How do absorbers work?

When the electromagnetic wave is perpendicular to the surface of the absorbing material, part of the electromagnetic wave is reflected back; The rest enters the material, and in the process of electromagnetic wave propagation, the electromagnetic energy is converted into heat energy dissipation or the electromagnetic wave is attenuated due to interference through the mechanism of conduction current loss, dielectric loss and magnetic loss. Part of the electromagnetic waves that are not dissipated or attenuated are reflected between the free space and the surface of the absorbing coating and the interface between the bottom surface of the coating and the metal plate, and some of the electromagnetic waves are absorbed and attenuated by the absorbing coating during the back and forth reflection process, and the part that is not attenuated returns to free space again through the upper surface of the coating.

Generally speaking, in order to achieve efficient absorption of electromagnetic waves, two basic conditions must be met: (1) the incident electromagnetic waves enter the material to the maximum extent without being reflected on the surface of the material, that is, the matching characteristics of the material. When an electromagnetic wave is incident on the surface of a material, whether and in what proportion it can enter the material depends entirely on the input wave impedance at the interface between the material and free space.

That is to say, only when the wave impedance of the material matches the wave impedance of free space, the incident electromagnetic wave can enter the material to a large extent. (2) The electromagnetic waves entering the material can be quickly absorbed and attenuated, that is, the attenuation characteristics of the material, in other words, the material is required to have high electromagnetic loss characteristics.

The first condition is achieved by creating special boundary conditions so that the incident electromagnetic waves are not reflected on the surface of the material medium and enter the material as much as possible. The simplest case is when electromagnetic waves are irradiated perpendicular from free space to the surface of the medium.

To achieve the second condition, the material is required to have high electromagnetic loss performance, that is, the electromagnetic wave must be quickly absorbed and attenuated after entering the material, which is related to the physical properties of the material itself.

Absorbing material is an important part of the RF shielding box, which can improve the shielding effect and absorbing efficiency and ensure the performance of the shielding box.

Absorber is a composite material with an absorber in it that can absorb electromagnetic waves. Target.

The so-called absorbing material refers to a class of materials that can absorb the energy of electromagnetic waves projected onto its surface and have little reflection, refraction and scattering. Electromagnetic wave absorbers are divided into conductive losses, dielectric losses, magnetic losses, etc., and can be divided into conductive absorber materials, dielectric absorber materials, and magnetic absorber materials. Under the action of the external alternating electric field, the electrons in the material fibers vibrate, which converts electromagnetic energy into heat energy and dissipates it.

Studies have shown that this material has the outstanding advantages of relative light weight (1kg m2), absorption frequency bandwidth (10MHz-18GHz), good absorption performance (5-30db), strong weather resistance (-40-180), anti-aging, easy bending, arbitrary cutting, moisture resistance, pressure resistance, long-term use, non-toxic and environmental protection. In production, the electromagnetic absorption parameters of the material can be adjusted by adjusting the length, diameter, arrangement, and content of dispersant of the fiber, and the electromagnetic absorption parameters of the material can be manufactured according to customer needs (10MHz-18GHz) for different uses, such as (military, industrial and civil), from different thicknesses and (flat type, corrugated, honeycomb, etc.) different shapes.

Main application fields: mobile phones, electronic instruments and equipment, high-frequency equipment, microwave active devices, radar and microwave communication system clutter suppression, anti-electromagnetic interference and other technical fields, according to different application frequency bands, can adjust the thickness and formula of functional materials, made of electromagnetic wave absorbing film with different thickness and efficacy, its thickness is in, and can produce absorbers of different thickness and function according to customer needs.

Electromagnetic waves are composed of orthogonal magnetic and electric fields, and their mechanisms are divided into the following three types:

1.High permeability materials can convert the magnetic field component in the electromagnetic wave into heat loss;

2.or use high conductivity materials to convert the electric field components in the electromagnetic wave into heat loss, such as the integral ** coating hatch cover of F22;

3.Energy-dissipating materials are used to convert the electric field and magnetic field in electromagnetic waves into heat loss, and carbon-energy-dissipating plastic materials are generally added to a matrix such as polyurethane foam.

Make the plane convenient, you can fly to the universe to explore the mysteries.

Nowadays, there are many absorbing materials, and there are different types, the scope of use and the effect of use. However, when the owner of the family chooses, he doesn't even know the basic types of materials, and he doesn't know how to choose. So what is a absorber?

1. The so-called absorbing material refers to a class of materials that can absorb or greatly reduce the electromagnetic wave energy received on its surface, thereby reducing the interference of electromagnetic waves.

2. In engineering application, in addition to requiring the absorber 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.

<> absorbers are mainly made of nickel-plated carbon fiber. Absorbing materials are divided into different types according to the differences of the elements and materials contained, and different shapes of absorbing materials will also be used in different scenarios, such as the absorbers of the sharp split-shaped mountain disturbance are often used on the absorbers of the microwave anechoic chamber, and the coating-shaped absorbing materials are often used on the surface of the aircraft. Absorbing materials have been widely used in stealth technology, security protection, microwave anechoic chambers and many other projects.

Nanoabsorbers are usually composites composed of one or more materials. These materials have special physical and chemical properties that allow them to absorb electromagnetic signals from detection radars.

Specifically, the absorbing properties of nanoabsorbers derive from the nanoscale microstructure and composition contained in their structures. These microscopic structures and components can enable nanoabsorbers to respond differently to electromagnetic wave signals at specific frequencies, such as reflection, scattering, and absorption. The absorption response refers to the ability of a material to convert electromagnetic wave energy into other forms of energy, such as heat.

In general, the fabrication of nanoabsorbers requires fine material design and control to enable them to exhibit optimal absorption performance over a specific frequency range. This can be achieved by adjusting factors such as the composition, morphology, and structure of the material.

In general, the wave-absorbing properties of nano-absorbers are a complex physical phenomenon, and their specific mechanism involves the interaction of multiple factors and parameters.

News of absorbing materials is waiting for you. Absorbers of absorbing materials. Hippo. My main question is, no, why am I so, so, and so, and I don't think I will? I think it's all Sissy.

1. Sharp split.

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Join a group chat. The absorbers used in the microwave anechoic chamber are often made into a pointed split shape (gold tower shape), which is mainly composed of polyurethane foam type, non-woven flame retardant type, silicate sheet metal film assembly type, etc. With the decrease of frequency (wavelength increase), the length of the absorber also increases greatly, and the ordinary sharp split-shaped absorber has an approximate relationship of L 1, so at 100MHz, the tip splitting length reaches 3000mm, which is not only difficult to achieve in the process, but also greatly reduces the effective usable space of the microwave anechoic chamber.

2. Single-layer flat shape.

The earliest absorber developed in foreign countries is a single-layer flat shape, and the absorber made later is directly attached to the metal shielding layer, which is thin in thickness and light in weight, but the working frequency range is narrow.

3. Double-layer or multi-layer flat shape.

The absorber can operate over a wide operating frequency range and can be made into any shape. For example, the Japanese NEC company evenly disperses ferrite and metal staple fibers in suitable organic polymer resins to make composite materials, and the working frequency band can be broadened by 40 50. Its disadvantages are large thickness, complex process and high cost.

4. Coating type.

Only coated absorbent materials can be used on the surface of the aircraft, and composite materials are generally used to broaden the frequency band. For example, when the thickness of lithium-cadmium ferrite coating is 2 5mm 5mm, it can attenuate 8 5db in the centimeter band; When the spinel ferrite coating thickness is 2 5mm, it can attenuate 24db at 9GHz; When the thickness of the ferrite plus neoprene coating is 1 7 mm 2 5 mm, the attenuation at 5 GHz 10 GHz is about 30dB.

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Question: What raw materials are used in rubber products, and the amount is used to absorb electromagnetic waves?

Does the question have to be butyl glue?

Is butyl plus carbon black OK.

Is butyl plus carbon black OK.

Question: Can you give me a recipe? Fees are available.

Question [covering face].

When we were young, we went to the place where we rode on the mountain....My family didn't listen to you...