CAJ | 학술논문

基于射频识别技术原理及Friis传输方程,导出了无源超高频射频识别系统链路模型,结合二端口网络分析方法,导出了标签密集环境下的标签天线互阻抗计算表达式.利用单阅读器单标签时的标签阻抗匹配条件,基于功率传输系数及调制因子,分析了互偶效应对系统链路的影响.在开阔室内环境中,测试了双标签及标签单、双平面布置情形下的阅读器天线最小发射功率及系统识别率.测试结果表明,双标签及双平面情形下,阅读器天线最小发射功率变化率分别为(?7%,11.6%)及(?10%,12.5%).
기우사빈식별기술원리급Friis전수방정,도출료무원초고빈사빈식별계통련로모형,결합이단구망락분석방법,도출료표첨밀집배경하적표첨천선호조항계산표체식.이용단열독기단표첨시적표첨조항필배조건,기우공솔전수계수급조제인자,분석료호우효응대계통련로적영향.재개활실내배경중,측시료쌍표첨급표첨단、쌍평면포치정형하적열독기천선최소발사공솔급계통식별솔.측시결과표명,쌍표첨급쌍평면정형하,열독기천선최소발사공솔변화솔분별위(?7%,11.6%)급(?10%,12.5%).
The close displacement of ultra high frequency radio-frequency identification (UHF RFID) tags can be considered as an elec-tromagnetically interconnected system which causes the mutual coupling effect among antennas of tags, thereby resulting in change in impedance matching condition. Based on the principles of RFID technology and Friis propagation equation, a link budget model of UHF RFID is provided which consists of one reader and one tag. Expressions of mutual impedance in dense environments are derived by using a two-port network. Utilizing the parameters of power transmission coefficient and modulation factor, the variation of system performance is discussed in theory and tested by three experiments which are conducted in open indoor environment. The measurement results show that the change rate of minimum power transmitted by the reader antenna is in a range from?7%to 11.6%for two-tag scene and from?10%to 12.5%for two-plane arrangement.