In RFID equipment, the electronic tag should be integrated or attached to the product. As a part of the equipment, the magnetic separator often has to stick the electronic tag (usually passive) on the surface of metal and other conductive objects or near the place where there are metal devices due to the limited space. In this way, the tag is excited by the signal from the card reader, and the induced alternating electromagnetic field is easy to be attenuated by the eddy current of the metal, which greatly weakens the signal strength and leads to the failure of the reading process. Therefore, it is necessary to add anti metal materials and absorbing materials in the products to improve the card reading sensitivity.
High permeability absorbing materials need higher real part u 'and lower imaginary part u ″ (commonly known as "low magnetic loss"), that is, they want higher quality factor (U ′ / u ″).
Analysis principle: the higher real part of permeability can increase the magnetic flux of cluster communication antenna signal, so as to effectively reduce or eliminate the "metal eddy current" phenomenon when the antenna is close to the metal. At the same time, the lower imaginary part of permeability U "will not cause excessive loss of communication signal energy, so as to ensure the response of communication identification and effective identification distance
Permeability test diagram of magnetic separator at 13.56MHz frequency:
Application features of NFC products:
1) It has excellent flexibility in processing;
2) It is light and can be installed in narrow space;
3) The absorption attenuation is large and the reflection attenuation is small;
4) It is easy to use, and the product can be pasted in the appropriate position in the equipment;