The absorbing material is a kind of functional composite electromagnetic wave absorbing material, which eliminates the back and forth reflection of electromagnetic waves in the shielding cavity, reduces the interference of clutter to its own equipment, and also effectively prevents the interference and damage of electromagnetic radiation to surrounding equipment and personnel. It is a kind of elimination of electromagnetic waves. Advanced pollution methods are widely used in various aspects such as noise reduction, wave absorption and EMC of electronic equipment. For example, they can help improve the performance of mobile payment and POS machines.
Traditional electromagnetic wave absorbing materials are mainly used in military countermeasures. Some aircraft, battleships, and armored tanks that cover and confuse the opponent's radar reconnaissance have a very high frequency of microwave range, and the application analysis is also a far-field model. Compared with absorbing materials in the traditional sense, RFID anti-metal absorbing materials are different in performance characterization and usage principles for 13.56MHz high-performance absorbing materials.
In NFC payment mobile phones, POS machines and other handheld devices, RFID electronic tags must be integrated or attached to the device, and function as a part of the device. Often due to limited space, it is inevitable to stick RFID electronic tags on metal and other conductive devices. The surface of the object or the place where there are metal devices nearby. However, with the use in a metal environment, the alternating electromagnetic field induced by the tag under the action of the signal sent by the card reader is easily attenuated by the metal eddy current, which greatly weakens the signal strength, and the reading distance will become closer. Interference will cause the reading process to fail. The current general solution is to stick a layer of magnetic electromagnetic wave absorbing material on the back of the electronic tag to make the RFID anti-metal interference, so that it can be better used for card reading.