Power Electromagnetic Interference Research Articles

Electromagnetic Interference Cancellation for RIS-Assisted Communications

Reconfigurable intelligent surface (RIS)-empowered communication is an emerging technology that has recently received growing attention as a potential candidate for next-generation wireless communications. Although RISs have shown the potential of manipulating the wireless channel through passive beamforming, it is shown that they can also bring undesired side effects, such as reflecting the electromagnetic interference (EMI) from the surrounding environment to the receiver side. In this study, we propose a novel EMI cancellation scheme to mitigate the impact of the EMI by exploiting its special time-domain structure and considering a clever passive beamforming method at the RIS. Compared to its benchmark, computer simulations show that the proposed scheme achieves superior performance in terms of the average signal-to-interference-plus-noise ratio (SINR) and outage probability (OP), especially when the EMI power is comparable to the power of the information signal impinging on the RIS surface.

An Electromagnetic Interference Immune PAM-4 Transceiver System

This article presents the design of a pulse amplitude modulation (PAM-4) transceiver that supports high-speed wireline communication in the presence of electromagnetic interference (EMI). The proposed PAM-4 transceiver uses an input level shifter (ILS) and a modified electrostatic discharge (ESD)-protection circuit to reduce the effects of EMI at the transmitter. In order to overcome the effects of EMI at the receiver, the front end is designed with an enhanced input common-mode range. The transverse electromagnetic (TEM) cell method, as provided in the IEC 62132-2 standard, is followed to experimentally verify the radiated EMI-immunity of the proposed PAM-4 transceiver system over its traditional counterpart. For proof of concept, the proposed EMI-immune PAM-4 transceiver and the traditional PAM-4 transceiver circuits are implemented using the 130-nm BiCMOS process. The proposed transceiver operates at a data rate of 6.5 Gbps while maintaining an eye-opening of 70 mV for each bit in the presence of EMI, meeting the requirement of the IEEE 802.3 bs standard. The proposed PAM-4 transceiver withstands a wide range of EMI frequencies that span from 150 kHz to 2 GHz with an EMI power of 0–20 dBm.

Electromagnetic interference shielding effectiveness of compression molded carbon nanofiber‐reinforced polyvinylidene difluoride film

AbstractIn this study, vapor grown carbon nanofiber (VGCNF) reinforced polyvinylidene difluoride (PVDF) composites were developed. Composites were fabricated by high shear mixing using a Banbury type mixer. The material was then subjected to compression molding resulting in films with an average thickness of 0.82 mm. The developed films were subjected to physico‐thermal, and electrical characterization including analysis of the shielding effectiveness (SE) of electromagnetic interference (EMI). Morphological analysis was conducted by scanning electron microscopy and characterization complemented with Fourier transform infrared spectroscopic and X‐ray diffraction analyses. The thermal properties were studied by differential scanning calorimetry and thermogravimetric analysis, which revealed the influence of carbon nanofibers on thermal stability and phase transitions. The electrical conductivity for in‐plane and through‐plane was gradually enhanced by increasing the concentration of VGCF loading; a percolation threshold was initiated at 5 wt% loadings. In plane and through plane resistivity decreased from 1011 Ω‐cm to 103 Ω‐cm and 102 Ω‐cm, respectively. An in‐depth EMI SE study was conducted depicting the influence of VGCNFs on skin depth, EMI power coefficients for reflection, absorption and transmission, and EMI SE for reflection, absorption, and total. The total SE of the developed nanocomposite films was observed to range between 6.6–16.4 dB in a frequency range of 30 kHz to 1.5 GHz. This study presents the processing‐structure–property relationships for lightweight and flexible NC films with enhanced electrical conductivity.

Magnetic field-induced strategy for synergistic CI/Ti3C2T /PVDF multilayer structured composite films with excellent electromagnetic interference shielding performance

Lightweight, scalable, mechanically flexible conductive polymer composite was always desirable for electromagnetic interference (EMI) shielding applications. In this work, we showcased a novel approach to the superior EMI shielding composite materials by orchestrating the multilayered structure and synergistic system. The asymmetric structure with the carbonyl irons (CI)-rich Ti3C2Tx/poly(vinylidene fluoride) (PVDF) magneto-electric layer jointly behind the Ti3C2Tx nanosheets filled PVDF layer was designed and fabricated with the aid of a facile but efficient magnetic field-induced method and was then hot-pressed into a multilayer structured film. Ti3C2Tx nanosheets were excluded by CI agglomeration layer in the asymmetric film to form the complete 3D electrical conductive skeletons. Based on this strategy, EMI shielding properties of the asymmetric multilayer structured composite was superior to the homogeneous blend and sandwiched or alternating layered composites. In addition, an increase in CI content in the composite referred to the thickening of CI-rich layers, making it gain the most powerful EMI SE values, i.e. 42.8 dB for DCMP20–10 film (20 wt% CI, 10 wt% Ti3C2Tx) at a thickness of 0.4 mm. More importantly, the composite transformed from a reflection type to an absorption dominating EMI shielding material due to the multireflections and magneto-electric synergism in the CI-rich Ti3C2Tx/PVDF layers. Meanwhile, the EMI SE of the composites can be adjusted by increase of either theoverall thickness, or the layer numbers of m-DCMP sheets. The thickness specific EMI SE was calculated as 165.25 dB mm−1 for 4-sheet composite film, a record high value among the high efficiency polymer-based EMI shielding materials. This method offered an alternative protocol for preferential integration of excellent EMI shielding performance with high mechanical performance in CPC materials.

Development of accelerated methods for calculating the pattern of current spreading over the surface of spacecraft

High-energy charged plasma particles pose a danger to space technology. The accumulation of charged particles on the body of the spacecraft generates discharges. Electrostatic discharge is a source of powerful electromagnetic interference that adversely affects the functioning of individual parts and entire systems. According to statistics, in about 30% of cases, the loss of satellites is the consequence of discharges. Before the operation of spacecraft, it is necessary to calculate the spreading of currents, which requires large machine and time costs. The article proposes original approaches for quickly constructing a picture of the spreading of currents over the surface of a spacecraft due to electrification. The key point of the first approach is the construction of a limited area for calculating the flow spreading. The calculation of transient currents will only take place in the electromagnetic compatibility area specified by the user without affecting the rest of it. The paper also developed new simplified computational schemes for a system of differential equations based on the Euler methods. With the help of new computational schemes, the time for calculating unknown quantities in a local area specified by the user has been reduced by several orders of magnitude compared to the calculation of unknown full models. The article presents conclusions on new computational schemes, indicating the complexity of their construction. The adequacy and accuracy of the new computational scheme are confirmed by a practical example.

The Influence of EMI Power Filter’s Layout on the Measurement of Mains Terminal Disturbance Voltage

In the first place, this article analyzes the principles of electro magnetic interference (EMI) power filter from the aspects of the differential mode and the common mode disturbance. Afterwards, the design requirements of key components in the EMI power filter and the layout principles of filter is investigated. Next, the influence of layout of EMI power filter on the measurement of mains terminal disturbance voltage has been studied experimentally by the lap quality of the filter onto the equipment under test, the distance between the input and output power line of filter, as well as the input cable length of EMI power filter. Finally, we draw the conclusion that the layout quality of power filter has important impact on the measurement of mains terminal disturbance voltage. It means that the related rules should be strictly abided by when the EMI power filter is used to restrain the conducted disturbance.

Electromagnetic shielding performance of Co0.5Zn0.4Cu0.1Fe2O4-GO/paraffin wax hybrid nanocomposite through magnetic energy morphing prepared by facile synthesis method

High-performance in electromagnetic interference (EMI) and lightweight materials with very effective shielding properties as well as wide bandwidth are extremely desirable, but their development remains a formidable challenge. With this objective, the present report provides a detailed analysis of the graphene oxide (GO)-Co0.5Zn0.4Cu0.1Fe2O4 (CZCF) nanocomposite (CZCFG) which serves an efficient shielding medium for EM interference in the GHz range. Simple co-precipitation method were used for the preparation of CZCFG nanoparticles. Structural including microstructure, dielectric, magnetic and EM shielding parameters are investigated to recognize their important role in EM shielding performance. Spherical nanoparticles with a maximum magnetization of 43.9 emu/g is achieved, which is well incorporated into the GO layers. Absorption is dominated over reflection loss for EMI shielding and presence of GO in nanocomposite disseminate this absorption power by transforming the magnetic energy to that of dielectric energy in combination with improved impedance matching. As a result, a significant electrical conductivity of 21 s/m and an high EMI shielding efficiency of approximately 53.2 dB over the X- and KU- bands were achieved for the resulting composite with a loading of 60 wt% in paraffin wax, which is quite attractive in the context of recent reported work on conductive polymer nanocomposites. In addition, dipole/interfacial polarization, eddy current effect, and multiple scattering also cause a powerful EMI shielding effect.

Using a fiber optic sensor for registration of pulsed plasma discharge current

The problem of increasing the accuracy of recording the pulse shape of a rapidly changing current of a powerful plasma emitter under conditions of powerful electromagnetic interference is considered. To register high-current pulsed discharges, it is proposed to use a polarimetric fiber-optic current sensor based on a Spun-type fiber. Using the indicated current sensor, a technique for recording high-current pulsed discharges of a plasma emitter in the mode of time profiling of the current pulse of two high-voltage capacitive storage devices with a total energy of up to 1800 kJ is realized. The discharge chamber, power supply circuits, and the formation of a plasma discharge are described. The design and principle of operation of a prototype of a two-pass polarimetric fiberoptic sensor with a Spun-type fiber and a Faraday compensator of mutual optical anisotropy are presented. The general scheme of current measurements, the sensor calibration scheme is presented, and the experience of using a prototype sensor for measuring high-power pulse currents is described. The features of the preliminary calibration of the sensor are discussed. The results of measuring the current by optical and traditional recording methods based on the Rogowski coil and Hall sensors are compared with each other, and a noticeable increase in the accuracy of reproducing the current pulse shape by the optical recording method is noted. Possible options for upgrading a fiber-optic sensor to expand the range of current recording are considered.

POWERFUL HIGH-CURRENT GENERATOR OF MICROSECOND VOLTAGE PULSES WITH VOLTAGE AMPLITUDE UP TO ±2 MV AND CURRENT AMPLITUDE UP TO ±150 kA WITH ELECTRIC ENERGY STORED IN CAPACITORS UP TO 1 MJ

Purpose. Development and evaluation, on the basis of existing ultra-high-voltage generator of pulsed voltages and currents of GINT-4 type, of the new scheme of design of its charging-discharging circuit (CDC), and creation of modernized powerful ultra-high-voltage high-current generator of GINT-2 type to form microsecond voltage pulses with amplitudes up to ±2 MV and current with amplitude up to ±150 kA in the electrical load, with electrical energy stored in its capacitive energy storage (CES) up to 1 MJ. Methodology. Fundamentals of theoretical and applied electrical engineering, electrical power engineering, electrophysical principles of high-voltage and high pulsed current engineering, fundamentals of electromagnetic compatibility (EMC), instrument engineering, high-voltage instrumentation and standardization. Results. The new scheme of design of CDC of the modernized powerful ultra-high-voltage, heavy-current generator of GINT-2 type of outdoor placement, that allows obtaining, with preservation of the main electrotechnical elemental base of existing powerful prototype generator GINT-4 (rated output voltage ±4 MV with rated electrical energy stored in CES of 1 MJ and maximal amplitude of output current pulse in electrical load up to ±75 kA) pulses of current of microsecond duration with doubled amplitude (up to ±150 kA) in the long (from 1 to 4 m length) air gap of standard two-electrode discharging «needle-plane» system, in comparison with parameters of current pulses with amplitudes up to ±75 kA that are formed in the discharging circuit of generator of GINT-4 type with the use of the analogous air discharging system, has been developed. Experimental evaluations of the developed new discharging circuit in CDC of the modernized generator of GINT-4 type has been performed in field conditions, and its advantages over the old discharging circuit in composition of CDC of generator of GINT-4 type have been shown. Calculated evaluations of rise rates of high pulsed current (HPC) in plasma channel of air spark discharge of CES with energy up to 1 MJ of generator of GINT-2 type, and strength of electric and magnetic field that are formed around this high-current channel of spark discharge and are powerful electromagnetic interference (PEMI) for objects of armaments and military equipment (OAME) were performed. It was shown that rise rates of HPC obtained for generator GINT-2 in the channel of long air spark discharge (of artificial lightning) and PEMI around this channel practically satisfy strict requirements of the NATO Standards AESTP-250: 2014 and USA MIL-STD-464C: 2010. Originality. The new scheme of design of CDC in composition of the modernized powerful ultra-high-voltage high-current generator of GINT-2 type (developer – Research & Design Institute «Molniya» of NTU «KhPI»), satisfying requirements of the mentioned standards for full-scale tests of OAME for EMC and immunity to action on them of PEMI from long atmospheric spark electric discharges (lightning) was developed for the first time. Practical value. Application of the created ultra-high-voltage high-current generator of GINT-2 type in tests of OAME for EMC and immunity to action on them of PEMI from artificial lightning will assist increase in reliability of OAME functioning in conditions of damaging (destabilizing) action on them HPC and PEMI of natural and artificial origin.

Interference of Spread-Spectrum EMI and Digital Data Links under Narrowband Resonant Coupling

In this paper, the effects of electromagnetic interference (EMI) coupled to a radio-frequency (RF) communication channel by resonant mechanisms are investigated and described in the framework of Shannon information theory in terms of an equivalent channel capacity loss so that to analyze and compare the effects of non-modulated and random Spread Spectrum (SS) modulated EMI. The analysis reveals a higher EMI-induced capacity loss for SS-modulated compared to non modulated EMI under practical values of the quality factor Q, while a modest improvement in the worst case capacity loss is observed only for impractical values of Q. Simulations on a 4-quadrature amplitude modulation (4-QAM) digital link featuring Turbo coding under EMI resonant coupling reveal that SS-modulated EMI gives rise to higher bit error rate (BER) at lower EMI power compared non-modulated EMI in the presence of resonant coupling for practical values of Q, thus suggesting a worse interfering potential of SS-modulated EMI.

Methods of protecting radio-electronic control systems from powerful electromagnetic interference

An analysis of methods of protecting control system equipment from powerful electromagnetic interference was done. The nature of possible damages of radio-electronic components under negative influence of electromagnetic fields was considered. All methods of protection against powerful electromagnetic interferences can were divided into three groups: structural, sheet-oriented and structurally functional. The most effective protection measures aimed at preventing possible damages were determined. The purpose of the paper was to consider thoroughly each of the existing methods aimed at increasing the resistance of radio electronic system to negative impact of powerful electromagnetic interferences.

Ultra-light 3D reduced graphene oxide aerogels decorated with cobalt ferrite and zinc oxide perform excellent electromagnetic interference shielding effectiveness

In this study, three dimensional interconnected graphene aerogels decorated with cobalt ferrite nanoparticles and ZnO nanorods were prepared for the application of absorption dominant electromagnetic interference (EMI) shielding. Because of low density, high porosity and large surface area, the graphene aerogel showed total EMI shielding effectiveness of 25.07 dB at a thickness of 5 mm, which was further improved to 42.10 dB with the inclusion of cobalt ferrite nanoparticles. The incorporation of magnetic cobalt ferrite not only enhanced the total EMI shielding of the aerogels but also improved the power absorption from ∼37.738% to ∼87.788%. By further incorporating ZnO nanorods along with cobalt ferrite nanoparticles into the aerogels, the total EMI shielding effectiveness and power absorption enhanced to 48.56 dB and ∼93.655%, respectively. In this work, the EMI shielding performances of different samples are compared and the underlying mechanism of such excellent absorption dominant EMI shielding is discussed in detail.

Application Research of Chaotic Carrier Frequency Modulation Technology in Two‐Stage Matrix Converter

The harmonics of line to line voltage in two‐stage matrix converter (TSMC) with fixed carrier frequency had discrete and high values and produced powerful electromagnetic interference (EMI). In this paper, chaotic carrier frequency modulation technique (CCFMT) was applied in TSMC for the first time to spread sideband range and suppress harmonic peak value. Although this technique could suppress EMI, it would increase the probability of narrow pulses. In order to improve reliability, the rectifier in the two‐stage matrix converter uses PWM modulation with zero vector to extend the zero current commutation time, solves the narrow pulse problem, and simplifies the commutation process. At last, an experiment platform was designed and experimental results showed that harmonics of line to line voltage was efficiently suppressed.

Enhanced electromagnetic interference shielding with low reflection induced by heterogeneous double-layer structure in BiFeO3/BaFe7(MnTi)2.5O19 composite

High-performance electromagnetic interference (EMI) shielding with low reflection is still a technical challenge for EMI shielding materials to reduce secondary pollution of electromagnetic wave irradiation. Here, we design a heterogeneous double-layer structure based on semiconductors BiFeO3 and BaFe7(MnTi)2.5O19 (BFO and BFMTO), which effectively decreases the reflection and greatly enhances EMI shielding effectiveness simultaneously. The absorption attenuation contribution of EMI power is close to 90%, and the shielding effectiveness exceed 10 dB in entire X-band, which is 150% of that of the homogeneous mixed structure. The experimental results demonstrate that the reduction of reflection is attributed to the decrease of the electrical conduction due to the formation of Schottky potential barriers in the interface between BFO and BFMTO. More importantly, the positive-negative charge pairs in the interface induce interfacial polarization which can interact with electromagnetic wave and thus cause strong attenuation. This work opens up a promising feasible route for the development of low-reflection and strong-absorption EMI shielding materials.

METHOD OF CODING INFORMATION DISTRIBUTED BY WIRELESS COMMUNICATION LINES UNDER CONDITIONS OF INTERFERENCE

The subject matter of the paper is the processes of analysis and evaluation of the effectiveness of information coding methods in wireless systems. The aim is to improve noise immunity of information messages under conditions of powerful electromagnetic interference, with the help of complex signal-code constructions. The objective is to develop a method for noise-immune encoding in a wireless information transmission system, providing increase in information transmission rate. The methods used: Simulation and digital signal coding. The following results have been obtained: A method for encoding information transmitted via wireless communication lines in presence of interference. For signal coding, it is proposed to use Gaussian monocycle with time-dependent position-pulse modulation (PPM). It is shown that for organization of independent channels within a single frequency band, it is practical to use a system of orthogonal codes. Pulses of the useful information signal accumulated in a receiver correlator provide significantly increase in signal-to-noise ratio, allowing transmission of information over a wide frequency range well below the noise level. As a result of encoding information in wireless information transmission systems with the help of ultra-short pulse signals, the effectiveness of the proposed method is a quantitatively and qualitatively evaluated. Conclusion. Using Pulse Position Modulation coding in wireless information transmission systems allows transmitting large volumes of information with high transmission rate and high noise immunity of the communication channel as well as protecting the channel from message interception. Ability to work with low radiating power and high signal capacity to penetrate various obstacles ensure fulfilment of electromagnetic compatibility requirements as well as stable communication in conditions of multipath radio wave propagation. A possibility that powerful electromagnetic disturbances accompanying a lightning discharge may have catastrophic impact on the information transmission channel is also eliminated.

AN ANTHOLOGY OF THE DISTINGUISHED ACHIEVEMENTS IN SCIENCE AND TECHNIQUE. PART 33: ELECTROMAGNETIC COMPATIBILITY AND PROTECTION FROM ACTION OF POWERFUL ELECTROMAGNETIC INTERFERENCE OF RADIOELECTRONIC, ELECTRICAL ENGINEERING AND ELECTRIC POWER EQUIPMENT

Purpose. Implementation of brief analytical review of basic scientific and technical achievements in area of electromagnetic compatibility (EMC) and protection from destabilizing and striking action of powerful electromagnetic interference (PEMI) of natural and artificial origin of radioelectronic, electrical engineering and electric power equipment. Methodology. Scientific methods of collection, analysis and analytical treatment of scientific and technical information in a sphere EMC and such areas of knowledge’s as radioelectronics, electrical engineering and electric power engineering. Results. A brief scientific and technical review is resulted modern positions problems EMC and protection of equipment from action on them PEMI. It is shown that PEMI can result in failures in-process and death of examined equipment. Annual harm in the industrially developed countries of the world from the striking affecting of PEMI modern equipment with integral microcircuits and semiconductor devices can make ten of milliards of USD. The basic methods of protection of equipment are resulted from PEMI and protective devices (PD), intended for the increase of effectiveness of modern equipment to the action of external PEMI. Principles of work of the resulted PD and their basic technical descriptions are described. Originality. On the basis of materials of scientific monographs, journal publications, normative documents and internet-reports systematization of basic PD, in-use presently in an area EMC and protection of different equipment from the hazard agency of external PEMI is executed. Practical value. Popularization of scientific and technical knowledge’s in an area EMC and protection of modern equipment from a dangerous action on them PEMI. Formulation of important for society scientific and technical problems and tasks, arising up in an area EMC and providing of the reliable functioning of modern equipment in power electromagnetic interference.

Overhauser Geomagnetic Sensor Based on the Dynamic Nuclear Polarization Effect for Magnetic Prospecting.

Based on the dynamic nuclear polarization (DNP) effect, an alternative design of an Overhauser geomagnetic sensor is presented that enhances the proton polarization and increases the amplitude of the free induction decay (FID) signal. The short-pulse method is adopted to rotate the enhanced proton magnetization into the plane of precession to create an FID signal. To reduce the negative effect of the powerful electromagnetic interference, the design of the anti-interference of the pick-up coil is studied. Furthermore, the radio frequency polarization method based on the capacitive-loaded coaxial cavity is proposed to improve the quality factor of the resonant circuit. In addition, a special test instrument is designed that enables the simultaneous testing of the classical proton precession and the Overhauser sensor. Overall, comparison experiments with and without the free radical of the Overhauser sensors show that the DNP effect does effectively improve the amplitude and quality of the FID signal, and the magnetic sensitivity, resolution and range reach to 10 pT/Hz@1 Hz, 0.0023 nT and 20–100 T, respectively.

EMI CONSIDERATION OF HIGH RELIABILITY DC-DC CONVERTER: IN AEROSPACE BASED ELECTRIC TRANSPORT SYSTEM CHARGER APPLICATION

High reliability and low electromagnetic interference (EMI) are two important factors for many industrial applications such as air based electric transport system charger (AETSC). Therefore, it is essential to introduce high reliability and low EMI power converters. This paper presents a new high reliability and low current ripple DC-DC converter. For the proposed converter, a spectrum analysis approach for suppressing the EMI using chaotic sinusoidal pulse width modulation is provided. In addition, the proposed converter has radio frequency (RF) EMI lower than 100 kHz. However, for higher than 100 kHz, EMI issue of the proposed converter has unsuitable situation. 1. NOMENCLATURE A: amplitude of signal, fc: carrier signal, υm(τ ): unitary amplitude of modulated signal, kω: a controlled factor, TC : the main frequency of switch which is a constant, xn :t henth output of chaotic mapping, β: a modulation factor.

Subharmonic Oscillations Induced by Continuous Wave Electromagnetic Interference on a Microwave Phase-Locked Loop

This paper presents measurements, simulations, and a theoretical basis to support the observation of spurious peaks on the output spectrum of a microwave phase-locked loop (PLL) exposed to a continuous wave electromagnetic interference (EMI). It is shown that high-power EMI combined to nonlinear characteristics of the PLL may induce subharmonic oscillation phenomena, which provoke the appearance of spurious peaks on the output spectrum. Measurements show that in addition to their dependence on the EMI power and frequency, these spurious peaks depend also on the natural frequency of the PLL and on its stability. Transient circuit simulations of the PLL allowing the prediction of these spurious peaks are presented. Finally, a theoretical explanation based on an analysis of a second-order PLL is given.

3-D Electromagnetic Modeling of Parasitics and Mutual Coupling in EMI Filters

The electromagnetic compatibility (EMC) analysis of electromagnetic interference (EMI) filter circuits using 3-D numerical modeling by the partial element equivalent circuit (PEEC) method represents the central topic of this paper. The PEEC-based modeling method is introduced as a useful tool for the prediction of the high frequency performance of EMI input filters, which is affected by PCB component placement and self- and mutual-parasitic effects. Since the measuring of all these effects is rather difficult and time consuming, the modeling and simulation approach represents a valuable design aid before building the final hardware prototypes. The parasitic cancellation techniques proposed in the literature are modeled by the developed PEEC-boundary integral method (PEEC-BIM) and then verified by the transfer function and impedance measurements of the L-C and C-L-C filter circuits. Good agreement between the PEEC-BIM simulation and the measurements is achieved in a wide frequency range. The PEEC-BIM method is implemented in an EMC simulation tool GeckoEMC. The main task of the presented research is the exploration of building an EMC modeling environment for virtual prototyping of EMI input filters and power converter systems.