EMI Absorber

RFID (Radio-Frequency Identification) and Near-Field Communication (NFC) allow for wireless or contactless communication. RFID technology is widely used in tracking and location of assets in logistic functions. An RFID system consists of a reader with an antenna and a transponder. On the other hand, NFC is most used for secure communications such as access controls, exchange digital content, and contactless payments. NFC operates on short-read range radio frequency, which requires devices to be in very close proximity.

Radio wave absorbers suppress the conductive noise of fundamental frequency and radiation noise of high-frequency components, enabling seamless and stable wireless communication. In addition, they reduce the surface noise on shields or other metal surfaces and lessen undesired coupling. They are made of fillers with high permeability mixed in an elastomeric matrix, making them suitable for the reduction of EMI noise. They are in sheet forms and are attached between the antenna and the metal. This reduces absorption of metal materials on the signal of the magnetic field, and the magnetic field strength and the induction distance are increased. Sosa81 offers radio wave absorbers with the permeability of 20µ’ to 130µ’ at 3MHz and 47µ’ at 6 MHz.