Shielding material is a type of material that can isolate the metal between two spatial regions to control the induction and radiation of electric fields, magnetic fields, and electromagnetic waves from one region to another. Specifically, it is the material used to make the shield. The shielding body surrounds the interference sources of components, circuits, assemblies, cables or the entire system to prevent the interference electromagnetic field from spreading out; the shielding body surrounds the receiving circuit, equipment or system to prevent them from being affected by the external electromagnetic field. For example, a wide range of copper foil tape and conductive cloth tape are used.
Absorbing material refers to a type of material that can absorb the electromagnetic wave energy projected on its surface, reducing the reflection of electromagnetic waves, such as "clay cows entering the sea", without sound. It converts incident electromagnetic waves into heat or other forms of energy through various loss mechanisms of materials to achieve the purpose of absorbing electromagnetic waves.
Therefore, the principles of absorbing materials and shielding materials are different. In layman's terms, absorbing materials absorb electromagnetic waves and convert them into heat, and prevent electromagnetic waves from being reflected on their surfaces. However, shielding materials mainly prevent electromagnetic waves from passing through and can reflect them to others. direction.
Personal opinion believes that the main difference between absorbing materials and electromagnetic shielding materials lies in the purpose of application. Taking military equipment as an example, the absorbing material is mainly used for the stealth protection of the equipment. The absorption of electromagnetic waves is completed by adjusting the impedance matching performance and the material absorbing ability. At this time, the electromagnetic waves are lost through various methods to minimize reflection. Electromagnetic shielding materials are mainly to protect a certain device from the interference of external electromagnetic fields. The materials used can deal with electromagnetic waves either by absorption or reflection.