What are the types of RFID absorber materials?

Flexible and thin magnetic load rubber absorbing material: tuned frequency absorbing material.

Tuned frequency absorbers, or resonant frequency RFID absorbers, have the characteristic of extremely large reflection losses at discrete frequencies, typically attenuating up to 20dB. Tuned frequency absorbers provide narrow-band absorption from 1 to 40 GHz.


Cavity resonant absorbent materials

Cavity resonant RFID absorbers are designed to exhibit high loss characteristics when placed in microwave cavities. Absorbers will effectively reduce the Q factor by attenuating cavity resonances, resonant frequencies, or harmonics. When the frequency is from 1 to 20 GHz, the cavity resonant absorber can absorb the electromagnetic wave energy incident from the normal direction and at a high angle.


RF absorbing foam

1.Surface wave-absorbing materials

Surface wave RFID absorbers are synthetic rubber absorbers with the strongest magnetic loads. Surface wave absorbers are designed to have the highest loss characteristics and are used to lay on conductive or metallic surfaces and absorb traveling or surface waves. Surface wave absorbing materials can absorb traveling waves or surface wave energy from 1 to 20 GHz.

2. Low frequency absorbing materials

Low-frequency RFID absorber materials have high attenuation characteristics in the sub-microwave frequency band. The material is made into magnetic particles of various shapes and exhibits high permeability in the frequency range from 1 MHz to 3 GHz.

rf shielding fabric rfid ferrite absorber sheet

Flexible media foam suction material

1,Suction material made of woven net foam

The weaving foam suction material is a very light type of carbon-loaded sheet material that can achieve a large attenuation of electromagnetic waves into electromagnetic waves in the direction of the method and deviation of the method. The woven foam material is processed with a continuous gradient coating, which has the characteristics of broadband reflection loss in the range of 1-20GHz.

2.Damaged foam suction material

The damaged foam suction material is a light, low-cost carbon loading board. It is processed with a uniform coating. Within the 1 to 20 GHz frequency range, it has the characteristics of high insertion losses.


RF absorbing materials

Curl foam absorbers are lightweight carbon-loaded sheet materials whose geometry resembles an “egg tray”. The tapered structure of the material enables high reflection loss from 1 to 20 GHz.

Spraying and pouring absorbent materials

Absorber coating materials can be fabricated for various application techniques, such as spray coating, injection, or immersion coating. The material can be processed from one or two-part materials of various viscosities.


Application of RFID absorber

RFID Antenna Anti-Metal Isolation Application

This application mainly uses the high magnetic field rate characteristics of a type of high magnetic field rate, low loss type wave absorbing material; when used, the wave absorber is inserted between the 13.56MHz loop antenna and the metal substrate to increase the induced magnetic field. The wave-absorbing material itself reduces the probability of passing through the metal plate, thereby reducing the generation of induced eddy currents in the metal plate and thereby reducing the loss of the induced magnetic field. At the same time, due to the insertion of the wave absorbing sheet, the measured parasitic capacitance will also be reduced, and the frequency offset will be reduced, which is consistent with the resonant frequency of the card reader, thereby improving the reading distance. Of course, the degree of improvement depends on the quality of the characteristics of the wave-absorbing material.

anti-interence wireless charging ferrite sheet

The so-called RFID absorber material is our absorbing material. Regarding its experiments and design, the development of microwave absorbing materials and anechoic chambers in anechoic chambers can be traced back to 1953, which is also this year. The research on RFID absorber materials began to go out of the laboratory and into the commercial field, and the first microwave anechoic chamber was built and applied to the absorbing performance test. During World War II, the application of RFID absorber materials in radar became more and more important, and Germany and the United States carried out a lot of work from the design, manufacture, and testing of absorbing bodies to performance improvement. The main task of shielded room design is how to improve the shielding effectiveness, and the key is the correct selection of shielding materials and node structure.


In theory, the location of the shielding room should be as far away from the interference source as possible to reduce the electric field strength of the interference, but in practical engineering, it is often limited by various conditions, especially because the interference factors often change, and new problems may appear at any time during the work. Strong interference source, so when designing, it is often necessary to consider the electric field strength of the strong interference source nearby. The shielding room is often located at the bottom of the building. At the same time, attention should be paid to the isolation of the transmitting and receiving equipment. In the multi-story building, the shielding room should be far away from the elevator room and the ventilation machine room. In order to save shielding materials, the external electrical equipment should be set as concentrated as possible under possible conditions. The shielding material plays a decisive role in the shielding effectiveness. Therefore, when designing a shielded darkroom, there are certain requirements and restrictions on the shielding material. For example, a good shielding attenuation coefficient is required, and materials with relatively large magnetic permeability and electrical conductivity are usually used.


Shenzhen PH Functional Materials is an experienced RFID absorber supplier. Our main products are flexible absorbent material, soft whiteboard, magnetic diaphragm, sintened ferrite film. Our products have the characteristics of absorbing and shielding electromagnetic waves, increasing magnetic flux, anti-metal interference, and isolation magnetic. Widely used in wireless charging modules, RFID electronic labels, smart cards, NFC modules, EMI, EMC and other fields. Welcome to consult us.

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