Electromagnetic Waves - Science topic

Broadening of hydrogenic spectral lines is an important tool in spectroscopic diagnostics of various laboratory and astrophysical plasmas. We review recent analytical advances in five areas. First, we review a new method for spectroscopic diagnostics of tokamak edge plasmas based on a peculiar Stark broadening of hydrogen or deuterium spectral line...

Terahertz electromagnetic waves are widely used in various fields, but their practical application often suffers from significant interfacial losses. In this paper, we present a terahertz antireflection film based on an all-dielectric metasurface consisting of a zirconia microsphere array assembled using a template-assisted method. Simulations and...

This research introduces an innovative design for a metamaterial-based compact multi-band biosensor aimed at early-stage cervical cancer detection. The device operates within the terahertz (THz) frequency range, specifically from zero to six THz. The proposed sensor architecture features a metamaterial layer composed of a patterned aluminum structu...

Wearable strain sensors translate mechanical deformations into electrical signals for healthcare monitoring. However, the limited ductility of conductive metals and polymers to maintain its conductivity under high degree of mechanical deformation is a crucial problem in existing fabrication methods for strain sensors. In this study, an intrinsicall...

We perform azimuth time tracking of multiple thunderstorm centers on the globe, which are sources of extremely low frequency (ELF) electromagnetic waves propagating in the spherical Earth‐ionosphere cavity. For observations made in September 2023 we identify azimuths of numerous global emission centers using our data sampled at 3 kHz at the Hylaty...

Programmable metasurfaces (PMSs) exhibit great potentials in target detection techniques, because they can take actions to change channel propagation characteristics which introduces further degrees of freedom for system optimizations. However, responses of most traditional PMSs are sensitive to incident angles of impinging electromagnetic waves, r...

Metamaterial absorbers have gained widespread applications in fields such as sensing, imaging, and electromagnetic cloaking due to their unique absorption characteristics. This paper presents the design and fabrication of a novel K-band polarization-sensitive metamaterial absorber, which operates in the frequency range of 20.76 to 24.20 GHz for bot...

When three or more objects in space orbit each other, there is an instability which arises from chaos theory - tiny changes in initial positions and velocities produce exponential results. Using a couple of ideas proposed by Albert Einstein, the instability appears to be eliminated. James Clerk Maxwell correctly predicted that the rings of Saturn w...

Surface phonon polaritons were electromagnetic waves that propagated at the surface of dielectrics. These polaritons had many attentions since the frequency can reach in the order of terahertz. Hence, it can be employ in terahertz technology. One of the general method to study polaritons was by solving Maxwell's equations. The results were dispersi...

Dielectric oxides with robust relaxation responses are fundamental for electronic devices utilized in energy absorption, conversion, and storage. However, the structural origins governing the dielectric response remain elusive due to the involvement of atomically complex compositional and structural environments. Herein, configurational entropy is...

MXenes are 2D materials known for their unique electromagnetic wave absorption (EMWA) properties arising from their varied composition and structure. In this study, a one‐step ice‐assisted process is utilized to directly transform 2D MXene into 3D single‐layer MXene aerogels (SMAs). Furthermore, the interlayer spacing of the SMAs is optimized by in...

The emergence of metadevices has provided an unprecedented ability to manipulate electromagnetic waves, especially in the terahertz band where natural materials are scarce. However, most metadevices have fixed and singular functions after fabrication, making them challenging to adapt to various application scenarios. The paper proposes a reconfigur...

Very low frequency electromagnetic waves adeptly propagate in harsh cross‐medium environments, surmounting the rapid attenuation that impedes high‐frequency counterparts. Traditional low frequency antennas, however, encounter challenges concerning size, efficiency, and power. Here, an isolation transformer based very low frequency loop antenna with...

The lack of a chemical platform with high spatial dimensional diversity, coupled with the elusive multi-scale amorphous physics, significantly hinder advancements in amorphous electromagnetic wave absorption (EWA) materials. Herein, we present a synergistic engineering of phenolic multiple kinetic dynamics and discrete crystallization thermodynamic...

Reducing our carbon footprint is one of the most pressing issues facing humanity today. The technology of Li‐rechargeable batteries is permeating every corner of our lives as a result of our efforts to reduce the use of carbon energy. Batteries can be seen metaphorically as “living cells”, and approaching the future of that technology requires obse...

This study aims to examine the applications of electromagnetic waves across fields such as daily life, military, and medicine. The research highlights the importance of electromagnetic waves in modern technology. A literature review method was employed to gather data from scientific journals focusing on the history, definitions, classifications, an...

Electromagnetic waves in 5G transmission in Indonesia, a cellular network based on electromagnetic waves, which has revolutionized wireless communications. This wireless technology is more advanced than previous wireless technologies (1G, 2G, 3G and 4G). Electromagnetic waves are a type of electromagnetic radiation consisting of electric and magnet...

We study the propagation of electromagnetic waves in tenuous plasmas, where the wave frequency ω 0 is much larger than the plasma frequency ω P . We show that in pair plasmas, nonlinear effects are weak for a 0 ≪ ω 0 / ω P , where a 0 is the wave strength parameter. In electron-proton plasmas, a more restrictive condition must be satisfied, namely,...

The aim of this work is to develop a method to improve the quality of the reconstructed image based on the signals of side electromagnetic fields using post-image processing. To do this, the paper considers the problem of analyzing the side electromagnetic radiation from video displays and ways to solve it. The analysis of the side radiation of ele...

Lightweight polymer nanocomposites with efficient electromagnetic interference (EMI) shielding properties play a crucial role in mitigating pollution caused by electromagnetic radiation. In this work, a combination of melt mixing and supercritical carbon dioxide (scCO2) is used to fabricate lightweight, high‐performance polylactic acid (PLA)‐based...

Recently, the issue of electromagnetic pollution has become increasingly prominent. Flexible polymer films with various conductive fillers are preferred to address this problem due to their highly efficient and durable electromagnetic interference (EMI) shielding performance. However, their applications are restricted by the unbalanced and insuffic...

Dual atoms (DAs), characterized by flexible structural tunability and high atomic utilization, hold significant promise for atom‐level coordination engineering. However, the rational design with high‐density heterogeneous DAs pairs to promote electromagnetic wave (EMW) absorption performance remains a challenge. In this study, high‐density Ni─Cu pa...

This study presents a four-port sequentially rotated circular polarized (SRCP) low-profile antenna array with enhanced isolation through a dual-layer, double-sided metasurface-based decoupling (DSMD) structure for 5G communications. The dual-layer DSMD structure is placed over the SRCP antenna array. The DSDM, with positive permeability and epsilon...

The article presents an analysis of the influence of building materials on the propagation of an electromagnetic wave and the values of the electric field intensity. The topics of the analysis were two types of walls (partition and load bearing) built of different building materials. Different variants of walls were considered due to the building m...

Extremely Low Frequency (ELF) electromagnetic waves are increasingly recognized for their potential in treating bone health as a safe and effective non-invasive method. Studies have shown that ELF can stimulate osteoblast activity, increase bone density, and accelerate fracture healing. This article reviews the mechanism of ELF, its application in...

The polarization degree of freedom is an inherent feature of plane waves propagating in an isotropic homogeneous medium. The miniaturization of optical systems leads to the high localization of electromagnetic waves, but also to the loss of polarization control, namely, breaking TE-TM polarization degeneracy. In this work, we discover the near-fiel...

The rapidly developing modern society has higher requirements for intelligent electromagnetic wave absorbing (EMA) materials than ever before. Herein, lightweight, multifunctional metal‐free carbon‐based aerogels (RCPs) with a longitudinal honeycomb porous framework and a transverse neatly layered structure are obtained by heat‐treating graphene ox...

This study aims to provide a review of how electromagnetic waves, primarily frequency bands in telecommunications networks, interact with cement-based materials and presents recent approaches, including the integration of functional fillers or structural components into the materials, to modify these interactions. Based on a dataset comprising expe...

Mott insulator possesses the property of converting into semiconductor under supernormal conditions and achieving the Mott insulator‐semiconductor transition (IST) holds great scientific value. Nevertheless, current IST methodologies possess certain limitations because they are not capable of being implemented under conventional conditions, thereby...

Abstract: The roles of dielectric materials in adjusting the electromagnetic wave (EMW) absorption performance of an EMW absorber are as crucial as the EMW absorbents. The commonly used cement-based materials, such as mortar, are typical composites of multiple dielectric materials, such as quartz sand and air in the pores. This study investigates t...

Characterization of electromagnetic wave polarization states is critical in various applications of materials, biomedical, and imaging. The emergence of metasurfaces opens up the possibility of implementing highly integrated full‐Stokes imagers. Despite rapid development, prevailing schemes on metasurface‐based full‐Stokes imagers require interleav...

The emergence of advanced wave-absorbing materials has led to a growing interest in biomass-derived porous carbon due to its abundant availability, low density, and eco-friendly nature. This study utilized peanut shell biomass waste to produce porous carbon material (KPS) through a two-step carbonation-activation process. We investigated the influe...

Navier-Stokes and Maxwell equations have been invented for fluid dynamics and electromagnetic systems, respectively, for centuries. The development of Navier-Stokes and Maxwell equations for homogeneous materials seems to be mature. However, when there is a phase interface, a coupling theory for the mass transport with the propagation of electromag...

At present, the preparation of absorbing materials that combine light weight, ultra-wideband absorption and good thermal insulation performance is still an insurmountable gap. Here, we constructed a three-dimensional porous structure in the hope of obtaining excellent microwave absorption and heat insulation properties. In this paper, a unique thre...

Electromagnetic waves (EMWs) have become an integral part of our daily lives, but they are causing a new form of environmental pollution, manifesting as electromagnetic interference (EMI) and radio frequency signal leakage. As a result, the demand for innovative, eco-friendly materials capable of blocking EMWs has escalated in the past decade, unde...

Digital coding metasurfaces (DCMS) offer a promising alternative to conventional metasurface designs for achieving common functionalities by controlling the phase of reflected or transmitted electromagnetic waves. Their simple unit cell designs allow for scalability across the THz spectrum and facilitate large-area fabrication. The true potential o...

In this work, we consider instantaneous transitions of an infinitely extended uniaxial dielectric into a wire medium (WM) of continuous infinitely long conducting wires. Due to the strong spatial dispersion in the WM the known (Morgenthaler's) theory of temporal discontinuities is not applicable. We solve this problem analytically in time domain. W...

In this research paper, we focus on analyzing the electromagnetic fields within the framework of a traversable wormhole that incorporates a cosmic string. We then extend our investigation to a traversable wormhole with a global monopole charge, addressing the same problem in this new context. To facilitate our study, we compute the electromagnetic...

Near-field focusing of an electromagnetic wave on the assembly of hexagonally asymmetric arranged close-contact nanofibers into a cylindrical Janus metalens is considered for different fiber sizes and optical properties. We propose combining the meta-material concept with a photonic hook based on the finite-difference time-domain technique. Simulat...

The development of nanotechnology offers transformative prospects for the military sector, promising advancements across numerous domains such as weaponry, protective systems, surveillance, and logistics. With the potential to revolutionize materials science, sensors, and biological applications, nanotechnology represents a critical frontier for e...

Electromagnetic wave dissipation is experienced in radiative absorbing-emitting processes and signal transmissions via media. The absorbed wave initiates thermal processes in the conducting medium. Conversely, thermal processes generate electromagnetic waves in the vacuum–material interface region. The two processes do not take place symmetrically,...

Modified Fresnel equations for the oblique incidence of plane elliptically polarized electromagnetic waves on a flat boundary of a non-absorbing isotropic gyrotropic medium have been obtained. We have taken into account the influence of near-surface inhomogeneity of the matter. The derived relationships allow determining the intensity, degree of el...

This study aims to investigate the effectiveness of the lattice Boltzmann method (LBM) in studying the scattering of electromagnetic waves by curved and complex surfaces. The computation of Maxwell’s equations is done by solving for a pair of distribution functions, which evolve based on a two-step process of collision and streaming. LBM bypasses t...

Reconfigurable intelligent surface (RIS) has emerged as a groundbreaking paradigm in shaping the future of wireless systems in late years. Derived from RISs, stacked intelligent metasurface (SIM), by enabling the real-time modulation of electromagnetic waves at the speed of light, and simultaneous transmitting and reflecting RIS (STAR-RIS), by dras...

Stacked intelligent metasurface (SIM) as an advanced signal processing paradigm enables real-time processing of electromagnetic waves at the speed of light. Benefiting from this technology, the current paper studies the downlink transmission of a wireless network, where a SIM-deployed base station (BS) serves two disjoint sets of energy-and informa...

The flexibility of the integral equation (IE) method is limited by the available numerical solutions with uniform‐grid schemes. In this paper, a general numerical solution of the IE is presented to predict long‐range low‐frequency (LF) groundwave propagation over irregular terrain. The general numerical solution is re‐derived with the aid of Legend...

Optical metasurfaces can manipulate electromagnetic waves in unprecedented ways at ultra-thin engineered interfaces. Specifically, in the mid-infrared (mid-IR) region, metasurfaces have enabled numerous biochemical sensing, spectroscopy, and vibrational strong coupling (VSC) applications via enhanced light-matter interactions in resonant cavities....

Atualmente, os levantamentos tridimensionais (3D) utilizam técnicas e equipamentos sofisticados. De acordo com [1], os sistemas LiDAR (Light Detection and Ranging) são tecnologias avançadas que utilizam sensores ativos para medir distâncias por meio de ondas eletromagnéticas. Para fins cartográficos, o LIDAR pode ser empregado tanto em plataformas...

This paper centers around a multi-antenna un-manned aerial vehicle (UAV) which leverages stacked intelligent metasurface (SIM) as a green technology for signal processing at the electromagnetic wave domain. To assess the performance of this system, a radio resource allocation problem is accordingly formulated for jointly optimizing the motion traje...

The development of functional building materials that can absorb electromagnetic radiation is important for preventing and controlling electromagnetic pollution in urban areas. In this study, cement-based electromagnetic wave (EMW)-absorbing materials were created using graphite tailings (GTs) as a conductive admixture and steel fiber (SF) as an EM...

In this paper, a hundred-watt level traveling wave tube operating in the G-band is designed and analyzed. A non-semi-arc folded waveguide (FW) slow wave structure (SWS) is adopted to achieve high output power. Compared with the conventional FW, this structure has a higher coupling impedance, which is beneficial for beam–wave interaction. To further...

Very-low-frequency (VLF) electromagnetic waves (3–30 kHz) are stable and attenuated, suitable for various applications in submarine communication and earthquake prediction. Very-low-frequency electromagnetic waves usually propagate in atmospheric waveguides formed between the anisotropic ionosphere at low to medium heights and the earth. However, t...

Future space-based far-infrared instruments rely on optical components that enable high-efficiency observations in challenging environments. Here we demonstrate membrane-based mesh bandpass filters for far-infrared electromagnetic waves, targeting wavelengths of 15-37 μm. The filter architecture consists of periodic in-plane patterns, combined with...

Sonic and photonic topological insulators that host topological edge states offer promising potentials for the resilient control of acoustic and electromagnetic waves, respectively. Despite the great progress on sonic or photonic topological insulators, the research of their integration, i.e., the phoxonic topological insulator, is less explored. I...

Electromagnetic wave-plasma interaction has drawn much attention recently due to numerous important technologies and applications, taking advantage of phenomena such as electromagnetic waves being reflected or absorbed in a plasma medium. The physics of wave-plasma interaction can be complicated, when non-uniform, non-equilibrium, or anisotropic pl...

The study of sounding modes based on the complex use of modulated and radio pulse signals for determining the properties of anisotropic medium above hydrocarbons was carried out. For the frequency modulation mode, regularities in the change in the components of the permittivity tensor of the medium for the right -hand polarization of electromagneti...

W-type Ba-hexaferrite, BaZn2−xCoxFe16O27, was synthesized via both conventional solid-state (x = 0.4, 0.5, 0.6, 0.75, 1.0, 1.25, 1.5) and molten-salt methods (x = 0.75, 1.0, 1.25). The structure, electromagnetic (EM) properties, and EM wave absorption characteristics were examined across a frequency range of 0.1–18 GHz, focusing on the influence of...

Using different laser irradiation patterns to modify of silicon surface, it has been demonstrated that, at rather small overlapping between irradiation spots, highly regular laser-induced periodic surface structures (LIPSS) can be produced already starting from the second laser pulse, provided that polarization direction coincides with the scanning...

p>Recently, significant research has been conducted on magnetic metamaterials that exhibit negative permeability and operate within the GHz and MHz frequency ranges. These metamaterial structures can be utilized to improve the efficiency of near-field wireless power transfer systems, subterranean communication, and position sensors. However, in mos...