The Journal of Korean Institute of Communications and Information Sciences (한국통신학회논문지)

The Korean Institute of Commucations and Information Sciences (한국통신학회)
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Low-Frequency Electromagnetic Leakage Signal Analysis According to Fundamental Operations of Smartphones

스마트폰 기본 동작 모드에 따른 저주파 대역 누설 전자파 신호 특성 분석

  • Lee, Young-Jun (The Attached Institute of Electronics and Telecommunications Research Institute(ETRI)) ;
  • Park, Heesun (The Attached Institute of Electronics and Telecommunications Research Institute(ETRI)) ;
  • Kwon, YoungHyoun (The Attached Institute of Electronics and Telecommunications Research Institute(ETRI)) ;
  • Lee, Jaeki (The Attached Institute of Electronics and Telecommunications Research Institute(ETRI)) ;
  • Choi, Ji-Eun (The Attached Institute of Electronics and Telecommunications Research Institute(ETRI)) ;
  • Cho, Sangwoo (The Attached Institute of Electronics and Telecommunications Research Institute(ETRI))
  • Received : 2016.05.03
  • Accepted : 2016.08.04
  • Published : 2016.09.30
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Abstract

This paper presents the spectral analysis and radiation pattern of low-frequency electromagnetic(EM) leakage signals according to the fundamental operations of smartphones. The EM leakage signals generated by the activation of four I/O sensor modules such as a touch-screen, a camera, a microphone and a speaker are captured by the commercial near-field magnetic probe with 1cm spatial resolution. The analysis results show that the leakage of the EM wave occurs strongly around the activated I/O sensor modules, AP(Application Processor) and memory modules. Also, the distinguishable frequency characteristic is shown in each spectrum of EM leakage signals.

본 논문에서는 스마트폰의 저주파 대역 누설 전자파가 미치는 악영향을 분석하기 위해 스마트폰 모델별로 기본 동작에 따라 누설되는 30 MHz 이하의 누설 전자파 신호의 스펙트럼 특성 및 방사 패턴을 분석하였다. 사용자와의 직접적인 인터페이스를 담당하는 스마트폰의 입출력 센서 모듈(터치스크린, 카메라, 마이크 및 스피커 모듈)을 활성화시키는 4가지 기본 동작 모드에 의해 누설되는 전자파 신호를 상용 Near-Field 마그네틱 프로브를 통해 1cm의 격자 간격으로 정밀하게 측정하였다. 측정된 누설 전자파 신호를 분석한 결과, 스마트폰의 모델 및 동작 모드별로 누설되는 저주파 대역 전자파는 특이한 피크(Peak) 또는 하모닉(Harmonic) 피크 성분을 보이며, 동작 모드에 따라 각각의 입출력 센서 모듈이 활성화될 경우 해당 센서 모듈 및 메인보드 상의 AP(Application Processor), 메모리 주위로 상대적으로 강한 저주파 대역의 전자파가 누설되는 것을 확인할 수 있었다.

Keywords

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