In many applications, RFID tags need to be attached to the surface of metal objects. When ordinary passive UHF RFID tags with dipole-like antennas are applied to metal surfaces, their performance will drop sharply, and they may not even be effectively read.
The impact of metal objects on tag antenna parameters and performance mainly has two aspects, one is the antenna field, and the other is the antenna parameters (such as impedance, S-parameter, radiation efficiency). In the field where the antenna works, there are the incident wave emitted by the reader and the reflected wave reflected by the metal plate. There is a certain phase difference between the incident wave and the reflected wave, which causes the two to cancel each other to a certain extent. In this way, the tag antenna working in this environment cannot induce enough current to provide energy for the tag chip, so that the tag chip cannot be activated and cannot work: the antenna parameter changes due to the antenna working on a metal surface , The metal plate is regarded as a part of the antenna itself, so even if the physical size of the antenna does not change, its impedance value, S parameters, etc. are still changed, resulting in a decrease in antenna performance.
Therefore, when it is suitable for metal environments, finding a suitable anti-metal tag is a prerequisite for ensuring the application effect of the RFID system.
So, what types of common UHF anti-metal electronic tags, and what are their advantages and disadvantages? What is the development trend of such tags?
What are the main types of UHF anti-metal electronic tags?
Speaking of common anti-metal tags, there are mainly ABS, PCB, epoxy, ceramic, foam, flexible anti-metal electronic tags, and they can be made into various styles and shapes, such as strips, squares, and circles. . Anti-metal tags are widely used in power asset management, enterprise asset management, equipment management, dangerous goods management, field metal management, pallet management in logistics, asset tracking, metal shelf management, etc.