Article
Optics
Ruoxing Wang, Guanhua Ren, Zhi Ren, Jianlong Liu, Songtao Li, Xianzhong Chen, Li Li
Summary: In this study, a multi-foci metalens model was proposed to reconstruct THz holographic images with subwavelength resolution. The model, based on dielectric metasurfaces composed of silicon micropillars with spatially variant orientations, can generate high-resolution target images on its focal plane. The experimental results demonstrate that the reconstructed images have subwavelength resolution.
Article
Materials Science, Characterization & Testing
Srijan Datta, Lalita Upda
Summary: This paper presents a novel negative index metamaterial (NIM) lens imaging sensor system for subwavelength microwave nondestructive evaluation (NDE) using homodyne detection measurements. The system provides a simple, low-cost, and highly sensitive imaging solution that can overcome the diffraction-limited resolution at far-field working distances. The study demonstrates the unique focus-scanning capability of NIM lenses for target localization without complex tuning mechanisms.
NDT & E INTERNATIONAL
(2023)
Article
Ecology
Rinke J. van Tatenhove-Pel, Tomaz Rijavec, Ales Lapanje, Iris van Swam, Emile Zwering, Jhonatan A. Hernandez-Valdes, Oscar P. Kuipers, Cristian Picioreanu, Bas Teusink, Herwig Bachmann
Summary: Metabolic interactions between cells are influenced by the distance between cells, and in a three-dimensional system, these interactions are constrained by competition or removal of metabolites, reducing the metabolic interaction distances in the low micrometer range.
Article
Materials Science, Multidisciplinary
Heath Gemar, Michael K. Yetzbacher, Ronald G. Driggers, C. Kyle Renshaw
Summary: The study investigates the effect of adding an absorber to silver slits in the mid-wave infrared range on optical behavior. By adding an absorbing layer to the slit, it broadens the spectral response of the cavity but reduces the cavity quality, partially decoupling the absorber with a thin isolating layer helps restore the slit's narrow spectral response.
OPTICAL MATERIALS EXPRESS
(2021)
Article
Engineering, Electrical & Electronic
Jianyu Chen, Hui Xiao, Han Xiong, Dongping Xiao, Wei Song, Huaiqing Zhang
Summary: A novel impedance matcher based on Zeta converter is designed to address the limitations of other impedance matching methods and improve load range in low resistances. The system-level verification demonstrates that this novel impedance matcher has potential application value in microwave wireless power transmission (MWPT) system.
IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Yuan Yu, Shuai Cui, Guijiang Yang, Luoqiu Xu, Yu Chen, Kaixiang Cao, Liang Wang, Yu Yu, Xinliang Zhang
Summary: We proposed and demonstrated a temperature sensor with both high resolution and large dynamic range based on simultaneous microwave photonic and optical measurements. By designing and fabricating two cascaded ring resonators (CRRs) with different temperature sensitivities and free spectral ranges (FSRs) as the sensing probe, and utilizing the ultrahigh-Q-factor microring in the CRR, we achieved a high temperature resolution with a microwave photonic notch filter (MPNF) and a large dynamic range with the optical transmission spectrum of the CRR. The combination of these two measurements realized the desired temperature sensor.
IEEE SENSORS JOURNAL
(2023)
Review
Optics
Minqi Chai, Yingxin Wang, Chuanxin Chen, Ziran Zhao, Meihua Jin, Tao He
Summary: Photoelectric conversion is an essential process for devices such as solar cells, and great advances have been made in utilizing metamaterials for PC devices from microwave to optical range. The absorption mechanism varies with the waveband, with electromagnetic polariton resonance dominating in the microwave and surface plasmon resonance in the optical band. Terahertz photoelectric devices exhibit unique characteristics different from electronics and optics, dependent on the frequency.
LASER & PHOTONICS REVIEWS
(2022)
Article
Engineering, Electrical & Electronic
Hao Chen, Erwin H. W. Chan
Summary: This new topology generates a DC voltage based on the phase difference of two input RF signals, utilizing a mixer concept and microwave photonics technology. It offers high phase detection resolution, small error, and can cover a wide frequency range. Measured results show excellent performance with a detection range of 0 to 180 degrees and a resolution of 2 degrees for input RF signal frequencies between 3.5 GHz and 18 GHz.
IEEE PHOTONICS JOURNAL
(2021)
Review
Biochemistry & Molecular Biology
Gunnar Jeschke
Summary: Labeling techniques such as EPR spectroscopy and single-molecule FRET can accurately measure distances within the range of tens of angstroms, providing valuable information for structural modeling of proteins and protein complexes. However, challenges such as limited restraints, label interference, and balancing fitting quality still need to be addressed for further progress in this field.
Article
Engineering, Marine
Valery Bondur, Alexander Murynin
Summary: The development and validation of a method for remote measurement of sea wave spectra is described, utilizing retrieval operators constructed through numerical simulation and compared with ground-based methods to ensure accuracy. The study demonstrates the applicability of the method under specific conditions.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2021)
Article
Engineering, Multidisciplinary
Huimin Ma, Ying Xu, Chao Yuan, Yiguang Yang, Rongji Zuo, Jinchuan Liu, Tao Li
Summary: A microwave transmission line sensor is proposed for on-line water fraction measurement, which overcomes the instability caused by water conductivity change. The study establishes an equivalent circuit and a two-port network, and finds that the sensor's S21 phase is linearly related to phase constant in a high conductivity environment, enabling water fraction measurement. Experimental and numerical investigations are conducted for an air-water stratified flow, and it is found that the phase is not affected by conductivity within the range of 3.31-8.52 S/m. Furthermore, experimental and numerical models are developed for predicting 0-100% water fraction, with absolute errors within 2.2% at 95% confidence probability. The simulation method provides a low-cost alternative for traditional gas-water flow testing.
Article
Engineering, Electrical & Electronic
Zahra Mehrjoo, Amir Ebrahimi, Kamran Ghorbani
Summary: In this article, a wide dynamic range reflective mode displacement sensor is designed based on the resonance frequency shift. The sensor enhances linearity and improves dynamic range by using a tapered metallic patch that forms the capacitance of the sensor. The sensing principle is analyzed using an accurate circuit model and electromagnetic simulations, and the concept can be extended to a 2-D displacement sensor.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2022)
Article
Engineering, Electrical & Electronic
Tomonori Arakawa, Seitaro Kon
Summary: This paper reports a calibrated microwave measurement method for accurately evaluating the scattering parameters of cryogenic microwave components over a wide temperature range. By using 3.5-mm connectors as reference planes, various components up to 26.5 GHz can be measured with precision.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2023)
Article
Geochemistry & Geophysics
Youming Wu, Kun Fu, Wenhui Diao, Zhiyuan Yan, Peijin Wang, Xian Sun
Summary: This article proposes a novel suppression approach based on time-variant transmission of chaotic frequency modulation signals for range sidelobe suppression in SAR images. It achieves superior performance in suppression and resolution preservation while maintaining signal energy and overcoming SNR loss.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2022)
Review
Chemistry, Multidisciplinary
Alexander A. Shcherbakov, Joao Medeiros-Silva, Nhi Tran, Martin D. Gelenter, Mei Hong
Summary: Internuclear distances are essential for molecular structure determination using solid-state NMR spectroscopy, and recent developments in fast MAS triple-resonance F-19 and H-1 NMR probes have enabled measurements in the 1-2 nm range with high sensitivity. This review highlights the principles and applications of multiplexed multidimensional correlation distance NMR experiments, emphasizing the use of F-19 and H-1 for long-distance measurements in biological and small molecules.
Article
Engineering, Electrical & Electronic
Khaleda Ali, Alessio Brizzi, Ahsan Noor Khan, Yang Hao
Summary: This article presents an analysis of on-body radio channels at millimeter-wave frequencies and proposes solutions to reduce the path loss, particularly at non-line of sight (NLoS) locations. The study conducted at 94 GHz reveals that the presence of textile and thin air between clothing and the human body surface can lower the path loss at NLoS. Additionally, attaching a thin metallic sheet underneath clothing further reduces the path loss.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2023)
Article
Optics
Grigorii Ptitcyn, Aristeidis Lamprianidis, Theodosios Karamanos, Viktar Asadchy, Rasoul Alaee, Marvin Mueller, Mohammad Albooyeh, Mohammad Sajjad Mirmoosa, Shanhui Fan, Sergei Tretyakov, Carsten Rockstuhl
Summary: This article explores the interaction between light and time-varying media, which not only provides fundamental insights but also opens up possibilities for various practical applications. Time modulation is a fundamental tool for controlling light in different ways, especially for complex systems with both spatial and temporal structures. The article develops and applies a self-consistent analytical theory of light scattering, focusing on a sphere made from a time-varying material with Lorentzian dispersion. The proposed theory is verified through full-wave simulations and reveals interesting effects such as energy transfer from the time-modulation subsystem to the electromagnetic field.
LASER & PHOTONICS REVIEWS
(2023)
Article
Engineering, Electrical & Electronic
Fu Liu, Do-Hoon Kwon, Sergei Tretyakov
Summary: Reconfigurable reflectors have great potential in future telecommunication systems, and there is active research on designing and realizing full and tunable reflection control. Reflectarrays, the classical approach to scanning reflectors, are based on phased-array theory and physical optics approximation. To overcome the limitations, researchers are actively studying inhomogeneous metasurfaces using diffraction grating theory. Unifying these two approaches and studying reconfigurable reflectors from a unified point of view is necessary for achieving tunability and realizing their full potential.
IEEE ANTENNAS AND PROPAGATION MAGAZINE
(2023)
Article
Engineering, Electrical & Electronic
Sergei Kosulnikov, Francisco S. Cuesta, Xuchen Wang, Sergei A. Tretyakov
Summary: Reconfigurable Intelligent Surfaces (RISs) are promising tools for optimizing propagation channels in advanced wireless communication systems, particularly in high-frequency (millimeter-band) links with directive antennas. RIS panels act as high-gain passive repeaters, creating complex field patterns in the far zone through interference with reflected waves from illuminated spots on supporting walls. In this study, we develop a simple link-budget model for non-line-of-sight (NLOS) channels using reflections from finite-size metasurfaces (MSs) designed as anomalous reflectors or splitters. The model considers diffraction at RIS panel edges and interference with reflections from supporting structures, taking into account realistic losses and validating results through numerical simulations.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2023)
Article
Engineering, Electrical & Electronic
Yubei He, Cheng-Xiang Wang, Hengtai Chang, Rui Feng, Jian Sun, Wensheng Zhang, Yang Hao, El-Hadi M. Aggoune
Summary: In this paper, a 3-dimensional non-stationary geometry-based stochastic model is proposed for maritime massive MIMO communication systems. A novel beam domain channel model is then proposed, which transforms the corresponding stochastic model from the array domain to the beam domain. Two methods are used to characterize the array non-stationarity, and important channel statistical properties are studied and compared based on the proposed models.
IEEE TRANSACTIONS ON COMMUNICATIONS
(2023)
Article
Optics
Mario G. Silveirinha
Summary: Topological photonics offers a valuable framework to explain complex wave phenomena in electromagnetic systems. The topological index of a physical system is a global property dependent on the operators describing wave propagation. We establish a significant geometric connection between topological physics and the topological theory of mathematical surfaces. Our findings demonstrate that topological band theory extends the surface topological theory, wherein the surface genus can be considered as a Chern number of a suitable surface operator. We also explore the implications of topology in radiation problems and the bulk-edge correspondence in physical systems.
Article
Nanoscience & Nanotechnology
Filipa R. Prudencio, Mario G. Silveirinha
Summary: In this study, it is demonstrated that isorefractive spacetime crystals with a travelling-wave modulation can rigorously mimic the response of moving material systems. Unlike generic spacetime crystals, which exhibit bi-anisotropic coupling in the co-moving frame, isorefractive crystals show an observer-independent response, resulting in isotropic constitutive relations without any bianisotropy. The researchers show how this property can be utilized in calculating the band diagrams of isorefractive spacetime crystals in the laboratory frame and studying synthetic Fresnel drag. Additionally, the impact of considering either a Galilean or a Lorentz transformation in the homogenization of spacetime crystals is discussed, revealing that the effective response is independent of the transformation considered.
Article
Physics, Applied
Filipa R. Prudencio, Mario G. Silveirinha
Summary: We demonstrate that space-time modulations can be used to achieve complex nonreciprocal couplings, particularly the elusive axion response. We develop an analytical formalism for homogenizing anisotropic space-time crystals in the long wavelength limit and find that space-time crystals with appropriate glide-rotation symmetry can exhibit a giant axion-type response, several orders of magnitude larger than in natural materials. The nonreciprocal axion response has interesting potential applications in optics, such as electromagnetic isolation, and can enable exciting forms of light-wave interactions.
PHYSICAL REVIEW APPLIED
(2023)
Review
Engineering, Electrical & Electronic
Young-Ok Cha, Achintha Avin Ihalage, Yang Hao
Summary: The past century has seen significant progress in antennas and propagation (A&P) research, bringing about major changes to society and technology. In this article, a natural language processing (NLP) and machine learning (ML) approach is introduced to review A&P research based on large-scale unstructured data, providing meaningful summaries and predictions. Through analyzing 159,000 research papers published between 1981 and 2021, and applying an encoder-decoder LSTM network with integrated attention mechanism, future trends in A&P research are predicted in the form of a Gartner's hype cycle.
IEEE ANTENNAS AND PROPAGATION MAGAZINE
(2023)
Article
Engineering, Electrical & Electronic
Grigorii Ptitcyn, Mohammad Sajjad Mirmoosa, Amirhosein Sotoodehfar, Sergei A. Tretyakov
Summary: In recent years, there has been increasing interest in using time-modulation techniques to realize new phenomena and create new applications by varying system properties. This field, which originated in the middle of the previous century, has gained revitalized attention. In this tutorial article, the authors provide a historical overview and review the basic concepts in this field. They introduce the general theory of linear time-varying systems, discuss accounting for frequency dispersion in nonstationary systems, and elucidate models of time-varying electrical circuits and materials.
IEEE ANTENNAS AND PROPAGATION MAGAZINE
(2023)
Article
Engineering, Electrical & Electronic
Sravan K. R. Vuyyuru, Risto Valkonen, Do-Hoon Kwon, Sergei A. Tretyakov
Summary: A perfect anomalous reflector is designed based on the receiving and scattering array antenna theory to optimize the scattering characteristics of a planar reflecting surface. By algebraic optimization of the load reactances, the reflection amplitudes into propagating Floquet modes can be controlled, avoiding the need for brute-force optimization via electromagnetic simulations. Numerical designs of wide-angle reflectors show that the proposed approach achieves higher reflection efficiencies compared to conventional reflectarray designs in a computationally efficient manner.
IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Mostafa Movahediqomi, Grigorii Ptitcyn, Sergei Tretyakov
Summary: This article discusses four main methods for designing anomalous reflectors for microwave and millimeter-wave applications and analyzes and discusses various performance aspects.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2023)
Editorial Material
Multidisciplinary Sciences
Mario G. Silveirinha
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Optics
Konstantin Y. Bliokh, Ebrahim Karimi, Miles J. Padgett, Miguel A. Alonso, Mark R. Dennis, Angela Dudley, Andrew Forbes, Sina Zahedpour, Scott W. Hancock, Howard M. Milchberg, Stefan Rotter, Franco Nori, Sahin K. Ozdemir, Nicholas Bender, Hui Cao, Paul B. Corkum, Carlos Hernandez-Garcia, Haoran Ren, Yuri Kivshar, Mario G. Silveirinha, Nader Engheta, Arno Rauschenbeutel, Philipp Schneeweiss, Juergen Volz, Daniel Leykam, Daria A. Smirnova, Kexiu Rong, Bo Wang, Erez Hasman, Michela F. Picardi, Anatoly Zayats, Francisco J. Rodriguez-Fortuno, Chenwen Yang, Jie Ren, Alexander B. Khanikaev, Andrea Alu, Etienne Brasselet, Michael Shats, Jo Verbeeck, Peter Schattschneider, Dusan Sarenac, David G. Cory, Dmitry A. Pushin, Michael Birk, Alexey Gorlach, Ido Kaminer, Filippo Cardano, Lorenzo Marrucci, Mario Krenn, Florian Marquardt
Summary: Structured waves are found in all areas of wave physics, both classical and quantum, where the wavefields are inhomogeneous and cannot be approximated by a single plane wave. These complex wavefields with inhomogeneities are crucial in various fields such as nanooptics, photonics, quantum matter waves, acoustics, water waves, etc. This Roadmap surveys the role of structured waves in wave physics, providing background, current research, and anticipating future developments.
Article
Materials Science, Multidisciplinary
Yihan Ma, Jonas Florentin Kolb, Achintha Avin Ihalage, Andre Sarker Andy, Yang Hao
Summary: Surface symmetry breaking and disorder have been utilized to address issues such as operation bandwidth, unwanted diffraction, and polarization dependence in metasurface designs. However, efficient simulation and optimization of large-scale electromagnetic structures remains challenging. This study presents an interactive learning approach to build meta-atom datasets with mutual coupling effects. A deep learning-based model extracts features from limited known meta-atoms to design aperture-efficient metasurfaces and metalenses at large scales.
ADVANCED PHOTONICS RESEARCH
(2023)
