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.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
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~~
关键词
射频识别
密集环境
互偶效应
互阻抗
radio frequency identification, dense environments, mutual coupling, mutual impedance