study reports a plasmonic optical leaky-wave antenna with low sidelobe level (SLL). By modulating the electric-field amplitude, the antenna achieves the conversion between guided waves and free-space waves, and reduces the SLL by controlling the aperture field. Experimental results demonstrate high directivity and low SLL, and the antenna allows for arbitrary wavefront shaping.
PHOTONICS RESEARCH
(2023)
Article
Materials Science, Multidisciplinary
Xinxin Gao, Bao Jie Chen, Kam-Man Shum, Qian Ma, Wen Yi Cui, Tie Jun Cui, Chi Hou Chan
Summary: The next-generation wireless communications and intrachip and interchip communications require high-speed terahertz (THz) interconnects, which can be achieved using spoof surface plasmon polaritons (SSPPs). This study proposes and experimentally demonstrates planar multifunctional THz plasmonic devices based on the interaction between SSPPs and spoof localized surface plasmon (SLSPs). These devices enable pass-through transmission, multifrequency resonances, and phase shift in THz plasmonic systems, making them promising for on-chip integrations, wireless communications, and sensing systems.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Article
Engineering, Electrical & Electronic
Rui Zhe Jiang, Qian Ma, Jing Cheng Liang, Qun Yan Zhou, Jun Yan Dai, Qiang Cheng, Tie Jun Cui
Summary: In this article, a wideband and wide-angle single-layered transparent metasurface is proposed to enhance the transmission of electromagnetic waves through glasses. The detailed mechanisms, analytical models, and numerical results validate the excellent electromagnetic performance of the metasurface. It is expected to have potential applications in 5G and 6G communication scenarios.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2023)
Article
Multidisciplinary Sciences
Si Ran Wang, Jun Yan Dai, Qun Yan Zhou, Jun Chen Ke, Qiang Cheng, Tie Jun Cui
Summary: Manipulating multiple carrier frequencies is crucial in fields like wireless communications and radar detection. Conventional radio-frequency architecture, though, faces challenges in integrating multi-frequency controls with antenna apertures, resulting in expensive systems and high power consumption. The proposed multi-partition asynchronous space-time-coding digital metasurface (ASTCM) offers a flexible and cost-effective solution to generate and manipulate multiple frequencies, simplifying traditional wireless systems.
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Geng-Bo Wu, Jun Yan Dai, Kam Man Shum, Ka Fai Chan, Qiang Cheng, Tie Jun Cui, Chi Hou Chan
Summary: The study proposes a microwave universal metasurface antenna (UMA) that can dynamically, simultaneously, independently, and precisely manipulate all properties of electromagnetic waves in a software-defined manner. The UMA has high integrability and programmability, and is expected to spark a surge of applications in various fields.
NATURE COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Guang Zhu Zhou, Bao-Jie Chen, Geng-Bo Wu, Shi-Wei Qu, Chi Hou Chan
Summary: Optical wavefront shaping achieved by holographic metal-insulator-metal plasmonic gap waveguides is reported. The amplitude and phase information of an arbitrary free-space wave can be recorded in the waveguide by the amplitude variation of the guided wave. By designing the plasmonic gap waveguide, complex free-space functions can be realized, such as highly directional beams, dual beams with arbitrary power ratio and radiation angles, focusing beams, and Airy beam generation. This study opens a new route for optical wavefront shaping via modulating guided waves, holding potential in optical communications, light detection and ranging, imaging, and displays.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Ka Kit Kelvin Ho, Geng-Bo Wu, Bao-Jie Chen, Ka Fai Chan, Chi Hou Chan
Summary: This article presents a novel approach to reducing coma for transmitarray OFF-axis scanning in the THz region. A dual transmitarray solution is proposed, in which a transmitarray with an optimized phase profile is placed behind a regular phase profile transmitarray. Experimental validation shows good focusing performances of the dual-transmitarray antenna.
IEEE TRANSACTIONS ON TERAHERTZ SCIENCE AND TECHNOLOGY
(2023)
Proceedings Paper
Engineering, Electrical & Electronic
Chi Hou Chan, Liang Gao, Shangcheng Kong, Geng-Bo Wu, Kam Man Shum, Ka Fai Chan
Summary: This paper provides an overview of the research conducted at the State Key Laboratory of THz and Millimeter Waves, City University of Hong Kong, on passive and active on-chip terahertz antennas and arrays. The focus for passive antennas is on impedance and gain bandwidth performance, as well as size reduction of feeding networks for arrays. For active on-chip antennas, the emphasis is on antenna size, array placement, and impedance matching to achieve high radiation power.
2023 INTERNATIONAL WORKSHOP ON ANTENNA TECHNOLOGY, IWAT
(2023)
