Electromagnetic Compatibility Research Articles

Design of a Dual‐Band Waveform‐Selective Metasurface Absorber Based on the Combination of Two Resonator Structures Loaded with Nonlinear Circuits

AbstractIn this paper, a design scheme for a dual‐band waveform‐selective metasurface absorber (MSA) is presented based on the combination of two metal resonator structures loaded with nonlinear circuits. Dual‐band MSAs with four different configurations are constructed by loading capacitor/inductor‐based nonlinear circuits into the gaps of two square‐patch (SP) and two square‐ring (SR) resonators, all of which can achieve selective absorption of short pulses and continuous waves (CWs) at two frequencies independently. As a typical example, the dual‐band MSA with the SP resonator loaded with the inductor‐based nonlinear circuit and the SR resonator loaded with the capacitor‐based nonlinear circuit is systematically studied. First, the selective absorption performance of the dual‐band MSA for CWs and pulses under different input powers is demonstrated. Second, the selective absorption properties of the dual‐band MSA for pulses with different pulse widths are studied. Third, the waveform‐selective absorption characteristics of the dual‐band MSA for oblique TE and TM waves are also illustrated. Finally, the influence of circuit component parameters on the selective absorption properties of pulses and CWs is systematically studied. The proposed dual‐band MSAs have potential application areas such as antenna design, wireless communications, and electromagnetic compatibility.

A*–Ant Colony Optimization Algorithm for Multi-Branch Wire Harness Layout Planning

The planning of multi-branch cable harness layouts holds significant practical importance in aircraft industrial contexts, yet it has received limited attention in prior research. This study aims to address the matter concerning the significance of managing multiple constraints and preventing loops. It formulates the problem as an optimization problem in 3D free-form space and resolves it using an extended A* path planning approach in combination with the ant colony optimization algorithm. Initially, a feasible search space for wiring is established through the repair and simplification of the input CAD model. Subsequently, the topology of a multi-branched wiring harness is identified, taking into account industrial requirements related to cable physics, turning, support, bundling, and electromagnetic compatibility constraints. Specifically, the disassembly or merging of branches and loops is employed to avoid wire loops. Ultimately, we propose an A*–ant colony optimization algorithm (A*-ACO) with an enhanced heuristic function for neighboring points, incorporating a concentration increment model. Experimental tests illustrate the effectiveness of this approach in minimizing wire loops and reducing the total cable layout cost, considering factors such as length, bundling, and turning costs. It results in a reduction of 67.0%, 68.5%, and 51.1% compared to A*, ACO, and manual wiring methods, respectively.

Polarization-insensitive, frequency- and amplitude-tunable transparent microwave absorber based on graphene metasurface

Transparent and flexible metamaterial absorbers can provide solutions for electromagnetic compatibility and electromagnetic radiation pollution. They also play key roles in platforms with optical windows that require low detectability and immunity to electromagnetic interference. Due to the lack of active adaptability to complex electromagnetic environments, early metamaterial absorbers need to be redesigned and manufactured once the application scenarios change. The new two-dimensional material graphene provides a practical technical approach for the realization of transparent tunable absorbers. In this work, we propose a polarization-insensitive dual-tunable microwave absorber based on graphene metasurface. By controlling two separate bias voltages applied to patterned graphene or continuous graphene, independent dynamic regulation of electromagnetic wave absorption frequency and amplitude is achieved. It also possesses the features of optical transparency and flexibility. The measurement results show that the absorption frequency can be shifted from 9.8 to 11.3 GHz, the peak absorption rate at each absorption frequency remains above 99.6%, and the reflection amplitude modulation can be achieved simultaneously at each absorption frequency. The proposed absorber integrates multiple modulation functions for electromagnetic waves, and the overall structure is optically transparent and flexible. Therefore, it can contribute to many practical wave absorbing applications.

STUDY OF TRANSMISSION PARAMETERS AND MUTUAL INFLUENCE OF SIGNAL-BLOCKING CABLES WITH CURRENT-CONDUCTIVE CORES WITH INCREASED FLEXIBILITY

In recent years, the intensive development of passenger high-speed and freight heavy traffic сreated increased demands on the organization and provision of transportation, the development and implementation of new, primarily infocommunication technical means and technologies of the track complex. Russian Railways is implementing a number of significant infrastructure projects, several of which have obtained federal status. One of the main directions of of the railway network development is its widespread electrification, development and implementation of innovative infocommunication technical means and technologies for the railway infrastructure of the track complex. During the operation of electrified railways, generted high-power electromagnetic fields posing a serious problem related to electromagnetic compatibility of equipment. Therefore, requirements are placed on the quality of cables of signaling, centralization and blocking systems of railways are rather high. The article observes the transmission parameters and mutual influence of signal-blocking cables and current-carrying cores with high-flexibility.

Analysis of the Radiation from a Complex Multi-Conductor Transmission Line

The Deployment of Power Line Transmission (PLT) and the development of new broadband services over the telephone network through technology like xDSL (x Digital Subscriber Line), requires higher data rates, consequently higher bandwidths, and operating frequencies. So it is generally accompanied with electromagnetic compatibility (EMC) phenomena, in particular the radiated emissions associated to the deployed system and used cables characteristics. In fact the electrical cable presents variations in their geometry, causing an increase in the electromagnetic radiation. This paper presents a theoretical approach to study a complex transmission line network over ground plane. This approach leads to an analytical expression for the evaluation of P.U.L. parameters of finite length twisted wires lines. These expressions give the capacitances and the inductances values in every point of the cable, the theoretical results are compared to measurements. The formalism is also derived to determine the distribution of the electromagnetic field radiated by Shielded or Unshielded Twisted Pair cables with discontinuity. The obtained results are compared to those provided by a code based on the antenna theory.

Insights for improving the electromagnetic properties of conductive nanocomposites manufactured with carbon nanotubes

Additive manufacturing (AM) technologies offer many advantages that are attractive for electromagnetic compatibility (EMC) in industrial environments, and possibilities include customizable sizes and new complex internal shapes (infill) for parts. The polymeric nanocomposites with carbon-based nanomaterials, such as multi-walled carbon nanotubes (MWCNT), are of great interest and can be used for the development of functional electromagnetic components using the material extrusion (MEX) technique,. However, the literature lacks a deeper understanding of the relationship between the MEX process, the slicing parameters, the structure generated, and the electromagnetic behavior of the nanocomposite-based parts. This work studied the influence of building direction, various infill patterns, and orientations of acrylonitrile-butadiene-styrene copolymer (ABS)/MWCNT nanocomposite with 3 wt% of MWCNT on the manufacture of samples by additive manufacturing, with the evaluation of the electromagnetic interference shielding effectiveness (EMI SE) and reflection loss (RL) performances of the prepared materials. The correlation between geometric parameters and the EM response was explored and corroborated with computational simulations. The results pointed out that parts using the building direction (ZX and XY) may achieve similar shielding results depending mainly on the infill orientation. When the deposited filament (or the entire layer) is aligned with the electric field, the EM shielding behavior is maximized. In contrast, when the deposited filaments are orthogonal to the electric field, the behavior is impaired. The computational simulation of the rheological flow of the nanocomposite and the EM behavior corroborated these findings, and the MEX sample matched the attenuation of the injection molded sample behavior for a greater thickness (16 dB at 9 mm). Additionally, the RL behavior of the parts with different infill patterns and thicknesses was studied. These results indicated that the MEX process might be a promising way to promote the reflection loss (RL) behavior of conductive materials that, in bulk, would not promote such a good response. The best RL performance found was − 18 dB and 1.4 GHz bandwidth for the 50 wt% hexagonal infill pattern with an extra layer in the middle of the body sample.

DISPLACEMENT CURRENTS EFFECTS ON EARTH-RETURN PARAMETERS

The article presents the earth's contribution to self and mutual impedances of double-wired aerial lines passing over a homogenous earth (one-layered earth) due to its importance in electromagnetic compatibility problems in electric power systems. In order to clarify the earth contribution of aerial line impedance, the earth-return parameters (resistance and reactance) for numerous types of earth soil were computed from the point of view of takes into account the longitudinal displacement currents using Wise modification of Carson integration. The most popular earth soil types in our region that takes into consideration in this research are clay, loamy, and sandy soils. In all cases under study, the effect of displacement currents is classified by using the ratio of displacement current density to resistive current density (denoted by k-ratio) that depends on the electromagnetic properties of each earth soil type. Hence, the behaviors of the earth-return parameters for each type of earth soil are mainly explained according to the k-ratio. This research displays how the calculated values of earth-return parameters were affected when the displacement currents were taken into consideration. As a result, the relative differences of these calculated values that got using Wise and Carson calculation methods become noticeable when the k-ratio is greater than 0.1 for all cases under study.

Deep learning method for predicting electromagnetic emission spectrum of aerospace equipment

AbstractThis paper proposes a deep learning method to predict the electromagnetic emission spectrum in the electromagnetic compatibility (EMC) test of aerospace products. A threshold‐based data decomposition method is used to propose the spike signal, reconstruct the original test data, and solve the contradiction between the overfitting and prediction accuracy of the deep learning method to deal with the EMC test spectrum. Using a long short‐term memory neural network architecture for predicting electromagnetic emission spectrum, the Bayesian optimization method is used to optimize the network hyperparameter, and the acquisition function is introduced into the loss function to improve the comprehensive training optimization of deep learning network. Apply the method to three numerical examples: signal line current conduction emission, power line voltage conduction emission, and electric field radiation emission. The analysis results indicate that at a 95% confidence level, the predicted electromagnetic emission spectrum is basically consistent with the test results. The prediction results can be used as the basis for EMC evaluation of aerospace electronic equipment.

Electromagnetic emission of integrated circuits induced by ionizing radiation and its measurement uncertainties

In this article, we show the change of electromagnetic emission (EME) of integrated circuits (ICs) and their external circuitry induced by the presence of ionizing radiation. We use the 150 Ohm method according to IEC 61967‑4 to characterize the conducted emission of our tested integrated circuit (IC) at the VDD pin. Simultaneously to measuring the electromagnetic emission, we irradiate the IC with X‑rays. The irradiation process is carried out up to a dose of 5 Mrad using a high-power X‑ray radiation source. The electromagnetic emission spectra are retrieved before, during and after the irradiation process. We also show that special caution regarding radio frequency (RF) measurements must be used when performing combined testing. Therefore, we analyze the composition of measurement uncertainties of electromagnetic compatibility in combination with ionizing radiation hardness characterization. This article contains measurement results showing the negative impact of ionizing radiation on the electromagnetic compatibility (EMC) of an IC. Additionally we provide measures to ensure properly combined measurements of EME and ionizing radiation. Therefore we show how to reduce the electromagnetic interference originating from the high-voltage generator that is necessary to generate X‑rays.

Patent Research of DC Electric Drive Power Supply Systems Based on Active Converters With Power Correction

Despite the fact that the AC electric drive has recently been increasingly “displacing” the DC drive, it is quite relevant, because completely satisfies the requirements of technological processes. Consideration of the problem of electromagnetic compatibility of DC converter installations with the supply electrical network occupies a large place. The article provides research and analysis of the influence of valve loads on the quality of the power supply network and ways to improve the quality of power supply by replacing existing converters with active DC-DC converters with power factor correction, as well as a patent study.

Common mode far field radiation mechanisms and prediction of a buck converter with cables based on common mode voltage mutation method

AbstractIn the field of electromagnetic compatibility (EMC) research, the knowledge of the formation mechanism of the far field electromagnetic radiation and its prediction is essential for the electromagnetic noise suppression design of a switched mode power supply. This paper investigates the equivalent driving sources of the common mode (CM) current of a Buck converter with cables. Based on the concept of CM voltage mutation, this paper proposes two mechanism models of the same‐direction CM voltage driving mode and the opposite‐direction CM voltage driving mode and derives the approximate analytical formulas for the far field intensity estimation of the horizontal cables. To evaluate the predictive effectiveness of the CM far field radiation model, a 30 MHz very high frequency (VHF) Buck prototype with shielded cables is built and tested, and a shielding shell and low impedance ground conductor suppression designs are then verified. The CM electromagnetic radiation mechanisms of a non‐isolated power converter are demonstrated here. The proposed electromagnetic radiation models, approximate analytical formulas, and improvement design can help to advance the CM radiation analysis and optimization design.

Far field radiated emissions prediction of a flyback adapter with curved cables utilizing electromagnetic simulation method

AbstractRadiated emissions (RE) testing has long been a challenge in the development of a switched mode power supply (SMPS) with respect to electromagnetic compatibility performance. Accurate far‐field RE prediction can effectively help SMPS designers reveal and understand the mechanisms of radiation generation, and reasonably suppress it. In this paper, a model for predicting the radiation from a single excitation source and a parasitic radiator for a flyback adapter are proposed after analysing the common mode voltage and current paths. Then, novel methods are proposed to predict the far‐field RE of the flyback adapter based on measurements and electromagnetic simulations. Using these methods, the 10‐m far‐field radiation of the flyback adapter under the curved cables layout is accurately predicted and verified by experiments. Then, the characteristics and influencing factors of the radiation are analysed, including the far‐field patterns, the load volume, and the sag degree of the output cable. Finally, a suppression design of the capacitor‐inductor (CL) notch filter is designed for the frequency points that are above the standard limits, and the RE are reduced to less than 30 dBµV/m from 30 to 300 MHz. The research methods proposed in this paper have good reference significance for radiation analysis and prediction of power electronic devices.

3D-Printed Carbon-Based Conformal Electromagnetic Interference Shielding Module for Integrated Electronics

Highlights3D printable functional inks incorporated with graphene and carbon nanotube nanoparticles were well-formulated by manipulating their rheological performanceThe frame with ultralight structure (0.076 g cm−3) and high-efficiency electromagnetic interference shielding (61.4 dB) was assembled3D-printed c-SE module was in situ integrated onto the electronics, affording multiple functions of electromagnetic compatibility and thermal dissipation.

Electromagnetic Susceptibility Analysis of the Operational Amplifier to Conducted EMI Injected through the Power Supply Port.

Operational amplifiers (op-amps) are widely used in circuit systems. The increasing complexity of the power supply network has led to the susceptibility of the power supply port to electromagnetic interference (EMI) in circuit systems. Therefore, it is necessary to investigate the electromagnetic susceptibility (EMS) of op-amps at the power supply port. In this paper, we assessed the effect of EMI on the operational performance of op-amps through the power supply port by a bulk current injection (BCI) method. Firstly, we conducted the continuous sine wave into the power supply port by a current injection probe and measured the change in the offset voltage under EMI. Secondly, we proposed a new method of conducted susceptibility and obtained the susceptibility threshold regularities of the op-amps at the power supply port under the interference of different waveform signals. Our study provided conclusive evidence that EMI reduced the reliability of the op-amp by affecting the offset voltage of op-amps and demonstrated that the sensitivity type of op-amps was peak-sensitive at the power supply port. This study contributed to a deep understanding of the EMS mechanism and guided the design of electromagnetic compatibility (EMC) of op-amps.

A modular and scalable system for electromagnetic compatibility testing of integrated circuits

To bring automotive integrated circuits (ICs) to market, manufacturers must subject their products to numerous electromagnetic compatibility (EMC) tests such as electromagnetic immunity and emission tests, or electrostatic discharge (ESD) tests. These tests need EMC test boards that meet the requirements of the specific standards. However, the current need to increase the frequency range of EMC tests poses a challenge in designing standard-compliant test boards. In this paper, we address this issue by introducing a modular and reusable IC level EMC test system. We demonstrate the system’s effectiveness with an example of two frequently used and conducted EMC tests: the direct power injection (DPI) immunity test and the 150Ω\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$150\\,\\mathrm{\\Omega}$$\\end{document} electromagnetic emission measurement. The two test setups are constructed and validated using the presented modules. It is shown how the frequency range can be expanded while minimizing costs and design efforts for the EMC test board design.

Influence of the IC power supply and decoupling capacitor arrangement on the electromagnetic emission

With the advancing development of integrated circuits (ICs), more and more complex functions and higher performance levels can nowadays directly be integrated into a single IC package. In this context, the issue of electromagnetic compatibility (EMC) is becoming more critical, as the higher the integration density, the higher the electromagnetic emissions tend to be. In this paper, an EMC test IC is used to investigate the influence of different power supply pinouts (arrangement of VDD and GND pins in center and corner configuration) on the electromagnetic emission of the IC. This is done on the basis of the surface-scanning technique described in the IEC 61967‑3 standard for characterizing the magnetic near field at the surface of the IC package, and on the basis of the 150 Ohm measurement method described in IEC 61967‑4 for determining the conducted interference emissions at the power supply pinout of the IC. Both measurement methods show a significant difference in electromagnetic emissions due to the dependence on the arrangement of the power supply pinouts. These results highlight the importance of careful power supply design in the development of electromagnetically compatible ICs.

Heterostructured BN@Co‐C@C Endowing Polyester Composites Excellent Thermal Conductivity and Microwave Absorption at C Band

AbstractThe trends of miniaturization, lightweight, and high integration in electronics have brought serious issues in heat dissipation and electromagnetic compatibility and also limited the simultaneous use of thermally conductive and microwave absorption materials. Therefore, it is imperative to design materials that possess those dual functions. In this work, one‐pot method is used to anchor zeolitic imidazolate framework ZIF‐67 coated with polydopamine (PDA) on boron nitride (BN) to obtain BN@ZIF‐67@PDA. The pyrolysis product BN@Co‐C@C is used as heterostructured thermally conductive/microwave absorption fillers and blended with polyethylene terephthalate (PET) to prepare BN@Co‐C@C/PET composites. When the mass ratio of BN to ZIF‐67@PDA is 7.5:1 and the mass fraction of BN7.5@Co‐C@C is 45 wt%, the BN7.5@Co‐C@C/PET composites exhibit excellent thermal conductivities and microwave absorption performances. The thermal conductivity coefficient is 5.37 W m−1 K−1, which is 35.8 times higher than that of PET (0.15 W m−1 K−1), and also higher than that of 45 wt% (BN7.5/Co‐C@C)/PET composites (4.03 W m−1 K−1) prepared by directly mixing. The minimum reflection loss of 45 wt% BN7.5@Co‐C@C/PET composites are −63.1 dB at 4.72 GHz, and the corresponding effective absorption bandwidth is 1.28 GHz (4.08–5.36 GHz), achieving excellent microwave absorption performance at C band.

Flexible Double‐Layer Adjustable Frequency Selective Surfaces Based on 3D Cross‐Shaped Kirigami Structure

AbstractFrequency‐selective surfaces (FSS) with flexible treatment can be employed in various applications. This paper develops a mechanically constructed flexible double‐layer adjustable FSS based on a 3D cross‐shaped kirigami structure design. Through mechanical stretching, the kirigami structure partly adhered to the ecoflex substrate enables this FSS to modulate the resonant frequencies of two filter bands synchronously. Meanwhile, the structural deformation triggered by mechanical stretching may function as a switch to adjust the filter band with a higher resonant frequency. According to the results of EM experiments and simulations, in the absence of stretching, the undeformed FSS with a double‐layer structure has two filter bands. Compared to the undeformed configuration, the stretching induces structural deformation, which results in apparent resonant frequency shifts of both the two filter bands and the contraction of the filter band with higher resonant frequency. A buckling model that has been theoretically, cumulatively, and experimentally proven is utilized to investigate the structural deformation of this FSS caused by stretching. It is convenient to switch flexible double‐layer adjustable FSS' deformation by mechanical method. This flexible double‐layer adjustable FSS offers a new design strategy for the application of FSS, paving the route for new developments in electromagnetic compatibility.

МИКРОКОНТРОЛЛЕРЫ ДЛЯ ПРИМЕНЕНИЯ В МЕДИЦИНСКИХ УСТРОЙСТВАХ: ВОЗМОЖНОСТИ И ВЫЗОВЫ

The article considers the use of microcontrollers in medical devices, analyzing their potential and challenges. The main opportunities, such as increasing functionality, energy saving and integration with other systems, as well as technical problems related to data security, reliability and electromagnetic compatibility are described. Prospects for technology development and overcoming existing limitations are discussed.

ЭЛЕКТРОМАГНИТНАЯ СОВМЕСТИМОСТЬ (EMC) В СОВРЕМЕННЫХ ЭЛЕКТРИЧЕСКИХ И ЭЛЕКТРОННЫХ УСТРОЙСТВАХ

Electromagnetic compatibility (EMC) is a critical aspect of the development of modern electrical and electronic devices, as it ensures the reliability and safety of their operation in challenging electromagnetic environments. This paper discusses the basic principles of EMC, the impact of electromagnetic interference on the performance and safety of devices, and modern approaches to minimizing these interferences at the design stage. Particular attention is paid to the challenges associated with new technologies such as 5G and IoT, and the prospects for the development of EMC in the context of the increasing integration of electronics into various areas of life. In conclusion, future research directions and innovations in the field of electromagnetic compatibility are discussed.