| As a rapidly developing wireless communication technology,RFID technology can realize two-way remote data exchange and reading and writing of target objects without requiring direct physical contact or being within the optical line of sight of the identifi cation system.RFID technology has been widely studied in the development and construction of modern society with its advantages such as large-capacity storage of data information,flexible reading and writing,fast scanning,non-line-of-sight identification,and reusability.Currently,this technology has been widely used in transportation,Storage management,production and many other fields.For tag antennas in RFID systems,passive tags with sensing functions are still in the stage of exploration and development,whether in theoretical experiments or market applications,so the focus of this article is on the design and analysis of passive sensor tag antennas.This paper proposed and tested three UHF antennas.The high-gain microstrip Yagi tag antenna has a max gain of 7.33dBi and is planned to replace the dipole antenna in passive tag sensor,then the reading distance will be raised.In this paper,the antenna is optimized for broadband,and the optimized antenna is processed and tested,which effectively increases the tag reading distance.When testing the reading performance of the antenna,it was found that the reading performance of the tag decreases significantly at high temperatures.Therefore,the input impedance of the chip is theoretically derived.I simulate and process two dipole antennas to carry out the theoretical analysis.The test was verified,and the final analysis concluded that the resistance of the electronic chip’s input impedance gradually increased and the reactance’s modulus gradually decreased as the temperature increased.A tag antenna based on the new temperature-sensitive material HDPE/BST is designed and processed in this article.The tag antenna can work normally at normal temperature,and the tag antenna has better reading performance than the conventional antenna under high temperature,alleviating the excessive degradation of the label’s performance in high temperature environments.Based on this research,this paper also designs a new type of microstrip Yagi sensor tag antenna.The innovation point of this antenna is that it can perfectly match the input impedance of the electronic chip with the best performance at room temperature and high temperature,which makes the tag obtain a more stable and excellent performance,providing a new way to improve the impedance mismatch between the antenna and the chip at different ambient temperatures. |
