Research

21 pages, 10292 KiB

Open AccessEditor’s ChoiceArticle

Signal Transformations for Analysis of Supraharmonic EMI Caused by Switched-Mode Power Supplies

by Leonardo Sandrolini and Andrea Mariscotti

Electronics 2020, 9(12), 2088; https://doi.org/10.3390/electronics9122088 - 07 Dec 2020

Cited by 15 | Viewed by 2582

Switched-Mode Power Supplies (SMPSs) are a relevant source of conducted emissions, in particular in the frequency interval of supraharmonics, between 2 kHz and 150 kHz. When using sampled data for assessment of compliance, methods other than Fourier analysis should be considered for better [...] Read more.

Switched-Mode Power Supplies (SMPSs) are a relevant source of conducted emissions, in particular in the frequency interval of supraharmonics, between 2 kHz and 150 kHz. When using sampled data for assessment of compliance, methods other than Fourier analysis should be considered for better frequency resolution, compact signal energy decomposition and a shorter time support. This work investigates the application of the Wavelet Packet Transform (WPT) and the Empirical Mode Decomposition (EMD) to measured recordings of SMPS conducted emissions, featuring steep impulses and damped oscillations. The comparison shows a general accuracy of the amplitude estimate within the variability of data themselves, with very good performance of WPT in tracking on stationary components in the low frequency range at some kHz. WPT performance however may vary appreciably depending on the selected mother wavelet for which some examples are given. EMD and its Ensemble EMD implementation show a fairly good accuracy in representing the original signal with a very limited number of base functions with the capability of exploiting a filtering effect on the low-frequency components of the signal. Full article

(This article belongs to the Special Issue Electromagnetic Interference and Compatibility)

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19 pages, 4921 KiB

Open AccessArticle

Performance Study of Split Ferrite Cores Designed for EMI Suppression on Cables

by Adrian Suarez, Jorge Victoria, Jose Torres, Pedro A. Martinez, Antonio Alcarria, Joaquin Perez, Raimundo Garcia-Olcina, Jesus Soret, Steffen Muetsch and Alexander Gerfer

Electronics 2020, 9(12), 1992; https://doi.org/10.3390/electronics9121992 - 24 Nov 2020

Cited by 8 | Viewed by 7098

Abstract

The ideal procedure to start designing an electronic device is to consider the electromagnetic compatibility (EMC) from the beginning. Even so, EMC problems can appear afterward, especially when the designed system is interconnected with external devices. Thereby, electromagnetic interferences (EMIs) could be transmitted [...] Read more.

The ideal procedure to start designing an electronic device is to consider the electromagnetic compatibility (EMC) from the beginning. Even so, EMC problems can appear afterward, especially when the designed system is interconnected with external devices. Thereby, electromagnetic interferences (EMIs) could be transmitted to our device from power cables that interconnect it with an external power source or are connected to another system to establish wired communication. The application of an EMI suppressor such as a sleeve core that encircles the cables is a widely used technique to attenuate EM disturbances. This contribution is focused on the characterization of a variation of this cable filtering solution based on openable core clamp or snap ferrites. This component is manufactured by two split parts pressed together by a snap-on mechanism which turns this into a quick, easy to install solution for reducing post-cable assembly EMI problems. The performance of three different materials, including two polycrystalline (MnZn and NiZn) materials and nanocrystalline (NC) solution, are analyzed in terms of effectiveness when the solid sleeve cores are split. The possibility of splitting an NC core implies an innovative technique due to the brittleness of this material. Thus, the results obtained from this research make it possible to evaluate this sample’s effectiveness compared to the polycrystalline ones. This characterization is carried out by the introduction of different gaps between the different split-cores and analyzing their behavior in terms of relative permeability and impedance. The results obtained experimentally are corroborated with the results obtained by a finite element method (FEM) simulation model with the aim of determining the performance of each material when it is used as an openable core clamp. Full article

(This article belongs to the Special Issue Electromagnetic Interference and Compatibility)

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10 pages, 2298 KiB

Open AccessArticle

Shielding Properties of Cement Composites Filled with Commercial Biochar

by Muhammad Yasir, Davide di Summa, Giuseppe Ruscica, Isabella Natali Sora and Patrizia Savi

Electronics 2020, 9(5), 819; https://doi.org/10.3390/electronics9050819 - 16 May 2020

Cited by 11 | Viewed by 2877

Abstract

The partial substitution of non-renewable materials in cementitious composites with eco-friendly materials is promising not only in terms of cost reduction, but also in improving the composites’ shielding properties. The water and carbon content of a commercial lignin-based biochar is analyzed with thermal [...] Read more.

The partial substitution of non-renewable materials in cementitious composites with eco-friendly materials is promising not only in terms of cost reduction, but also in improving the composites’ shielding properties. The water and carbon content of a commercial lignin-based biochar is analyzed with thermal gravimetric analysis. Cementitious composite samples of lignin-based biochar with 14 wt.% and 18 wt.% are realized. Good dispersion of the filler in the composites is observed by SEM analysis. The samples are fabricated in order to fit in a rectangular waveguide for measurements of the shielding effectiveness in the X-band. A shielding effectiveness of 15 dB was obtained at a frequency of 10 GHz in the case of composites with 18 wt.% biochar. Full-wave simulations are performed by fitting the measured shielding effectiveness to the simulated shielding effectiveness by varying material properties in the simulator. Analysis of the dimensional tolerances and thickness of the samples is performed with the help of full/wave simulations. Lignin-based biochar is a good candidate for partial substitution of cement in cementitious composites, as the shielding effectiveness of the composites increases substantially. Full article

(This article belongs to the Special Issue Electromagnetic Interference and Compatibility)

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10 pages, 3884 KiB

Open AccessArticle

Synthesis and Characterization of Polyaniline-Based Composites for Electromagnetic Compatibility of Electronic Devices

by Kamil G. Gareev, Vladislava S. Bagrets, Vladimir A. Golubkov, Maria G. Ivanitsa, Ivan K. Khmelnitskiy, Victor V. Luchinin, Olga N. Mikhailova and Dmitriy O. Testov

Electronics 2020, 9(5), 734; https://doi.org/10.3390/electronics9050734 - 29 Apr 2020

Cited by 13 | Viewed by 3575

Abstract

Polyaniline-based composites designed to ensure the electromagnetic compatibility of electronic devices were obtained. The surface morphologies of the obtained films were studied using optical and electron microscopy. The electrical resistivity of polyaniline (PANI) films were measured at various thicknesses. For films of various [...] Read more.

Polyaniline-based composites designed to ensure the electromagnetic compatibility of electronic devices were obtained. The surface morphologies of the obtained films were studied using optical and electron microscopy. The electrical resistivity of polyaniline (PANI) films were measured at various thicknesses. For films of various compositions and various thicknesses, the frequency dependencies of the complex dielectric permittivity, in the range of 100–2000 kHz, as well as the electromagnetic radiation (EMR) absorption coefficient in the frequency range 0.05–2 GHz were obtained. It was found that flexible gelatin-PANI composite films with a thickness of 200–400 μm, a bending radius of about 5 cm, and a real part of complex permittivity of not more than 10 provide an EMR absorption coefficient of up to 5 dB without introducing additional EMR absorbing or reflecting fillers. The resulting gelatin-PANI composite films do not possess a through electrical conductivity and can be applied directly to the surface of protected printed circuit boards. Full article

(This article belongs to the Special Issue Electromagnetic Interference and Compatibility)

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19 pages, 1613 KiB

Open AccessArticle

Electromagnetic Susceptibility of Battery Management Systems’ ICs for Electric Vehicles: Experimental Study

by Orazio Aiello

Electronics 2020, 9(3), 510; https://doi.org/10.3390/electronics9030510 - 19 Mar 2020

Cited by 30 | Viewed by 5426

Abstract

The paper deals with the susceptibility to electromagnetic interference (EMI) of battery management systems (BMSs) for Li-ion and lithium-polymer (LiPo) battery packs employed in emerging electric and hybrid electric vehicles. A specific test board was developed to experimentally assess the EMI susceptibility of [...] Read more.

The paper deals with the susceptibility to electromagnetic interference (EMI) of battery management systems (BMSs) for Li-ion and lithium-polymer (LiPo) battery packs employed in emerging electric and hybrid electric vehicles. A specific test board was developed to experimentally assess the EMI susceptibility of a BMS front-end integrated circuit by direct power injection (DPI) and radiated susceptibility measurements in an anechoic chamber. Experimental results are discussed in reference to the different setup, highlighting the related EMI-induced failure mechanisms observed during the tests. Full article

(This article belongs to the Special Issue Electromagnetic Interference and Compatibility)

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16 pages, 9002 KiB

Open AccessArticle

Modeling and Optimization of Impedance Balancing Technique for Common Mode Noise Attenuation in DC-DC Boost Converters

by Shuaitao Zhang, Baihua Zhang, Qiang Lin, Eiji Takegami, Masahito Shoyama and Gamal M. Dousoky

Electronics 2020, 9(3), 480; https://doi.org/10.3390/electronics9030480 - 14 Mar 2020

Cited by 7 | Viewed by 3988

Abstract

As an effective means of suppressing electromagnetic interference (EMI) noise, the impedance balancing technique has been adopted in the literature. By suppressing the noise source, this technique can theoretically reduce the noise to zero. Nevertheless, its effect is limited in practice and also [...] Read more.

As an effective means of suppressing electromagnetic interference (EMI) noise, the impedance balancing technique has been adopted in the literature. By suppressing the noise source, this technique can theoretically reduce the noise to zero. Nevertheless, its effect is limited in practice and also suffers from noise spikes. Therefore, this paper introduces an accurate frequency modeling method to investigate the attenuation degree of noise source and redesign the impedance selection accordingly in order to improve the noise reduction capability. Based on a conventional boost converter, the common mode (CM) noise model was built by identifying the noise source and propagation paths at first. Then the noise source model was extracted through capturing the switching voltage waveform in time domain and then calculating its Fourier series in frequency domain. After that, the conventional boost converter was modified with the known impedance balancing techniques. This balanced circuit was analyzed with the introduced modeling method, and the equivalent noise source was precisely estimated by combining the noise spectra and impedance information. Furthermore, two optimized schemes with redesigned impedances were proposed to deal with the resonance problem. A hardware circuit was designed and built to experimentally validate the proposed concepts. The experimental results demonstrate the feasibility and effectiveness of the proposed schemes. Full article

(This article belongs to the Special Issue Electromagnetic Interference and Compatibility)

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17 pages, 1863 KiB

Open AccessArticle

Simple Setup for Measuring the Response to Differential Mode Noise of Common Mode Chokes

by Pablo González-Vizuete, Carlos Domínguez-Palacios, Joaquín Bernal-Méndez and María A. Martín-Prats

Electronics 2020, 9(3), 381; https://doi.org/10.3390/electronics9030381 - 25 Feb 2020

Cited by 5 | Viewed by 8356

Abstract

This work presents a technique to measure the attenuation of differential mode noise provided by common mode chokes. The proposed setup is a simpler alternative to the balanced setup commonly employed to that end, and its main advantage is that it avoids the [...] Read more.

This work presents a technique to measure the attenuation of differential mode noise provided by common mode chokes. The proposed setup is a simpler alternative to the balanced setup commonly employed to that end, and its main advantage is that it avoids the use of auxiliary circuits (baluns). We make use of a modal analysis of a high-frequency circuit model of the common mode choke to identify the natural modes actually excited both in the standard balanced setup and in the simpler alternative setup proposed here. This analysis demonstrates that both setups are equivalent at low frequencies and makes it possible to identify the key differences between them at high frequencies. To analyze the scope and interest of the proposed measurement technique we have measured several commercial common mode chokes and we have thoroughly studied the sensitivity of the measurements taken with the proposed setup to electric and magnetic couplings. We have found that the proposed setup can be useful for quick assessment of the attenuation provided by a common mode choke for differential mode noise in a frequency range that encompasses the frequencies where most electromagnetic compatibility regulations impose limits to the conducted emissions of electronic equipment. Full article

(This article belongs to the Special Issue Electromagnetic Interference and Compatibility)

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17 pages, 1830 KiB

Open AccessFeature PaperArticle

EMI Susceptibility of the Output Pin in CMOS Amplifiers

by Anna Richelli, Luigi Colalongo and Zsolt Kovacs-Vajna

Electronics 2020, 9(2), 304; https://doi.org/10.3390/electronics9020304 - 09 Feb 2020

Cited by 3 | Viewed by 3027

Abstract

Measurements in commercial devices demonstrate a considerable susceptibility of the operational amplifiers to the electromagnetic interferences coupled to their output pin. This paper investigates some basic architectures starting from single stage amplifiers up to a whole operational amplifier. The result is a correlation [...] Read more.

Measurements in commercial devices demonstrate a considerable susceptibility of the operational amplifiers to the electromagnetic interferences coupled to their output pin. This paper investigates some basic architectures starting from single stage amplifiers up to a whole operational amplifier. The result is a correlation between the different amplifier configurations, the output impedance and the susceptibility to the interferences. The simulations are perfomed by using the standard CMOS UMC 180nm technology and by running the netlist of the schematics extracted from the layout. Full article

(This article belongs to the Special Issue Electromagnetic Interference and Compatibility)

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18 pages, 11088 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

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

by Paolo Stefano Crovetti and Francesco Musolino

Electronics 2020, 9(1), 60; https://doi.org/10.3390/electronics9010060 - 01 Jan 2020

Cited by 15 | Viewed by 3775

Abstract

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 [...] Read more.

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. Full article

(This article belongs to the Special Issue Electromagnetic Interference and Compatibility)

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14 pages, 709 KiB

Open AccessFeature PaperArticle

Hall-Effect Current Sensors Susceptibility to EMI: Experimental Study

by Orazio Aiello

Electronics 2019, 8(11), 1310; https://doi.org/10.3390/electronics8111310 - 08 Nov 2019

Cited by 23 | Viewed by 5602

Abstract

The paper deals with the susceptibility to Electromagnetic Interference (EMI) of Hall-effect current sensors. They are usually employed in power systems because of their galvanic isolation. The EMI robustness of such contactless device was compared with that of resistive current sensing (wired method). [...] Read more.

The paper deals with the susceptibility to Electromagnetic Interference (EMI) of Hall-effect current sensors. They are usually employed in power systems because of their galvanic isolation. The EMI robustness of such contactless device was compared with that of resistive current sensing (wired method). To this purpose, a printed circuit board (PCB) was fabricated. EMI tests methods such as Bulk Current Injection (BCI), Transverse-Electromagnetic (TEM) cell and Direct Power injection (DPI) were performed to evaluate the robustness of the Hall-Effect current sensor. EMI-induced failures are highlighted by comparing the different measurements tests and setups. Full article

(This article belongs to the Special Issue Electromagnetic Interference and Compatibility)

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14 pages, 6643 KiB

Open AccessArticle

A Novel Meander Split Power/Ground Plane Reducing Crosstalk of Traces Crossing Over

by Jung-Han Lee

Electronics 2019, 8(9), 1041; https://doi.org/10.3390/electronics8091041 - 17 Sep 2019

Cited by 6 | Viewed by 3901

Abstract

In this paper, a novel meander split power/ground plane is proposed for reducing crosstalk between parallel lines crossing over it. The working mechanism of the meander split scheme is investigated by simulations and measurements. The LC equivalent circuit and transmission line model are [...] Read more.

In this paper, a novel meander split power/ground plane is proposed for reducing crosstalk between parallel lines crossing over it. The working mechanism of the meander split scheme is investigated by simulations and measurements. The LC equivalent circuit and transmission line model are developed for modeling interactions between the meander split and the signal lines. The proposed meander structure enhances electromagnetic coupling between split planes. The capacitive coupling across the split ensures signal integrity and magnetic coupling between adjacent finger shaped structures suppresses lateral wave propagation along the split gap, which in turn helps suppress the crosstalk. The effectiveness of the meander split remains valid over very wide frequency ranges (up to 9 GHz). Experimental results show that the proposed structure improves the signal quality and reduces the near/far end crosstalk over 30 dB and 50% in the frequency domain and time domain, respectively. Full article

(This article belongs to the Special Issue Electromagnetic Interference and Compatibility)

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13 pages, 4344 KiB

Open AccessArticle

A Dual-Perforation Electromagnetic Bandgap Structure for Parallel-Plate Noise Suppression in Thin and Low-Cost Printed Circuit Boards

by Myunghoi Kim

Electronics 2019, 8(6), 719; https://doi.org/10.3390/electronics8060719 - 25 Jun 2019

Viewed by 3398

Abstract

In this study, we propose and analyze a dual-perforation (DP) technique to improve an electromagnetic bandgap (EBG) structure in thin and low-cost printed circuit boards (PCBs). The proposed DP–EBG structure includes a power plane with a square aperture and a patch with an [...] Read more.

In this study, we propose and analyze a dual-perforation (DP) technique to improve an electromagnetic bandgap (EBG) structure in thin and low-cost printed circuit boards (PCBs). The proposed DP–EBG structure includes a power plane with a square aperture and a patch with an L-shape slot that overcomes efficiently the problems resulting from the low-inductance and the characteristic impedance of the EBG structure developed for parallel-plate noise suppression in thin PCBs. The effects of the proposed dual-perforation technique on the stopband characteristics and unit cell size are analyzed using an analytical dispersion method and full-wave simulations. The closed-form expressions for the main design parameters of the proposed DP–EBG structure are extracted as a design guide. It is verified based on full-wave simulations and measurements that the DP technique is a cost-effective method that can be used to achieve a size reduction and a stopband extension of the EBG structure in thin PCBs. For the same unit cell size and low cut-off frequency, the DP–EBG structure increases the stopband bandwidth by up to 473% compared to an inductance-enhanced EBG structure. In addition, the unit cell size is substantially reduced by up to 94.2% compared to the metallo–dielectric EBG structure. The proposed DP–EBG technique achieves the wideband suppression of parallel plate noise and miniaturization of the EBG structure in thin and low-cost PCBs. Full article

(This article belongs to the Special Issue Electromagnetic Interference and Compatibility)

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