With the development of modern science and technology, the impact of electromagnetic wave radiation on the environment is increasing. In airports, planes and flights are delayed due to electromagnetic interference; in hospitals, mobile phones often interfere with the normal operation of various electronic medical instruments. Therefore, it has become a major subject of material science to control electromagnetic pollution and find a material that can resist and weaken electromagnetic wave radiation – absorbing material.
The so-called absorbing material refers to a class of materials that can absorb the energy of electromagnetic waves projected on its surface. In engineering applications, in addition to requiring the absorbing material to have a high absorption rate of electromagnetic waves in a wide frequency band, it is also required to have light weight, temperature resistance, moisture resistance, corrosion resistance and other properties.
Electromagnetic radiation causes direct and indirect damage to the human body through thermal effects, non-thermal effects and cumulative effects. Studies have confirmed that ferrite absorbing materials have the best performance, and it has the characteristics of high absorption frequency band, high absorption rate, and thin matching thickness. The application of this material in electronic equipment can absorb leaked electromagnetic radiation and achieve the purpose of eliminating electromagnetic interference. According to the law that electromagnetic waves propagate in the medium from low magnetic to high magnetic permeability, high-permeability ferrite is used to guide electromagnetic waves, and through resonance, a large amount of radiation energy of electromagnetic waves is absorbed, and then the energy of electromagnetic waves is converted into heat energy through coupling.
The role and status of electromagnetic wave absorbing materials are very prominent, and they have become the secret weapon of electronic countermeasures in modern military. Its engineering applications are mainly in the following aspects:
Stealth technology
Coating absorbing materials on various weapons and equipment and military facilities such as aircraft, missiles, tanks, ships, warehouses, etc. can absorb reconnaissance radio waves and attenuate reflected signals, thereby breaking through the defense area of enemy radar. This is a kind of anti-radar reconnaissance. A powerful means of reducing the exposure of weapon systems to infrared-guided missiles and laser weapons.
Improve machine performance
The false signal generated by the reflection of electromagnetic waves by the aircraft body may lead to false interception or false tracking of the highly sensitive airborne radar; when several radars on an aircraft or a ship work at the same time, the crosstalk between the radar transceiver antennas is sometimes very serious. Jammers onboard or onboard can also interfere with onboard radar or communications equipment. In order to reduce such interference, excellent magnetic shielding of absorbing materials is commonly used abroad to improve the performance of radar or communication equipment. If the fuselage, antenna and surrounding interference objects of radar or communication equipment are coated with absorbing materials, they can be more sensitive and more accurate to detect enemy targets; It can reduce the interference of the side lobe to the main lobe and increase the working distance of the transmitting antenna, and it can reduce the interference of the false target reflection for the receiving antenna; the application of absorbing materials in the satellite communication system will avoid the interference between the communication lines and improve the Sensitivity of on-board communicators and ground stations to improve communication quality.
Safety protection
Due to the application of high-power radar, communication machine, microwave heating and other equipment, preventing electromagnetic radiation or leakage and protecting the health of operators is a new and complex topic, and absorbing materials can achieve this purpose. In addition, the electromagnetic radiation problem generally exists in current household appliances, which can be effectively suppressed by rational use of absorbing materials and their components.
RDID|NFC wireless charging magnetic separator
When NFC/RFID is working, the magnetic field formed by the antenna is easily interfered by objects such as metals, resulting in unnecessary errors in device identification, and the use of nfc absorber can eliminate such errors well. For example, the NFC/RFID antenna is generally placed between the back cover of the mobile phone and the battery, and the battery easily interferes with the magnetic field. At this time, we only need to put a layer of absorbing material between the antenna and the battery to eliminate the adverse effects of this interference. The nfc absorber can interfere with the paste where it is, and it is convenient, environmentally friendly and fast, solves the heating problem of wireless charging, and improves the efficiency of wireless charging.
Shenzhen PH Functional Materials is a professional sheet absorbing material factory, our wave absorbing products include nfc absorber, silicone absorber, EMC absorber and rf absorber, etc. Our products have strict production standards and stable quality. If you need a variety of absorbing materials, please contact our staff, we will provide you with the best service. We look forward to a win-win cooperation with you!
