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This paper addresses and compares the modeling of typical EMI filters used in three-phase power equipment obtained through two different approaches, namely, physical and behavioral. Firstly, an innovative physical EMI filter modeling procedure is presented, which relies on an analytical formulation in terms of chain-parameters matrices and allows for an easy evaluation of its attenuation characteristics. The considered procedure builds an overall filter model by combining simple components models, requiring the determination of only a limited number of parasitic elements. Furthermore, the latter can be easily estimated without the need to build any prototype, avoiding the costly trial-and-error design procedures currently applied in the industrial context. Additionally, the considered physical model is tailored for high-power filters, built with thick wires, while most of the physical models available in the literature are aimed at small-sized filters built on printed circuit boards. The procedure is validated step by step, discussing the accuracy of each component model and its impact on overall accuracy compared to the actual measurements of the final assembled filter. Secondly, a behavioral modeling procedure is presented, which is based on external measurements performed on the filter prototype and provides an equivalent circuit model. Specifically, it extends to three-phase filters a circuit model previously developed for the single-phase case. Lastly, a critical comparison between the proposed physical and behavioral models is presented, highlighting the strengths and limitations of both and suggesting optimal uses for each. [ABSTRACT FROM AUTHOR]

Electronic power converters are widespread and crucial components in modern energy scenarios. Beyond mere electrical energy conversion, their electronic structure allows several functionalities to be naturally embedded in them, including energy management, diagnosis, communication, etc. The operation of the converter itself, or the system interfaced by the same, commonly produces undesired electromagnetic interferences (EMIs) that should comply with prescribed limits. This paper presents a digital active EMI filter designed to mitigate such disturbances. The proposed hardware implementation can acquire and analyze the common-mode (CM) noise affecting the circuit and inject a compensation signal to attenuate the measured interference. A novel adaptive algorithm is introduced to compute the necessary signals for effective noise cancellation. The implementation is integrated within a single printed circuit board interfaced with a field-programmable gate array (FPGA) running the control algorithm. The digital filter's efficacy in EMI reduction is demonstrated using a synchronous buck converter with gallium nitride (GaN) power devices, achieving significant noise reduction. Additionally, potential functionalities are envisioned to fully exploit the capabilities of the proposal beyond EMI filtering, like fault detection, predictive maintenance, smart converter optimization, and communication. [ABSTRACT FROM AUTHOR]

This paper deals with the mitigation of magnetic field levels produced by a wireless power transfer (WPT) system to recharge the battery of an electric vehicle (EV). In this work, an array of active coils surrounding the WPT coils is proposed as a mitigation technique. The theory and new methodological aspects are the focus of the paper. Magnetic field levels in the environment are calculated numerically without and with the presence of an array of active coils in a stationary WPT system for automotive applications. By the proposed mitigation method, the field levels beside the vehicle are significantly reduced and comply with the reference levels (RLs) of the ICNIRP 2010 guidelines for human exposure to electromagnetic fields and the magnetic flux density limits proposed by ISO 14117 for electromagnetic interference (EMI) in cardiac implantable electronic devices (CIEDs). [ABSTRACT FROM AUTHOR]

In this paper, a frequency selective surface (FSS) for n41, n78, n257, n258, n260, and n261 bands electromagnetic interference (EMI) shielding is proposed using a deep learning method. The size of the FSS unit cell is 4.8 mm (0.071 λ 0 ), where λ 0 is the wavelength corresponding to the cutoff frequency of the −10 dB stopband where the n41 and n78 bands are located. This FSS exhibits three key characteristics. Firstly, it possesses ultrawideband capability, with a stopband frequency range of 23.922–40.023 GHz and a relative bandwidth reaching 50.4%. Secondly, it effectively shields against electromagnetic radiation in multiple 5 G bands, including n41, n78, n257, n258, n260, and n261. Thirdly, it demonstrates high selectivity, with a very narrow transition band of only 0.405 GHz between the passband and the stopband. To validate the designed FSS, a prototype of this structure was first fabricated for experimentation. The experimental results show that the measured S21 is highly consistent with the simulated S21. Secondly, the unit cell array of FSS is placed above the monopole antenna for co-simulation. It can be observed that after placing the FSS, the intensity of electromagnetic radiation propagating in space is significantly reduced by up to more than 90%. Therefore, the proposed FSS can be effectively applied for EMI shielding in 5 G bands. [ABSTRACT FROM AUTHOR]

Aiming at the quantitative evaluation requirements of radar second-order intermodulation false alarm (SIFA) effect, a radar SIFA effect model is established from the field-circuit coupling mechanism, and the parameter test method of the model is given. Taking a certain type of radar as the test object, the SIFA effect test is carried out by using the method of electromagnetic injection equivalent substitution irradiation. The results show that the tested radar will produce a SIFA signal higher than the selected sensitive level when the frequency difference of dual-frequency electromagnetic interference (EMI) is within 3 MHz and the frequency offset is within ± 200 MHz. Using the model parameters of the SIFA interference effect measured in the experiment, it is assumed that they do not change with the interference field strength. Combined with the SIFA interference field strength of the tested radar and the single frequency blocking critical interference field strength, the effect model can evaluate the degree of radar SIFA interference.

Environmental electromagnetic interference (EMI) has always been a major interference source for multiple-channel neural recording systems, and little theoretical work has been attempted to address it. In this paper, equivalent circuit models are proposed to model both electromagnetic interference sources and neural signals in such systems, and analysis has been performed to generate the design guidelines for neural probes and the subsequent recording circuit towards higher common-mode interference (CMI) rejection performance while maintaining the recorded neural action potential (AP) signal quality. In vivo animal experiments with a configurable 32-channel neural recording system are carried out to validate the proposed models and design guidelines. The results show the power spectral density (PSD) of environmental 50 Hz EMI interference is reduced by three orders from 4.43 × 10−3 V2/Hz to 4.04 × 10−6 V2/Hz without affecting the recorded AP signal quality in an unshielded experiment environment. [ABSTRACT FROM AUTHOR]

The application of GaN power devices has significantly increased the power density of flyback power supplies but has also caused severe electromagnetic interference (EMI) issues. To address the challenge of conducted interference in flyback power supplies, a comprehensive analysis of the transmission mechanism of conducted common-mode noise is undertaken. This analysis involves simplifying the equivalent model of conducted interference and leveraging the circuit characteristics of conducted noise to propose a solution for attenuating common-mode noise. Considering the constraints of external compensation capacitors, a balanced winding is further introduced to mitigate the impact of noise. To enhance the efficacy of conducted interference suppression, it is suggested to change the winding structure of the transformer and incorporate a shielding winding. This configuration aims to minimize the generation and propagation of common-mode noise within the transformer. Finally, experimental verification is carried out using a 150 W GaN flyback power supply prototype. The experimental results demonstrate that the proposed method effectively suppresses common-mode noise in the circuit. [ABSTRACT FROM AUTHOR]

Focused on addressing harmonic suppression in multiphase indirect matrix converters (IMCs), this study explores spread-spectrum modulation technology through ripple analysis calculations. We introduce a current ripple spread-spectrum modulation (CR-SSM) method tailored for multiphase IMC systems. In this approach, a 3 × 6-phase IMC is modeled as a two-port network, and a small-signal model of the output side is established. The transfer function is utilized to analyze the two-port network in the complex frequency domain (s-plane). The time-domain expression of the output current ripple is derived in vector form. Subsequently, the distribution of the output ripple and locus are determined based on specified constraints. The carrier frequency is dynamically adjusted online according to the specified ripple locus. Compared to classical periodic PWM methods, this approach offers a broader range of frequency variations and achieves a more uniform output spectrum. Furthermore, CR-SSM optimizes system efficiency and enhances spread-spectrum modulation. Experimental results demonstrate that this method effectively enhances the quality of input and output waveforms in multiphase IMC systems. [ABSTRACT FROM AUTHOR]

Aiming at the quantitative evaluation requirements of radar second-order intermodulation false alarm (SIFA) effect, a radar SIFA effect model is established from the field-circuit coupling mechanism, and the parameter test method of the model is given. Taking a certain type of radar as the test object, the SIFA effect test is carried out by using the method of electromagnetic injection equivalent substitution irradiation. The results show that the tested radar will produce a SIFA signal higher than the selected sensitive level when the frequency difference of dual-frequency electromagnetic interference (EMI) is within 3 MHz and the frequency offset is within ±200 MHz. Using the model parameters of the SIFA interference effect measured in the experiment, it is assumed that they do not change with the interference field strength. Combined with the SIFA interference field strength of the tested radar and the single frequency blocking critical interference field strength, the effect model can evaluate the degree of radar SIFA interference. [ABSTRACT FROM AUTHOR]

Electromagnetic Interference (EMI) plays a significant role on degraded image quality under specific operating conditions. During our product characterizations, we analyzed an event that shows bright vertical chain‐like spots on mobile Organic Light‐emitting Diode (OLED) display due to the transmit operation of Global System for Mobile (GSM) phone nearby the device under test (DUT). The cause of the event is laid out as follows. The transmitted Radio Frequency (RF) power travels through Flexible Printed Circuit (FPC) to Display Driver Integrated Circuit (DDIC). Then the transistors respond to RF power as unintended RF diodes, which generate unexpected Direct Current (DC) voltage, which pushes the panel‐driving buffer Operational Amplifier's (OPAMP) output drifted. [ABSTRACT FROM AUTHOR]

This paper demonstrates a unique symmetric structure excellent metamaterial absorber (MMA) loaded with circular-ring tied arcs. The FR4 substrate-based MMA can accomplish 98.88 % and 99.81 % absorption maximums at the Wi-Fi and 5G frequencies of 2.4 GHz and 5.0 GHz respectively. The unit cell dimension of 0.16λ0×0.16λ0×0.0128λ0 is considered where the wavelength, λ0 is calculated at 2.4 GHz. The performance of the absorber is analyzed through the electric field, magnetic field, surface current, and effective parameters. The dimensions are optimized through the parametric analysis of the developed model in CST software. The model exhibits stability up to 60° for Transverse electric and magnetic polarizations. During electromagnetic interference (EMI) shielding demonstration, it can achieve a high shielding effectiveness (SE) of 54.34 dB at 2.4 GHz and 77.96 dB at 5.0 GHz. For sensing operation, it can attain a quality factor (Q-factor) of 25.61, a sensitivity of 3.30 %, and a figure of merit (FoM) of 84.51. The prototype measurements of the MMA for EMI shielding and impurity sensing of oil samples have a strong correlation with the simulation performance. Because of the high SE, Q-factor, sensitivity, and FoM, the developed MMA can be a competitive candidate in EMI shielding and oil impurity sensing applications.

This paper introduces a perfect metamaterial absorber (MMA) achieving exceptional electromagnetic signal absorption at application-oriented frequencies of 2.40 and 3.50 GHz in addition to 6.09 GHz. The MMA exhibits absorption rates of 99.85, 98.6, and 96.7%, with high shielding effectiveness (SE) of 36.44, 32.58, and 31.13 dB against electromagnetic interference (EMI) at those frequencies. The structure of the copper resonator on the FR4 substrate allows the on-design frequency switching from 3.43 to 3.70 and 5.65 to 6.55 GHz, respectively. The structural symmetry enables polarization and incidence angle independence up to 60° for both transverse electric and magnetic modes. The perfect absorption of the MMA is shown by the near-zero polarization conversion ratio. There is an adjacent correlation between the measurement and simulation results. The proposed MMA emerges as an efficient EMI shield for Wi-Fi and 5G signals, offering perfect absorption and extensive polarization characteristics.

AbstractA standard magnetic field generation system from 1 to 30 μT between DC and 20 kHz has been demonstrated for the calibration of DC/AC magnetometers. The system includes a laboratory-designed Helmholtz coil, shunt resistor, digital multimeter, and dedicated power source. The DC coil constant of the Helmholtz coil was determined to be 10.586 μT/A using a single-axis fluxgate magnetometer. The homogeneity analysis was carried out for the Helmholtz coil to identify the uniformity along the x, y, and z axes. The system for DC generation was standardized and compared by measuring the field values using a single-axis fluxgate magnetometer. Further, the system was validated for AC generation by a search coil with a known turn area (1.3767 ± 0.0027 m2). Moreover, the measured magnetic field values using a search coil were compared with a commercial magnetometer to identify the variation in generated and measured magnetic fields. The described system can have significant utilities in calibration, electromagnetic interference electromagnetic interference/electromagnetic compatibility (EMI/EMC) testing, magnetic susceptibility testing, and magnetic field therapy applications. The expanded uncertainty of the Helmholtz coil in generating a magnetic field was 0.2–1.6% (at k = 2) from DC to 20 kHz. [ABSTRACT FROM AUTHOR]

It is difficult to describe the electromagnetic radiation generated by the explosion of energetic materials using an accurate mathematical model. This paper uses the test data from the literature as input to study the interference of TNT detonation electromagnetic radiation on a specific detonation control circuit using the electromagnetic simulation software CST. Based on the traditional simplified PCB model, a microprocessor model is established, and the plane wave radiation is carried out on it and the cable model. The coupling induced voltages and currents inside the cable and processor pins on the PCB are simulated. The resulting coupling voltage was then injected into the executable circuit as an interference source. The simulation results show that the maximum coupling voltage observed for the device on the PCB can cause a disturbance of 15 mA in the output current of the detonator circuit. However, a single wire subjected to radiation coupling with a peak voltage of 5 V applied to the input port may generate pulse interference, potentially causing a level transition in the input signal. This will cause the transistor in the detonation control circuit to turn on in advance, thus triggering the detonation circuit action earlier. [ABSTRACT FROM AUTHOR]

The rapid evolution of the digital landscape through advancements in electronic devices, wireless communication, and electromagnetic wave technologies has brought both convenience and new security concerns. One such security challenge is TEMPEST (Transient Electromagnetic Pulse Emanation Standard), which exploits electromagnetic waves for potential information leakage. This paper focuses on analyzing and restoring leaked electromagnetic waves, particularly in the context of video systems operating under identical clock frequencies-a scenario not adequately addressed by previous researches. The main content involves presenting and experimentally verifying a method for identifying leaked electromagnetic waves from systems with identical clock frequencies by analyzing electromagnetic characteristics related to frequency and phase.

While three-phase six-switch rectifiers are typically used in power conversion systems, this paper explores the potential of three-phase four-switch (TPFS) rectifiers for wind energy systems. Current advancements in TPFS rectifiers aim to enhance system efficiency and reduce the component count, addressing issues such as total harmonic distortion (THD) and electromagnetic interference (EMI). However, existing solutions often involve complex control strategies and an increased number of electronic components, which elevate costs and system complexity. This work introduces an approach to TPFS rectifiers for wind energy conversion by simplifying the traditional topology by eliminating one inductor, which can be represented as two-boost single-phase rectifiers for mathematical modeling. This modification significantly decreases common-mode (CM) currents and voltages, mitigating input current distortion and reducing EMI. We provide a comprehensive mathematical analysis demonstrating that this topological change allows for the decoupling of phases and simplifies mathematical modeling and control, treating the system as two independent single-phase half-bridge rectifiers. A 1 kW prototype validates the modified rectifier, with experimental results confirming feasibility and reliability. Results, which achieve a THD of 3.85% across each phase and a power factor of 0.993, meet IEC standards and confirm the efficacy of the approach for power factor correction.

This article provides a comprehensive overview of on-board wireless motors based on WPT system. Based on the mathematical models of common wireless motors, the coupling strength of on-board wireless motors is divided, and their characteristics and advantages are comprehensively summarized and classified. In order to provide power to the three-phase wireless motors, the rotary transformer is used to replace the common coupling coil in the WPT system. This paper conducts electromagnetic model on the rotary transformer, as well as a comprehensive summary of structures and materials of the rotary transformer. The resonant compensation topology of WPT system is crucial. Comparing the transmission characteristics and advantages and disadvantages of various compensation topologies is beneficial for selecting appropriate compensation topologies in different application scenarios. For the control strategy of WPT system, this paper mainly focuses on the issues of output power and transmission efficiency. Finally, the research difficulties and directions of on-board wireless motors are proposed, such as electromagnetic interference and resonance, and this technology is extended to other fields, including wireless charging, robotics, etc.

This study focuses on the effect of waveforms, i.e., signal length and period in intermittent transmission, on electromagnetic interference (EMI) with medical devices. It was already shown that intermittent transmission with the period of 1 s (500 ms: ON and 500 ms: OFF) tends to cause EMI on medical devices compared to continuous transmission. To evaluate the impact of waveforms on EMI with medical devices, we conducted an experiment at 837.5 MHz and 1950 MHz using five medical devices that yielded the following results. For EMI dissipation, the input power of an antenna simulating mobile phones increased and the separation distance between the antenna and medical device decreased as the signal length became shorter in the case of a signal length of less than 10 ms. On the other hand, the signal period exhibited no specific tendency regarding such power and distance. We confirmed that previous EMI tests, in which we used a radio signal with the length and period of 100 ms in intermittent transmission, were conservative from the viewpoint of waveforms. Results of this investigation indicate that the influence of EMI on medical devices does not depend on the average power but on the burst power. Based on this, EMI characteristics with medical devices for a certain radio system could be estimated based on previous EMI test results for other radio systems if their frequencies are close to each other and their signal specifications are clearly determined.

One of the threats to industrial unmanned aerial vehicles (UAVs), which require a high level of safety, is the degradation of control wireless communication performance due to electromagnetic interference. Self-jamming caused by unintentional electromagnetic (EM) noises from the multiple electronic devices installed in a UAV, such as the power supply and camera, is a fundamental issue independent of the surrounding environment. UAVs are susceptible to self-jamming since electronic devices as noise sources are densely mounted inside their chassis. Therefore, evaluating the self-jamming problem and taking countermeasures to achieve high safety in wireless communication performance are important. In this paper, we focus on mobile communications used for UAV operation and evaluate the impact of EM noise generated by a commercial industrial UAV on the receiver sensitivity of an onboard mobile communication device. It was found that EM noise generated by the UAV degrades the sensitivity in the three communication bands, 800 MHz, 1800 MHz, and 2100 MHz, used over the air. In particular, receiver sensitivity was degraded by up to 29 dB in the 800 MHz band. These results indicate that the self-jamming problem is not negligible for the safe operation of industrial UAVs. In addition, countermeasures for self-jamming were taken at the mechanical design level to suppress EM noise to a level that does not degrade mobile communication performance. This paper clarified that countermeasures for self-jamming are an important element for safe UAV operation.

This paper addresses and compares the modeling of typical EMI filters used in three-phase power equipment obtained through two different approaches, namely, physical and behavioral. Firstly, an innovative physical EMI filter modeling procedure is presented, which relies on an analytical formulation in terms of chain-parameters matrices and allows for an easy evaluation of its attenuation characteristics. The considered procedure builds an overall filter model by combining simple components models, requiring the determination of only a limited number of parasitic elements. Furthermore, the latter can be easily estimated without the need to build any prototype, avoiding the costly trial-and-error design procedures currently applied in the industrial context. Additionally, the considered physical model is tailored for high-power filters, built with thick wires, while most of the physical models available in the literature are aimed at small-sized filters built on printed circuit boards. The procedure is validated step by step, discussing the accuracy of each component model and its impact on overall accuracy compared to the actual measurements of the final assembled filter. Secondly, a behavioral modeling procedure is presented, which is based on external measurements performed on the filter prototype and provides an equivalent circuit model. Specifically, it extends to three-phase filters a circuit model previously developed for the single-phase case. Lastly, a critical comparison between the proposed physical and behavioral models is presented, highlighting the strengths and limitations of both and suggesting optimal uses for each.

Transformerless grid-connected inverters for photovoltaic (PV) applications provide several advantages such as reduced cost and volume as well as an increased efficiency. However, the removal of the transformer gives rise to several problems related to leakage currents and electromagnetic interferences (EMI). This paper presents different chaotic unipolar sine-pulse width modulation (C-USPWM) techniques for a transformerless grid-connected PV inverter based on parameter selection. The main objective behind this proposed chaotic modulation technique is to reduce the conducted EMI without worsening the power quality and the common-mode voltage (CMV). The method is validated through numerical simulations and experimental tests carried out on laboratory prototype of an optimized H5 inverter (oH5). The obtained results showed its superiority to the conventional unipolar sine-pulse width modulation (USPWM). We showed also that the appropriate parameter selection of the C-UPSWM could advantageously combine an improved EMI performance and an efficient control, making it possible to deliver a significant reduction of the peaks' amplitudes in the frequency spectrum of the common-mode (CM) voltage. [ABSTRACT FROM AUTHOR]

The development of new advanced functionalities, miniaturization, and the aim of obtaining optimized performance in electronic devices significantly impacts their electromagnetic compatibility (EMC). As electronic components become more densely packed on a printed circuit board (PCB), unintended coupling between components can cause electromagnetic interference (EMI). These requirements result in design restrictions that make using a board level shield (BLS) essential in reducing intra-system EMI in PCB designs. This contribution focuses on studying and characterizing a BLS solution based on combining a noise suppression sheet (NSS) with an aluminum layer to reduce intra-system EMI coupling. This hybrid solution has the advantage of providing a shielding option that does not require any electronic redesign. It does not need a footprint or a ground connection as it can be affixed over the EMI source. The solution is expected to provide higher attenuation levels than using only an NSS by combining the absorbing properties of the magnetic material and the loss mechanism of the metal. In order to verify the effectiveness of the hybrid BLS proposed solution, the magnetic near-field emissions of an EMI source are analyzed in this study. The experimental measurements and simulated results demonstrate a significant increase (51.6 dB at 1 GHz) in the shielding effectiveness (SE) provided by the proposed solution compared to a conventional NSS. [ABSTRACT FROM AUTHOR]

Fast switching within static converters is a key to high-efficiency operation and a source of electromagnetic disturbances that can harm the proper functioning of the converters themselves or the electronic equipment placed in their neighborhood. To characterize disturbances, engineers are mainly focused on the spectral content since the higher the switching speed, the more important the high-frequency components are. In this article, a figure of merit (FOM) independent of switching speed is proposed. It allows us to compare switching patterns produced by a gate driver to each other, using as a reference the mathematical optimum of a Gaussian pattern as well as other elementary forms for which the FOM is known. A complete implementation methodology is presented to properly use this FOM that considers an adapted sampling frequency and filtering of signals before processing in order to correctly obtain information for the optimal adjustment of a driver. [ABSTRACT FROM AUTHOR]

This work proposes a frequency‐selective surface‐based radome structure to selectively allow the radar altimeter operating band and also minimize the interference from Sub‐6GHz 5 G frequency bands. A Jerusalem cross and combinational loop (JCL) based frequency selective surfaces (FSS) unit cell of overall dimension 0.37λ was synthesized using a thin flexible substrate for use in fuselage of airborne systems. The proposed FSS unit cell exhibits transmission zero at 3.61 and 6.025 GHz and highly selective pass band at 4.3 GHz. The effect of bends and angle of incidence on the frequency response of the synthesized FSS was studied in transverse electric and transverse magnetic modes. A lumped element‐based equivalent circuit model for the proposed design was also presented. Finally, the fabricated prototype was experimentally validated in an Anechoic chamber setup and the suitability of the proposed FSS layers for aviation radar systems was confirmed. [ABSTRACT FROM AUTHOR]

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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. [ABSTRACT FROM AUTHOR]

Robotic systems and the human body consist of numerous joint structures, all of which require precise angle adjustments. At present, encoder, strain gauge, and electrical resistance-based sensors are commonly used for angle measurement. However, these sensors have limitations when used in underwater or in environments with strong electromagnetic waves. Therefore, we have developed an angle sensor based on step-index profile plastic optical fiber (SI-POF), which is cost-effective and highly durable, in this study in order to overcome the limitations of existing angle measurement sensors. To this end, the amount of light loss according to the gab and angle changes that occur when the POF angle sensor is applied to the robot arm was experimentally measured, and based on the results, a simulation of the amount of light loss when the two losses occurred at the same time was conducted. In addition, the performance of the POF angle sensor was evaluated by measuring sensitivity and resolution, and comparative verification with a commonly used encoder was conducted to verify the reliability of sensors in extreme environments, such as those with electromagnetic fields and those that are underwater. Through this, the reliability and practicality of the POF angle sensor were confirmed. The results obtained in this study suggest that POF-based angle sensors can contribute to the development of the biomimetic robot industry as well as ordinary robots, especially in environments where existing sensors are difficult to apply, such as areas with underwater or electromagnetic interference (EMI). [ABSTRACT FROM AUTHOR]

To meet the demands for flexible electromagnetic interference (EMI) shielding materials, a type of conductive fabric is prepared by generating three-dimensional (3D) porous laser-induced graphene (LIG) in situ on the surface of the aramid fabric (AF) and then electroless plating copper. After LIG treatment, the porous AF demonstrates admirable conductivity due to the generation of graphene. The superior surface resistance of the conductive fabric can reach 1.57 Ω/sq after copper deposition, and the average EMI shielding effectiveness (SE) can reach 34.3 dB in a frequency range of 8.2 to 12.4 GHz, with the EMW absorption accounting for about 80%. The proposed technology provides a new idea for preparation of flexible EMI shielding materials. [ABSTRACT FROM AUTHOR]

This paper deals with the mitigation of magnetic field levels produced by a wireless power transfer (WPT) system to recharge the battery of an electric vehicle (EV). In this work, an array of active coils surrounding the WPT coils is proposed as a mitigation technique. The theory and new methodological aspects are the focus of the paper. Magnetic field levels in the environment are calculated numerically without and with the presence of an array of active coils in a stationary WPT system for automotive applications. By the proposed mitigation method, the field levels beside the vehicle are significantly reduced and comply with the reference levels (RLs) of the ICNIRP 2010 guidelines for human exposure to electromagnetic fields and the magnetic flux density limits proposed by ISO 14117 for electromagnetic interference (EMI) in cardiac implantable electronic devices (CIEDs).

Environmental electromagnetic interference (EMI) has always been a major interference source for multiple-channel neural recording systems, and little theoretical work has been attempted to address it. In this paper, equivalent circuit models are proposed to model both electromagnetic interference sources and neural signals in such systems, and analysis has been performed to generate the design guidelines for neural probes and the subsequent recording circuit towards higher common-mode interference (CMI) rejection performance while maintaining the recorded neural action potential (AP) signal quality. In vivo animal experiments with a configurable 32-channel neural recording system are carried out to validate the proposed models and design guidelines. The results show the power spectral density (PSD) of environmental 50 Hz EMI interference is reduced by three orders from 4.43 × 10−3 V2/Hz to 4.04 × 10−6 V2/Hz without affecting the recorded AP signal quality in an unshielded experiment environment.

An efficient dual-scale method, which integrates parabolic equation (PE) with electric field integral equation (EFIE) formulated via the Rao-Wilton-Glisson moment method (RWG-MOM), is proposed to analyze the electromagnetic interference (EMI) problems resulted from radiation sources. This method is implemented by decomposing the original intractable multi-scale problem domain into two sub-regions: (1) modeling of the complicated ambient electromagnetic fields by PE and (2) solution of the fields coupling to the exposed electronic devices by RWG-MOM. Frequency-sweep and Fourier synthesis techniques are applied to calculate the transient currents and voltages. The proposed method is able to fully model the disturbances of the electromagnetic fields by multi-path effects. Besides, it reduces the memory footprint and the CPU computing time effectively compared to the traditional full-wave electromagnetic methods. Numerical examples are presented, and the simulation results indicate that this method is well suitable for the EMI analysis of external radiation sources. [ABSTRACT FROM AUTHOR]

With the global attention given to energy issues, the electrification of aviation and the development of more electric aircraft (MEA) have become important trends in the modern aviation industry. The electric actuator plays multiple roles in aircraft such as flight control, making it a crucial technology for MEA. Given the limited space available inside an aircraft, the power density of electric actuators has become a critical design factor. However, the pursuit of high power density results in the need for larger rated power and higher switching frequency, which can lead to severe electromagnetic interference (EMI) issues. This, in turn, poses significant challenges to the overall reliability of the electric actuator. This paper provides a comprehensive review of EMI in high power density motor drive systems for electric actuator systems. Firstly, the state of the art of electric actuator systems are surveyed, pointing out the contradictory relationship between high power density and EMI. Subsequently, various EMI modeling approaches of motor control systems are reviewed. Additionally, the main EMI suppression methods are summarized. Active EMI mitigation methods are emphasized in this paper due to their advantages of higher power density compared with passive EMI filters. Finally, the paper concludes by summarizing the EMI research in motor drive systems and offering the prospects of electric actuators. [ABSTRACT FROM AUTHOR]

The increasing development and application of wireless devices and systems that radiate electromagnetic waves makes electromagnetic interference (EMI) shielding more and more important in everyday life. In practice, rigid EMI shields are the most commonly used ones. However, for humans or in automotive and aviation applications, flexible, drapable materials, such as textile fabrics, can be more effective and useful. Textile fabrics are usually nonconductive and not magnetic, i.e., they lack the requirements for EMI shielding. However, shielding properties of textile fabrics can be achieved by blending yarns with fine wires or coating fibers or by blending complete textile layers with conductive or magnetic materials. In this paper, shielding textile fabrics and 3D-printed materials, as references with different conductive (and partly also magnetic) properties, are examined. The measurements show a high shielding effectiveness of 80 dB given by densely woven fabrics with a thin metallic coating in the frequency range of 6.5–11 GHz, while large pores in crocheted fabrics significantly reduce the EMI shielding effectiveness, and other samples did not show shielding at all, suggesting that a combination of conductivity and the structure of the samples is responsible for the shielding potential. [ABSTRACT FROM AUTHOR]

In this paper, we propose a theoretical approach to estimate the power level of electromagnetic waves radiated into a structure by a specific external source. The target structure is a multistory building on a university campus that is used primarily for academic purposes and is much larger than the target wavelength. To verify the accuracy and efficiency of the proposed theoretical approach, measurements were carried out and a commercially available simulation tool, Wireless Insite, was adopted. We then analyzed the influence of an area of vegetation as an external environmental factor that could affect the radiated electromagnetic waves because of its location in front of the target structure. For this, a precise simulation environment was designed to derive the quantitative values of the electromagnetic attenuation caused by the external environmental factor. Furthermore, those values were applied to the theoretical approach. The results of the theoretical approach accounting for the external environmental factor were similar to those of the actual measured results. The results were also similar to those of the simulation tool, Wireless Insite, but the theoretical approach provided more efficient analysis results in terms of time consumption and computer resources.

In the paper, a simulation-based design procedure for the implementation of a TEM cell (the Crawford cell) is presented. The empirical approach uses computer simulations carried out in the CST Microwave Studio to design the cell that operates in the frequency range from 100 kHz to 400 MHz. Following the developed procedure, the TEM cell was implemented, and the cell was tested experimentally. The TEM cell can be used for electromagnetic susceptibility (EMS) measurements, where the DUT is irradiated by the field in a wide frequency band. The DUT is tested to operate without the performance degradation under the influence of electromagnetic disturbances. In addition, the cell can be used for electromagnetic interference (EMI) measurements focused on interference emissions generated by the DUT.

Focused on addressing harmonic suppression in multiphase indirect matrix converters (IMCs), this study explores spread-spectrum modulation technology through ripple analysis calculations. We introduce a current ripple spread-spectrum modulation (CR-SSM) method tailored for multiphase IMC systems. In this approach, a 3 × 6-phase IMC is modeled as a two-port network, and a small-signal model of the output side is established. The transfer function is utilized to analyze the two-port network in the complex frequency domain (s-plane). The time-domain expression of the output current ripple is derived in vector form. Subsequently, the distribution of the output ripple and locus are determined based on specified constraints. The carrier frequency is dynamically adjusted online according to the specified ripple locus. Compared to classical periodic PWM methods, this approach offers a broader range of frequency variations and achieves a more uniform output spectrum. Furthermore, CR-SSM optimizes system efficiency and enhances spread-spectrum modulation. Experimental results demonstrate that this method effectively enhances the quality of input and output waveforms in multiphase IMC systems.

Electromagnetic Interference (EMI) is generated and mitigated in power converters. EMI problems are related to high-speed power converters. This article focuses on conducted electromagnetic interference in adjustable-speed drive (ASD) systems. The electromagnetic compatibility of three-phase/level grid-connected drive inverters is investigated. The test setup is built per the CISPR16-1–2 standard, and the interferences produced from the inverter to the grid are measured. The main dependencies of conducted emissions of a power inverter, changes in the length/shape of main cables, and motor speed have been investigated under load and no load conditions. Factors affecting EMI performance and filter design issues will be addressed. A statistical approach to quantifying the frequency domain impact of conducted emission noise created on the three-phase system by operating various emission sources. Fast Fourier Transform (FFT) was applied for time–frequency domain conversion, and to evaluate with a statistical approach Minitab software was used. Then, a filter design is created to prevent these interferences from being conducted to the grid. Also, the noise attenuation of the EMI filter has been validated in the simulation. Briefly, this study fills in the blanks of uncertainties involved in measuring three-phase emissions, which helps the engineers at the design stage of three-phase converters.

Electromagnetic compatibility (EMC) is an important factor in ensuring the safe operation of the sensitive electronic equipment on urban rail trains. The pulse width modulation (PWM) encoder of an urban rail train exported from China to Brazil is sometimes affected by electromagnetic interference (EMI), which causes the train to fail to run properly. To solve this problem, the EMC test is performed on the PWM encoder to identify the coupling path and the type of interference source. The EMI coupling model and the vehicle-catenary-rail model are established by using an electromagnetic transients program (EMTP) to analyze the mechanism of interference coupling. It is shown that the unbalanced voltage of the train body caused by the backflow of the grounding current is the root cause of the interference of the PWM encoder. The maximum voltage coupled to the internal port of the PWM encoder is about 1894 V, which is sufficient to burn out the encoder. A measure to suppress the interference by installing thyristor surge suppressors (TSS) P0300SC is proposed, which effectively solves the EMI problem of the PWM encoder. [ABSTRACT FROM AUTHOR]

An ultra-wideband common-mode (CM) filter for a gigahertz (GHz) data rate signal is proposed in this paper. The proposed filter was designed only on the printed circuit board (PCB) ground plane; no additional components wererequired. We took advantage of producing second-order transmission zero by an asymmetrical magnified coupled DGS to extend the suppression bandwidth. Full-wave simulations and equivalent circuit models of the DGS resonator were established to predict the suppression performance. The measured differential-mode insertion loss (Sdd21) from direct current (DC) to 12.35 GHz was obtained within the −3 dB definitionin the frequency domain. The CM noise was suppressed by more than10 dB in the frequency range from 2.9 GHz to 16.2 GHz. The fractional bandwidth (FBW) reached 139.3%. The proposed filter blocked 62.3% of the CM noise magnitude in the time domain measurement. In addition, the eye diagram measurement proved that good transmission quality was maintained. The proposed filter can be widely implemented to reduce electromagnetic interference (EMI) in radio frequency (RF) andWi-Fi (wireless fidelitystandard) 5 and 6E wireless communication applications. [ABSTRACT FROM AUTHOR]

This paper investigates the Electromagnetic Interference (EMI) noise signature of three-phase three-level (3L) Triangular Current Mode (TCM)-modulated grid-tied Photovoltaic (PV) inverters that achieve full Zero Voltage Switching (ZVS) and thus minimal switching losses over the entire mains period and/or ensure >99% efficiency. Further required is a very high power density, which facilitates installation and is achieved with high switching frequencies >100kHz. The impact of the characteristic variation of $f_{\mathrm {sw}}$ in all three phases and the therefore different instantaneous switching frequencies in each phase on the overall converter EMI noise signature is analyzed and it is found that the consideration of only one single phase is sufficient to characterize the noise emissions. Numeric approaches to estimate the detector output of EMI test receivers are compared and it turns out that the peak value of the noise voltage envelope is a useful measure to determine the required filter attenuation, provided the phase-shift of the harmonics is considered in the envelope detection. Finally, a hardware demonstrator of a 6.6kW, >99% efficiency three-phase 3L-TCM PV inverter with a power density of 6.2kW/dm3 (102 W/in3) is designed and the theoretical findings are verified. Moreover, the impact of parasitic capacitances from the switch-nodes and from the floating dc link to Protective Earth (PE) is thoroughly studied qualitatively and quantitatively with the result that these capacitances considerably reduce filter attenuation (35dB at 150,kHz in the case at hand), requiring sufficient design margin.

The electromagnetic interference (EMI) from pulsed electromagnetic field (PEMF) on pacemakers is unignorable in modern power grids and healthcare environments, but there is limited study on the interaction mechanisms and protective measures. In this paper, an in-vitro human chest model for pacemaker implantation is made by using pork tissues immersed in 0.9% sodium chloride solution. The effect of PEMFs generated by the switching actions of common electrical equipment and low-frequency medical equipment on pacemakers is simulated by using fast-front current sources. The pulse forming line theory is employed for analyzing the waveform compression of PEMFs in human thoracic cavity. Further, the parameterized bio-electromagnetic transient model of pacemaker in combination with biological tissues is established in finite element software. The results show that pacemaker malfunctions including pacing inhibition and P pulmonale occur under PEMF. The “Window effect” in subcutaneous pouch under PEMF is found by changing the winding of pacemaker leads in the pouch. Based on the research finding, a protective strategy by using composite materials to shield the window area is proposed. The theoretical feasibility of this protective measure is confirmed by simulation, where the intensity of pacemaker EMI could be reduced by 80 dB when the composite materials shielding is used. Finally, a safe distance is developed for pacemaker wearers in electrical and medical environments.