Research On Antenna Design Method For A Miniature UHF RFID Tag Embedded In Metal

As a maturely developed wireless communication method,RFID technology has been widely used in various fields.With the development of computer technology and communication technology and the further popularization of the Internet of Things technology,the use scenarios of RFID tags have gradually become more diverse,and higher requirements have been placed on the size and environmental adaptability of tags.In some special cases,to ensure that the tag is not damaged,the tag needs to be embedded in the metal groove for use.However,due to the influence of the metal environment,the performance of the tag is seriously deteriorated,and the maximum reading distance of the tags is significantly reduced or even not recognized at all.In view of the above situations,this paper mainly studies the antenna design method of small embedded metal tags,and deeply analyzes the change rule of tag antenna performance in metal slot,and verifies it through a series of simulation analysis and experimental tests.The work of the thesis mainly includes the following parts:1)According to the Friis transmission equation and the radar distance equation,the theoretical calculation formula of the maximum reading distance of the tag is deduced in detail,and the working principle and related design method of the metal-resistant lags are deeply analyzed.Based on the theory of electromagnetic wave transmission and antenna theory,a series of modeling simulations and parameter analyses of dipole antenna and microstrip antenna are carried out by the electromagnetic simulation software.The reasons for the deterioration of dipole antenna performance on the metal surface and the influence law of metal edge effect on microstrip antenna performance are studied.2)The miniaturized design method of the tag antenna is analyzed in detail,and the simulation model of the tag antenna in the metal slot is established.The influence of the metal slot size and packaging material on the performance of the tag antenna is studied,and the structure of the tag antenna is optimized.Finally,a miniaturized UHF RFID tag antenna structure based on the planar inverted-F antenna(PIFA)is proposed by the meandering technology,and its overall size is 25.8mm×19.8mm×2mm.3)The designed tag antenna is processed and formed,and the relevant test results are carried out for the input impedance of the tag antenna and the maximum reading distance of the tag.It can be found that the measured results are basically consistent with the simulation results,and the measured maximum reading distance of the tag in the metal slot can reach 126 cm,which verifies the feasibility of the tag antenna design method.Further,the tag is applied to the tubing identification,the storage coding format of the tubing identification information in the tag is defined,and a tubing tag reading and writing software is designed based on the C++programming language and the MFC microsoft foundation class library,realizing the effective identification and scientific management of the tubing.