Electromagnetic Compatibility Research Articles

Synopsis of the June 2024 Issue of the IEEE Letters on Electromagnetic Compatibility Practice and Applications

Synopsis of the June 2024 Issue of the IEEE Letters on Electromagnetic Compatibility Practice and Applications

3D-Networks Based Polymer Composites for Multifunctional Thermal Management and Electromagnetic Protection: A Mini Review

The rapid development of miniaturized, high-frequency, and highly integrated microelectronic devices has brought about critical issues in electromagnetic compatibility and thermal management. In recent years, there has been significant interest in lightweight polymer-based composites that offer both electromagnetic interference (EMI) shielding and thermal conductivity. One promising approach involves constructing three-dimensional (3D) interconnection networks using functional fillers in the polymer matrix. These networks have been proven effective in enhancing the thermal and electrical conductivity of the composites. This mini-review focuses on the preparation and properties of 3D network-reinforced polymer composites, specifically those incorporating metal, carbon, ceramic, and hybrid networks. By comparing the effects of different filler types and distribution on the composite materials, the advantages of 3D interconnected conductive networks in polymer composites are highlighted. Additionally, this review addresses the challenges faced in the field of multifunctional thermal management and electromagnetic protection materials and provides insights into future development trends and application prospects of 3D structured composites.

Research on Electromagnetic Environment Characteristic Acquisition System for Industrial Chips

With the system interconnection and intelligence of application scenario equipment, the electromagnetic environment of chips is becoming more and more complex. Problems such as communication interruption and data loss caused by electromagnetic interference often occur. The electromagnetic reliability of chips has become an important index to measure their availability. In order to effectively detect the electromagnetic reliability of industrial chips applied to specific scenarios, it is necessary to measure and analyze the electromagnetic characteristics of the application scenarios, as the boundary conditions of the electromagnetic protection simulation analysis and design of the chip, and to develop Electromagnetic Compatibility (EMC) test items, test limits and test methods suitable for carrying out tests and monitoring on chips. The paper presents an acquisition system, which can complete the collection of transient electromagnetic interference, steady electromagnetic field, temperature, humidity and near-field data. The transient interference measurement frequency range is 300 kHz–500 MHz, with a rising edge of 1.5 ns; the steady-state electromagnetic field measurement frequency ranges from 100 Hz to 3 GHz. By collecting the electromagnetic environmental characteristics of chips and analyzing situations in which chips are prone to interference, protective measures can be implemented.

Enhancing electromagnetic compatibility and energy efficiency of electric vehicle charging stations

Problem. The article proposes a single-link structure for an electric vehicle charging station utilizing an active four-square rectifier with power factor correction. A Matlab model of the proposed charging station is developed, taking into account parameters such as the power network, the switches of the active rectifier, its automatic control system, and an equivalent model of the battery compartment. Additionally, a mathematical model for calculating static and dynamic losses is created based on polynomial approximation of the energy dependencies of IGBT modules. The analysis investigates power quality parameters, components of energy losses, and efficiency of the charging station across various charge currents and PWM frequencies during a full battery charge interval. Goal. The aim of this study is to propose a single-link structure for an electric vehicle charging station using an active four-square rectifier with power factor correction. It includes an analysis of power quality parameters, components of energy losses, and efficiency of the charging station at different charge currents and PWM frequencies during a full battery charge interval. Methodology. To achieve the goal, several key steps are considered. These include theoretical substantiation of the scheme of the electric microgrid charging station for electric vehicles with one-stage energy conversion, analysis of the battery connection scheme in the Tesla Model S electric car, research and calculation of efficiency, modeling of the charging station, development of a Matlab model of a microgrid system for the charging station, SAC analysis of battery charge voltage and current of a three-phase AV with PWM, modeling of losses in IGBT modules by polynomial approximation of dependencies, distribution of losses in the charging station system, and analysis of energy efficiency parameters. Results. The study presents the energy efficiency parameters of an external DC EV charging station using an active rectifier. It reveals that maximum efficiency of the system is achieved at minimum charge current. However, decreasing the charge current prolongs the charge process and slightly affects power quality parameters. Originality. A mathematical model for calculating static and dynamic losses was developed based on polynomial approximation of the energy dependencies of IGBT modules. The analysis encompasses power quality parameters, components of energy losses, and efficiency of the charging station across various charge currents and PWM frequencies during a full battery charge interval. Practical value. This study contributes to the further development of electric vehicles by improving the energy indicators of electric vehicle batteries and converters of electric vehicle charging stations, enabling fast charging modes. Active development is observed in each of these directions.

Cross‐talk reduction in metamaterial and non‐uniform transmission lines

AbstractThe electromagnetic compatibility analysis of RF circuitry is essential due to the adverse effects on sensitive components. Two metamaterial unit cells with slow‐wave properties are presented for cross‐talk reduction in transmission lines. The analytical expressions for computing equivalent lumped elements of the lines are then provided. The dispersion diagram is obtained from the parameters extracted from the measurement. A microstrip as the generator line and five identical CRLH unit cells as the receptor line are then used and a significant reduction in cross‐talk is observed in comparison to conventional lines. A non‐uniform transmission line with two different CRLH unit cells as the receptor line is then employed and found effective in further cross‐talk reduction between the lines. The lengths of the lines and numbers of cells are kept the same in all lines for comparison. The simulated results are validated by measurements.

Experimental and analytical analysis of conformal and polarization insensitive electromagnetic absorber

The study introduces an ultra-wideband polarization-insensitive conformal meta-absorber. The single meta-absorber unit cell comprises quad metallic-sectorial-resonators connected to a small octagonal metallic ring through quad-resistors. This unit cell is fabricated on a conformal 0.07 mm ultra-thin substrate followed by air-spacing and backed with a copper sheet. Notably, this structure achieves ‘near-to-unity’ absorption and a reflection coefficient of less than −20 dB for flat and conformal surfaces throughout the C and X frequency bands (5–13 GHz). Further, the investigation also explores equivalent circuit modeling (ECM) assisted by Particle Swarm Optimization (PSO) for getting maximum bandwidth. Lastly, the structure is fabricated and systematically analyzed, and it shows excellent agreement with the simulations. This design can potentially be utilized for Electromagnetic Interference and Electromagnetic Compatibility (EMI-EMC), shielding, Radar cross-section (RCS) reductions, stealth, and biomedical and industrial applications.

Common‐mode current reduction in EMP coupling with the star‐quad cable having a reference conductor

AbstractThe coupling of electromagnetic pulse (EMP) with the star‐quad cable having reference conductor is analyzed by using the proposed model, which is based upon multi‐conductor transmission line theory. Expressions for common‐mode (CM) and differential‐mode (DM) currents are developed. Two cases are mainly discussed: the first case is the star‐quad cable with a central reference conductor, and the second case with the outside reference conductor. A rigorous comparison between these two cases shows that when the reference conductor is placed at the center, the magnitude of CM current is reduced dramatically, which is beneficial for electromagnetic compatibility (EMC). The CM current magnitude of the outside reference conductor is relatively very high due to the large CM current loop area, which is the least possible for the central reference conductor. There is no significant change in the DM current magnitude for both cases because the DM current has no direct dependence on the CM current loop area. A commercial software, FEKO, which utilizes the method of momentum (MoM), is used to compare the results of our proposed method, which are in good agreement.

Моделирование помех в электронном устройстве при воздействии импульсного магнитного поля с использованием искусственной нейронной сети

Modern electronic means are quite sensitive to electromagnetic interference. At the same time, they must function reliably in the existing electromagnetic environment. Lightning discharges and industrial sources make a significant contribution to the formation of the electromagnetic environment around electronic equipment. In this case, pulsed magnetic fields with microsecond parameters most often arise. The most rational approach to ensuring electromagnetic compatibility of electronic means is the most complete accounting and protection from possible phenomena at the design stage. Different methods for modeling the consequences of exposure to electromagnetic interference have their own advantages and disadvantages. To develop a technique and modeling interference in electronic means based on an artificial neural network using the example of the influence of a pulsed magnetic field a the purpose of this work. A practical technique for calculation the magnitude of interference in electronic means using an artificial neural network the paper proposes. All stages of the technique are described: analysis of the main input parameters affecting the amount of interference in the electronic means; the use of a special experimental stand for measuring interference depending on significant input parameters; choosing the structure and parameters of an artificial neural network to modeling interference; choosing a training method for an artificial neural network; choosing a criterion for assessing the quality of training when solving a regression problem; normalization of training data; training an artificial neural network using measured data; modeling the amount of interference in the communication line of an electronic means when exposed to a pulsed magnetic field; assessment of consequences and selection of methods of protection against interference. As an example, we consider the problem of modeling the amount of interference in a communication line inside an electronic means when exposed to a pulsed magnetic field. The magnetic field has parameters recommended by the requirements of the regulatory document on electromagnetic compatibility of devices. In the problem under consideration, an acceptable discrepancy in results is achieved with an acceptable number of neural network training epochs.

Aramid Nanofiber‐Based Artificial Nacre‐Supported Graphene/Silver Nanowire Nanopapers for Electromagnetic Interference Shielding and Thermal Management

AbstractThe development of next‐generation flexible electronics hinges on the creation of materials that are not only mechanically robust but also multifunctional. Herein, a novel approach is presented to fabricate an aramid nanofibers/cellulose nanocrystals/montmorillonite nanoplates (ACM) composite substrate with a robust “brick and mortar” microstructure. This substrate is seamlessly integrated with a high‐performance graphene/silver nanowire (G/Ag) composite conductive layer, resulting in the creation of ACM&G/Ag nanopapers. The resulting nanopapers achieve remarkable tensile strength (δc) (543.82 MPa), tensile modulus (Ec) (10.93 GPa), and toughness (Uc) (95.18 MJ m−3). Notably, when normalized by weight, the specific tensile strength of these nanopapers surpasses that of commercial titanium alloy, reaching 399.87 MPa g−1 cm3, compared to titanium alloy's 257.00 MPa g−1 cm3. With a high conductivity of 1398.08 S cm−1, ACM&G/Ag nanopapers exhibit impressive electromagnetic interference shielding effectiveness (EMI SE) of 39.59 dB and EMI SE/t of 16359.26 dB cm−1. Moreover, ACM&G/Ag nanopapers exhibit exceptional thermal management performance, featuring high electrical heating temperature (280 °C), rapid response time (<6 s), enduring heating stability, deicing capacity, and reliable heating performance even in humid environments. These results underscore the substantial potential of these high‐performance nanopapers in diverse applications such as wearable devices, electromagnetic compatibility, thermal management, human health, and aerospace.

Experimental electromagnetic compatibility of conducted electromagnetic interferences from an IGBT and a MOSFET in the power supply

Introduction. Most electromagnetic compatibility studies carried out in the context of power switch research are generally valid for low frequencies. This frequency restriction appears to be too restrictive for a complete analysis of the electromagnetic interference conducted. The novelty of this work lies in the load-dependent an optimal selection of IGBTs and MOSFETs for least-disturbance power switching in the frequency range from 150 kHz to 30 MHz, based on an optimal experimental selection procedure and show the impact of load value on switch switching and noise generation. Purpose. Analysis of the fundamental possibility of selecting a switching device with a power supply based on an experimental measurement which allows to increase the reliability of the entire mechanism operation and significantly simplify the design. Methods. In this paper, the proposed study is used and compared with experimental results at low and high frequencies. Then, a comparison is made for conducted electromagnetic interference (common-mode and differential-mode) generated by IGBT and MOSFET for different loads, and the proposed methodology is verified on an experiment suitable for predicting terminal overvoltage analysis and conducted electromagnetic interference problems. Practical value. The primary method for establishing a conducted electromagnetic interference source for switching devices is based on IGBT and a MOSFET depending on the resistive load. References 22, figures 17.

High easy-plane anisotropy Y-Co intermetallic nanoparticles for boosting gigahertz magnetic loss ability

Soft magnetic materials with ferromagnetic loss abilities have been proven effective in solving gigahertz electromagnetic problems. However, it remains a challenge to synergistically improve their loss capacities and working frequencies due to the Snoek limit. Here, we proposed Y-Co nanoparticles with optimized magnetic anisotropy to break this limit and boost microwave absorption properties. As a result, the soft magnetic phases have manipulated the ferromagnetic loss ability, resulting in the improvement of the easy-plane anisotropy, thus increasing the resonance frequency. A loss peak at 6.2 GHz with a loss capacity (μ") of 0.74 can be found in soft magnetic phase-rich nanoparticles with easy-plane anisotropy, which is higher than that of hard magnetic phase-rich with easy-axis anisotropy (0.76, 4.3 GHz) and Co phase (0.4, 3.95 GHz) nanoparticles. The minimum reflection loss of it can reach −26.4 dB (6.85 GHz) with a broad effective absorption bandwidth of 4.35 GHz (5.85 ∼ 10.20 GHz). The present study provides intrinsic insight into the relationship between easy-plane anisotropy and magnetic loss ability, inspiring the design of high-frequency electromagnetic compatibility materials.

Theoretical study on Stark effect of Rydberg atom in super low frequency electric field measurement

AbstractSuper low frequency electric field measurements are crucial in analysing electromagnetic compatibility, assessing equipment status, and other related fields. Rydberg atom‐based super low frequency electric field measurements are performed by observing the Stark shift in the spectrum of the Rydberg state. In a specific range of field strength (E < Eavoid, where Eavoid is the threshold to avoid crossing electric fields), the Rydberg atomic spectrum experiences a quadratic frequency shift in relation to the field strength, with the coefficient being determined by the atomic polarisability α. The authors establish a dynamic equation for the interaction between the external electric field and the atomic system, and present the Stark structure diagram of the Caesium Rydberg atom. The mathematical formulae for α and Eavoid in different Rydberg states are also obtained: α = A × (n*)6 + B × (n*)7 and Eavoid = C/(n*)5 + D/(n*)7, where A(B) = 2.2503 × 10−9(7.49,948 × 10−11) and C(D) = 1.68,868 × 108(2.45,991 × 109). The error of α and Eavoid compared with the experimental values does not exceed 8% and is even lower in the low Rydberg states. Accurately calculating the values of α and Eavoid is crucial in incorporating the Rydberg atom quantum coherence effect into super low frequency electric field measurements in new power systems.

Simultaneous rotary and linear displacement sensor based on soft pneumatic sensing chambers

Specific industrial or research applications necessitate specialized displacement measurement conditions, thereby driving researchers to innovate sensors based on novel operating principles. One such challenging condition is the prevalence of strong electromagnetic waves, which precludes using any sensor with a metallic structure or one that operates on electrical measurement principles. Additionally, space constraints in applications requiring multidimensional displacement measurements mandate the development of sensors capable of measuring displacements simultaneously in multiple directions. This paper introduces a novel soft sensor designed to simultaneously measure linear and rotational displacements using Soft Pneumatic Sensing Chambers (SPSCs). This sensor is unique in its ability to measure both linear and rotational movements and, due to its Electro-Magnetic Compatibility (EMC) and compact size, is suitable for environments with significant electromagnetic interference and spatial constraints. Furthermore, its flexibility makes it appropriate for body-interacting applications. The Abaqus software was employed to optimize the operating parameters. Subsequently, a laboratory setup was assembled, and the sensor's performance was assessed using two calibration methods: mathematical modeling and machine learning. According to the machine learning method, the accuracy in the linear and rotational directions was 0.49 mm and 5.4°, while the Root Mean Square Error (RMSE) was 0.05mm and 0.48°, respectively.

Improved Numerical Estimation Method for Surface Wave Attenuation on Metasurfaces

AbstractComprehensive numerical tools to investigate and analyze the surface wave attenuation on a metasurface waveguide that consists of periodic patches deposited on a dielectric substrate are presented. The surface wave attenuation is evaluated in both waveguide and open‐space environments at high frequencies around the 28‐GHz band. Two approaches including a driven modal approach and an integrated eigenmode approach for investigating the attenuation behaviors in a metasurface waveguide operating in transverse electromagnetic (TEM) mode are employed. These results show different attenuation values depending on the waveguide height due to an unavoidable coupling issue despite the same metasurface design. Thus, an alternative method for more accurately evaluating the frequency‐dependent attenuation characteristics through field distribution in open space with a customized horn antenna is proposed. A relationship between the surface wave attenuation and the propagation distance by analyzing the analytical electric field distribution at different points on the propagation path in the open space is established. Thus, this study provides an improved method for assessing surface wave attenuation characteristics, which contributes to designing surface wave control for wireless communications, wireless power transfer, signal processing, and electromagnetic compatibility.

Stability and reliability analysis for broadband current array sensing system applied to GIS

Abstract In order to further improve the defect detection capability of gas insulated switchgear and avoid equipment faults, broadband current array sensing system is designed to simultaneously monitor the system status such as partial discharge, relative dielectric loss, and power frequency overvoltage. The dynamic model of the system is analysed, and based on which, the system state equation is obtained meanwhile fault observer is designed, and the system stability criterion under H ∞ condition is calculated. The reliability of the system under different packet loss rates is verified based on cloud models, and the principle of using appropriate electromagnetic compatibility to prevent packet loss rates below 50% is proposed.

Implementation of a Cross-Platform Development Board for Embedded Internet-of-Things Systems

A prototype of a printed circuit board (PCB) with radio frequency electromagnetic compatibility specifications is designed using the top-down methodology for the two-layer Internet of Things with free open-source hardware and software, using the following techniques: requirements, analysis, modular design, schematics, manufacturing and functional testing. The study of the influence of the design parameters is carried out applying the standards of the Printed Circuit Institute and the characteristics of the technological production process for a free multiplatform for wireless networks. Finally, functional tests of the universal asynchronous transmit and receive (UART) communication with the microcontroller, the radio modules, the general-purpose input and output pins, and the over-the-air (OTA) configuration are performed to program the board wirelessly, without the need of a universal serial bus (USB) interface.

Environmental Interference Suppression by Hybrid Segmentation Algorithm for Open-Area Electromagnetic Capability Testing

Compared with electromagnetic compatibility (EMC) testing in anechoic rooms, open-area EMC testing takes advantage of in situ and engine running status measurement but suffers from non-negligible external electromagnetic interference. This paper proposes a novel environmental interference suppression method (named the EMC environmental interference suppression algorithm (E2ISA)) that separates signals from backgrounds via image segmentation and recognizes the near–far site signal via a group of time-varying features based on the difference in the near-site EM radiative characteristic. We find that the proposed E2ISA method, which combines the deep learning segmentation network with the classical recognition methods, is able to suppress environmental interference signals accurately. The experiment results show that the accuracy of E2ISA reaches up to 95% in the face of VHF (Very High Frequency) EMC testing tasks.

Active low frequency band expansion mechanism of electromagnetic wave absorber composite structure

Bandwidth expansion of modern antennas and communication systems raises growing demand for electromagnetic wave absorber in compatibility equipment. Single absorption mechanism is hard to reach well-balanced characteristics including wide bandwidth, low frequency absorption and small thickness. Based on the composite structure concept, composite structure for electromagnetic wave absorber’s active low frequency band expansion is proposed, by combining circuit-analog absorber and active absorber to form a superimposed structure. The characteristic of composite structure is better than the single absorber structure, which improves enhancement mechanism brought by the composite structure. Sample fabrication and experiments indicate reflectivity curve envelope reaches −10 dB in 2.15–18 GHz frequency range (relative bandwidth 157.3%), and the tunable absorption frequency range in low-frequency domain is greater than 1.3 GHz. The structure has good adaptation on TE and TM polarizations, as well as good angle insensitivity. This composite structure has application potential in intelligent response system related with electromagnetic compatibility, energy absorption and object security management.

All-liquid frequency selective absorber design with flexibility and wide-angle stability

An all-liquid flexible metamaterial crossing the ultrabroadband range of S, C, X, and Ku bands is reported. This work demonstrates for the first time a frequency selective absorber (FSA) using all-flexible materials, which enables a transmission band of 2.4–4 GHz and a 6–20 GHz ultrawideband absorption. Firstly, liquid metal (LM) as a new functional material with self-healing capability and high reflectivity, based on its metasurface can realize the minimum insertion loss of 0.72 dB at 3.2 GHz. Then, utilizing dielectric resonance and diffraction grating effects of the water-based metasurface, the design can achieve greater than 90% absorption in the frequency band of 6–20 GHz, with a relative bandwidth of 107%. Furthermore, by miniaturizing the design, the FSA exhibits high stability in TM mode with oblique incidence up to 60° and TE mode at 45°. Our design can be fabricated using polydimethylsiloxane lithography and encapsulated with water and LM with a thickness of only 8 mm. Finally, the fabricated FSA are tested by bending to different curvatures, and the good performance indicates its promising applications in electromagnetic stealth, compatibility and wearable devices.

Enhancing Interface Connectivity for Multifunctional Magnetic Carbon Aerogels: An In Situ Growth Strategy of Metal-Organic Frameworks on Cellulose Nanofibrils.

Improving interface connectivity of magnetic nanoparticles in carbon aerogels is crucial, yet challenging for assembling lightweight, elastic, high-performance, and multifunctional carbon architectures. Here, an in situ growth strategy to achieve high dispersion of metal-organic frameworks (MOFs)-anchored cellulose nanofibrils to enhance the interface connection quality is proposed. Followed by a facile freeze-casting and carbonization treatment, sustainable biomimetic porous carbon aerogels with highly dispersed and closely connected MOF-derived magnetic nano-capsules are fabricated. Thanks to the tight interface bonding of nano-capsule microstructure, these aerogels showcase remarkable mechanical robustness and flexibility, tunable electrical conductivity and magnetization intensity, and excellent electromagnetic wave absorption performance. Achieving a reflection loss of -70.8dB and a broadened effective absorption bandwidth of 6.0GHz at a filling fraction of merely 2.2wt.%, leading to a specific reflection loss of -1450dBmm-1 , surpassing all carbon-based aerogel absorbers so far reported. Meanwhile, the aerogel manifests high magnetic sensing sensibility and excellent thermal insulation. This work provides an extendable in situ growth strategy for synthesizing MOF-modified cellulose nanofibril structures, thereby promoting the development of high-value-added multifunctional magnetic carbon aerogels for applications in electromagnetic compatibility and protection, thermal management, diversified sensing, Internet of Things devices, and aerospace.