Design And Research On UHF RFID Tag Antenna

RFID(Radio Frequency Identification) is a kind of non-contact and automatic identification communication technology which is realized by radio frequency communication technology.The application of which has involved in various fields with the rapid development of Radio Frequency Identification,including the field of integrated circuit,asset management,network information,etc. As the key component of the RFID system,the design and research of the tag antenna has become v ery critical and urgent.It is of theoretical significance and practical value for the mature and widely used RFID technology.Among them,the tag antenna has attracted more and more attention because of its size,cost and other constraints.The miniaturization,low cost,wide band and high performance of tag antennas become the goal of designers.In the thesis,the high frequency RFID tag antenna theory is introduced mainly from the aspects of influencing factors,tag classification and impedance matching.Then,the radiation,performance parameters of dual polarized antennaand impedance matching technology is analyzed with the RFID system.The optimized bending dipole antenna is made to measure with actual application. Meanwhile,the design principle and process of tag antenna is introduced, mainly analyzed from tag antenna impedance matching technology to the gain,mobility and reliability of tag antenna,And then the test methods of RFID tag antenna are discussed and analyzed to select one of high feasibility to test the antenna designed.Finally,the difficulties of tag antenna design arediscussedwith the current technology.This thesis is mainly for the analysis and research of RFID tag antenna design.With the introduction of the optimized design of simple bending dipole antenna and deep analysis,two small UHF RFID tag antennas are designed which satisfy the conjugate impedance matching of tag antenna and optimize the antenna size by means of horizontal loading, inductive coupling,tandem stub feeding and T-match technology. Furthermore,the conjugate matching transmitted by maximum power is achievedwith the characteristics of omnidirectional radiation,and the tag antenna is applicable to the RFID system byoptimizing and adjusting parameter valuesby using HFSS software.