标签密集环境下天线互偶效应研究  

Theory and measurement for mutual coupling effect of ultra high frequency radio-frequency identification in dense environments

作　　者：佐磊[1] 何怡刚[1,2] 李兵[1] 朱彦卿[1] 方葛丰[3] 

机构地区：[1]湖南大学电气与信息工程学院,长沙410082 [2]合肥工业大学电气与自动化工程学院,合肥230009 [3]电子测试技术国防科技重点实验室,青岛266555

出　　处：《物理学报》2013年第4期115-123,共9页Acta Physica Sinica

基　　金：国家杰出青年基金(批准号:50925727);国家自然科学基金(批准号:60876022);国家自然科学基金青年科学基金(批准号:51107034);国防预研重大项目(批准号:C1120110004);湖南省科技计划(批准号:2011J4;2011JK2023);湖南省自然科学基金(批准号:12JJA004);湖南省教育厅科学研究项目(批准号:11C0479)资助的课题~~

摘　　要：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%).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.

关 键 词：射频识别 密集环境 互偶效应 互阻抗 

分 类 号：TP391.44[自动化与计算机技术—计算机应用技术] TN820[自动化与计算机技术—计算机科学与技术]