Field Intensity Distribution Research Articles

A Triple-Tunable Dual-Band Metamaterial Absorber Based on Dirac Semimetal and InSb

The dynamically triple-tunable dual-band metamaterial absorber that can be electrically, thermally, and magnetically controlled is proposed in this paper. The absorber is composed of bulk Dirac Semimetal (BDS), SiO2, and InSb layers. The physical absorption mechanism can be analyzed theoretically by the equivalent circuit model (ECM) and electric field intensity distributions at absorption peaks. In the absence of applied magnetic field, based on the bright–bright coupling effect, the average absorption rate of dual-band absorber can reach 99.4% when the Fermi energy of the BDS is 0.13 eV and the temperature of the InSb is 475 K. When the applied magnetic field is along the X axis, the absorption frequencies and rates of dual-band absorber can be electrically tuned by adjusting the BDS Fermi energy and thermally and magnetically controlled by adjusting the InSb temperature and magnetic field. Furthermore, the impacts of parameters in dual-band absorbers and the application prospects of the dual-band absorber model as a refractive index sensor are further discussed. This work provides a theoretical basis for the designs of triple-tunable absorbers and sensors.

A facile strategy for customizing multifunctional magnetic‑dielectric carbon microflower superstructures deposited with carbon nanotubes

The novel fabrication of multiple components and unique heterostructure can inject infinite vitality into the electromagnetic wave (EMW) attenuation field. Herein, through the self-assembly of polyimide complexes and catalytic chemical vapor deposition, porous carbon microflowers were synthesized accompanied by carbon nanotubes (CNTs). By regulating the metal ions, the composition and structure of the as-obtained hybrids are modified correspondingly, and thus the adjustable thermal management and EMW absorption capabilities are obtained. In detail, the rich pores and huge specific surface area endow the hierarchical structures with distinguished thermal insulation ability (λ<0.07). The carbon framework and CNTs are beneficial for consuming EMWs via conductive loss and defect polarization loss while reducing the filling ratio and thickness. The doped heteroatoms and abundant heterointerfaces generate ample dipole polarization and interface polarization losses (supported by DFT calculation). The metal nanoparticles uniformly embedded in the carbon framework offer optimized impedance matching, proper defect polarization, and suitable magnetic loss. Accordingly, the synergy of magnetic-dielectric balance and flower-like superstructure enables FNCFN2 and NNCFN2 to accomplish remarkable microwave absorbing capacity with thin thickness (14 wt.%). Therefore, respectable specific reflection loss and specific effective absorption bandwidth are acquired (215.39 dB mm–1 and 22.10 GHz mm–1, 257.23 dB mm–1 and 22.12 GHz mm–1 respectively), superior to those of certain renowned carbon-based absorbers. The simulation results of electric field intensity distributions, power loss density, and radar cross section reduction (maximum value of 36.02 dBm2) also verify the prominent radar stealth capability. Moreover, the customizable approach can be applied to other metals to obtain fulfilling behaviors. Henceforth, this work provides profound insights into the relationship between structure and performance, and proposes an efficient path for mass-producing multifunctional and high-performance EMW absorbers with excellent thermal properties.

Beam quality measurement and image analysis of RF optical emission system

With the development of radio-over-fiber (ROF), beam quality is also an important parameter in evaluating ROF systems. Therefore, this paper selects the low-frequency to very high frequency (VHF) direct modulated optical emission system to verify its feasibility and excellent performance. It then analyzes the beam quality and image processing. In this paper, MATLAB is selected for the theoretical simulation, then CMOS is used to collect light spots, RayCiV2.5 is used to Gaussian fit the light field intensity distribution, and finally the ideal and actual light spot parameters are compared. Due to the influence of noise, this paper also preprocessed the image by brightness adjustment, filtering, edge fitting, etc. It proposed a fast two-sided filtering algorithm, which obtained a high peak signal-to-noise ratio (PSNR) and strong applicability. The results show that the edge-mode rejection ratio is as high as 33.6 dB, the beam quality is good, and it can be well applied in ROF. The M2 factor is 2.75, the optical field intensity Gaussian fit is 99.8 %, and the signal-to-noise ratio (SNR) is as high as 54.7 dB. Moreover, the image is robust after fast bilateral filtering.

A VLA Study of Newly Discovered Southern Latitude Nonthermal Filaments in the Galactic Center: Polarimetric and Magnetic Field Properties

A population of structures unique to the Galactic Center (GC), known as the nonthermal filaments (NTFs), has been studied for over 40 yr, but much remains unknown about them. In particular, there is no widely accepted and unified understanding for how the relativistic electrons illuminating these structures are generated. One possibility is that there are compact and extended sources of cosmic rays, which then diffuse along magnetic flux tubes leading to the illumination of the NTFs through synchrotron emission. In this work, we present and discuss the polarimetric distributions associated with a set of faint NTFs in the GC that have only been studied in total intensity previously. We compare the derived polarized intensity, rotation measure, and intrinsic magnetic field distributions for these structures with the results obtained for previously observed GC NTFs. The results are then used to enhance our understanding of the large-scale polarimetric properties of the GC. We then use the derived polarimetric distributions to constrain models for the mechanisms generating the relativistic electrons that illuminate these structures.

Research on Distribution of Sound Field Intensity in Substation Based on Noise Array Monitoring Sensor

Research on Distribution of Sound Field Intensity in Substation Based on Noise Array Monitoring Sensor

Abstract A008: The effect of body mass index on Tumor Treating Fields (TTFields) intensity distribution in the abdomen: results of a simulation model study

Abstract Introduction: Tumor Treating Fields (TTFields) are electric fields that disrupt processes critical for cancer cell viability and tumor progression. They are generated by a portable medical device and delivered noninvasively to the tumor site via skin-placed arrays. TTFields therapy is approved for the treatment of recurrent and newly diagnosed glioblastoma as well as pleural mesothelioma. Recently, the randomized, pivotal (phase 3) LUNAR study (NCT02973789) demonstrated improved overall survival for TTFields therapy (150 kHz) delivered continuously until progression or intolerable toxicity together with an immune checkpoint inhibitor (ICI) or docetaxel (DTX) vs ICI/DTX alone in patients with metastatic non-small cell lung cancer following progression on or after platinum-based therapy. PANOVA-3 (NCT03377491) is an ongoing pivotal (phase 3), randomized, open-label study evaluating the safety and efficacy of TTFields therapy (150 kHz) together with nab-paclitaxel and gemcitabine for the treatment of patients with unresectable, locally advanced pancreatic adenocarcinoma. The effects of TTFields are dependent on several factors (i.e., intensity, frequency, and distribution) which may be affected by tissue composition/conductivity and array layout. Here, we evaluate guideline TTFields array layouts for TTFields delivery to the abdominal region at therapeutic intensities (∼1 V/cm [amplitude]) using simulation models with varying body mass index (BMI). Methods: Computerized phantom models (Ella, females with BMIs of 22, 26 and 30 kg/m2) were used to simulate the distribution of TTFields. Two different arrays sizes (small [13 disks] and large [20 disks]) were applied to the abdominal region of the models based on abdominal TTFields array layout guidelines. Region of interest (ROIs) included the left and right hypochondriac, left and right lumbar, epigastric, and umbilical regions. Simulations were performed using the Sim4Life platform v6.2.1.4910 (Zurich MedTech, Zurich, Switzerland). Electric field intensity distribution maps were generated for each model, and electric field intensity values across all ROIs in the abdomen were analyzed. Results: Electric field intensities were generally lower in the higher BMI model compared with the lower BMI models (field intensities across all ROIs were 1.60–2.57 V/cm for the 22 kg/m2 BMI model, 1.36–2.13 V/cm in the 26 kg/m2 BMI model and 1.35–1.97 V/cm in the 30 kg/m2 BMI model). However, all BMI models achieved TTFields intensities at therapeutic levels (∼1 V/cm) in all ROIs. Conclusions: Results from this simulation-based study demonstrate the feasibility of delivering TTFields at therapeutic intensities to patients with abdominal tumors regardless of their BMI when using abdominal guideline layouts. Citation Format: Ariel Naveh, Nadav Shapira. The effect of body mass index on Tumor Treating Fields (TTFields) intensity distribution in the abdomen: results of a simulation model study [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr A008.

Influence of beam polarization on underwater femtosecond laser machining of silicon wafer

This paper investigates the effect of polarization directions on underwater femtosecond laser machining of silicon wafer. Firstly, laser ablation in liquids produces laser-induced periodic surface structures (LIPSS) on both edges of the groove. The direction of LIPSS has direct correlation with the polarization of the laser beam. Secondly, the electric field intensity distribution within the groove is analyzed by numerical simulation employing the finite-difference-time-domain (FDTD) method. The simulation and experimental results reveal that the distribution of the inter electric field intensity within the grooves varies with polarization direction. As the angle between the polarization and scanning directions decreases, the peak electric field strength and groove depth gradually increase. Finally, changing the direction of polarization of the beam affects the symmetry of the groove profile. The groove profile produced by ablation is symmetrical when the beam polarization direction is parallel to the scanning direction. By modulating and optimizing the direction of polarization, grooves with large depth and symmetrical shape can be obtained.

Two-photon polymerization-based fabrication of millimeter-sized precision Fresnel optics

Two-photon polymerization (2PP) is known to be the most precise and highest resolution additive manufacturing process for printing optics, but its applicability is restricted to a few applications due to the limited size of printable objects and low throughput. The presented work is intended to demonstrate the performance of printing millimeter-scale optics by implementing appropriate stitching methods into a setup that combines a Galvo scanner and translational axes. In this work, specifically, Fresnel axicons with a diameter of 3.5 mm are manufactured by 2PP to substantiate the applicability of the process. Manufacturing Fresnel optics instead of volumetric optics allows for attaining acceptable process times with durations of tens of hours highlighting the appeal of 2PP for rapid prototyping in optics. The suitability of the Fresnel axicons for beam shaping is confirmed through illumination with a laser beam. The resulting ring-shaped intensity distribution in the far field behind the Fresnel axicon is captured using a beam profiler. Furthermore, the influence of different stitching parameters on the resulting intensity distribution is investigated. The experimental results are validated by simulations, where the intensity distribution in the far field behind an axicon was calculated by Fourier transformation. Simulations were carried out to discuss the effect of manufacturing errors on the far field intensity distribution.

Features of distribution of electric field strength and current density in the reactor during treatment of liquid media with high-voltage pulse discharges

Purpose. Development and use of a mathematical model of the stages of formation of high-voltage pulse discharges in gas bubbles in the discharge gap «rod-plane» to identify the features of the electric field intensity distribution in the reactor and determine the current density in the load during disinfection and purification of liquid media by high-voltage pulse discharges and find the most rational treatment. Methodology. To achieve this goal, we used computer modeling using the finite element method as a method of numerical analysis. An experimental reactor model was created that takes into account the dynamics of discharges in gas bubbles in water. The equations describing the system include the generalized Ampere equation, the Poisson equation and the electric displacement equation, taking into account the corresponding initial and boundary conditions, as well as the properties of materials. The dependence of the potential of a high-voltage electrode on time has the form of a damped sinusoid, and the specific electrical conductivity in a gas bubble is a function of time. Processes occurring at the front of the voltage pulse from 0 to 20 ns are considered. Results. It is shown that with an increase in conductivity and high-voltage potential to amplitude values in a gas bubble, the electric field strength in the water layer in the reactor reaches 70 kV/cm, and it is in the water layer that there is a strong electric field. The calculations show that already by 19th ns the density of conduction currents in water prevails over that of displacement currents. At the same time, additional inclusions in the water significantly affect the distribution of electric field strength and current density, creating a significant difference in their values at the boundaries of the interface between the bubble, conductive element and water. Originality. A simulation of the dynamics of transient discharge processes in a gas bubble and a layer of water with impurities was carried out, including an analysis of the distribution of the electric field strength and current density in a system with rod-plane electrodes in the phase transition section of a gas bubble-water. This approach allows us to reveal the features of processes in reactors and to investigate the influence of phase transitions on the distribution of electrophysical quantities. Practical value. Computer simulations confirm the prospect of using nanosecond discharges generated in gas bubbles within a volume of water for widespread industrial use and are of great interest for further experimental and theoretical research. References 25, figures 9.

Spatial mode conversion of a reflected polarized beam from an isotropic medium at brewster angle

Abstract In this study, the spatial mode evolution of a chiral polarized beam during reflection on an isotropic medium surface at Brewster angle is both theoretically and experimentally investigated. In this process, the topological charge of the reflection field’s horizontal component increases (decreases) by one, relative to the specific left (right) elliptical polarization incident beam. While incident l i -order vortex beam is in a certain polarization state, the intensity distribution of the reflection field’s horizontal component appears as the interference pattern of the l i ± 1 -order output vortex beams. The conversion occurs between the spin and orbital angular momentum and does not violate the conservation of the total angular momentum. We explain the physical mechanism of this phenomenon using phase shift theorem, and analyze the effect of ellipticity and polarization angle on this physical phenomenon.

Perfect space-time vortices.

We introduce the concept of perfect space-time vortices (PSTVs) that can exist in media with anomalous dispersion. If the topological charge of a PSTV is not too large, the spatiotemporal intensity distribution of the vortex field does not depend on the magnitude of the topological charge. We show theoretically how a PSTV can be realized in the optical context through spatiotemporal focusing of a Bessel-Gaussian space-time optical vortex source that is placed in the focal plane of a space-time lens composed of an ordinary lens and a time lens with matched spatial and temporal focal lengths.

Investigation of a newly developed shear built-in valve type MR damper with high damping: Theories and experiments

Magnetorheological (MR) dampers are widely used as semi-active energy-dissipation devices in structural vibration control. Traditional MR dampers, particularly their working mode, often struggle to achieve a high damping force output and sometimes fail to meet the needs of practical engineering. Therefore, it is necessary to study MR dampers that can provide a high damping force. This study proposes an MR damper that combines a built-in shear valve with various working modes of shear extrusion. The damper generates a higher damping force by applying a current to the coils at different positions and altering its working mode. First, the ANSYS Maxwell software simulates the internal magnetic circuit of the damper to assess whether the magnetic field intensity distribution and circuit direction meet the design requirements. Analysis revealed that the internal magnetic circuit distribution was reasonable and satisfied the operating requirements of the damper. Furthermore, the mechanical models of the two working modes were derived based on the Bingham and double-viscous models. Finally, the accuracies of the mechanical models were verified experimentally. The experimental results showed that the simulation values closely matched the experimental values under all the working conditions. Therefore, the proposed mechanical models are reasonable, and can provide significant reference values for practical engineering applications.

Simulations of Femtosecond-Laser Near-Field Ablation Using Nanosphere under Dynamic Excitation.

Femtosecond lasers have garnered widespread attention owing to their subdiffraction processing capabilities. However, their intricate natures, involving intrapulse feedbacks between transient material excitation and laser propagation, often present significant challenges for near-field ablation predictions and simulations. To address these challenges, the current study introduces an improved finite-difference time-domain method (FDTD)-plasma model (plasma)-two-temperature model (TTM) framework for simulating the ablation processes of various nanospheres on diverse substrates, particularly in scenarios wherein dynamic and heterogeneous excitations significantly influence optical-field distributions. Initially, FDTD simulations of a single Au nanosphere on a Si substrate reveal that, with transitions in the excitation states of the substrate, the field-intensity distribution transforms from a profile with a single central peak to a bimodal structure, consistent with experimental reports. Subsequently, simulations of a polystyrene nanosphere array on a SiO2 substrate reveal that different excitation states of the nanospheres yield two distinct modes, namely near-field enhancement and masking. These modes cannot be adequately modeled in the FDTD simulations. Our combined model also considers the intrapulse feedback between the electromagnetic-field distribution resulting from near-field effects and material excitations. Furthermore, the model can quantitatively analyze subsequent electron-phonon coupling and material removal processes resulting from thermal-phase transitions. Consequently, our model facilitates predictions of the femtosecond-laser ablation of single nanospheres or nanosphere arrays with varying sizes and materials placed on substrates subjected to near-field effects.

Effect of insulation materials and power on microwave heating characteristics of SiC susceptor under material–specific parametric conditions

High-quality microwave absorber materials play a crucial role in the efficient and uniform processing of variety of materials through microwave hybrid heating. Silicon carbide (SiC) is an excellent microwave absorber at room temperature, which enhances the heating rate of the target materials significantly. In the present study, effects of heat insulation materials and their configurations on microwave heating characteristics of SiC were investigated at different power levels. The responses were assessed in terms of the heating capability (maximum temperature achieved), radiation heat loss, temperature gradient, and heating uniformity under different parametric conditions. A 3D COMSOL Multiphysics simulation model, coupled with microwave heating and heat transfer module, was developed with surface-to-ambient radiation boundary conditions. Electromagnetic and thermal properties of the SiC utilized in the model were selected based on physical properties, such as porosity/density, particle size, and chemical composition of SiC. The model outputs were validated with experimental findings. Results showed that microwave heating characteristics were highly sensitive to the susceptor (SiC) properties, insulation materials and power levels. Insulation materials prevented heat losses significantly; at the same time, different insulation configurations altered the electrical field intensity distribution within the SiC sample, which affected the responses. Microwave power levels also influenced the responses and quantity of insulation required.

Metamaterial terahertz device with temperature regulation function that can achieve perfect absorption and complete reflection conversion of ultrawideband

The field of terahertz devices is important in terahertz technology. However, most of the current devices have limited functionality and poor performance. To improve device performance and achieve multifunctionality, we designed a terahertz device based on a combination of VO2 and metamaterials. This device can be tuned using the phase-transition characteristics of VO2, which is included in the triple-layer structure of the device, along with SiO2 and Au. The terahertz device exhibits various advantageous features, including broadband coverage, high absorption capability, dynamic tunability, simple structural design, polarization insensitivity, and incident-angle insensitivity. The simulation results showed that by controlling the temperature, the terahertz device achieved a thermal modulation range of spectral absorption from 0 to 0.99. At 313 K, the device exhibited complete reflection of terahertz waves. As the temperature increased, the absorption rate also increased. When the temperature reached 353 K, the device absorption rate exceeded 97.7% in the range of 5–8.55 THz. This study used the effective medium theory to elucidate the correlation between conductivity and temperature during the phase transition of VO2. Simultaneously, the variation in device performance was further elucidated by analyzing and depicting the intensity distribution of the electric field on the device surface at different temperatures. Furthermore, the impact of various structural parameters on device performance was examined, offering valuable insights and suggestions for selecting suitable parameter values in real-world applications. These characteristics render the device highly promising for applications in stealth technology, energy harvesting, modulation, and other related fields, thus showcasing its significant potential.

Inverse design for laser-compatible infrared camouflage metasurface enabled by physics-driven neural network and genetic algorithm

Metasurface-based multi-band camouflage holds significant value in both military and civilian applications due to its superior performance and structural simplicity. Combining a physics-driven neural network (PNN) and genetic algorithm (GA), we designed the AZO-Ge disk metasurface capable of achieving 1.06 μm laser stealth, mid-infrared thermal camouflage and efficient thermal management. In contrast to conventional spectra prediction neural networks, the PNN adopts a data dimensionality reduction prediction paradigm, resulting in enhanced accuracy and accelerated convergence. The combination of PNN and GA in the inverse design effectively addresses the prevalent “one-to-many" and single-solution challenges encountered in tandem neural networks. Such data-driven approach makes metasurface design faster and more efficient. Finally, four groups of metasurface geometric parameters were designed by the PNN-GA framework. The designed metasurfaces exhibit low average emissivities (<0.3 and < 0.2, respectively) in the two atmospheric windows (3∼5 μm and 8∼14 μm), high average emissivity (>0.75) in the non-atmospheric window (5∼8 μm) and high absorptivity (>0.8) at 1.06 μm. We also demonstrate that these spectral properties are insensitive to the incident angles and polarizations. In addition, the electric field intensity distribution plots of the cross sections reveal that surface plasmon polariton (SPP) predominantly contributes to the high emission in the non-atmospheric window band, while the high absorptivity at 1.06 μm is attributed to the resonance and the intrinsic absorption of the Ge material. The designed metasurface with its simple structure suggests the potential for low-cost and large-scale fabrication in the future. Meanwhile, the combination of machine learning and evolutionary algorithms is a pioneering work in metasurface design and we believe our work will provide guidelines for the multi-solution design of complex metasurfaces.

ВИЗНАЧЕННЯ ВПЛИВУ РОЗПОДІЛУ ЗОВНІШНЬОГО ЕЛЕКТРИЧНОГО ПОЛЯ ОПОРНО-СТРИЖНЕВОГО ІЗОЛЯТОРА НА ЙОГО СУХОРОЗРЯДНУ НАПРУГУ

A mathematical model has been developed for calculating the internal and external electric field of insulators based on the solution of the Laplace equation with respect to the phasor of the electric potential using the finite element method. The specified model has been used to calculate electric field intensity distributions in the surrounding air spaces of support-rod insulators С4-80-I, C4-80-II and also C4-80-IIСm (Chinese-made). It has been proposed to establish a relationship between the distribution of the electric field around the insulators and their test dry discharge voltage based on the average integral values of the modulus of the electric field intensity along the possible paths of the dis-charge, taking into account the sign of its tangential component. The average integral values of the electric field have been compared with the known experimental values of the air breakdown intensity between two rod electrodes, as well as in the electrode system of the rod and the grounded plane. It has been shown that the most probable path of devel-opment of the discharge for each of the considered insulators is the path closest to the minimum distance in the air between the cap and the flange, the discharge process is two-stage (firstly the section «cap-the rib nearest to the cap» is broken down), and the breakdown intensity of the air around the insulators corresponds to the breakdown intensity between two rod electrodes (the difference in values was 2,1...5,9%). References 10, tables 3, figures 3.

Simulation Computation of Two-dimensional Hexagonal Honeycomb Photonic Crystals Energy Band Structure Based on COMSOL

This study employs COMSOL software, integrating the plane wave expansion method and finite element method, to simulate and analyze the energy band structure of two-dimensional hexagonal honeycomb photonic crystals. By setting parameters and conducting scans, this paper not only maps out the electric field intensity and energy band distribution but also discovers a significant enhancement of electric field intensity at the lattice's high symmetry points, indicating a higher likelihood of electromagnetic waves' presence at these points. Furthermore, the notable energy gaps between the second and third energy bands provide directions for subsequent research. The findings of this study are of significant value for research and development in optoelectronic integration and communication, demonstrating an effective comprehensive method for analyzing the energy band structure of two-dimensional hexagonal honeycomb photonic crystals.

Probing the Local Near-Field Intensity of Plasmonic Nanoparticles in the Mid-infrared Spectral Region.

The enhanced local field of gold nanoparticles (AuNPs) in mid-infrared spectral regions is essential for improving the detection sensitivity of vibrational spectroscopy and mediating photochemical reactions. However, it is still challenging to measure its intensity at subnanometer scales. Here, using the NO2 symmetric stretching mode (νNO2) of self-assembled 4-nitrothiophenol (4-NTP) monolayers on AuNPs as a model, we demonstrated that the percentage of excited νNO2 mode, determined by femtosecond time-resolved sum-frequency generation vibrational spectroscopy, allows us to directly detect the local field intensity of the AuNP surface in subnanometer ranges. The local-field intensity is tuned by AuNP diameters. An approximate 17-fold enhancement was observed for the local field on 80 nm AuNPs compared to the Au film. Additionally, the local field can regulate the anharmonicity of the νNO2 mode by synergistic effect with molecular orientation. This work offers a promising approach to probe the local field intensity distribution around plasmonic NP surfaces at subnanometer scales.

Electromagnetic field simulation modeling method and distribution characteristics of electric vehicle wireless charging system

In recent years, wireless charging technology for electric vehicles has gained significant attention. To accurately analyze the distribution characteristics of the electromagnetic field during the wireless charging process of electric vehicles, a finite element-based electromagnetic analysis method was employed. Applied in the commercial simulation software, the electromagnetic environment of the resonant coil and electric vehicle model was simulated under high-power charging conditions, resulting in an overall electromagnetic field distribution for the electric vehicle. The results indicated that within the coil region, the magnetic induction intensity in the central area of the coil was zero, and it increased as the distance from the center of the coil grew. Outside the coil region, the magnetic induction intensity gradually decreased. The electric field intensity of the resonant coil was maximum in the central area of the coil, and it weakened as the distance from the center of the coil increased. When a magnetic shielding resonant coil was used, the electromagnetic field was confined between the shielding materials, and the magnetic field rapidly attenuated on both sides of the magnetic shield. The electromagnetic field energy of the electric vehicle body was mainly concentrated at the bottom of the vehicle near the coil. When the coil was located in the front of the car body, the maximum electric field intensity distribution in the car body was 8.50 V/m, and the maximum magnetic induction intensity was 0.024 μT. When the coil was located in the middle of the car body, the maximum electric field intensity was 2.31 V/m, the maximum magnetic induction intensity was 0.019 μT. As the distance from the coil position increased, the energy weakened.