In many scene applications, RFID anti-metal electronic tags need to be attached to the surface of metal objects. However, the metal object itself will affect the RFID tag, causing it to be interfered with by the signal, resulting in a sharp decline in the performance of the tag, and even its data cannot be effectively read by the corresponding equipment. In order to solve this problem, RFID anti-metal electronic tags came into being.
The early anti-RFID and anti-metal electronic tags are often large in size, which limits their practical application. With the gradual release of the demand for RFID tags in the fields of smart manufacturing and smart medical care, high-performance, miniaturized RFID anti-metal electronic tags are increasingly favored by the market.
Three implementations of RFID anti-metal electronic tag
At present, RFID anti-metal electronic tags mainly have the following three implementation methods:
- Use absorbing materials.
At present, the most commonly used method is to paste a layer of magnetic absorbing material behind the RFID anti-metal electronic tag. The magnetic permeability of the absorbing material is usually higher than that of the metal material, so as to change the magnetic field environment of the RFID tag, and adjust the tag and reader to the same frequency at the same time, so that the relevant equipment can normally read important information such as item data on the RFID anti-metal electronic tag.
- Using ceramic labels
The second way to achieve this is to use ceramic labels. Because the molecular gap between the ceramic materials is relatively large, it is not easily interfered with or destroyed by electromagnetic waves, which improves the reading efficiency of the reader for the RFID anti-metal electronic tag. However, ceramic materials are extremely fragile, so, at present, ceramic RFID tags have not been widely used in the market.
- Increase the distance between the label and the metal surface.
In addition, there is a common way to save the cost of using RFID anti-metal electronic tags by making a tag mold and increasing the distance between the tag and the metal. At a certain distance, the impact of electromagnetic waves on the tag will relatively decrease.
As far as the three implementation methods are concerned, the mainstream is still the first one – RFID anti-metal electronic tags using absorbing materials.
In addition, in order to adapt to different application scenarios and requirements, RFID anti-metal electronic tags can be said to be quite rich in morphological changes. Common RFID anti-metal electronic tags mainly include ABS, PCB, ceramic, flexible anti-metal electronic tags (printable), and can be made into various styles and shapes, such as bars, squares, circles and so on.
The structural situation of electronic tags is developing in the direction of lightness, thinness, smallness and softness. In this regard, flexible electronic devices have incomparable advantages over other materials, so the future development of electronic tags in radio frequency identification systems is likely to be combined with flexible electronic manufacturing, making the use of RFID anti-metal electronic tags more extensive and convenient. In addition, it can also greatly reduce costs and bring higher benefits.
Making low-cost flexible electronic tags has two meanings. On the one hand, it is a beneficial attempt to make flexible electronic devices. Electronic circuits and electronic devices are developing in the direction of “light, thin, small and soft”, and the development of flexible electronic circuits and electronic devices is more eye-catching.
A flexible circuit board, for example, is now available, a circuit that contains delicate wires and is fabricated from a thin, flexible polymer film that is capable of surface mount technology and can be bent into an infinite number of desired shapes.
Flexible circuits using SMT technology are thin and lightweight, with an insulation thickness of less than 25 microns. The flexible circuits can be bent arbitrarily and can be bent and placed into a cylinder to fully utilize the three-dimensional volume.
It breaks the traditional thinking set of inherent use area, thus forming the ability to make full use of the volume shape, which can greatly increase the effective use density in the current method, and form a high-density assembly form, which conforms to the development trend of “flexibility” of electronic products.
On the other hand, it can accelerate the process of recognition and development of RFID technology in our country. In the radio frequency identification system, the transponder is the key to the technology. Electronic tags are one of the many forms of RFID transponders, and flexible electronic tags are suitable for more occasions. The reduction of the cost of electronic tags will vigorously promote the real wide application of radio frequency identification technology.
Many RFID anti-metal electronic tags need to be attached to the surface of metal objects. When ordinary passive UHF RFID electronic tags with dipole-like antennas are applied to metal surfaces, the performance will drop sharply, and even can not be effectively read.
The influence of metal objects on the parameters and performance of the tag antenna is mainly reflected in two aspects. To put it simply, one is the antenna field, and the other is the antenna parameters (eg: impedance, S-parameter, radiation efficiency).
The field in which the antenna works has the incident wave emitted by the reader and the reflected wave reflected back by the metal plate, and there is a certain phase difference between the incident wave and the reflected wave, causing the two to cancel each other to a certain extent, making the field strong weakened. 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. Therefore, a suitable anti-metal tag is a prerequisite to ensure the application effect of the RFID system.
Shenzhen PH Functional Materials is a professional rf shielding fabric supplier, we have advanced technology and excellent product quality. If you want to choose a professional supplier of electromagnetic wave absorption and shielding materials, then please contact us, we will provide you with the best service.
