Article
Materials Science, Multidisciplinary
Fei Yang, Rui Huang, Zi Qiang Wang, Han Zhang, Shuang Peng, Chen Xi Liu, Xiao Jian Fu, Jun Wei Wu
Summary: A programmable metasurface antenna, based on electrically tunable elements, is proposed in this paper for operation in the 5G millimeter-wave band. The antenna has the advantages of low cost, ease of manufacturing, low profile, and easy integration with planar circuits. By controlling the varactor-mounted elements with a DC bias signal, the antenna can dynamically change its coding and achieve beam steering. Experimental results demonstrate a wide scanning range and good agreement between simulated and measured results, indicating the potential applications of this electrically tunable metasurface array in radar and communication systems.
ADVANCED ENGINEERING MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Fei Yang, Fan Xu, Chenxi Liu, Xinyu Yang, Ziqiang Wang, Junwei Wu, Xiaojian Fu
Summary: This article proposes a compact programmable coding metasurface with PIN diodes for beam steering in the Ka band. The simulation and experimental results validate the performance of the metasurface and demonstrate its potential applications in sensing and wireless communications. This novel metasurface offers greater flexibility and integration, providing new insights for the development of millimeter wave technology.
APPLIED SCIENCES-BASEL
(2022)
Article
Engineering, Electrical & Electronic
Ji-Wei Lian, Dazhi Ding, Rushan Chen
Summary: A wideband metasurface antenna operating at millimeter-wave spectrum in substrate-integrated waveguide (SIW) technology is proposed. The proposed metasurface antenna achieves a wide 10 dB impedance bandwidth in simulation from 19.2 to 42.4 GHz, indicating a fractional bandwidth of 75%. The development of the proposed metasurface antenna can be divided into four stages, and its working mechanism is explained in detail.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2022)
Article
Computer Science, Information Systems
Yu Zhang, Zhiqin Wang, Yuxin Ren, Chong Pan, Jinling Zhang, Lifei Jia, Xiongzhi Zhu
Summary: In this paper, a metasurface lens is proposed for testing 5G millimeter-wave antennas by controlling the phase-shift distribution of incident spherical waves. The lens is shown to generate a uniform amplitude and phase-field distribution at a reduced distance of 1.2 m, making it a compact and effective solution for achieving plane-wave conditions in 5G millimeter bands.
Article
Computer Science, Information Systems
Daniyal Ali Sehrai, Muhammad Asif, Wahab Ali Shah, Jalal Khan, Ibrar Ullah, Muhammad Ibrar, Saeedullah Jan, Mohammad Alibakhshikenari, Francisco Falcone, Ernesto Limiti
Summary: This paper introduces a wideband MIMO antenna design based on metasurfaces, which shows good performance and compact structure, suitable for millimeter-wave 5G communication systems.
Article
Engineering, Electrical & Electronic
Xiaohe Cheng, Zihao Liu, Yuan Yao, Tao Yu, Junsheng Yu, Xiaodong Chen
Summary: A novel millimeter-wave wideband circularly polarized horn antenna using iris polarizer is reported with improved electrical contact at high frequencies. Analysis of air gap effects on antenna performance was conducted, showing that small air gaps do not harm performance after loading a metasurface. Experimental results confirmed good performance with 37.8% bandwidth from 75 to 110 GHz.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Chemistry, Multidisciplinary
Mohammadreza F. Imani, Sergi Abadal, Philipp del Hougne
Summary: This paper introduces the concept of smart radio environments and explores their application on the chip scale. By endowing the wireless on-chip environment with in situ programmability, the issues currently faced by wireless networks-on-chips (WNoCs) in inter-core communication can be overcome. The design and optimization of a programmable metasurface allows for equalization of wireless on-chip channels and demonstrates the feasibility of higher modulation speeds with shaped channel impulse responses (CIRs). These findings provide new insights and solutions for the development of WNoCs.
Article
Engineering, Electrical & Electronic
Zamir Wani, Mahesh P. Abegaonkar, Shiban K. Koul
Summary: This article introduces a thin metasurface planar lens for millimeter-wave MIMO applications. The lens is composed of an array of mm-wave resonators that can modify the phase profile of the electromagnetic wave propagating through it. Experimental results show that the three-port antenna with the lens achieves beam scanning and high gain.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2022)
Article
Optics
Qi Hu, Jianmin Zhao, Ke Chen, Kai Qu, Weixu Yang, Junming Zhao, Tian Jiang, Yijun Feng
Summary: Reconfigurable metasurfaces are versatile platforms for reshaping the wireless environment at low cost. Unlike traditional metasurfaces, these can support both reflection and transmission modes, providing ubiquitous full-space service coverage for multiuser wireless communication applications.
LASER & PHOTONICS REVIEWS
(2022)
Article
Chemistry, Physical
Maria Elena de Cos Gomez, Humberto Fernandez Alvarez, Alicia Florez Berdasco, Fernando Las-Heras Andres
Summary: Three metasurfaces (MTS) are designed to be combined with a series end-fed 1 x 10 array antenna to achieve imaging applications in the millimeter frequency range. The MTS-array combination reduces secondary lobes, increases FTBR, widens operation bandwidth, enhances gain and radiation efficiency, while maintaining the size. The envisioned application is collision avoidance for visually impaired people at a medium-long distance.
Article
Engineering, Electrical & Electronic
Shaocheng Huang, Ming Xiao, H. Vincent Poor
Summary: This paper investigates the achievable rates of mmWave channels and the relationships among rate, latency, and reliability. Analytical expressions of achievable rates under different parameters are derived by studying the channel state information in different scenarios. It is also found that there exists a critical bandwidth for maximizing the achievable rate for non-line-of-sight mmWave signals with imperfect channel state information.
IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS
(2022)
Article
Engineering, Electrical & Electronic
Yeonju Kim, Ratanak Phon, Eiyong Park, Sungjoon Lim
Summary: This paper proposes a deployable broadband millimeter-wave metasurface lens antenna using a 3-D printed accordion origami structure. The metasurface lens is designed on the 3-D-printed origami with two 3-D-printed rectangular gratings and an inkjet-printed I-shaped pattern. The proposed antenna achieves broad bandwidth, high transmission efficiency, and complete 360 degrees phase coverage. Numerical and experimental results demonstrate its performance, including a 10-dB impedance bandwidth of 24.0-34.9 GHz (38%) and a 3 dB gain bandwidth of 25.0-33.5 GHz (30%). Additionally, the folded antenna has a reduced overall volume of 1/3 of its original size. The simple additive manufacturing process used also provides the advantages of lightweight and low cost.
IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Hai Lin Wang, Hui Feng Ma, Tie Jun Cui
Summary: This paper proposes a programmable polarization-modulated information metasurface for wireless communication encryption. The encoding and hiding of a meta-key in different linear polarization channels, modulation and transmission using the information metasurface, and reception and decoding using polarization discrimination antennas are demonstrated. The feasibility of the scheme is verified through a wireless transceiver system.
Article
Materials Science, Multidisciplinary
Wei-Mang Pan, Jiu-Sheng Li, Chen Zhou
Summary: This study presents a new approach for creating a reconfigurable terahertz digital metasurface using vanadium dioxide integrated metasurface unit cells, achieving beam splitting and switching functionalities. Numerical simulations verify the behavior of terahertz waves under different conditions and illustrate the accuracy of general theoretical predictions. This scheme offers a new effective method for designing multifunctional terahertz devices.
OPTICAL MATERIALS EXPRESS
(2021)
Article
Chemistry, Analytical
Ke Han, Yuchu Yan, Ze Yan, Chongwei Wang
Summary: A millimeter-wave broadband metasurface-based antenna with a low profile is proposed, which utilizes characteristic mode analysis (CMA) for design and optimization. Four sets of coplanar patches are used to generate adjacent broadside modes, and a new resonant mode is introduced to expand the low-frequency bandwidth. Dual slots are etched on the mid patch to reduce cross-polarization levels. The antenna achieves an impedance bandwidth of 25.02% (30-38.58 GHz) with a realized gain of 8.35-11.3 dB.
Article
Engineering, Electrical & Electronic
Robert Guirado, Abbas Rahimi, Geethan Karunaratne, Eduard Alarcon, Abu Sebastian, Sergi Abadal
Summary: Hyperdimensional computing (HDC) is a computing paradigm that uses hypervectors to represent and manipulate data. In-memory computing (IMC) is an efficient hardware platform for executing HDC algorithms. This article introduces WHYPE, a scale-out HDC architecture that uses wireless in-package communication to connect distributed IMC cores, enabling massive parallelization and efficient computation.
IEEE JOURNAL ON EMERGING AND SELECTED TOPICS IN CIRCUITS AND SYSTEMS
(2023)
Article
Physics, Applied
Hamidreza Taghvaee, Fu Liu, Ana Diaz-Rubio, Sergei Tretyakov
Summary: Breaking the diffraction limit on optical devices and achieving subwavelength focusing requires tailoring the evanescent spectrum of wave fields. This paper presents a feasible strategy based on the concepts of the perfect lens and power flow-conformal metasurfaces, allowing for subwavelength hotspot size in near-field focusing. The findings have potential applications in antennas, beam-shaping devices, nonradiative wireless power transfer systems, microscopy, and lithography.
PHYSICAL REVIEW APPLIED
(2023)
Article
Engineering, Civil
Nouman Ashraf, Taqwa Saeed, Hamidreza Taghvaee, Sergi Abadal, Vasos Vassiliou, Christos Liaskos, Andreas Pitsillides, Marios Lestas
Summary: Reconfigurable Intelligent Surfaces (RIS) are a promising solution for blockage problem in millimeter-wave (mm-wave) and terahertz (THz) communications, especially for 6G and vehicular networking applications. HyperSurfaces (HSF) is an enabling technology with embedded controllers that enhance intelligence and autonomy in wireless networks. This work focuses on feedback-based autonomous reconfiguration of HSF controller states for reliable communication via programmable reflection on HSF in the absence of line-of-sight (LoS). Extremum Seeking Control (ESC) is used to regulate the reflection angle on the metasurface and maximize power at the receiver. Simulation results demonstrate the effectiveness of this method, even for mobile receivers, and characterize the spatiotemporal nature of traffic for different sampling periods.
IEEE TRANSACTIONS ON INTELLIGENT TRANSPORTATION SYSTEMS
(2023)
Article
Computer Science, Information Systems
Taqwa Saeed, Sergi Abadal, Christos Liaskos, Andreas Pitsillides, Hamidreza Taghvaee, Albert Cabellos-Aparicio, Vassos Soteriou, Eduard Alarcon, Ian F. Akyildiz, Marios Lestas
Summary: Programmable metasurfaces, with powerful control over electromagnetic waves, are expected to be a key technology for Reconfigurable Intelligent Surfaces (RIS). The HyperSurface (HSF) enhances this paradigm by embedding a network of integrated circuit (IC) controllers for added intelligence and autonomy. This paper introduces a methodology to characterize the workload of programmable metasurfaces and analyzes beam steering HSFs. The workload characterization provides insights into traffic behavior, including spatio-temporal load and limitations in tracking moving targets. Statistical analysis shows that incoming traffic can be represented by an ON-OFF model.
IEEE TRANSACTIONS ON MOBILE COMPUTING
(2023)
Article
Telecommunications
Konstantinos Ntontin, Alexandros-Apostolos A. Boulogeorgos, Emil Bjornson, Wallace Alves Martins, Steven Kisseleff, Sergi Abadal, Eduard Alarcon, Anastasios Papazafeiropoulos, Fotis I. Lazarakis, Symeon Chatzinotas
Summary: In this paper, the feasibility of fully-energy-autonomous operation of reconfigurable intelligent surfaces (RIS) through wireless energy harvesting (EH) is examined. A suitable energy-consumption model is proposed, based on the integrated controller architecture, to identify the main RIS energy-consuming components and include the energy consumption needed for channel estimation. A novel RIS architecture is introduced, enabling EH through RIS unit-cell (UC) splitting. An EH policy is presented, where a subset of the UCs is used for beamsteering while the remaining UCs absorb energy. The results demonstrate the feasibility of the proposed architecture and the efficiency of the presented algorithms.
IEEE TRANSACTIONS ON GREEN COMMUNICATIONS AND NETWORKING
(2023)
Article
Computer Science, Hardware & Architecture
Pau Escofet, Anabel Ovide, Carmen G. Almudever, Eduard Alarcon, Sergi Abadal
Summary: Modular quantum computing architectures offer a promising alternative to overcome the scaling limitations of current quantum computers. To improve the performance and scalability of quantum computing systems, efficient distribution of qubits across multiple processing cores is critical. The Hungarian Qubit Assignment (HQA) algorithm, which considers the interactions between qubits across the circuit, achieves fine-grained partitioning and enhanced qubit utilization. Through comprehensive experiments, the HQA algorithm demonstrates superiority over existing methods, with an average improvement of 1.28x.
IEEE COMPUTER ARCHITECTURE LETTERS
(2023)
Article
Telecommunications
Konstantinos Ntontin, Emil Bjornson, Alexandros-Apostolos A. Boulogeorgos, Zaid Abdullah, Agapi Mesodiakaki, Sergi Abadal, Symeon Chatzinotas
Summary: In this work, the performance of time-splitting and unit cell-splitting protocols for reconfigurable intelligent surfaces (RISs) are compared analytically in terms of their ability to fulfill energy needs through wireless energy harvesting. Analytical solutions are provided for optimal resource allocation in both protocols under various fading distributions. The article also reveals trends in achievable rates relative to RIS energy consumption based on analysis. The numerical results validate the findings and show that the unit cell-splitting protocol achieves higher average rates, but at the cost of reduced signal-to-noise ratio as RIS energy demands increase.
IEEE TRANSACTIONS ON GREEN COMMUNICATIONS AND NETWORKING
(2023)
Proceedings Paper
Computer Science, Artificial Intelligence
Eduard Alarcon, Sergi Abadal, Fabio Sebastiano, Masoud Babaie, Edoardo Charbon, Peter Haring Bolivar, Maurizio Palesi, Elena Blokhina, Dirk Leipold, Bogdan Staszewski, Artur Garcia-Saez, Carmen G. Almudever
Summary: This position paper presents a vision for a new generation of scalable quantum computing architectures that feature distributed quantum cores interconnected via quantum-coherent qubit state transfer links and orchestrated via an integrated wireless interconnect.
2023 IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS, ISCAS
(2023)
Proceedings Paper
Computer Science, Artificial Intelligence
Bernat Olle, Pau Talarn, Albert Cabellos-Aparicio, Filip Lemic, Eduard Alarcon, Sergi Abadal
Summary: This work explores the design space of multi-channel Medium Access Control (MAC) protocols for chip-scale networks, addressing the issue of channel sharing. Different channel assignment strategies for random access and token passing are presented and evaluated under realistic traffic patterns. The study shows that, even with multiple channels, both protocols maintain their intrinsic advantages and disadvantages.
2023 IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS, ISCAS
(2023)
Proceedings Paper
Computer Science, Artificial Intelligence
Anabel Ovide, Santiago Rodrigo, Medina Bandic, Hans Van Someren, Sebastian Feld, Sergi Abadal, Eduard Alarcon, Carmen G. Almudever
Summary: Current quantum computer architectures face limitations in scalability, but a potential solution is to adopt a modular or multi-core architecture where quantum processors are interconnected. However, this poses new challenges like expensive inter-core communication. To address this, an efficient mapping technique for executing quantum algorithms is required. This paper provides a critical discussion on the quantum circuit mapping problem for multi-core quantum computing architectures, and evaluates the performance of a mapping method through architectural scalability analysis.
2023 IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS, ISCAS
(2023)
Proceedings Paper
Automation & Control Systems
Rafael Medina, Joshua Kein, Giovanni Ansaloni, Marina Zapater, Sergi Abadal, Eduard Alarcon, David Atienza
Summary: Multi-Chiplet architectures are increasingly used to design large systems in a single package, simplifying integration and improving manufacturing. Limited inter-chiplet routing resources complicate design, but in-package wireless technology can address these challenges. In this study, we explore the performance of in-package wireless communication, showing its competitiveness with wired chiplet interconnects, especially for AI workloads.
2023 28TH ASIA AND SOUTH PACIFIC DESIGN AUTOMATION CONFERENCE, ASP-DAC
(2023)
Proceedings Paper
Computer Science, Information Systems
Konstantinos Ntontin, Alexandros-Apostolos A. Boulogeorgos, Zaid Abdullah, Agapi Mesodiakaki, Sergi Abadal, Symeon Chatzinotas
Summary: In this paper, a time- and unit cell-splitting protocol for wireless energy harvesting in reconfigurable intelligent surfaces (RISs) is proposed. The optimal resource allocation solutions for both protocols are provided, and it is shown that the unit cell-splitting protocol outperforms the time-splitting protocol in performance.
2022 IEEE GLOBAL COMMUNICATIONS CONFERENCE (GLOBECOM 2022)
(2022)
Article
Computer Science, Theory & Methods
Sergi Abadal, Akshay Jain, Robert Guirado, Jorge Lopez-Alonso, Eduard Alarcon
Summary: Graph Neural Networks (GNNs) have gained significant attention in recent years for their ability to model and learn from graph-structured data. However, the efficient processing of GNNs remains a challenge due to various reasons. This article provides a comprehensive review of the field of GNNs from a computing perspective and analyzes current software and hardware acceleration schemes, proposing a new vision for GNN accelerators.
ACM COMPUTING SURVEYS
(2022)