The Impact of Metals on RFID Systems

At present, radio frequency identification is most widely used in high frequency and ultra high frequency. However, radio frequency in the UHF band is sensitive to the environment, especially metal, which makes the passive tag of this working frequency unable to work on objects with metal surfaces, and the most widely used logistics industry for radio frequency identification is metal environment. Therefore, the shortcoming of metal sensitivity greatly limits its application in the logistics industry.

When RFID systems are used in metal environments, the impact of metals on UHF RFID readers is mainly reflected in two aspects: reflectivity and shielding. A metal plate is placed directly in front of the reader antenna. The distance between the metal plate and the fixed RFID reader at 2.5 m. The reader works in the UHF band and conforms to the ISO18000--6 standard.

When the metal is close to the reader antenna, due to electromagnetic induction, the RF energy is absorbed into its own electric field energy, thus reducing the total energy of the original RF field strength, and also generating an induced magnetic field, which is perpendicular to the metal surface. The distribution of the RF field strength is deformed on the metal surface, and the magnetic curve tends to be gentle. Therefore, when the label is attached to the metal surface or very close to the metal surface, there is actually no RF field strength distribution in the space, and the tag antenna cannot cut the magnetic field line to obtain the electromagnetic field energy, and the label cannot work normally.

This paper studies the effects of metals on RFID systems through theoretical analysis and experimental testing combined with simulation. The metal will have reflection and shielding on the field of the reader. The reflection will cause read and write holes, and the shielding will reduce the reading rate, but it is not completely unreadable. When the tag is placed near the metal, it will be difficult to receive the energy of the reader and the impedance and gain of the tag antenna will change.

Tags : UHF RFID readers fixed RFID reader

Next Post

Copyright © 2019 Shenzhen Hopeland Technologies CO., Ltd. All Rights Reserved. Powered by

welcome to hopeland
If you have questions or suggestions, please leave us a message,we will reply you as soon as we can!





Service Online

If you have questions or suggestions, please leave us a message,we will reply you as soon as we can!