In terms of solving high-frequency electromagnetic interference technology, shielding solutions are increasingly unable to meet regulatory requirements. In many devices, the requirements for port settings, ventilation, and windows make it impossible for the actual shielding method to form a fully shielded cage like a Faraday cage. Port size technology is the main threat to high-frequency equipment. In addition, there is another confusing technique. After the equipment is effectively shielded, the external interference technology is solved, but there is still electromagnetic interference technology in the shielding system, even if the shielding causes the interference to increase, and even the equipment cannot work normally.
Absorbing material is a material that can effectively absorb and attenuate incident electromagnetic waves. It can absorb electromagnetic waves by converting incident electromagnetic waves into heat or other forms of energy through various loss mechanisms of materials.
Unlike shielding solutions, its effectiveness lies in reducing the number of interfering electromagnetic waves. It can not only absorb electromagnetic waves alone, but also cooperate with a shielding system to improve the high-frequency efficiency of the equipment. At present, common absorbing materials can deal with the frequency range of electromagnetic interference from 0.72 GHz to 40 GHz. Higher and lower frequency absorbing materials can also be used. Absorbing materials can generally be divided into coating type, plate type and structure type; absorption mechanism can be divided into electric absorption type and magnetic absorption type; absorption structure can be divided into absorption type, interference type and resonance type.
The absorption effect of absorbing materials depends on various electromagnetic mechanisms inside the medium, such as Debye relaxation, resonance absorption, interface relaxation, resonance relaxation of domain walls of magnetic media, electron diffusion and micro-eddy currents. At present, manufacturers and suppliers of absorbing materials mainly produce and supply magnetic absorbing materials.