The Design Of RFID Read-write System Based On The Application Of Library System

Currently, as the key technology of internet of things, RFID is applied in many fields, such as borrowing and sorting books in the library etc. However, there are a few problems appearing during the use of the UHF RFID library system. Misreading is one of the problems. It is solved from two aspects of simulation design and actual test.First of all, the paper describes the basic theory about RFID system. They are the components of the RFID system, the detailed working process and the specific principle, as well as the theory related to the antenna. The system designed in this paper consists of the two parts. They are RFID antenna and RFID read-write module. This system works in UHF.Secondly, by using the electromagnetic simulation software of HFSS, the simulation to the RFID antenna has been made. In this paper, three forms of circularly polarized micro-strip antenna have been made into a simulation. In the simulation of A-Type single-feed circularly polarized micro-strip antenna, by using the meandering technology does the antenna have been realized miniaturization. Also, an analysis of the problem that how the slot length of both x direction and y direction can influence antenna’s characteristics of circular polarization has been made. For B-type single-feed circularly polarized micro-strip antenna, by fine tuning resonant length antenna generates two orthogonal polarization modes. In this way, the antenna achieves circular polarization characteristics. For the dual-feed circularly polarized micro-strip antenna, an orthogonal feed network is designed by means of a principle of strip-line, which provides two input signals equal in amplitude that has 90 degree’s difference in phase. In this way, the circular polarization of the antenna has been achieved.Thirdly, a read-write module circuit based on PR9000 is designed,whose transmit power is adjustable. The antenna model with a good performance in the simulation has been made into real. The read-write system consists of the real of antenna and the read-write module. By using the spectrum analyzer can the system’s performance be tested. It is necessary to perform statistical analysis on the data obtained from the test.Finally, a comparison between the simulation results and the test results has been made. The comparison result shows that both of them are basically the same. The performance of directional and circular polarization have been validated in both of the simulation results and the test results. By adjusting the transmit power of the read-write system, the effective reading distance can be controlled. Taking all the above into consideration, the RFID read-write system based on the application of library designed in this paper can solve the misreading phenomenon in the UHF RFID library system.