Article
Engineering, Electrical & Electronic
Rafael Goncalves Licursi de Mello, Anne Claire Lepage, Xavier Begaud
Summary: The bow-tie antenna is a simple planar shape with wideband input impedance, making it suitable for various wideband applications. However, its radiation pattern is not stable and the gain in the broadside direction deteriorates with increasing frequencies. This article thoroughly investigates the operation and performance of both triangular and rounded-edge versions of the bow-tie antenna and presents a technique to maximize performance by inserting radially aligned grooves in the radiators' ends. Simulation and measurement results show that this technique improves the bandwidth and increases the broadside gain without significant change in the radiation patterns and reflection coefficient magnitude.
IET MICROWAVES ANTENNAS & PROPAGATION
(2022)
Article
Physics, Applied
Haruki Anzai, Shota Inoue, Yu Tokizane, Hiroko Yoshida, Takeshi Yasui, Fusao Shimokawa, Noriaki Tsurumachi
Summary: Researchers investigated the strong coupling interaction between a magnetic field and a magnetic dipole using a Fabry-Perot microcavity structure in the THz region. They found that normal mode splitting and anti-crossing behavior occur in the transmission properties of the structure. Samples were designed and fabricated using the finite difference time-domain method, and their transmission spectra were measured using THz time-domain spectroscopy. The experimental results showed a splitting of the transmission peak due to mode coupling between the magnetic field and the magnetic dipole in the structure.
APPLIED PHYSICS LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Kexin Liu, Dong Yu, Hanyang Wang
Summary: The mechanism for the radiation efficiency local minimum in antennas, in particular open-slot antennas and T-shaped antennas, has been investigated. The local minimum in these antennas always corresponds to an ideal differential mode, and the frequency position of this mode is determined by the parasitic parts of the antennas. Simple methods for estimating the local minimum position have been proposed based on this mechanism, as well as a discussion on the duality relation between the two types of antennas. These findings offer guidance for designing mobile phone antennas with improved efficiency.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Engineering, Electrical & Electronic
Vitaly Yu Leushin, Alexander G. Gudkov, Igor O. Porokhov, Sergey G. Vesnin, Mikhail K. Sedankin, Igor A. Sidorov, Yuriy Solov'ev, Svetlana Agasieva, Sergey Chizhikov
Summary: This article discusses the issues of interference immunity in medical radiothermographs and explores the possibility of enhancing immunity by optimizing the design of applicator antennas. Using computer simulation methods, the electrical parameters of the optimal design for a slot printed applicator antenna were determined. A method for evaluating interference immunity of an applicator antenna on the surface of a biological object simulator was proposed.
SENSORS AND ACTUATORS A-PHYSICAL
(2022)
Article
Engineering, Electrical & Electronic
Xi Chen, Jiasong Huang, Chonghu Cheng, Leilei Liu
Summary: This paper proposes a novel miniaturized wideband planar bow-tie slot antenna. By analyzing the effects of the dimension and shape of the bow-tie slot and feed structure, miniaturization and wide bandwidth are achieved. The antenna adopts a water droplet slot and an optimized asymmetric coplanar waveguide (CPW) feed, improving the impedance characteristic and broadening the bandwidth. Experimental results show that the proposed antenna has a wide bandwidth and small size, making it suitable for various wireless applications.
INTERNATIONAL JOURNAL OF ANTENNAS AND PROPAGATION
(2022)
Article
Physics, Multidisciplinary
Md Mottahir Alam, Rezaul Azim, Ibrahim Mustafa Mehedi, Asif Irshad Khan
Summary: This paper presents a CPW-fed small antenna designed to operate over an ultra-wide frequency band for portable communication devices. The antenna features a simple design, small size, good gain and efficiency, stable radiation characteristics, and good time-domain behavior, making it a potential candidate for use in portable communication devices.
CHINESE JOURNAL OF PHYSICS
(2021)
Article
Engineering, Electrical & Electronic
Yinuo Li, Juan Chen
Summary: A high gain low-frequency bow-tie antenna with artificial magnetic conductor (AMC) and metamaterial lens for ground penetrating radar (GPR) is proposed, which can effectively improve the performance of the antenna.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2022)
Article
Computer Science, Artificial Intelligence
Yujie Huang, Zhipeng Zhang, Yu Tao, Hao Hu
Summary: With the increasing speed of railway transportation, rail right-of-way intrusions can cause high-consequence accidents and pose severe challenges to railway safety. This paper proposes a novel methodological framework based on text mining techniques and fuzzy bow-tie modeling to systematically investigate railway intrusion risks. The framework includes lexical co-occurrence analysis, structured bow-tie diagrams, and cause-consequence-based probabilistic analysis. The application of this framework on the Hualien Derailment accident demonstrates its effectiveness in identifying critical risk factors and enhancing railway safety through proactive and reactive measures.
ADVANCED ENGINEERING INFORMATICS
(2022)
Article
Engineering, Electrical & Electronic
Shin-Yi Ooi, Pei-Song Chee, Eng-Hock Lim, Jen-Hahn Low, Fwee-Leong Bong
Summary: The zeroth-order resonance of a compact patch structure is studied for designing a metal-mountable tag antenna in the US ultrahigh-frequency (UHF) radio frequency identification (RFID) passband. The proposed single-element zeroth-order resonator (ZOR) structure, consisting of a cap-shaped patch loaded with two L-shaped slots and coupled to the ground through two inductive stubs, provides sufficient antenna impedance for a conjugate match with the RFID chip impedance. This tag antenna exhibits good omnidirectional radiation characteristics with vertically polarized fields when placed on a metallic surface, and has a stable read distance of approximately 15 m with even coverage in the entire azimuth plane.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2023)
Article
Engineering, Electrical & Electronic
Xuemeng Chen, Hongji Li, Xianling Liang, Xiaohan Zhang, Ronghong Jin, Cunjuan Xia, Yuezeng Su
Summary: A dual-stopband rectangular waveguide slot array antenna is proposed, which consists of a rectangular filtering waveguide with dual stopbands and radiation slots on the top broad wall. The proposed concept is verified through analysis and measurement, showing good agreement between measured and simulated results. The proposed waveguide slot antenna achieves comparable radiation performance in the -10 dB impedance bandwidth of 5.51-5.95 GHz, while providing additional suppressions of greater than 24.5 dB in 6.6-7.1 GHz and 34.6 dB in 8.4-9.3 GHz without occupying extra space.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2023)
Article
Telecommunications
Ketavath Kumar Naik, Ravikumar Palla, S. Sandhya Rani, B. V. S. Sailaja
Summary: This paper presents the design of a compact bow-tie patch antenna with concentric ring slots on the ground plane for wireless communications. The proposed antenna demonstrates a wide impedance bandwidth and high gain, with good performance in dual frequency bands.
WIRELESS PERSONAL COMMUNICATIONS
(2022)
Article
Engineering, Electrical & Electronic
Xiong Zou, Dingwang Yu, Ya Fan, Jing Li, Wei Luo
Summary: A new type of eye-shaped transverse slot element is proposed, which allows for continuous beam scanning. The relationship between phase difference and element size is obtained through simulation, and the internal field distribution of a leaky-wave antenna is analyzed. With a small antenna length, wide beam scanning range, and high gain, the antenna can be widely used in wireless communication or radar systems.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Engineering, Mechanical
Gizem Elidolu, Emre Akyuz, Ozcan Arslan, Yasin Arslanoglu
Summary: Cargo operations on tanker vessels pose high risks to crew and the marine environment, including the potential for explosions caused by static electricity. This study focuses on static electricity-related accidents and identifies key contributing factors such as inadequate monitoring, operational failures, and unsafe practices.
ENGINEERING FAILURE ANALYSIS
(2022)
Article
Engineering, Electrical & Electronic
Zaheer Dayo, Qunsheng Cao, Yi Wang, Permanand Soothar, Imran Khoso, Gulab Shah, Muhammad Aamir
Summary: This paper presents a new compact, high-gain, and multiband planar bowtie slot antenna with stable multi-resonant behavior obtained through material selection, slot dimensions, and position optimization. The proposed antenna achieves high performance features with an ultra-compact modified triangular shaped metallic ground plane.
APPLIED COMPUTATIONAL ELECTROMAGNETICS SOCIETY JOURNAL
(2021)
Article
Chemistry, Analytical
Jose Alfredo Tirado-Mendez, Hildeberto Jardon-Aguilar, Ruben Flores-Leal, Luis Alberto Vasquez-Toledo, Arturo Rangel-Merino, Rricardo Marcelin-Jimenez, Enrique Rodriguez-Colina, Michael Pascoe-Chalke
Summary: This article presents a combination of rectangular loop array and slot radiator for multiband applications. The antenna configuration includes rectangular loop radiators excited by electromagnetic coupling from a dumbbell slot, designed to achieve stable gain and radiation pattern.
Article
Optics
Fabian Loth, Thomas Kiel, Kurt Busch, Philip Trost Kristensen
Summary: This article presents a practical approach to construct meshes of rough surfaces with prescribed autocorrelation functions based on unstructured meshes of nominally smooth surfaces. The approach utilizes a well-known method to construct correlated random numbers from white noise using a decomposition of the autocorrelation matrix. The authors discuss important details and provide a corresponding software implementation for modeling surface roughness. As an example application, the impact of surface roughness on the resonance frequencies and quality factors of a plasmonic nano-sphere dimer is demonstrated. The approach can be utilized in various numerical methods to analyze the effects of surface roughness in different fields of science and engineering.
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
(2023)
Article
Physics, Multidisciplinary
Vibhuti Rai, Lukas Gerhard, Nico Balzer, Michal Valasek, Christof Holzer, Liang Yang, Martin Wegener, Carsten Rockstuhl, Marcel Mayor, Wulf Wulfhekel
Summary: This article presents a new method to activate single molecules by decoupling them from a metallic substrate using the tip of a scanning tunneling microscope, thus achieving individual molecule luminescence. The emission performance of this method compares favorably in terms of quantum efficiency, stability, and reproducibility to that of single molecules deposited on thin insulating layers.
PHYSICAL REVIEW LETTERS
(2023)
Article
Materials Science, Multidisciplinary
L. Simonson, S. K. Ozdemir, K. Busch, R. El-Ganainy
Summary: We propose a theoretical framework to explain the scattering lineshapes in non-Hermitian resonant systems and establish the connection with the input/output scattering channels. We present a transparent derivation of the resolvent operator associated with a non-Hermitian system and highlight its connection with the underlying eigenspace decomposition. Additionally, we provide a simple solution to the problem of self-orthogonality associated with the left and right Jordan canonical vectors and show how the left basis can be constructed systematically. Our work provides a unified mathematical framework for studying non-Hermitian systems implemented using dielectric cavities, metamaterials, and plasmonic resonators.
OPTICAL MATERIALS EXPRESS
(2023)
Article
Chemistry, Multidisciplinary
Natalie Munding, Magdalena Fladung, Yi Chen, Marc Hippler, Anthony D. Ho, Martin Wegener, Martin Bastmeyer, Motomu Tanaka
Summary: Cell behaviors depend on the elastic properties of the microenvironments, which differ from polymer-based substrates. Metamaterials, with adjustable elastic properties, offer a promising way to mechanically control stem cells. By designing microstructured bio-metamaterials based on a silicon elastomer-like photoresist and two-photon laser printing, the differential responses of human mesenchymal stem cells (hMSCs) correlate with the calculated elastic properties of the bio-metamaterials, suggesting the potential of using bio-metamaterials for cell behavior regulation.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Michael Fidelis Gross, Jonathan Ludwig Guenter Schneider, Yu Wei, Yi Chen, Sebastian Kalt, Muamer Kadic, Xiaoning Liu, Genkai Hu, Martin Wegener
Summary: In classical Cauchy elasticity, 3D materials have six eigenmodes of deformation. Extremal elastic materials are classified based on the number of easy eigenmodes out of these six, leading to hexamode (N=6), pentamode (N=5), tetramode (N=4), trimode (N=3), dimode (N=2), and monomode (N=1) materials. Pentamode metamaterials have attracted significant attention, and in this study, microstructured 3D polymer-based tetramode metamaterials were designed, characterized, and compared to theoretical expectations. The potential application as a compact and broadband polarizer for acoustical phonons at ultrasound frequencies was demonstrated.
ADVANCED MATERIALS
(2023)
Article
Optics
K. O. N. R. A. D. Tschernig, A. R. M. A. N. D. O. Perez-Leija, K. U. R. T. Busch
Summary: This study investigates the possibility of introducing randomness into artificial gauge fields through local random phase shifts in the modulation of optical waveguide networks. Numerical simulations demonstrate the occurrence of Anderson localization under specific modulation phases. Furthermore, the results of this study have implications for the engineering design of waveguide networks, enabling the realization of dynamic localization and defect-free surface states.
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
(2023)
Article
Optics
Daniel Wendland, Marlon Becker, Frank Brueckerhoff-Plueckelmann, Ivonne Bente, Kurt Busch, Benjamin Risse, Wolfram H. P. Pernice
Summary: The number of systems used for computation in the physical domain has significantly increased in recent years. Optical and photonic systems have gained interest due to their potential for energy-efficient linear operations and faster computation speed. However, scaling up integrated photonic designs to meet the requirements of meaningful computation remains a challenge.
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
(2023)
Article
Optics
Mingwei Yang, Elizabeth Robertson, Luisa Esguerra, Kurt Busch, Janik Wolters
Summary: This work presents the realization and characterization of a three-layer optical convolutional neural network, where the linear part is based on a 4f-imaging system and the optical nonlinearity is achieved through the absorption profile of a cesium atomic vapor cell. The system achieved an 83.96% accuracy in classifying the handwritten digital dataset MNIST, which is consistent with corresponding simulations. Thus, our results demonstrate the feasibility of utilizing atomic nonlinearities in neural network architectures with low power consumption.
Article
Materials Science, Multidisciplinary
Viktor Bender, Tobias Bucher, Mohammad Nasimuzzaman Mishuk, Yuxuan Xie, Isabelle Staude, Falk Eilenberger, Kurt Busch, Thomas Pertsch, Bayarjargal N. Tugchin
Summary: Photoluminescence spectroscopy is used to study the excitonic properties of mechanically exfoliated monolayer MoS2 under various physical and chemical stimuli. The study characterizes midgap exciton states originating from lattice defects and compares them to existing models. Statistical data analyses reveal a photoluminescence enhancement through physisorption of water molecules on the controversial excited-state A biexciton (AXX*). Additionally, the study shows that surface roughness does not account for changes in doping level within monolayer MoS2 on gold substrates, and reports a shift in the electron-phonon coupling properties due to physisorbed water films on top of the samples.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2023)
Article
Physics, Multidisciplinary
Richard Craster, Sebastien Guenneau, Muamer Kadic, Martin Wegener
Summary: Mechanical metamaterials, designed composites with elastic behaviors and effective mechanical properties beyond those of their individual ingredients, have made significant progress in the last decade due to advances in computational science and manufacturing. This review provides a tutorial on its mathematical basis and summarizes the state-of-the-art in both conceptual and experimental aspects.
REPORTS ON PROGRESS IN PHYSICS
(2023)
Article
Physics, Multidisciplinary
Yi Chen, Ke Wang, Muamer Kadic, Sebastien Guenneau, Changguo Wang, Martin Wegener
Summary: Previous theory and experiment have shown that introducing strong nonlocal interactions in addition to local interactions into metamaterials can lead to unusual wave dispersion relations. In this study, the authors investigate the frequency-dependent acoustical phonon transmission in a slab of nonlocal metamaterial. They find a series of bound states in the continuum and sharp transmission resonances next to sharp transmission minima. The findings are validated by numerical calculations on three-dimensional metamaterial microstructures.
COMMUNICATIONS PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Gino Wegner, Dan-Nha Huynh, N. Asger Mortensen, Francesco Intravaia, Kurt Busch
Summary: The paper discusses the impact of an extended model proposed by Halevi on the nonlocal response of plasmonic materials and nanostructures. It reevaluates the Mie scattering coefficients for a cylinder and corresponding plasmon-polariton resonances within this framework. The analysis reveals a nonlocal, collisional, and size-dependent damping term that affects the resonances in the extinction spectrum. The implementation of the Halevi model in the time domain is particularly important for efficient and accurate modeling of nanogap structures and other nanoscale features in nanoplasmonics applications.
Article
Physics, Multidisciplinary
A. Hashemi, K. Busch, S. K. Ozdemir, R. El-Ganainy
Summary: This research investigates the effects of applying uniform gain to photonic systems in order to reverse the optical energy distribution and impose chirality, leading to changes in the direction of light propagation. The findings suggest a new direction in non-Hermitian optics by altering the average value of non-Hermitian parameters.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Optics
M. Oelschlaeger, D. Reiche, C. H. Egerland, K. Busch, F. Intravaia
Summary: We investigate the nonconservative dynamics of an atom in a complex structured electromagnetic environment at finite temperature. The frictional force acting on the atom when it moves along the environment's translation-invariant axis is due to the nonequilibrium interaction with the fluctuating quantum electromagnetic field, which establishes a privileged reference frame. We study the impact of quantum and thermal fluctuations on the interaction, revealing qualitatively different types of viscosity.
Article
Nanoscience & Nanotechnology
Qi Zhong, Haoqi Zhao, Liang Feng, Kurt Busch, Sahin K. Ozdemir, Ramy El-Ganainy
Summary: Optical resonators are structures that use wave interference and feedback to control light. They can support standing- or traveling-wave modes depending on the feedback mechanism. This article introduces a new class of photonic resonators that support a hybrid optical mode, which can be implemented using chip-scale photonics and free-space optics.
