Hello everyone, I am the editor. Today, I will introduce the absorbing materials to you. The following content is organized by the editor, and the relevant content is for reference.
The application of microwave absorbing materials in the engineering field, in the increasingly important stealth and electromagnetic compatibility (EMC) technology, the role and status of electromagnetic wave absorbing materials are very prominent, and they have become the magic weapon and "secret weapon" of electronic countermeasures in modern military. The application is mainly in the following aspects.
1. Stealth technology of absorbing materials:
Coating absorbing materials on various weapons and military facilities such as airplanes, missiles, tanks, ships, warehouses, etc. can absorb reconnaissance radio waves and attenuate reflected signals, thereby breaking through enemy radar defenses. This is a kind of anti-radar reconnaissance. A powerful method to reduce the weapon system from being attacked by infrared guided missiles and laser weapons. For example, because the American B-1 strategic bomber is coated with absorbing material, its effective reflection cross section is only 1/50 of that of the B-52 bomber; after coating the absorbing material on the fairing of the 0H-6 and AH-1G Cobra helicopter engines The infrared radiation of the engine can be reduced by about 90%. In the 1990 Gulf War, the first US F-117A aircraft that entered the territory of Iraq were stealth aircraft coated with absorbent materials. They effectively avoided Iraq’s radar monitoring.
2. Absorbing materials improve the electromagnetic compatibility of the whole machine
The false signals generated by the reflection of electromagnetic waves by the aircraft fuselage may lead to false interception or false tracking of highly sensitive airborne radars; when several radars on an aircraft or a ship are working at the same time, the crosstalk between the radar transmitting and receiving antennas is sometimes very serious , The jammer on the plane or on the ship will also interfere with the radar or communication equipment that comes with it....... In order to reduce such interference, the excellent magnetic shielding of absorbing materials is commonly used abroad to improve the performance of radar or communication equipment. If the radar or communication equipment fuselage, antenna and all surrounding interferences are coated with absorbing material, it can make them more sensitive and accurate to find the enemy target; coating the absorbing material on the surrounding walls of the opening of the radar parabolic antenna, It can reduce the side lobe's interference to the main lobe and increase the distance of the transmitting antenna, and it can reduce the interference of false target reflection on the receiving antenna; the application of absorbing materials in the satellite communication system will avoid the interference between communication lines and improve The sensitivity of the spaceborne communicator and the ground station, thereby improving the communication quality.
3. Anti-metal isolation application of RFID antenna of absorbing material
This application mainly uses the high track rate characteristics of a type of high magnetic track rate, low loss type absorbing material; when used, insert the wave absorbing plate between the 13.56MHz loop antenna and the metal substrate to increase the induced magnetic field through the wave absorbing material In itself, it reduces the chance of passing through the metal plate, thus reduces the induced eddy current in the metal plate, thereby reducing the loss of the induced magnetic field. At the same time, because of the insertion of the absorber, the measured parasitic capacitance will also be reduced, and the frequency offset will be reduced. It is consistent with the resonant frequency of the card reader, thereby improving the reading distance. Of course, the degree of improvement depends on the excellent degree of the characteristics of the absorbing material.