Tangential Component Of Electric Field Research Articles

Modulation of hybrid plasmon phonon polaritons mode in circular cylindrical three-layer graphene waveguide

In this present research article, we have investigated analytically the characteristics of the fundamental mode of hybrid surface plasmon phonon polariton (HSPPhPs) mode in a circular cylindrical three-layer graphene (CTLG) waveguide structure. The dispersion equation of HSPPhPs is derived by using Maxwell’s equations and continuity conditions of tangential components of electric and magnetic fields in cylindrical geometry. The dispersion curve has been illustrated and thoroughly examined in relation to the effects of temperature and chemical potential (μc) of graphene, as well as variations in the thickness of silicon dioxide (SiO2) and hexagonal boron nitride (hBN) layers, and found that in the presence of hBN, the effective mode index exhibits hyperbolic behavior with wave number. Up to the first Reststrahlen band (∼830.57 cm⁻¹), it varies slightly with graphene temperature; increasing graphene's (μc) lowers the index, while a thicker hBN layer reduces it, whereas the index increases with SiO₂ layer thickness. Also, we looked at how the CTLG waveguide structure is affected by the electric field distribution, phase speed, and propagation length.

Computational analysis of conductive fluid flow with tangential components of magnetic flux density and electric field in metallic and non-metallic circular pipe

This paper has focused on the study of flow characteristics of a steady conductive fluid through a circular pipe in the presence of an applied transverse uniform magnetic field. A numerical simulation of the fluid flow was performed using a multi-physics computational tool. The radial velocity distribution due to the effect of the tangential component of induced magnetic flux density and electric fields at various axial positions is examined in metallic and non-metallic surfaces of the circular pipe. This simulation study helps to analyse the effect of drag force on the variation in axial velocity close to the metallic and non-metallic walls. The induced electric potential is directed along the normal to the Laplacian tangential surface of the pipe. In addition to that, sigmoidal-shaped field profiles are observed when the fluid flow crosses from the upstream to downstream of the magnet edge and vice versa along the axial length of the circular pipe. Simultaneously, it is observed that the average velocity of the fluid flow decreases for a laminar and increases for turbulent Reynolds number. Streamline plots pertinent flow variable such as flow velocity are presented for non-conducting and conducting walls.

EMC Impact of Disturbances Generated by Multiple Sources

In this paper, the impact of an increasing number of arbitrary electrical/electronic devices on the overall radiated emissions is investigated. Understanding and quantifying such an impact are prerequisites to the proper evaluation of electromagnetic compatibility (EMC) of various electronic systems and devices and, if needed, to revisiting the international standards. To evaluate the radiated emissions from multiple electronic devices, each arbitrary electronic device is characterized using an equivalent Huygens’s surface, in which the tangential components of electric and magnetic near fields are calculated (or measured). The radiated emission from the arbitrary electronic device can be calculated using the electric and magnetic near fields for an arbitrary phase (correlated or uncorrelated), position, and orientation. The influence of several parameters affecting the radiated emissions from multiple arbitrary electronic devices, including the number of disturbance sources, the polarization of each device, the radiation pattern of each device, the location and orientation of each device, and the phase shifts between devices, are analyzed. The numerical results show that the mentioned parameters have a significant effect on the radiated emissions, and cannot be neglected in EMC considerations. In general, increasing the number of electronic devices leads to an increase in the level of radiated emissions. However, the increase depends on other parameters such as the arrangement (the radiation pattern for each device, the distance between the devices, and the orientation and/or polarization of each device). The proposed method can be straightforwardly applied to devices characterized by near-field measurements or multimodular large equipment with long cables.

An Electrohydrodynamic analysis for the characterisation of fluid flow within conducting and non-conducting channels

This paper presents a generalized non-dimensional theoretical formulation with boundary conditions to analyze the EHD flow within the conducting and non-conducting channels. The substantial effect of normal and tangential components of electric field on fluid flow within the channel is presented through simulation results based on the non-dimensional parameters of strength, penetration, and repulsion of electric forces. The simulation results reveal that the normal component of induced electric field transits the flow regime within surfaces of a channel. The tangential component of applied electric field increases the thickness of viscous boundary layer, leading to skewed velocity profiles.

A Boundary Element Procedure for 3D Electromagnetic Transmission Problems with Large Conductivity

We consider the scattering of time-periodic electromagnetic fields by metallic obstacles, or the eddy current problem. In this interface problem, different sets of Maxwell equations must be solved both in the obstacle and outside it, while the tangential components of both electric and magnetic fields are continuous across the interface. We describe an asymptotic procedure, applied for large conductivity, which reflects the skin effect in metals. The key to our method is a special integral equation procedure for the exterior boundary value problems corresponding to perfect conductors. The asymptotic procedure leads to a great reduction in complexity for the numerical solution, since it involves solving only the exterior boundary value problems. Furthermore, we introduce a FEM/BEM coupling procedure for the transmission problem and consider the implementation of Galerkin’s elements for the perfect conductor problem, and present numerical experiments.

Coherent Asymmetric Absorbers

Most applications of metasurfaces require excitation and control of both electric and magnetic surface currents. For such purposes, the metasurface must have a finite thickness to handle magnetic surface currents. For metasurface sheets of negligible thickness that offer only electric response, coherent illumination can compensate the need to create discontinuities of the tangential electric field component using magnetic surface currents. Most of the known coherent metasurfaces are space uniform and can control only plane-wave absorption and specular reflection. However, it is also known that periodical space-modulated (inhomogeneous) metasurfaces can be used to realize anomalous reflection, refraction, and other useful effects. In this paper, we propose the concept of a coherently illuminated space-modulated metasurface that functions as a coherent asymmetric absorber. We study its behavior under nonideal illumination and suggest applications related to sensing.

The properties of mid infrared surface modes at the interface of air and one dimensional ternary photonic crystal

In the present manuscript, theoretical design of truncated one dimensional ternary photonic crystal is proposed for analyzing the properties of transverse electric (TE) surface modes viz. band structures, its localization in photonic band gaps (PBGs), field profiles and energy carried by these modes. The periodicity of the structure (comparable to the wavelength of incident electromagnetic waves) is chosen as such the modes are localized in mid-infrared frequency domain (600cm−1 to 1800cm−1 or 5μm to 16μm). The dispersion relation of surface modes is derived by using continuity condition of tangential components of electric and magnetic fields and transfer matrix method. It is found that by varying the cap layer thicknessdc and thickness of first layerdt of each unit cell, surface modes are either strongly (near center of PBG with decay length ~8.8μm) or weakly (near edge of PBG with decay length ~42.5μm) bounded to the interface. The energy carried by the surface modes along the interface plane is around 3.3mJ while across the interface plane it is of the order of10−14. It has been proved that the material rich modes (~2V/m) have high field enhancement compared to material deficient modes (~1V/m). The study stresses on different aspects of the proposed model that can be sought for suitable practicable applications in mid-infrared photonics, especially in design of mid-infrared bio-chemical sensors, mid-infrared temperature sensors, waveguides, omnidirectional reflectors, optical filters, band edge lasers, multiplexers, mitigators, compensators, etc.

Machine Learning-Based Prediction of MRI-Induced Power Absorption in the Tissue in Patients With Simplified Deep Brain Stimulation Lead Models

Interaction of an active electronic implant such as a deep brain stimulation (DBS) system and MRI RF fields can induce excessive tissue heating, limiting MRI accessibility. Efforts to quantify RF heating mostly rely on electromagnetic (EM) simulations to assess individualized specific absorption rate (SAR), but such simulations require extensive computational resources. Here, we investigate if a predictive model using machine learning (ML) can predict the local SAR in the tissue around tips of implanted leads from the distribution of the tangential component of the MRI incident electric field, Etan. A dataset of 260 unique patient-derived and artificial DBS lead trajectories was constructed, and the 1 g-averaged SAR, 1gSARmax, at the lead-tip during 1.5 T MRI was determined by EM simulations. Etan values along each lead's trajectory and the simulated SAR values were used to train and test the ML algorithm. The resulting predictions of the ML algorithm indicated that the distribution of Etan could effectively predict 1gSARmax at the DBS lead-tip (R = 0.82). Our results indicate that ML has the potential to provide a fast method for predicting MR-induced power absorption in the tissue around tips of implanted leads such as those in active electronic medical devices.

Simulation and experimental observations of axial position control of a photonic nanojet by a dielectric cube with a metal screen.

In this Letter, we report on a numerical study, fabrication, and experimental observations of photonic nanojet (PNJ) shaping by control of a tangential electric field component. Here the PNJs are generated by a single mesoscale micro-cube that is fabricated from polydimethylsiloxane, deposited on a silicon substrate and placed on thick metal screen at illuminating wavelengths of 405, 532, and 671 nm. It is shown that the length, focal length, and width of the PNJ can be significantly reduced in the presence of the metal masks along the side faces of the micro-cube. Experimental measurements of the PNJ imaging are performed by a scanning optical microscope with laser sources. Our experimental results are in reasonable agreement with simulation predictions of the finite-difference time-domain method. Due to the appearance of the metal masks, the PNJ focal length decreases 1.5 times, the PNJ decay length decreases 1.7 times, and the PNJ resolution increases 1.2 times. Such PNJs possess great potential in complex manipulation, including integrated plasmonic circuits, biosensing, and optical tweezers.

Multispectral Photonic Jet Shaping and Steering by Control of Tangential Electric Field Component on Cuboid Particle

In this study, we present the simulations and experimental observations of photonic jet (PJ) shaping by control of tangential electric field components at illuminating wavelengths of 405 nm, 532 nm, and 671 nm. The PJs are generated by a single dielectric 4-micrometer cube that was fabricated from polydimethylsiloxane (PDMS). The dielectric cube is deposited on a silicon substrate and placed on two aluminum masks with a width equal to the side length of the cube. Due to the appearance of the metal masks, the focal length and decay length of the generated PJs decreased almost twice, while the PJ resolution increased 1.2 times. Thus, PJ shaping can be controlled by the presence of the metal mask along the lateral surface of the cube without changing the external shape or internal structure of the cube. This effect is based on the control of the tangential components of the electric field along the lateral surface of the cube. In the case of a one-sided metal mask, the effect of optical deflection and bending is predicted to form a photonic hook. Due to the low cost of these dielectric cubes, they have potential in far-field systems to better meet the requirements of modern optical integration circuits and switches.

Signal «crosstalk» effect in the structure of the polarization attenuator channels

An ideal model of a polarization attenuator implies the full absorption of the tangential component of the electric field both in the resistive layer of rotor plates and those of stator plates. In a real attenuator, however, due to the incomplete absorption in the resistive layer of plates the so called “crosstalk” occurs. In most cases the “crosstalk” results in diminished attenuation values of a polarization attenuator. Furthermore, with the high frequencies and especially when the attenuation is high, it significantly affects the attenuation error of a polarization attenuator. This paper analyzes the effect of a series of geometric and electric parameters of the structure of a polarization attenuator’s channels on the “crosstalk” value. As distinct from the well-known calculation methods based on the calculation of separate elements of a polarization attenuator, an algorithm of point-to-point calculation from input to output ports of the entire device is offered. From the general principles of classical electrodynamics, in order to calculate the attenuation of electromagnetic wave in the longitudinal direction of the channel of the attenuator’s conduction system, a formula derived from the method of perturbation theory has been applied. This was possible thanks to an assumption about the weak perturbation of a conducted electromagnetic wave. This condition proves true in the said system thanks to choosing certain correlations between longitudinal and transverse dimensions of the polarization attenuator’s structural channels when the length of a plate with a resistive film is several times greater than the expanding electromagnetic wave as well as to choosing certain upper range values of a film’s surface resistance. From the general correlation of the perturbation theory method a precise expression aimed at defining the attenuation value in a polarization attenuator which is regarded as a result of functioning of geometric and electric parameters with consideration of frequencydependence of attenuation, is obtained. For numerical calculations an algorithm of reprojecting the electric field onto two orthogonal components with respect to a plate from the resistive film followed by defining with the help of the superposition principle the resulting field has been used. This procedure has been fulfilled with respect to each single unit every time the structure in the cross section of the polarization attenuator’s channels appeared heterogeneous. The authors performed the numerical calculations of characteristics of a polarization attenuator with operating frequency range from 53.57 to 78.33 GHz. A diagonally structured graph reflecting the changes of “crosstalk” in function of surface resistance of the film Rп in the range from 300 Оhm/m2 to 700 Оhm/m2 is offered. It graphically explains the physical process of transition from linear region of attenuation to saturation region. Recommendations on choosing Rп are provided. The authors demonstrate how with the use of the widely known in the literature results and the data on calculations provided in this paper one can evaluate the effect, which the heterogeneity of the plate with a film, in the form of out-of-flatness “fractures”, in particular, may have on the “crosstalk”. The numerical evaluations of the effect a diameter of the polarization attenuator channel has on the “crosstalk” are provided in the paper with the help of a double graph illustrating the “crosstalk” value being “expanded” on the attenuation deviations scale. The numerical calculation of the effect of a distortion of the plate with films in input/output ports of the polarization attenuator has been carried out. The paper proves the possibility of linearizing the characteristics and reducing the attenuation errors both by separate regulation of distortion wall in input/output ports and their common interaction. The physical interpretation of the calculation results of the polarization attenuator is provided. It describes the general principles and can be applied to any other operating frequency range of the polarization attenuator.

Scattering and diffraction of a uniform complex-source beam by a slit in a perfectly conducting plane screen

Abstract. A new multipole solution in plane-polar coordinates for the scattering of an arbitrary TE- or TM-polarized incident field by an infinitely extended slit in a plane screen is derived. To this end a classical three-domain problem with a complete multipole expansion in each of the domains is formulated. The unknown multipole amplitudes are found from the continuity conditions of the tangential electric and magnetic field components. Finally an infinite system of linear equations is derived which can be approximated by a numerically tractable finite one leading to a solution with an arbitrary accuracy. The results are numerically successfully compared to those ones obtained by classically solving the strip problem using Mathieu functions and by a subsequent application of the rigorous form of the Babinet principle. Numerical results include the comparison of the scattered fields obtained for an incident uniform complex-source beam and for an incident plane wave.

Numerical Studies of the Electric Field of a Power Cable with Sector Strands and Impregnated Paper–Plastic Insulation for a Voltage of 20 kV

In power cables with sector current-carrying strands (SCSs), impregnated with paper insulation, there is a tangential electric field component along the layers. The permissible electric strength along the paper tapes is about ten times less than in the normal direction, which is taken into account when developing three-wire power cables impregnated with paper insulation for voltages of 20 and 35 kV. The use of modern paper—plastic-impregnated insulation having higher performance characteristics than conventional impregnated paper insulation, can promote the creation of more efficient cable designs with individually shielded sector-shape conductors in a common lead sheath for a voltage of 20 kV. Each insulated strand of such cables has a copper shield, and so it is enough to consider the electric field in the cross section of the insulation of one SCS. The electric potential distribution is described by the Laplace differential equation, the solution of which is implemented by the finite element method using the Ansys Maxwell software package. A numerical study of the electric fields has been carried out for power cables with SCSs that have a cross section of 400 mm2 for a voltage of 20 kV. The curvature radius of the cable sectors varied from 5 to 7 mm with an insulation thickness of 7 to 9 mm. Based on the research results, the maximum values of the normal and tangential electric field components depending on the curvature radius of the sector strand and insulation thickness have been obtained. Insulation areas have been allocated in which the maximum absolute values of the tangential electric field strength components have been observed. The allowable values of the sector curvature radius and the thickness of insulation for power cables with paper-impregnated insulation for 20 kV have been determined.

Role of the tangential electric field component to the terahertz jet and hook formation by dielectric cube and sphere

The mechanism of formation of a terahertz jet by a dielectric cuboid and a sphere surrounded by ideally conducting screens is considered. The maximum screen influence is observed when the screen is located near the alight cuboid base. The screen influence eases when the screen is shifting along the dielectric object. Power flux density localization area is almost completely shifted inside the object when the screen is situated in the center. The minimum influence is observed when screen placed in the shadow plane of the cuboid base. This effect caused by the screen influence on electric field component tangential to the side edges and thus on the power flux directed to the central axis of the object. The screen influence on the terahertz jet in spherical object has been compared. Value of the power flux density after passing the object is higher in a cuboid, but the focusing characteristics are better (appearing on shorter distances) in a sphere.

Optical axis-driven field discontinuity in a hyperbolic medium.

The altering permittivity tensor of a hyperbolic medium from diagonal to off-diagonal by the constructive manipulation of the optical axis (also called tilted hyperbolic medium) has attracted much interest recently. Here, the electromagnetic field solutions of waves interacting with a tilted hyperbolic medium are established. Detailed calculations reveal that when a transverse magnetic (TM) polarized wave is incident from a tilted hyperbolic medium to a dielectric medium, tangential components of electric fields are expected to be discontinuous at the interface. Extraordinary surface voltages are induced at the inner boundary of the tilted hyperbolic medium, which prevents the reflection of electromagnetic waves. This alternative behavior of induced extraordinary surface voltages enriches the understanding of continuity across the boundary and provides a novel perspective for their realizations among multiple experimental platforms.

An Improved Equivalent Dipole Moment Source Model Based on Regularization Optimization Method for Near Field-Far Field Conversion

The radiation emission from high-speed digital circuit may result in radio-frequency interference (RFI) problems in modern electronic devices. In this paper, an improved equivalent dipole source based on a new transfer model and a new regularization method is proposed. The equivalent source is obtained by solving an inverse equation with near-field data. The tangential component of electric field used in conventional equivalent source extraction is replaced by the normal component, which can reduce the test difficulty and enhance the measurement efficiency. The new regularization method based on Tikhonov and truncated singular value decomposition (TSVD) can enhance the stability and accuracy of the dipole solution. In addition, the new transfer model and regularization method are verified by simulations and measurements.

Investigation on surface electric field distribution features related to insulator flashover in SF6 gas

The gas-solid interface is generally considered to be the weakest part in gas-insulated systems. The flashover voltage of a gas-solid interface is difficult to predict because it involves an extremely complex physical process affected by multiple factors. In this paper, we employ the support vector regression (SVR) method based on mass data on the features of the electric field that are indicators of the flashover voltage. We cast 48 kinds of epoxy resin post insulators as samples, and 61 features are extracted to characterize the surface electric field distribution and the flashover voltage under standard lightning impulse voltage. Four indicators that may be useful in predicting the flashover voltage were obtained; the maximum electric field along the surface of the insulator (E max ), the normal electric field components of E max (E n_Emax ), the maximum gradient of the surface tangential electric field component (E t_gm ), and the integral of the area in which the E value exceeds x% of E max along the insulator surface (V t60 ). We establish an SVR flashover voltage prediction model with these four features, whose average deviation is 7% in 10,000 predictions. It is expected that this study may provide a reference for the continued study of the gas-solid surface flashover mechanism.

Multi-field variational formulations and mixed finite element approximations for electrostatics and magnetostatics

In this paper we propose different multi-field variational formulations for electrostatics and magnetostatics, which can provide optimal discrete approximation of any particular vector field. The proposed formulations are constructed by appealing to mechanics point of view amenable to using general constitutive equations, which is quite different from electrostatics and magnetostatics formulations typical of physics and electrical engineering focusing on the corresponding global form suitable only for linear case. In particular, the formulations we propose can be combined with mixed discrete approximations that can ensure the continuity of tangential component of electric or magnetic field and normal component of electric displacement and magnetic flux even for low order interpolations. The choice of this kind is quite different from currently favorite choice of high order finite element interpolations used for coupling electromagnetism with mechanics. The discrete approximation is based upon Whitney’s interpolations representing the vector fields in terms of corresponding differential forms, with electric and magnetic fields as one-form and electric displacement and magnetic flux as two-form. The implementation of interpolations of this kind is made for 3D tetrahedron elements with non-standard approximation parameters defined not only at vertices (for zero-form), but at edges (for one-form) and at facets (for two-form). The results of several numerical simulations are presented to illustrate the performance of different formulations proposed herein.

On the Proper Generalized Decomposition applied to microwave processes involving multilayered components

Many electrical and structural components are constituted of a stacking of multiple thin layers with different electromagnetic, mechanical and thermal properties. When 3D descriptions become compulsory the approximation of the fields along the thickness direction could involve thousands of nodes. To circumvent the numerical difficulties that such a rich description imply, we recently propose an in-plane–out-of-plane separated representation with the aim of computing fully 3D solutions as a sequence of 2D problems defined in the plane and others (1D) in the thickness. The main contribution of the present work is the proposal of an efficient in-plane–out-of-plane separated representation of the double-curl formulation of Maxwell equations able to address thin-layer laminates while ensuring the continuity and discontinuity of the tangential and normal electric field components respectively at the plies interface.

Dispersion properties of one-dimensional magnetized ferrite photonic crystals in transverse magnetization configuration for transverse magnetic modes

The dispersion characteristics of electromagnetic wave in one-dimensional magnetized ferrite photonic crystals containing yttrium iron garnets and nickel ferrite in a unit cell is investigated for transverse magnetic mode when external magnetic field is perpendicular to the plane of wave propagation. The dispersion relation is derived using transfer matrix method based on the continuity conditions of tangential electric and magnetic field components. It is observed that dispersion properties and phase index are strongly dependent on the normalized parallel wave vector and the filling factor. At the Brewster angle, width of photonic band gap shrinks to zero. Also, the considered structure indicates its dielectric behavior for electromagnetic wave propagation.