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[IEEE 2018 Applications of Electromagnetics in Modern Techniques and Medicine (PTZE) - Rac?awice (2018.9.9-2018.9.12)] 2018 Applications of Electromagnetics in Modern Techniques and Medicine (PTZE) - Electrical Parameters of Chosen Organs of Abdominal Cavity and Their Influence on Electromagnetic Waves Propagation
摘要： The electrical conductivity and relative permittivity of chosen organs of abdominal cavity for the popular range of VHF and LF have been presented. They have been used for determining a dielectric loss angle of the wave's penetration into particular organs where the wave may be propagated. The change in the wavelength and its speed in the organ and the conventional depth of its penetration were computed. A considerable signification was made assuming that the electromagnetic wave hits directly from the air to the organ and there exists only the running wave moving in the direction of axis "z", described for the electrical component (analogous formula is valid for the magnetic component by relationship (2).
关键词： flat,harmonic electromagnetic waves,well- and weakly-conducting media,organs and tissues of abdominal cavity
更新于2025-09-23 15:22:29
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[IEEE 2018 20th International Symposium on High-Current Electronics (ISHCE) - Tomsk, Russia (2018.9.16-2018.9.22)] 2018 20th International Symposium on High-Current Electronics (ISHCE) - Measurements of Sub-Nanosecond Pulsed Electromagnetic Waves by Strip-Line Sensors with Long Transmitting Coaxial Cable
摘要： Antennas of strip-line types with transmitting coaxial cable are presented as ultra-wideband sensors of the E(t)- field impulses in electromagnetic traveling-waves at free space. The cable of 1-10 m length produces noticeable attenuation and distortion of sub-nanosecond signals. Computer models of coaxial cables are given. A way to increase the sensor sensitivity for rapid signals to compensate of the cable losses is shown by simulated and experimental results. Considered laboratory antenna sensor of microstrip design with 4m cable length has 0.36 V/(kV/m) sensitivity, 50 ps rise-time and 4.2 ns time-gap.
关键词： sub-nanosecond pulsed electromagnetic waves,strip-line antenna sensor,transient responses of coaxial cables
更新于2025-09-23 15:21:21
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Permittivity and Permeability Characterization of SiC and Ferro Metals for Structural Health Monitoring Utilization
摘要： The need for wireless sensing technology has rapidly increased recently, specifically the usage of electromagnetic waves which becoming more required as a source of information. Silicon carbide (SiC) Nano particles has been used in this study, the material under test (MUT) was exposed directly to a microwave field to examine the electromagnetic behavior. The permittivity and permeability were investigated with different filler materials to approach best and optimal electromagnetic absorbing characteristics to assist engineers to monitor structure-based composite for defects evaluation that may occur during operation conditions or through manufacturing process. XRD, FESEM and both complex permittivity and permeability were measured for the pure materials that candidate for this study. The results showed that all the selected nanostructure material exhibit a good purity with proper electromagnetic properties in the X- band, this can lead to absorbing and transmission properties that can be used in monitoring structures or manufactured part during fabrication process.
关键词： Silicon carbide,electromagnetic waves,structural health monitoring,permittivity,permeability
更新于2025-09-23 15:21:21
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[Springer Series in Optical Sciences] Fano Resonances in Optics and Microwaves Volume 219 (Physics and Applications) || Storage and Retrieval of Electromagnetic Waves in Metamaterials by Dynamical Control of EIT-Like Effect
摘要： The storage of light is one of the most significant applications of electromagnetically induced transparency (EIT) effects in atomic systems. It is also possible to mimic the EIT effect using artificial media, or metamaterials, which are based on coupled resonators. This chapter focuses on metamaterials that realize the storage and retrieval of electromagnetic waves in the same way as the atomic EIT system. We introduce tunable metamaterials that are loaded with variable capacitors, which realize dynamical modulation of the EIT-like effects and the control of asymmetric spectra unique to the Fano resonance. Experiments are performed to show that electromagnetic waves are stored and released coherently in a multi-layered metamaterial designed for the operation in the microwave region. In addition, we show the frequency conversion of the stored waves and the extension of the storage time using parametric amplification.
关键词： Fano resonance,storage of electromagnetic waves,EIT,Electromagnetically induced transparency,parametric amplification,metamaterials
更新于2025-09-23 15:21:21
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Features of electromagnetic wave propagation in two- and three-layer cylindrical dielectric waveguides
摘要： Various characteristics of electromagnetic waves propagating in two- and three-layer open-dielectric waveguide structures of cylindrical shape are studied. Parameters of wave components in separate areas of the waveguide are considered. Electrodynamic characteristics and frequency dependencies for several values of layer dielectric permittivity obtained during the study are analyzed. The corresponding graphs of dependencies are presented. The dependencies of the power flux density of transverse magnetic (TM) waves in two- and three-layer waveguide structures in the absence of field dependence on azimuthal angle are considered.
关键词： dielectric waveguides,TM waves,power flux density,electromagnetic waves,cylindrical waveguides
更新于2025-09-23 15:21:01
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Photonic transmission spectra in graphene-based Gaussian random multilayers
摘要： The light-matter interaction is a very active and attractive research field and it is the basis of the photonic devices based on the generation, processing and storage of photons. In this work, we theoretically study the propagation of electromagnetic waves in one-dimensional photonic crystals consisting of two different dielectric slabs (silicon dioxide and titanium dioxide) separated by graphene. The spatial arrangement of the slabs is periodic, but we introduce randomness by using a Gaussian distribution of thickness with a specific standard deviation σ. The well-known transfer-matrix method is used as the mathematical approach. Our main goals are to investigate how the presence of such randomness can change the light transmission spectra and the emergence of robust photonic band gaps. For a given angle of incidence, our numerical results show that the two lowest frequency bandgaps are insensitive to the influence of the Gaussian distribution. Those band gaps emerge from two different mechanisms: one is due to the presence of graphene, while the other is due to the Bragg’s scattering. A strong transmission dependence on the standard deviation σ is also observed in our numerical results. More interesting, for the transversal magnetic case (angle of incidence θ ? 60°) the system can be adjusted to present transmission coefficient near to 1 and work like a perfect transparent media, what is useful for technological applications.
关键词： Electromagnetic waves propagation,Light waves transmission,Graphene,Photonic crystals,Random multilayers
更新于2025-09-23 15:21:01
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Polymers and Electromagnetic Radiation || Front Matter
摘要： This book concentrates on the interaction of electromagnetic waves with polymers and deals only exceptionally with particle radiation. Electromagnetic waves comprise a very broad range of frequencies that extends over more than 20 orders of magnitude from the radiofrequency region up to the region of hard c-rays emitted from radionuclides or being part of the cosmic rays.
关键词： microwave,radiofrequency,visible light,infrared radiation,gamma rays,polymers,electromagnetic waves,interaction,X-rays,ultraviolet light
更新于2025-09-23 15:21:01
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Narrowing of filters and laser mirror in tilt-modulated chiral sculptured thin films
摘要： Helicoidal multi-layered nanostructures obsess intriguing optical properties to develop various optical and photonic devices. The optical properties of such spiral materials are adjacent with helical rotation. Tilt-modulated chiral sculptured thin film (STF) can totally reflect or transmit light in the Bragg regime for varying amplitudes of oscillation angles. Particularly, twist defect chiral STFs of same handedness creating spectral hole for circularly polarized light at different oscillation amplitudes. A narrow bandstop or wide bandpass filters and Bragg reflectors are created in defect modulated chiral STF. While, increasing the number of oscillations in a structural half period of chiral STF, the filters are flattering and narrower having blue shift. For large number of oscillation, the modulated chiral STF behave as laser mirror and creating Bragg fringes in the Bragg regime. Similarly, for different angles of incidence light the spectral holes and optical filters are become narrowing and shifted to lower wavelength regime, eventually die out in the Bragg regime, with maximum reflection for large angle of incident light. Therefore, it is suggested that such chiral STF are very useful in optical devices which operating in different wavelength regime.
关键词： Electromagnetic waves,Laser mirror,Optical properties,Bragg reflector,Optical filters
更新于2025-09-23 15:19:57
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Polarization-Controlled Dual-Programmable Metasurfaces
摘要： Programmable metasurfaces allow dynamic and real-time control of electromagnetic (EM) waves in subwavelength resolution, holding extraordinary potentials to establish meta-systems. Achieving independent and real-time controls of orthogonally-polarized EM waves via the programmable metasurface is attractive for many applications, but remains considerably challenging. Here, a polarization-controlled dual-programmable metasurface (PDPM) with modular control circuits is proposed, which enables a dibit encoding capability in modifying the phase profiles of x- and y-polarized waves individually. The constructed extended interface circuit is able to extend the number of control interfaces from a field programmable gate array by orders of magnitude and also possesses memory function, which enhance hugely the rewritability, scalability, reliability, and stability of PDPM. As a proof-of-concept, a wave-based exclusive-OR logic gate platform for spin control of circularly-polarized waves, a fixed-frequency wide-angle dual-beam scanning system, and a dual-polarized shared-aperture antenna are demonstrated using a single PDPM. The proposed PDPM opens up avenues for realizing more advanced and integrated multifunctional devices and systems that have two independent polarization-controlled signal channels, which may find many applications in future-oriented intelligent communication, imaging, and computing technologies.
关键词： orthogonally-polarized electromagnetic waves,beam controls,digital logic platforms,modular control circuits,dual-programmable metasurfaces
更新于2025-09-23 15:19:57
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Eigenwaves in Sommerfeld–Goubau Line: Spectrum
摘要： The problem on normal waves in an inhomogeneous metal-dielectric waveguide structure is reduced to a boundary value problem for the longitudinal components of the electromagnetic field in Sobolev spaces. Nonhomogeneous filling and entering of spectral parameter in transmission conditions leads to necessity of special definition of solution of the problem. We formulate the definition of solution using variational relation. The variational problem is reduced to the study of an operator function. We investigate properties of the operators of the operator function needed for the analysis of its spectral properties. We prove theorem of discrete spectrum and theorem of localization of eigenvalues of the operator-function on complex plane.
关键词： operator-function,inhomogeneous waveguide,Maxwell’s equations,non-linear eigenvalue problem,spectrum,Non-polarized azimuthal-symmetric electromagnetic waves
更新于2025-09-19 17:15:36