Antenna Performance Variation near a Lossy Material

손실성 물질 근접 시 안테나 성능변화

  • Lee, Jae-Won (School of Electrical and Electronics Engineering, Yonsei University) ;
  • Wi, Sang-Hyuk (School of Electrical and Electronics Engineering, Yonsei University) ;
  • Kim, Young-Soo (College of Electronics and Information, Kyung Hee University) ;
  • Yang, Hoon-Gee (Department. of Electronic Engineering, Kwang Woon University) ;
  • Yook, Jong-Gwan (School of Electrical and Electronics Engineering, Yonsei University)
  • 이재원 (연세대학교 전기전자공학과) ;
  • 위상혁 (연세대학교 전기전자공학과) ;
  • 김영수 (경희대학교 전자정보대학) ;
  • 양훈기 (광운대학교 전파공학과) ;
  • 육종관 (연세대학교 전기전자공학과)
  • Published : 2005.11.05

Abstract

There have been many researches on the antenna performance degradation with the presence of the human body around the antenna structure to accomodate personal communication service [1][2]. To better understand the human body effects on the antenna resonance, radiation pattern, and input impedance, simulation was carried out with changing of the distance between antenna and lossy material. Effects on the antenna performance by the surrounding materials are also important in the case of the RFID system. It is desirable that the tag antennas for RFID system must reveal isotropic radiation pattern as well as attain the good impedance matching. In this paper, we investigated the antenna resonance and input impedance characteristic when there exist a lossy material sphere near various types of antenna at 900 MHz. In short antenna resonance was mostly affected by lossy material in the case of a rectangular loop antenna, and impedance variation was smallest in the case of a halfwave dipole.

Keywords

RFID tag;Lossy Material;Dipole antenna