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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. [ABSTRACT FROM AUTHOR]

This letter proposes a method to calculate the expected value of the shielding effectiveness of a composite material slab, including a planar array of randomly oriented metal helices as chiral particles. Helix‐loaded concrete composite materials are advantageous for electromagnetic interference shielding applications. While planar periodic arrays of chiral particles have been extensively studied, this research discusses a non‐periodic array in which the helical particle axis direction in each unit cell is random. This method estimates the slab's shielding effectiveness by defining it as a random variable expanded into three independent basis‐like functions. Comparisons with full‐wave simulations show acceptable agreement across a wide frequency range, with a total RMS error of 0.9 dB. This study additionally includes an experimental measurement to validate the proposed method. This technique provides the initial step in developing an analytical method to analyse and estimate the transmitted power of general structures using a stochastic approach. Examples include concrete composites containing randomly distributed helical steel particles with significant shielding effectiveness. [ABSTRACT FROM AUTHOR]

Generally, various technologies, including waveguide below cutoff (WBC), gasket sealing, and bonding, are employed in metallic enclosures to achieve the high electromagnetic shielding performance required for EMP protection and EMC countermeasures in shielding structures or facilities. While the shielding structure or facility is properly constructed and maintained according to design specifications, its electromagnetic shielding performance can remain at the required level, effectively protecting internal electrical and electronic equipment from external electromagnetic interference. However, unintended apertures often occur during the construction or maintenance of shielding facilities, compromising their shielding performance. Therefore, it is crucial to develop technologies that prevent shielding effectiveness degradation caused by both intentional and unintentional apertures. This paper proposes a structure incorporating a composite absorber (made of dielectric and magnetic absorber) within a double metal panel of enclosure featuring an aperture, aimed at maintaining and improving the facility's shielding performance. The effectiveness of the proposed structure was validated through numerical simulation. [ABSTRACT FROM AUTHOR]

Microwave absorbing materials play an increasingly important role in modern electronic warfare technology for enhancing electromagnetic compatibility and suppressing electromagnetic interference. High‐entropy ceramics (HECs) possess extraordinary physical and chemical properties, and more importantly, the high tunability of multi‐component HECs has brought new opportunities to microwave absorbing materials. Rich crystallographic distortions and multi‐component occupancies enable HECs to have highly efficient microwave absorption properties, excellent mechanical properties, and thermal stability. Therefore, the structural advantages of HECs are integrated from comprehensive perspectives, emphasizing on the role of dielectric and magnetic properties in the absorption phenomenon. Strategies are proposed to improve the microwave absorption capacity of HECs, including composition optimization, microstructure engineering, and post‐treatment technology. Finally, the problems and obstacles associated with high‐entropy materials (HEMs) research are discussed. The innovative design concepts of high‐entropy microwave absorbing ceramics are highlighted. [ABSTRACT FROM AUTHOR]

Direct current (DC) motors are crucial in drones, robotics, and electrical devices. Conventionally, the DC motor is driven by a switching electricity converter, which utilizes electrical energy to drive mechanical motion. However, the rapid on-off switching actions in the switching electricity converter would cause electromagnetic interference (EMI), impairing the functionality of drive systems. Here, we propose a photon-driven DC motor system based on photonic converter, which utilizes optical energy to drive mechanical motion, and therefore avoids EMI derived from electrical switching and immunizes against EMI during electrical energy transmission in conventional switching electricity-driven DC motor system. The operation principle and power modulation-based speed control are also presented for the proposed photon-driven DC motor system. The experiments demonstrate that the motor accurately follows the speed reference and withstands load disturbances. This innovation opens new potential for DC motor applications by improving electromagnetic compatibility. The researchers showcase a photon-driven DC motor system, that utilizes optical energy to drive mechanical motion, avoids EMI derived from electrical switching action and immunizes against EMI in conventional electricity-driven DC motor systems [ABSTRACT FROM AUTHOR]

Time reversal exploits the invariance of electromagnetic wave propagation in reciprocal and lossless media to localize radiating sources. Time‐reversed measurements are back‐propagated in a simulated domain and converge to the unknown source location. The focusing time (i.e. the simulation instant at which the fields converge to the source location) and the source location can be identified using field maxima, entropy, time kurtosis, and space kurtosis. This paper analyses the spatial energy‐density distribution of time‐reversed electromagnetic fields by introducing a convergence metric based on the spatial average and variance of the energy density. It is analytically proven that the proposed metric identifies the focusing time and the source location, with direct links to the source frequency content. The analytical results are verified in a free‐space numerical simulation and the proposed metric is then compared to existing ones in a simulated inhomogeneous medium. Next, this metric is applied and compared in an experimental case study to localize electromagnetic interference sources. The proposed metric outperforms existing ones to identify the focusing time and can also be used to locate the source. Finally, because of its tensorial nature, it can handle anisotropic media, opening the door to quantitative analyses of time‐reversal focusing in metamaterials. [ABSTRACT FROM AUTHOR]

Summary: In this article, we investigated a new structure of a protective meander line (ML): a meander microstrip line (MSL) with two passive conductors. The existing theory of ultra‐short pulse (USP) attenuation in MLs is presented for the first time. Based on this theory, we determined the number of decomposed pulses at the output of the MSL line with two passive conductors, and, for the first time, formulated the conditions for pulse decomposition in the line. The folding of the MSL line into non‐core turns was studied in detail. As a result of this article, we proposed a new theory that involves the utilization of additional groups of decomposed pulses for enhanced USP attenuation. These additional groups were thoroughly examined, and the delays of pulses from these groups were defined. This analysis allowed identifying the reason for their appearance. It was revealed that folding the ML into non‐core turns allows further attenuation of the USP amplitude, which increases with the increase of the number of non‐core turns. To validate the obtained simulation results, we performed experimental measurements and obtained good consistency of the results. The N‐norms analysis demonstrated that the combined use of such folding and passive conductors reduces the probability of electrical breakdown, arc discharge, and dielectric breakdown. The maximum USP attenuation at the output was 24.9 dB. As a result of useful signal integrity analysis, it is proposed to use a folded MSL together with a USB 2.0 "Full‐speed" interface with a data transfer rate of 12 Mbit/s. In addition, it is proposed to use such MSLs in DC power circuits. [ABSTRACT FROM AUTHOR]

This research paper proposes a unique way to safeguard delicate systems on submerged platforms from the undesirable effects of underwater explosion shock loads. The underwater detonation of an explosive charge and mines produce devastating underwater shocks against underwater platforms. Shock load developed underwater has been analyzed, and a shock response spectrum (SRS) approach to compute shock peak responses has been adopted. SRS shock absorption frequency satisfies requirements for both shock absorption and delicate systems. The shock load was reduced to 2g by altering the delicate system stiffness and damping properties. The analytical model for a single DOF system was formulated, and simulation was carried out using ANSYS solver. The stiffness has been spread across various points along the length of the delicate system, allowing it to undergo translational oscillations when subjected to shock loads. This research paper presents an innovative design approach for a shock absorption system intended for underwater sensitive objects, emphasizing simplicity, distinctiveness, compactness, reliability, and electromagnetic compatibility. Experimental testing validated the shock absorption design on the prototype. Shock testing determined the absorber's maximum displacement and sensitive object acceleration. [ABSTRACT FROM AUTHOR]

The objective of this study is to assess the impact of low-frequency electromagnetic fields (LF EMFs) generated by power infrastructure on the nearby environment. Measurements of electric (E) and magnetic (H) field intensities were conducted around high-voltage power lines, transformer stations and facilities related to them. Numerical simulations were also performed to model the distribution of the field values around real buildings in close proximity to power delivery systems. Given the ongoing scientific debate regarding the effects of EMFs on living organisms, the current analysis was based on the existing standards—particularly ICNIRP 2010 guidelines, which set the maximum allowable E and magnetic induction (B) values at 5 kV/m and 200 μT, respectively. Stricter national regulations were also examined, such as Poland's 1 kV/m E limit in residential areas and Belgium's 10 μT limit for B. The results showed that while most cases complied with ICNIRP 2010 standards, certain stricter local regulations were exceeded. Specifically, 9 of 14 cases exceeded Poland's E limits, and 8 failed to meet Belgium's B requirements. Only in one place—a warehouse near 110 kV power lines (in a critical case)—the ICNIRP limit B was exceeded. These findings underscore the variability in regulatory standards and highlight the need for localized assessments of EMF exposure. [ABSTRACT FROM AUTHOR]

Copyright of Automotive Digest is the property of Automotive Digest Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper presents a schematic solution of a transistor converter for induction heating equipment featuring two/three frequency output current. The proposed solution enables discrete adjustment of the input voltage of the inverter within the converter, facilitating alignment with the load impedance of the induction heating equipment through the sequential modulation of currents at different frequencies. Detailed descriptions of the operational modes of the DC/DC converter are provided, highlighting its unique characteristic of operating semiconductor elements in an almost static mode with minimal dynamic losses. This innovative approach not only enhances energy efficiency but also elevates electromagnetic compatibility in converters designed for induction heating equipment with two/three-frequency output currents. References 10, figures 4. [ABSTRACT FROM AUTHOR]

Introduction. The presence of broad-spectrum and high-amplitude electromagnetic interference (EMI) within a single-phase induction motor (SPIM) drive poses a significant threat to both the system and other electronic equipment. High-frequency (HF) models of electrical motors play a critical role in overcoming these challenges, as they are essential for characterizing electromagnetic compatibility (EMC) in drives and designing effective EMI filters. The novelty of this study proposes an enhanced HF motor model based on transfer functions (TFs) to accurately represent the motor’s behavior at HFs for frequency-domain analyses in the range of 100 Hz to 30 MHz. Purpose. The equivalent HF model for a SPIM is discussed in this paper. The suggested equivalent circuit describes a motor’s common-mode (CM) properties. Methodology. HF model was developed by a frequency-domain analysis utilizing an experimental setup and MATLAB software. The motor impedance analysis is based on the measurement of variations in motor characteristics as a function of frequency in the CM setup. Originality. TF has been tuned using an asymptotic identification method of Bode to match the behavior of the real impedances of the motor parameters as a function of the frequency in the CM configuration. This tuned TFs are then synthesized into a comprehensive wideband EMC equivalent circuit model using the Foster network technique, which can be then simulated in any Spice-based simulator tools. Results. The proposed mathematical model was employed to conduct simulations, and the resulting predictions were validated against experimental data. CM response of the EMC equivalent circuit at low, medium, and HFs were compared between simulations and experimental measurements using Lt-Spice simulator software. Practical value. It is observed that results show satisfactory agreement with the measurements over a large frequency bandwidth [100 Hz–30 MHz], and the equivalent model of SPIM can be cascaded with other electronic and electrical modules to form a complete single-phase electric drive system model for fast analysis and prediction of system level EMI and electromagnetic sensitivity. [ABSTRACT FROM AUTHOR]

The Method of Moments (MoM) is a non-embedded uncertainty analysis method that has been widely used in Electromagnetic Compatibility (EMC) simulations in recent years due to its two major advantages of high computational efficiency and immunity from dimensional disaster. A random variable sensitivity calculation method based on the Complex Number Method of Moments (CNMoM) is proposed in this paper to improve the accuracy of the MoM in standard deviation prediction and thereby enhance the credibility of EMC simulation uncertainty analysis results. In the parallel cable crosstalk prediction example in the literature, the result of the Monte Carlo Method (MCM) is used as the standard, and the accuracy of the new method proposed in this paper is quantitatively verified using the Feature Selective Validation (FSV) method. Compared with the MoM, the proposed method can significantly improve the calculation accuracy of the standard deviation results without sacrificing simulation efficiency. [ABSTRACT FROM AUTHOR]

Copyright of Telecommunication Engineering is the property of Telecommunication Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The 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. [ABSTRACT FROM AUTHOR]

In this paper, a comparison of the emissions of grid-connected converters under grid distortion in the supraharmonic range is performed. The investigated supraharmonic grid distortion is divided into two types, namely odd-integer and even-integer multiples of the grid frequency. It is found that the first distortion type does not affect the emissions of the grid-connected converters, while the second distortion is responsible for the 2N-harmonic emissions that appear in the frequency spectra of the grid-connected converters, which, in turn, interact with the supraharmonic primary emissions of these converters, resulting in additional supraharmonic emissions. To explain this behavior, a mathematical analysis is provided for two types of grid-connected converters with an inverter interface and with a diode bridge rectifier interface. Simulations and experimental studies are performed to verify the main findings of the mathematical analysis. [ABSTRACT FROM AUTHOR]

The localization of electromagnetic radiation leakage through cabin gaps is a critical and challenging aspect of electromagnetic compatibility (EMC) design for spacecraft with complex electromagnetic environments. This paper proposes a localization method based on synthetic aperture interferometric passive radiometry imaging. Electromagnetic radiation signals are measured at a certain distance from the spacecraft surface to form visibility samples. A Fourier transform pair between the visibility sample and the corrected brightness temperature for electromagnetic radiation leakage is established. The spacecraft surface electromagnetic leakage location image is obtained through the inverse Fourier transform. A sparse sampling method based on ant colony optimization was proposed to improve testing efficiency. The impacts of various factors, including positional parameters, positioning accuracy of the test antenna, scanning parameters, and measurement receiver amplitude/phase errors on the imaging results are analyzed. Experiments were conducted on a 1 m × 1 m × 1 m cabin with 51 holes on one surface, and the algorithm proposed in this paper was validated to effectively image and locate electromagnetic leakage points at different frequencies. The effectiveness of sparse sampling was also verified, with a localization accuracy of 90.2% and a testing time savings of 81.9%. [ABSTRACT FROM AUTHOR]

Coconut coir-based porous carbon (CCPC) and magnetic iron (Fe) particle composite (CCPC/Fe) have been developed and characterized for potential applications in unmanned aerial vehicles (UAVs). Coconut coir was extracted from coconut husks and Fe compounds are impregnated to form CCPC/Fe. A comprehensive analysis was conducted, encompassing XRD analysis, revealing the presence of crystalline Fe particles and amorphous carbon, with broadened peaks and a crystalline size of 16.68 nm. Raman spectroscopy showed distinctive structural properties. UV-Vis spectroscopy exposed unique absorption peaks and SEM imaging confirmed the retention of porous structures and the successful integration of Fe particles. EDS analysis provided insights into the elemental composition, emphasizing the varying compositions of the sample. The VNA testing reflection loss value of -26 dB (2 mm thick sample) calculated from VNA testing indicated EM wave attenuation of > 99 %. These results underscores the potential of CCPC/Fe, making it an attractive candidate for advanced applications like EM wave attenuation in UAVs. The research contributes to materials science by offering a sustainable, cost-effective solution to enhance electromagnetic compatibility in UAVs, ensuring dependable and secure operation across diverse environments. [ABSTRACT FROM AUTHOR]

The analysis of magnetic near‐field radiation emissions (MNRE) has recently raised more attention in device‐level electromagnetic compatibility testing. Pattern clustering of MNRE for integrated circuits manually is very time‐consuming because of the multi‐dimensional characteristics of MNRE, such as frequency, spatial position, emission intensity, etc. This paper proposes a novel pattern clustering method of MNRE, including strong emission frequency extraction, feature extraction, and density‐based clustering. Ring oscillator and five working states are designed on a Field Programmable Gate Array with 256 Ball Grid Array package, which are used to create a complex multi‐source emission case for verifying the effectiveness of the clustering method. The verification results show that the proposed method can correctly cluster the multi‐source emission patterns. Further, the method is also applied to a Microcontroller Unit with unknown operating states; the results show that the proposed method also can effectively distinguish the unknown emission patterns and locate the unknown interference source. The accuracy of the interference source location is proven by 3D X‐ray microscope inspection. [ABSTRACT FROM AUTHOR]

Copyright of Automotive Engineer (1674-6546) is the property of Auto Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Time reversal exploits the invariance of electromagnetic wave propagation in reciprocal and lossless media to localize radiating sources. Time‐reversed measurements are back‐propagated in a simulated domain and converge to the unknown source location. The focusing time (i.e. the simulation instant at which the fields converge to the source location) and the source location can be identified using field maxima, entropy, time kurtosis, and space kurtosis. This paper analyses the spatial energy‐density distribution of time‐reversed electromagnetic fields by introducing a convergence metric based on the spatial average and variance of the energy density. It is analytically proven that the proposed metric identifies the focusing time and the source location, with direct links to the source frequency content. The analytical results are verified in a free‐space numerical simulation and the proposed metric is then compared to existing ones in a simulated inhomogeneous medium. Next, this metric is applied and compared in an experimental case study to localize electromagnetic interference sources. The proposed metric outperforms existing ones to identify the focusing time and can also be used to locate the source. Finally, because of its tensorial nature, it can handle anisotropic media, opening the door to quantitative analyses of time‐reversal focusing in metamaterials.

Introduction. The presence of broad-spectrum and high-amplitude electromagnetic interference (EMI) within a single-phase induction motor (SPIM) drive poses a significant threat to both the system and other electronic equipment. High-frequency (HF) models of electrical motors play a critical role in overcoming these challenges, as they are essential for characterizing electromagnetic compatibility (EMC) in drives and designing effective EMI filters. The novelty of this study proposes an enhanced HF motor model based on transfer functions (TFs) to accurately represent the motor’s behavior at HFs for frequency-domain analyses in the range of 100 Hz to 30 MHz. Purpose. The equivalent HF model for a SPIM is discussed in this paper. The suggested equivalent circuit describes a motor’s common-mode (CM) properties. Methodology. HF model was developed by a frequency-domain analysis utilizing an experimental setup and MATLAB software. The motor impedance analysis is based on the measurement of variations in motor characteristics as a function of frequency in the CM setup. Originality. TF has been tuned using an asymptotic identification method of Bode to match the behavior of the real impedances of the motor parameters as a function of the frequency in the CM configuration. This tuned TFs are then synthesized into a comprehensive wideband EMC equivalent circuit model using the Foster network technique, which can be then simulated in any Spice-based simulator tools. Results. The proposed mathematical model was employed to conduct simulations, and the resulting predictions were validated against experimental data. CM response of the EMC equivalent circuit at low, medium, and HFs were compared between simulations and experimental measurements using Lt-Spice simulator software. Practical value. It is observed that results show satisfactory agreement with the measurements over a large frequency bandwidth [100 Hz–30 MHz], and the equivalent model of SPIM can be cascaded with other electronic and electrical modules to form a complete single-phase electric drive system model for fast analysis and prediction of system level EMI and electromagnetic sensitivity. References 37, table 5, figures 13.

Absorption of electromagnetic (EM) wave has been widely studied and applied in EM, optics, and material research. By constructing an adaptive multi-mode absorption, an EM absorber approach that can be used in a variety of EM environments is provided in this research. This property demonstrates the absorber has an improved environment compatibility. It is used as an application example to address the issue that has recently come up in phased array research on the need to reduce the coupling between antenna elements in varied beam-scanning cases. After analyzing the electric and magnetic characteristics of a patch antenna array in different beam-scanning states, an absorber structure is constructed, with electric absorption in the sum beam case, magnetic absorption in the difference beam case, and combined electric-magnetic absorption in other beam scanning cases. The proposed method is systematically investigated and, finally validated by simulation and measurement evidently. In arbitrary beam-scanning states, the absorber exhibits good absorption and coupling reduction performance, while the radiation performance of the array is well maintained after introducing the absorber. This research can be used in absorber and coupling reduction studies, as well as, potentially in metamaterial and electromagnetic compatibility (EMC). [ABSTRACT FROM AUTHOR]

Introduction. Electromagnetic shielding is used as an additional design tool to ensure electromagnetic compatibility of electronic devices. The shielding material is selected based on its electrophysical parameters at the design stage of electronic devices, taking its electrical and operational characteristics into account. The shielding effectiveness (SE) of composite, layered, or fabric materials with a high electrical conductivity and relative magnetic permeability in a wide frequency range (10 Hz…10 GHz) is difficult and, in some cases, impossible to assess a priori. At the same time, the number of studies in this direction is currently limited.Aim. To generalize models and methods for calculating and measuring the insertion losses (IL) and SE of materials using dual and coaxial TEM cells in a wide frequency range.Materials and methods. A method for calculating IL for the electric (E) and magnetic (H) components of the field based on the measured S parameters in a dual TEM cell is described. Expressions for calculating an unloaded dual TEM cell are proposed. These expressions differ in terms of considering the thickness of the material and the tooling that prevents sagging of thin materials, thus allowing the difference between the measured and calculated values of S parameters to be reduced to 3.2 dB. Methods for measuring and calculating the SE of composite materials are described. The results obtained using these methods are compared with those obtained by a standardized method for SE calculation.Results. The frequency dependencies of the IL for the E and H fields calculated on the basis of the measured S parameters of a dual TEM cell with a cotton and knitted shielding fabric placed inside are presented. The results obtained by the classic and electrodynamic modeling are compared with experimental results for a composite material in a new patented coaxial TEM cell.Conclusion. Models and methods for calculating and measuring IL and SE can be effectively used for a relatively rapid control and testing of new and available shielding materials, taking the above assumptions and limitations into account.

Abstract This work proposes two differential magnetic‐field resonant probes, consisting of a U‐shaped single‐loop resonant probe (S_probe) and a dual‐loops resonant probe (D_probe). These resonant probes are composed of a pair of LC resonant circuits, a pair of strip‐lines with two outputs, two rows of via fences, and two different sensing structures (single‐loop and dual‐loops). Among them, a pair of open stubs as capacitor and shorted stubs as inductor is used to form the LC resonant circuit, via fences are utilized to suppress unwanted electromagnetic wave modes, a U‐shaped single‐loop and a pair of differential dual‐loops is used to receive the electromagnetic signal. In order to prove the rationality of the design, simulation models of the S_probe and D_probe are optimized and manufactured based on four‐layers PCBs. In addition, a near‐field scanning system with a standard 50 Ω straight microstrip line as calibration kit is used to measure and calibrate these resonant probes. The tested results indicate that these designed magnetic‐field probes could operate at 1.575 GHz and have high detection sensitivity and electric‐field suppression.

Abstract Active gate driving (AGD) is a promising concept for achieving high‐performance power transistor switching. This is particularly crucial for Silicon Carbide (SiC) MOSFETs since their inherently fast switching characteristics give rise to severe overshoots and oscillations which translate into increased levels of electromagnetic interference (EMI) emissions. In this paper, an AGD strategy using a single‐pulse applied during the switching transient is considered for a 1200 V 400 A SiC MOSFET module. The effect of single‐pulse timing, load current, and temperature on the switching performance is analyzed in detail. The radiated EMI reduction benefits are quantified by H‐field and E‐field probes. A conceptual closed‐loop AGD approach is presented and compared to open‐loop operation. For the transistor turn‐off case under full load current of 400 A, experimental results show that it is possible to reduce voltage overshoot by 43.3%, voltage and current oscillations by 69.7% and 52.2% respectively, and EMI by 76.6%, with a trade‐off in the switching energy by a relatively minor increase of 18.2%, compared to the conventional gate driving case. For the turn‐on case, current overshoot was reduced by 32.7%, EMI by 52%, voltage and current oscillations by 54.6% and 52.8%, respectively, with a penalty of 50.9% increase in the switching loss.

Abstract Harmonics and electromagnetic interference (EMI) pose serious threats to the safety and efficiency of grid‐tied inverters. Although the inductor‐capacitor‐inductor (LCL) filter offers commendable harmonic suppression, it does not sufficiently mitigate leakage current and EMI caused by high‐frequency pulse‐width modulation (PWM). This paper examines the use of a symmetrical LCL filter to reduce the AC side leakage current in grid‐tied inverters. The symmetrical structure bolsters the conducted EMI suppression capability of the LCL filter. A magnetic integration scheme for symmetric LCL filters is introduced, and through thoughtful structural design, it achieves filter inductance integration on the EIE magnetic core. An experimental platform, equipped with a high‐frequency SiC‐MOSFET voltage source inverter with a 600 W output, is utilized. The LCL filter, symmetric LCL filter, and magnetic integrated symmetric LCL filter are contrasted, proving the effectiveness and feasibility of the proposed scheme. Furthermore, the experimental results demonstrate that the proposed magnetic integration scheme significantly reduces the filter's volume and weight, thereby enhancing the power density of the grid‐tied inverter system.

Abstract Radiated 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.

Abstract In 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.

Ensuring the correct operation of electrical equipment in tandem is a critical engineering concern, particularly when addressing the issue of electromagnetic compatibility (EMC). In satellite systems, EMC considerations must be addressed from the initial design phases, as methods such as shielding or the addition of suitable filters are not always feasible or optimal. This article examines the necessity of shielding the LVDS (Low-Voltage Differential Signaling) bus cabling of the satellite's camera, which is located on the satellite's exterior. The study begins with the simulation of the LVDS bus cabling to assess the need for shielding, and the results are subsequently validated through electromagnetic compatibility testing. The research findings indicate that, while shielding the LVDS bus cable of the camera can improve protection by a factor of ten thousand in the worst-case scenario during Radiated Emission (RE) and Radiated Susceptibility (RS) tests, the low level of interference radiation in RE (approximately E7–8 V/m or E4/1–11 A/m) and the small amplitude of the interference signal in RS (approximately 0.001 V) suggest that shielding is not necessary. Shielding would only increase the satellite's mass and complicate the connection without significant benefits. It is evident from this study that simulating Conducted Emission (CE) and Conducted Susceptibility (CS) tests in subsequent design phases is essential to ensure comprehensive EMC assessment.

The proton therapy system has significant clinical advantages over traditional tumor radiation treatment equipment and is also far more complex in terms of system architecture. However, due to the large size and complexity of these devices, electromagnetic compatibility testing faces considerable challenges. To address these challenges, this paper studies the electromagnetic characteristics and working principles of various components in the proton therapy system, combines them with corresponding standard requirements, and delves into the difficulties and testing methods of electromagnetic compatibility immunity detection through actual repeated tests. Furthermore, the paper proposes testing key points for beam quality tests and provides references for the selection of emission sources and distance settings in radio frequency electromagnetic field radiation immunity testing. The paper also supplements and improves the descriptions of alternative methods in the standards and offers solutions and testing suggestions for issues such as the excessive thickness of cables in the proton therapy system and the lack of suitable fixtures in conducted anti-interference tests. The provision of these solutions offers more effective references for related staff during testing, helps address difficulties encountered in practical operations, and thus more effectively ensures the safety and effectiveness of proton therapy systems.

Active gate driving (AGD) is a promising concept for achieving high‐performance power transistor switching. This is particularly crucial for Silicon Carbide (SiC) MOSFETs since their inherently fast switching characteristics give rise to severe overshoots and oscillations which translate into increased levels of electromagnetic interference (EMI) emissions. In this paper, an AGD strategy using a single‐pulse applied during the switching transient is considered for a 1200 V 400 A SiC MOSFET module. The effect of single‐pulse timing, load current, and temperature on the switching performance is analyzed in detail. The radiated EMI reduction benefits are quantified by H‐field and E‐field probes. A conceptual closed‐loop AGD approach is presented and compared to open‐loop operation. For the transistor turn‐off case under full load current of 400 A, experimental results show that it is possible to reduce voltage overshoot by 43.3%, voltage and current oscillations by 69.7% and 52.2% respectively, and EMI by 76.6%, with a trade‐off in the switching energy by a relatively minor increase of 18.2%, compared to the conventional gate driving case. For the turn‐on case, current overshoot was reduced by 32.7%, EMI by 52%, voltage and current oscillations by 54.6% and 52.8%, respectively, with a penalty of 50.9% increase in the switching loss. [ABSTRACT FROM AUTHOR]

With the advancements in Industry 4.0 and the global demand for sustainable energy, power electronics devices are emerging as pivotal components for modern industrial, transportation, and energy delivery. Ensuring the security of these devices is of paramount importance for safeguarding the reliable operation of critical systems against any threats. In recent years, the issue of intentional electromagnetic interference (IEMI) attack and their related countermeasures have gained widespread attention in both military and civilian power electronics sectors. Here, a review of IEMI in power electronics is provided. Starting from the electromagnetic compatibility standards, the test setups for evaluating the device immunity are introduced. Due to different attack modes and propagation paths, IEMI illuminations are typically categorized into conduction and radiation, where their susceptibility studies, applications, and defence strategies are discussed, respectively. Finally, the existing challenges, ongoing trends, and future topics in this field are discussed. [ABSTRACT FROM AUTHOR]

In 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. [ABSTRACT FROM AUTHOR]

Radiated 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. [ABSTRACT FROM AUTHOR]

Harmonics and electromagnetic interference (EMI) pose serious threats to the safety and efficiency of grid‐tied inverters. Although the inductor‐capacitor‐inductor (LCL) filter offers commendable harmonic suppression, it does not sufficiently mitigate leakage current and EMI caused by high‐frequency pulse‐width modulation (PWM). This paper examines the use of a symmetrical LCL filter to reduce the AC side leakage current in grid‐tied inverters. The symmetrical structure bolsters the conducted EMI suppression capability of the LCL filter. A magnetic integration scheme for symmetric LCL filters is introduced, and through thoughtful structural design, it achieves filter inductance integration on the EIE magnetic core. An experimental platform, equipped with a high‐frequency SiC‐MOSFET voltage source inverter with a 600 W output, is utilized. The LCL filter, symmetric LCL filter, and magnetic integrated symmetric LCL filter are contrasted, proving the effectiveness and feasibility of the proposed scheme. Furthermore, the experimental results demonstrate that the proposed magnetic integration scheme significantly reduces the filter's volume and weight, thereby enhancing the power density of the grid‐tied inverter system. [ABSTRACT FROM AUTHOR]

This work proposes two differential magnetic‐field resonant probes, consisting of a U‐shaped single‐loop resonant probe (S_probe) and a dual‐loops resonant probe (D_probe). These resonant probes are composed of a pair of LC resonant circuits, a pair of strip‐lines with two outputs, two rows of via fences, and two different sensing structures (single‐loop and dual‐loops). Among them, a pair of open stubs as capacitor and shorted stubs as inductor is used to form the LC resonant circuit, via fences are utilized to suppress unwanted electromagnetic wave modes, a U‐shaped single‐loop and a pair of differential dual‐loops is used to receive the electromagnetic signal. In order to prove the rationality of the design, simulation models of the S_probe and D_probe are optimized and manufactured based on four‐layers PCBs. In addition, a near‐field scanning system with a standard 50 Ω straight microstrip line as calibration kit is used to measure and calibrate these resonant probes. The tested results indicate that these designed magnetic‐field probes could operate at 1.575 GHz and have high detection sensitivity and electric‐field suppression. [ABSTRACT FROM AUTHOR]

Traditional electromagnetic interference–shielding materials are predominantly electrically conductive, posing short-circuit risks when applied in highly integrated electronics. To overcome this dilemma, we propose a micro capacitor-structure model comprising conductive fillers as polar plates and intermediate polymer as a dielectric layer to develop insulating electromagnetic interference–shielding polymer composites. The electron oscillation in plates and dipole polarization dielectric layers contribute to the reflection and absorption of electromagnetic waves. Guided by this, the synergistic nonpercolation densification and dielectric enhancement enable our composite to combine high resistivity, shielding performance, and thermal conductivity. Its insulating feature allows for direct potting into the crevices among assembled components to address electromagnetic compatibility and heat-accumulation issues. [ABSTRACT FROM AUTHOR]

Definition: On 1 January 2001, the IEC 61000-3-2 regulation became effective. Since then, mitigating current harmonics has been essential to ensure that electronic equipment connected to single-phase power distribution lines conforms to electromagnetic compatibility directives. Today, high-quality rectification, commonly known as power factor correction (PFC), is a well-established technique widely adopted by the industry for powering various devices from the ac line. The topic has been studied by academia and industry since the mid-1980s; thus, an enormous amount of research has been published and countless solutions have been proposed since then. However, only a few of those solutions have encountered wide industrial usage. So, it is not the authors' intention to provide a comprehensive review, but to take stock of the most used PFC techniques from an industry perspective. This paper will review the power factor theory with non-sinusoidal currents, the practical and regulatory aspects of using PFC, and the most common industry solutions for power factor correction in equipment operated from the single-phase, public, low-voltage supply system, with a special focus on boost PFC pre-regulators, their control methods, design procedures, and issues. [ABSTRACT FROM AUTHOR]

In low frequency band, miniaturized EMC(Electromagnetic Compatibility) test antennas are mostly electrically small antennas, which have the problems of high antenna factor and low test sensitivity. To solve the problem, based on active matching technology, the electrically small antennas loaded with negative impedance converter circuit and field effect transistor high-impedance input circuit are simulated and analyzed respectively. The simulation results show that the field effect transistor high-impedance input circuit has advantages over the negative impedance converter circuit in the ability of reducing antenna factor and the stability of circuit, and is helpful to the design and implementation of miniaturized EMC test antenna. The test results of the miniaturized EMC test antenna loaded with field effect transistor high-impedance input matching circuit show that, in 2~30 MHz, antenna factor can be improved by 22~46 dB compared with the EMC test antenna without matching circuit. [ABSTRACT FROM AUTHOR]

Measurements of Martian magnetic field, atmosphere and sampling are core missions of Martian exploration. Since the successful demonstration of the Ingenuity Helicopter, a large amount of researches have emerged on Mars rotor-craft. However, Mars rotor-crafts have short endurance and limited detection range. This paper proposes a solar-powered tilt-rotor unmanned aerial vehicle (UAV) named Archaeopteryx-I, which can perform vertical take-off and landing (VTOL) and long-endurance level flight. Its general concepts are first elucidated. Then, a multidisciplinary modeling and optimization method is proposed. Considering the harsh magnetic field and atmospheric environment of Mars, the detailed designation of mission system is carried out to further enhance the performance of Archaeopteryx-I, including avionics, energy flow, control system and electromagnetic compatibility (EMC) design. Finally, the conceptual design scheme is validated through simulation and ground testing. The results illustrate the efficaciousness and applicability of Archaeopteryx-I for Mars exploration. • A novel solar-powered tilt-rotor UAV for Martian medium granularity exploration. • The proposed conceptual design framework can deal with multidisciplinary constraints. • Avionics, energy, control, and EMC can enable the UAV to flight in high-performance. • In each cycle, the UAV can cruise on Mars at 33.24 m/s for 0.5 h and hover for 2 min. • The tilt-rotor UAV can achieve 7 to 8 complete mission cycles per Mars day. [ABSTRACT FROM AUTHOR]

The discontinuous PWM technique, with its advantage over the continuous PWM technique in reducing switching losses in power converters, is gaining popularity. However, its deterministic nature results in discrete harmonics with significant amplitudes, which leads to electromagnetic interference (EMI) emissions. The randomised PWM technique is gaining more interest because of its effectiveness in spreading the harmonic spectrum and thus reducing EMI problems in power converters. This paper presents a carrier-based dual randomised discontinuous PWM (DRDPWM) method for a three-phase voltage inverter. The DRDPWM method combines the random carrier frequency (RCF-DPWM) and random pulse position (RPP-DPWM) schemes. In addition to reducing switching losses, DRDPWM can achieve a broad spread of the voltage spectrum with significantly smaller amplitudes. Furthermore, it produces less inverter output current distortion when compared to traditional DPWM and simple random (RCF-DPWM and RPP-DPWM) schemes. Simulations and experimental results confirm the effectiveness of the suggested method for spreading the voltage spectrum compared to simple random schemes. Additionally, an evaluation of the performance of all randomised discontinuous schemes is conducted based on a number of assessment metrics, including the switching loss factor (SLF), the power spectral density (PSD), the harmonic spread factor (HSF), and the quality factor (QF). [ABSTRACT FROM AUTHOR]

This paper demonstrates the design, modeling, and analysis of a small size 180 × 165 × 1.6 mm3 printed broadband Vivaldi antenna for electromagnetic compatibility measurements. The proposed antenna is intended to be utilized as a reference antenna for emission and immunity tests inside the EMC Chamber through the band (0.8–5.5 GHz). Exponentially tapered slots were created based on mathematical equations to form an end-fire radiation antenna. Furthermore, microstrip and slot line stubs were employed to tune the impedance bandwidth. This antenna could be considered a 2-D Horn antenna with a size reduction of 64% and 67% since both antennas, Vivaldi and Horn are based on the same principle. Two rectangular slots were engraved near the feeding point to reshape and enhance the gain at lower frequency bands. Furthermore, the realized gain has been improved by approximately 3.5 dB and reached up to 10.7 dBi by introducing a pair of triangular reversal slots at the top edges of the structure. Moreover, this antenna has specifications that make it a suitable candidate to work as a reference antenna inside the EMC chamber compared to the classical Horn antenna offered for sale (PowerLOG® PRO 30800 and TBMA4). [ABSTRACT FROM AUTHOR]

This research investigates the characterization of bituminous mixes utilizing microwave imaging and non-destructive testing. We studied the electromagnetic characteristics of various samples, including bituminous concrete (BC) and open-grade friction course (OGFC) samples. A novel ring filter with log-periodic feedlines, designed on the RT/Duroid 5880 substrate, was utilized within the frequency range of 0.3–0.7 GHz. The samples were assessed using average attenuation and group delay measures, which detailed clear electromagnetic characteristics. The samples' flow value and specific gravity were correlated to these parameters. The calculated flow value and specific gravity (using the filter) and measured flow value and specific gravity (using the conventional method) coincided well. The filter could predict the parameters of the samples with a high accuracy of roughly 99.8% for the flow value and specific gravity, whereas the OGFC sample displayed an accuracy of 99.7%, correspondingly, as shown in high R2 values. This demonstrates that the filter can precisely measure the parameters required for studying the interaction between the binder and aggregate in bituminous mixes without being invasive. The findings indicate a significant disparity between OGFC and BC samples in their responses to electromagnetic fields and their characteristics. This demonstrates the high sensitivity and significant value of microwave techniques in the study of bitumen and the construction of roadways. [ABSTRACT FROM AUTHOR]

Geophysics is a fundamental tool to detect buried structures of archaeological interest through non-destructive techniques. The Messapian city walls in Ugento (Puglia, southern Italy) are of great archaeological importance, and some sections are still visible. In order to locate a stretch of the city walls, geophysical prospections were performed using the low-frequency electromagnetic method and ground-penetrating radar. The surveys were carried out in a peripheral area of Ugento, near a visible section of the city walls. The analysis and interpretation of the measured data revealed clear anomalies that could be ascribed to the city walls that aligned with an adjacent section of the visible walls. Archaeological excavation campaigns found a part of the walls and some important elements, as identified by the geophysical data interpretation. [ABSTRACT FROM AUTHOR]

The proposed system aims at reproducibility in ultrasound follow-up examinations by storing the position of the ultrasound transducer in relation to acquired images. The system utilizes an electromagnetic tracking system. It includes a guidance feature to assist in placing the transducer correctly on the patient. Evaluation of the system involved technical accuracy tests on a phantom and accuracy tests on human subjects. The results showed that the technical accuracy of the system met the required criteria, but the transducer positioning error in realistic scenarios was above the threshold. Usability testing indicated potential benefits for medical training and provided suggestions for improving the user interface. Overall, the system shows promise for further development and can already be used for training ultrasound examinations. [ABSTRACT FROM AUTHOR]