Reasearch And Design Of UHF Flexible Anti-metal RFID Tag Antenna

Internet of Things(IOT) is the most important part of the modern information industry.Radio Frequency Identification(RFID)is the cornerstone of the IOT because it can achive the global range of information sharing and tracking.Ultra-high Frequency(UHF)RFID receive a wide range of attention and application because of its long reading range,high reading rate and other advantanges.However,with the increase in application requirements and the expansion of the application scope,more kinds of RFID tags are in demand,which make the higher requirements of the design of the RFID antennas.Antimetal tag antennas are designed to solve the problem that the conventional tag antennas can't work well in the metal environment.However,the most current anti-metal tag antennas are thick,which limit the application.Therefore,this paper focus on the flexible anti-metal tag antennas to solve the application on the surface of curved matal objects.UHF flexible anti-metal RFID tag antenn is based on the anti-metal tag antenna,using the flexible substrate and designing the tag antenna which can work well when it curved even though conformal to the metal suface.The main contents of this paper are as fellows:Firstly,based on the reading distance of the tag,the influence of the tag antenna parameters on the maximum reading distance of the tag is further analyzed by calculating the maximum reading distance of the tag.Then,for the ordinary type of dipole-like RFID tag antenna,the influence of metal on the tag antenna parameters is studied,and the design method of anti-metal tag antenna is further analyzed and the design principle of flexible anti-metal tag antenna is put forward.The performance changes of the dipole tag antenna after bending conformal are studied,which can be used to further analyze the design of conformable anti-metal tag antenna.Next,A flexible PIFA anti-metal RFID tag antenna based on short-circuit stub feed is designed.The antenna is 51×25×1mm3,and the medium is foam.It has the advantages of small size,light weight,cheap price and easy bending.And it still has a good read performance in the conformal.Further,a new kind of flexible anti-metal tag antenna based on microtrip antennas is designed,and the thickness of the antenna is 0.5mm.The antenna is low profile,flexible,low cost and with good conformal characterisitics.And through studying the effects of the thickness,a new kind of altra-thin UHF RFID tag antenna is designed based on microstrip antennas.The thickness of the antenna is only 0.25 mm,which is shinnest anti-metal tag antenna as known now.The tag antenna has good performance and ultra-thin size,so it has a high research and application value.At last,the performance of flexible anti-metal tag antenna is studied after bending and conformal to metal suface.It shows that the flexible antimetal tag antenna has good capability of bending and conformal to metal suface.The simulation and measure results shows that the flexible anti-metal tag antenna has good performance and it can meet the design target and the most applications.