• Title, Summary, Keyword: Radiated EMI

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The Reduction Method for Radiated EMI in USB Power Line of Cable (USB 케이블의 전원선 에서의 방사성 EMI 개선)

  • Park, Kyoung-Jin;Lee, Dae-Woo;Ko, Yong-Mok;Gang, Eun-Gyun;Park, Jong-Hyun;Kim, Keun-Yong;Ra, Keuk-Whan
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.9
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    • pp.201-208
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    • 2013
  • In this paper, we studied on improvement for radiated EMI of USB power line of cable. it is made by using wireless video access point system for confirming the phenomenon of radiated EMI from cable. then, we make sure that the limit exceed through the initial measurement of radiated EMI limit criteria in comparison to about 3 [dBuV/m]~15 [dBuV/m]. after that we confirmed the resonance in power line of cable through measurement of s-parameters. so, we confirmed the relation radiated EMI and power line of cable resonance and we reduced radiated EMI in power line of cable through a capacitor and low pass-band filter using the technique of power networks management. in conclusion, we suggested how to reduce power line of cable resonance applied for the improved method. and we confirmed that suggested reduction method is suitable through testing radiated EMI. the result of radiated EMI reduction limit criteria 40[dBuV/m]~47[dBuV/m] in comparison to about 3 [dBuV/m]~20 [dBuV/m].

Reduction of Radiated Noise of EMI using Shielding Methods of High Frequency Transformer (고주파 변압기 차폐에 따른 EMI 방사 노이즈 저감에 관한 연구)

  • Lee Wan-Yun;Chung Gyo-Bum
    • Proceedings of the KIPE Conference
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    • pp.811-814
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    • 2004
  • Radiated noise from high frequency transformers (HTFs) of switching mode power supply is mainly caused by the leakage inductance and the parasitic capacitance of HTFs. Generally, the radiated noise can be reduced by adding snubbers to switching power circuits or shielding HTFs. Radiated noise, however, is mainly affected by the shielding method. In this paper, the various shielding methods to reduce the radiated noise of EMI are analyzed, compared in the experimental studies. And it is proved that the radiated noise can be reduced according to the shielding methods of HFTs and the electrical connection between shields and power circuit.

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A Study on the EMI Denoising Using the Ferrite Core for Facsimile (페라이트 코어를 이용한 팩시밀리에서의 EMI 제거에 관한 연구)

  • Yun, Ki-Bang;Yu, Rin;Kim, Ki-Doo
    • Journal of the Institute of Electronics Engineers of Korea TE
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    • v.37 no.5
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    • pp.28-35
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    • 2000
  • In this paper, we design a ring inductor using the ferrite core to denoise the EMI(Electromagnetic Interference) for facsimile. The EMI for facsimile is radiated from the signal line of PSTN(Public Switching Telephone Network) between facsimile and PSTN. We denoise the radiated noise by inserting a ferrite core(Ni-Zn) between facsimile and PSTN. Even though we may denoise the radiated noise using two or more than two ferrite cores, we only concentrate on denoising EMI by adjusting number of turns of one ferrite core since it gives economical gain. As a result of measuring EMI using the designed inductor with 4 turns inserted in the line connected between facsimile and PSTN, the value of radiated emission is reduced below 30 dB$\mu$V/m.

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Analysis of Split Power/Ground Plane Structures for Radiated EMI Reduction (EMI 저감을 위해 분할된 전원/접지 평판 구조에서의 방사성 방출 분석)

  • Lee, Jang-Hoon;Lee, Pil-Soo;Lee, Tae-Heon;Kim, Chang-Gyun;Song, In-Chae;Wee, Jae-Kyung
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.47 no.6
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    • pp.43-50
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    • 2010
  • In this paper, we analyzed radiated emission generated by the split power/ground plane structures in order to reduce EMI in system modules. The magnetic fields and electric fields were simulated and measured on the test boards under various conditions. In order to reduce radiated emission, we have to determine spacing and location of the split ground gap so that input signal frequency does not coincide with the resonance frequency of the split power/ground plane structure and the phase of reflection coefficient is close to $0^{\circ}$ at input signal frequency. Moreover, we found that inserting a stitching capacitor could reduce the radiated emission. Low magnitude of reflection coefficient and the phase close to $0^{\circ}$ are required to reduce radiated emission. It is necessary to properly decide value and location of a stitching capacitor to fulfil those requirements.

The EMI Suppression Technology for Radiated Emissions from PCB Traces (PCB 선로에서 복사되는 불요전자파를 억제하기 위한 기술)

  • 박이섭;이중근
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.11 no.7
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    • pp.1121-1127
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    • 2000
  • Among many EMI suppression techniques for radiated emissions from PCB traces, image technique is adapted in this paper. A model for the analysis of the effect of image plane on the radiation of a microstrip trace is presented. After a simulation was carried out by using the FEM(Finite Element Method), field strength was measured with electric probe. The radiated emission levels were measured for various image plane width, separation distances, and their results show that the measured data are very close to those of simulation result. It proves that a proper use of image planes on the PCBs is very effective means of reducing EMI emissions on the PCBs.

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An Investigation of EMI Reduction Technique using the Spread Spectrum for an Automotive Power Converter (EMI 개선을 위해 자동차용 전력변환기에 적용된 주파수 확산 기법 분석)

  • Chae, Gyoo-Soo
    • Journal of the Korea Convergence Society
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    • v.9 no.2
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    • pp.1-6
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    • 2018
  • In this study, the investigation results of conducted and radiated emission for DC/DC converter circuit applied in electric vehicles are presented. A frequency spreading circuit was used to improve the EMI characteristics of a power converter designed by using MPQ4433 chip. The frequency spreading circuit using a TLV3201 chip was designed and applied to the power converter. A PCB was fabricated based on the EMI minimization procedures and simulated and measured results were presented for the far-field and near-field conducted and radiated emissions using the fabricated circuit. The measurement were done as CISPR 25 standardized test procedures. It is clearly showed that the EMI characteristics were improved 20% in case frequency spreading was applied. The EMI reduction technique using the frequency spreading proposed in this study was first applied to the design of power converter module for automobile. It is expected that the method presented here can be effectively used for EMI improvement in the future.

EMI Analysis on Microstrip Line with Defected Ground plane (결함구조를 갖는 접지면을 고려한 마이크로 스트립 선로의 EMI 분석)

  • Oh Sang-Bae;Kim Hyeong-Seok;Choi Kyoung
    • 한국정보통신설비학회:학술대회논문집
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    • pp.158-161
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    • 2006
  • In this paper, we deal with EMI Analysis on Microstrip with Defected Ground plane. Specially, we investigate reflection, transmission, crosstalk, radiated emission on Microstrip with Defected Ground plane structure. And investigates undesired effects on various defected ground plane such as ground with split, slot, short end and open end gap. To analyze reflection, transmission and crosstalk of microstrip with defected ground plane, we used concept of the microstrip to slot line transition model. Besides, investigate radiated emission using FDTD Commercial tools such as CST MW

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A Study on the Effects of I&C Systems by EMI Generating from Corona Discharge at Transformer Area (변압기 지역 코로나 전자파 간섭에 의한 계측제어설비 영향에 관한 연구)

  • Min, Moon-Gi;Lee, Jae-Ki;Park, Jin-Yeub;Kim, Hee-Je
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.63 no.2
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    • pp.266-271
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    • 2014
  • The Electromagnetic Interference(EMI) generating from corona discharge of transformer area can interference the digital Instrument and Control(I&C) systems located nearby transformers. When the potential gradient of the electric field around the conductor is high enough to form a conductive region but not high enough to cause electrical breakdown to nearby objects, the EMI of corona discharge emits with the conducted and radiated noise and it interferences the signals of the I&C systems. Since digital I&C systems have an efficiency and competitive price, the analog I&C systems have been upgraded and displaced with the digital I&C systems but which have less EMI Immunity. There was no assessment to I&C systems by EMI generating corona discharge nearby transformers. When the safety-related I&C systems are installed in plants, the verification of equipment EMI should be done not in site-specific test but in test facilities. There are the need to do the site-specific EMI evaluation of corona discharge nearby transformers. This paper assesses the margin between plant emission limits and the highest composite plant emission of corona. When the non safety-related I&C systems are placed in transformer area, it suggests the appropriate radiated susceptibility level to EMI of corona discharge.

A Study on the Insulation Diagnosis to measure Radiated Electromagnetic Waves with Partial Discharge Propagation at being of Conductive Particle in model GIS (모의 GIS 내부에 도전성 이물질 존재시 부분방전 진전에 따른 전자파 측정에 의한 절연진단연구)

  • Park, Kwang-Seo
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.1
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    • pp.157-164
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    • 2008
  • Partial discharge were simulated by conductive particle which could be easy accumulated charge and concentrated electric field in the model GIS. Radiated electromagnetic waves were measured and analyzed by using spectrum analyzer and antenna ($30{\sim}2000[MHz]$) for measurement of EMI EMC in accordance with occurrence and propagation of partial discharge. This paper suggested the other method of detecting and estimating of partial discharge for insulation diagnosis of GIS being conductive particle by measurement and analysis of radiated electromagnetic waves. From results of this study, it was confirmed that if the suggested method should be used for the diagnosis of insulation in the model GIS being conductive particle, detecting partial discharge and estimating discharge propagation will be possible.

EMI Prediction of Slew-Rate Controlled I/O Buffers by Full-Wave and Circuit Co-Simulation

  • Kim, Namkyoung;Hwang, Jisoo;Kim, SoYoung
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.14 no.4
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    • pp.471-477
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    • 2014
  • In this paper, a modeling and co-simulation methodology is proposed to predict the radiated electromagnetic interference (EMI) from on-chip switching I/O buffers. The output waveforms of I/O buffers are simulated including the on-chip I/O buffer circuit and the RC extracted on-chip interconnect netlist, package, and printed circuit board (PCB). In order to accurately estimate the EMI, a full-wave 3D simulation is performed including the measurement environment. The simulation results are compared with near-field electromagnetic scan results and far-field measurements from an anechoic chamber, and the sources of emission peaks were analyzed. For accurate far-field EMI simulation, PCB power trace models considering IC switching current paths and external power cable models must be considered for accurate EMI prediction. With the proposed EMI simulation model and flow, the electromagnetic compatibility can be tested even before the IC is fabricated.