기지국용 판넬 안테나(4 X 2 Dipole Array)의 근역장 분석

Analysis of Near Field for Base Station Panel Antenna(4 X 2 Dipole Array)

  • 이덕로 (Sk텔레콤 중부 Network 본부) ;
  • 박주덕 (한국전자통신연구원 전자파환경연구팀) ;
  • 최재익 (한국전자통신연구원 전자파환경연구팀) ;
  • 김남 (충북대학교 전기전자공학부)
  • Lee, Dugro (Middle Regional Network Division, SK Telecome) ;
  • Park, Ju-Derk (EME Team, Radio Technology Research Group, ETRI) ;
  • Choi, Jae-Ic (EME Team, Radio Technology Research Group, ETRI) ;
  • Kim, Nam (Dept. of Computer & Communication Engineering, Chungbuk National University)
  • 발행 : 2004.05.01

초록

본 논문에서는 cellular 이동통신용 기지국 안테나와 같이 사용되는 파장에 비해 비교적 부피가 큰 해석 대상 체의 근거리장에서 전력 밀도를 계산한 내용을 다루었다. 현재 국내에서 cellular 이동통신 기지국용 안테나로 널리 사용되는 판넬형 섹터 안테나를 모델링하고 FDTD 계산법으로 reactive 근거리장의 전자계 분포를 계산하였으며 near to far 변환 통하여 원거리장의 안테나 이득을 구하였다. 그리고 radiating 근거리장의 전력밀도를 계산하기 위하여 원거리장의 이득을 이용하여 gain-based 모델을 적용하였다. 끝으로 radiating 근거리장의 전력밀도 계산 결과와 ICNIRP guideline의 전력밀도에 대한 일반인 및 직업인의 노출 제한 값을 고려하여 인증 거리(compliance distance)를 산출하였다. Gain based 모델을 이용한 계산 결과를 표면주사(surface scanning) 방식을 이용한 전력밀도의 측정 결과와 비교한 결과 주방사 방향의 중심 위치에서 계산된 값은 gain based model을 이용할 경우 -14.55 ㏈m이고, 측정된 값은 -15.75 ㏈m으로 케이블 및 커넥터의 손실을 감안하면 매우 정확한 것으로 나타났다.

In this paper, power density in near field is calculated about analytic object which has comparatively large volume in considering used wavelength such as cellular base station antenna. Panel sector antenna which is used widespreadly in domestic cellular wireless communication system is modeled and electromagnetic field distribution in reactive near field region is calculated by FDTD (Finite Difference Time Domain) method. After that, antenna gain in far field region is obtain by near to far transformation. Power spectral density in radiated near field is calculated in applying to gain-based model with antenna gain in far field. Finally, compliance distance is obtained in considering the result from radiated near field calculation and basic restrictions on occupational and general public exposure limits in ICNIRP guideline. In the center of main radiating position, the result from gain-based model is -14.55 ㏈m and the result from surface scanning method is -15.75 ㏈m. When the losses from cables and connectors used in measurement are considered, the results from gain-based model and surface scanning method are nearly coincident.

키워드

참고문헌

  1. Health Physics. v.74 no.4 Guidelines for limiting exposure to time-varying electric, magnetic, and electromagnetic Fields(up to 300 GHz) ICNIRP
  2. The European Standard EN 50383 Basic standard for the calculation and measurement of electromagnetic field strength and SAR related to human exposure from radio base stations and terminal stations for wireless telecommunications system(110MHz~40GHz) CENELEC
  3. Antenna Theory, Analysis and Design, second edition C.A.Balanis
  4. Advanced in Computational Electrodynamics: The finite-Difference Time-Domain Method Allen Taflove
  5. IEEE Trans. on VT v.49 Estimation of the average power density in the vicinity of cellular base-station collinear array antennas A.Faraone;Y.T.Roger;K.H.Joyner;Q.Balzano
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