CN114315254B - Rapid-assembly type electromagnetic wave absorbing plate structure and preparation method thereof - Google Patents

Abstract

The invention provides a rapid assembly type electromagnetic wave absorbing plate structure and a preparation method thereof. Firstly, the electromagnetic wave absorbing agent is added into the cement-based material to endow the cement-based material with an electromagnetic absorption loss function, and the purpose of flexibly regulating and controlling high electromagnetic wave absorbing efficiency in different frequency bands is achieved through the structural design of multilayer and super surface. The electromagnetic wave transmission distance can be effectively increased, the electromagnetic wave loss is increased by combining the actions of multiple reflection refraction, resonance and the like, the surface layer protruding structure can be in a pyramid shape, a wedge shape, a conical shape, a regular quadrangular prism shape, a cylindrical shape and the like, and the protruding height is 15-30 mm. The free regulation and control of the electromagnetic wave absorption loss can be realized according to the protruding height of the surface layer and the lower part layer number of the structure in the microwave frequency range of 0.1-18 GHz. The prefabricated slab prepared by the structure can achieve the purpose of rapid emergency protection on the existing building structure, has the advantages of short construction period, good wave absorbing effect, detachable repair and the like, and solves the problem of rapid electromagnetic protection in the fields of civil and industrial use and the like.

Description

Rapid-assembly type electromagnetic wave absorbing plate structure and preparation method thereof

Technical Field

The invention belongs to the technical field of novel building electromagnetic protection materials, and particularly relates to a rapid assembly type electromagnetic wave absorbing plate structure and a preparation method thereof.

Background

With the innovation of modern technology, electronic and electric equipment are widely applied in the fields of communication, industry, broadcasting, medical treatment and scientific research, and electromagnetic waves widely appear in human production and life, and relate to military safety, communication safety, precision instrument accuracy, human body health and the like. Common technical means for solving the electromagnetic pollution include electromagnetic shielding and electromagnetic absorption. Electromagnetic shielding is essentially a barrier to electromagnetic radiation transmission and does not completely attenuate or attenuate electromagnetic radiation energy, and reflected waves may cause secondary electromagnetic wave contamination. Electromagnetic absorption, which can significantly reduce or eliminate electromagnetic radiation through energy conversion to heat or other forms of loss, or destructive interference, is currently the most effective electromagnetic pollution protection technology. The coating type wave-absorbing material is easy to change by environmental temperature and humidity and different using modes, so that the service life is short, the coating type wave-absorbing material is easy to fall off and crack, the environment friendliness is poor, and the thickness and the material uniformity of a coating layer cannot be well guaranteed. The structural wave-absorbing material well avoids the defects of a coating wave-absorbing material, can better meet the requirement of broadband strong absorption through reasonable structural design, and can meet the requirement of better strength.

Disclosure of Invention

The invention provides a rapid assembly type electromagnetic wave absorbing plate structure and a preparation method thereof based on modern electromagnetic protection requirements. The structure is a plate-shaped structure, can be made into different specifications, can easily realize batch production in a factory, can be quickly assembled and put into operation, can be independently disassembled and repaired, and can realize free adjustment of reflection loss according to specific physical shape parameters and the wave absorbent content of the plate structure in a microwave frequency band of 0.1-18 GHz.

In order to achieve the purpose, the invention adopts the technical scheme that:

a fast-assembly type electromagnetic wave-absorbing plate structure and a design method thereof are characterized in that the purpose of flexibly regulating and controlling high electromagnetic loss of different frequency bands is achieved by adjusting the surface layer protrusion height and the number of base layers in a multi-layer and super-surface structure through the wave-absorbing plate structure; the structure of the multilayer and the super surface is an upper part and a lower part: the lower part of the wave absorber is of a multilayer structure, the overall thickness is 25-30 mm, layered pouring is carried out according to the content of the wave absorber, and the purpose of optimal absorption of electromagnetic waves is achieved according to different layer impedance gradient designs; the upper part is a super-surface structure, and a surface convex periodic structure is formed by arranging different shape units and is marked as a surface layer 3D structure.

The upper super-surface unit structure form can be pyramid type, wedge type, cylinder type, cone type, regular quadrangular prism type, etc.; the height of the upper super-surface unit structure is 15-30 mm.

Preferably, the vertex angle of the pyramid structure is 40-50 degrees; the top angle of the wedge-shaped structure is 40-50 degrees, and the length is two times of the width; the diameter of the cylindrical structure is 15-20 mm; the vertex angle of the conical structure is 40-50 degrees, and the diameter is 15-20 mm; the length of the regular quadrangular side is 15-20 mm; the material ratio of the surface layer 3D structure is the same as that of the first layer of the lower part multilayer structure, and the surface layer 3D structure and the first layer of the lower part multilayer structure are cast simultaneously during manufacturing. The lower part of the multi-layer structure can be 3, 4 and 5 layers, the total thickness is 25-30 mm, the thickness of each layer is the same, and each layer controls the electromagnetic parameters of the cement-based material by changing the concentration of the wave absorbing agent, so that good impedance matching between the free space and the wave absorbing material and between layers is realized.

The structure of the invention can improve the optimized absorption of low-frequency electromagnetic waves and increase the effective wave-absorbing bandwidth by controlling the height of the surface layer bulge. The height of the surface layer bulge is 15-20 mm, the reflectivity can reach below-10 dB in a wave band of 2.0-18.0 GHz, the average reflectivity reaches below-30 dB, and the highest reflectivity reaches below-45 dB; the height of the bulge is 20-25 mm, the reflectivity of the wave band of 1.0-18.0 GHz can reach below-10 dB, the average reflectivity can reach below-35.0 dB, and the highest reflectivity can reach below-52 dB; when the height of the surface layer bulge is 25-30 mm, the reflectivity is below-10 dB in the wave band of 0.1-18.0 GHz, the average reflectivity is below-39 dB, and the highest reflectivity is below-58 dB. The more layers of the bottom multilayer structure are under the condition of the same thickness, the better the wave absorbing effect is, and the highest reflectivity and the average reflectivity are correspondingly improved. When the height of the surface layer is 25mm, the number of layers of the lower multilayer structure is 5, and the reflectivity can reach below-15 dB in the wave band of 0.1 GHz-18 GHz.

The multilayer structure is a cement-based electromagnetic wave-absorbing material, the wave-absorbing agent is acetylene black, the dielectric loss capacity is high, the particle size is 30nm, the doping amount range is 1-3%, and the doping amount of each layer is distributed in a gradient manner according to the number of layers. For example, in the case of three layers, the wave absorber content of each layer: 1 to 1.6 percent, 1.7 to 2.3 percent and 2.4 to 3 percent. And five layers: 1 to 1.4 percent, 1.4 to 1.8 percent, 1.8 to 2.2 percent, 2.2 to 2.6 percent and 2.6 to 3 percent; the impedance matching component can be selected from porous materials such as foamed glass particles, foamed polystyrene, expanded perlite and the like to improve the impedance matching between the wave-absorbing material and the free space.

The total thickness of the electromagnetic wave absorbing plate structure is 40-60 mm, the length and the width of the electromagnetic wave absorbing plate structure can be flexibly regulated according to transportation and construction requirements, the electromagnetic wave absorbing plate structure is set to be 800mm, 900mm, 400mm, 1200mm, 1000mm, and the like, and the electromagnetic wave absorbing plate structure is convenient to prefabricate and can be rapidly assembled.

The electromagnetic wave absorbing plate structure is prepared in a mode of reverse molding, an upper super-surface structure is required to be prepared at first, and then each layer of structure in the lower multilayer structure is prepared, the upper super-surface structure is made of the same material as the first layer of structure in the lower multilayer structure, and the upper super-surface structure and the lower multilayer structure both have good impedance matching and certain electromagnetic loss characteristics. The method comprises the following specific steps:

1) Preparing a soft silica gel mold for preparing cement mortar, inverting the soft silica gel mold, pouring the uniformly stirred cement mortar into the soft silica gel mold, and preparing a first layer with a surface 3D structure and a multilayer structure;

2) Performing layered pouring on the first layer of foundation, wherein the interval time of each layer of pouring is one hour, vibrating on a vibration table for 1min to eliminate bubbles after each layer of pouring is finished, scraping the surface, and then performing next layer of pouring, namely performing next layer of pouring after the previous layer of cement reaches initial setting; not only guarantees the flatness between layers, but also keeps the better bonding capability of cement;

3) And (3) after 24h, carrying out mould removal treatment on the structure prepared in the step 2), wherein the integrity of the convex form needs to be preserved when the mould is removed, and maintaining for 28d at the temperature of 20 ℃.

Compared with the prior art, the invention improves and innovates the construction process and the wave-absorbing mechanism of the material, and has the following main advantages:

1) This rapid Assembly formula electromagnetism wave-absorbing plate structure is brand-new panel form design, can carry out the mass production according to different specifications in the mill, can be relatively easy carry out rapid Assembly and come into use at the job site, can effectively shorten construction cycle, for catering to the actual application needs of the emergent protection of contemporary quick.

2) The wave absorbing effect is good. According to the multilayer cement-based wave absorbing plate with the 3D structure surface, the good impedance matching between the wave absorbing material and the free space is realized by integrating the physical shape of the surface layer and the gradient change of the substrate impedance, and the reflectivity of the electromagnetic wave on the surface of the material is greatly reduced, so that more electromagnetic waves enter the wave absorbing material to be absorbed and lost. The density of the cement-based material is reduced by the doping of the porous material (impedance matching component), the impedance matching is also adjusted to a certain extent, and meanwhile, electromagnetic waves can be reflected and refracted for many times between or inside the foamed glass particles, so that the absorption loss and interference loss can be enhanced. Meanwhile, the incident electromagnetic waves increase the transmission distance of the electromagnetic waves through multiple reflection and refraction between the surface layer raised structures, the interference loss effect can be obviously enhanced, and multiple interfaces formed by the substrate multilayer structure can enable more reflected waves to be overlapped and superposed to generate interference cancellation, so that the electromagnetic wave loss is also acted to a certain extent.

3) The invention can realize the optimized absorption of microwaves in different frequency ranges by controlling the gradient change of the surface layer protrusion height, the number of cement substrate layers and the wave absorbing agent content. The increase of the height of the bulge can expand the effective wave-absorbing bandwidth to low frequency. The height of the surface layer bulge is 15-20 mm, the reflectivity can reach below-10 dB in a wave band of 2.0-18.0 GHz, the average reflectivity (0.1-18 GHz) reaches below-30 dB, and the highest reflectivity reaches below-45 dB; the height of the bulge is 20-25 mm, the reflectivity can reach below-10 dB in a wave band of 1.0-18.0 GHz, the average reflectivity reaches below-35.0 dB, and the highest reflectivity reaches below-52 dB; when the height of the surface layer bulge is 25-30 mm, the reflectivity is below-10 dB in the wave band of 0.1-18.0 GHz, the average reflectivity is below-39 dB, and the highest reflectivity is below-58 dB. The more layers of the bottom multilayer structure are under the condition of the same thickness, the better the wave absorbing effect is, and the highest reflectivity and the average reflectivity are correspondingly improved. When the protruding height of the surface layer is 25mm, the number of the substrate layers is 5, the reflectivity can reach below-15 dB in the 0.1 GHz-18 GHz wave band, and the free regulation and control of the reflection loss in the 0.1 GHz-18 GHz microwave frequency band are realized.

4) The surface of the wave-absorbing material is provided with the 3D structure, and the three-dimensional structure of the surface layer provides a larger contact area for electromagnetic waves relative to the plane plate, so that the electromagnetic waves have more opportunities to enter the wave-absorbing material to be absorbed and lost. Secondly, the surface layer three-dimensional structure changes the transmission route of electromagnetic waves, so that more reflected waves generate interference loss, the number of absorption peaks is increased, the effect of broadband strong absorption can be realized, the wave-absorbing material with the 3D structure surface is integrally analyzed, and the problems of low wave-absorbing strength and narrow frequency band of the wave-absorbing coating and the plane wave-absorbing plate are well avoided. Aiming at the rare manufacture of surface layer bulges on a cement-based material at present, the preparation method of the invention adopts the form of a soft silica gel mould and a layered pouring mode to enable cement, namely the special-shaped bulges prepared from the material to realize good bonding among layers, can avoid the problem that the tips of a diagonal cone and a cone shape are easy to break, realizes the ideal wave absorbing effect in a low frequency band of 0.1-3 GHz by combining a super surface and a multilayer structure, avoids the problems of large height and difficult manufacture caused by independently adopting the surface layer bulges, and realizes the good wave absorbing effect on the low frequency band by matching the surface layer bulges with the multilayer structure.

5) The invention can reduce the surface layer protrusion height (for reaching a certain wave absorbing effect of a low frequency band) by adjusting the bottom layer number, and can reach the reflection loss effect of-10 dB by reasonably coordinating the surface layer protrusion height and the substrate layer number at 0.1-18 GHz. The structure can be prepared into a prefabricated plate, the purpose of rapid emergency protection on the existing building structure can be achieved, the prefabricated plate has the advantages of short construction period, good wave absorbing effect, detachable repair and the like, and the problem of rapid electromagnetic protection in the fields of civil and industrial use and the like is solved.

Drawings

Fig. 1 is a schematic structural diagram of surface layer 3D structures with different shapes, wherein (a) a pyramid shape (b) a wedge shape (c) a cylinder shape (D) a cone shape (e) a regular quadrangular prism shape.

FIG. 2 is a schematic view of a structure of the rapidly assembled electromagnetic wave absorbing plate with different surface shapes according to the present invention, wherein the surface protrusions are in the shape of an angle cone or a cylinder;

FIG. 3 is a schematic view of a cylindrical protruded surface structure of a rapid-assembling electromagnetic wave-absorbing plate with different surface shapes according to the present invention.

Detailed Description

The present invention is further explained with reference to the following examples and drawings, but the scope of the present invention is not limited thereto.

The invention relates to a rapid assembly type electromagnetic wave absorbing plate structure, which achieves the purpose of flexibly regulating and controlling high electromagnetic loss of different frequency bands by designing the protruding height of a surface layer, the number of layers of a substrate and the like in a 'multi-layer + super-surface' structure.

The upper super-surface unit structure form can be pyramid type, wedge type, cylinder type, cone type, regular quadrangular prism type, etc.; the height of the upper super-surface unit structure is 15-30 mm.

Preferably, the vertex angle of the pyramid structure is 40-50 degrees; the top angle of the wedge-shaped structure is 40-50 degrees, and the length is two times of the width; the diameter of the cylindrical structure is 15-20 mm; the vertex angle of the conical structure is 40-50 degrees, and the diameter is 15-20 mm; the length a of the regular quadrangular side is 15-20 mm; the proportion of the surface layer 3D structural material is the same as that of the first layer of the lower multilayer structure, and the surface layer 3D structure and the first layer of the lower multilayer structure are poured simultaneously during manufacturing. The lower part of the multi-layer structure can be 3, 4 and 5 layers, the total thickness is 25-30 mm, the thickness of each layer is the same, and each layer controls the electromagnetic parameters of the cement-based material by changing the concentration of the wave absorbing agent, so that good impedance matching between the free space and the wave absorbing material and between layers is realized.

Under the premise that other conditions are the same, the rapid assembly type electromagnetic wave absorbing plate structure can improve the optimized absorption of low-frequency-band electromagnetic waves and increase the effective wave absorbing bandwidth by controlling the height of the surface layer protrusion. The height of the surface layer bulge is 15-20 mm, the reflectivity can reach below-10 dB in a wave band of 2.0-18.0 GHz, the average reflectivity reaches below-30 dB, and the highest reflectivity reaches below-45 dB; the height of the bulge is 20-25 mm, the reflectivity of the wave band of 1.0-18.0 GHz can reach below-10 dB, the average reflectivity can reach below-35.0 dB, and the highest reflectivity can reach below-52 dB; when the height of the surface layer bulge is 25-30 mm, the reflectivity is below-10 dB in the wave band of 0.1-18.0 GHz, the average reflectivity is below-39 dB, and the highest reflectivity is below-58 dB. The lower multilayer structure has the advantages that the more layers are, the better the wave absorbing effect is, and the highest reflectivity and the average reflectivity are correspondingly improved. When the protruding height of the surface layer is 25mm, the number of the substrate layers is 5, and the reflectivity can reach below-15 dB in the wave band of 0.1 GHz-18 GHz.

The wave absorbing agent in the cement-based material can adopt acetylene black, ferrite, carbon fiber and the like, and has high electromagnetic loss capacity. When the wave absorbing agent is selected, the optimal doping amount range of the corresponding wave absorbing agent is selected according to the impedance matching characteristic and the electromagnetic loss characteristic, and then the multilayer structure of the cement substrate is designed according to the impedance matching gradient principle, namely, the wave absorbing agent in the multilayer structure is distributed in a gradient mode according to the doping amount in the optimal doping amount range.

The wave absorbing agent in the cement-based material adopts acetylene black, has high dielectric loss capacity, has the grain diameter of 30nm and the doping amount range of 1-3 percent, and is distributed in a gradient way according to the layer number. For example, in the case of three layers, the wave absorber content of each layer: 1 to 1.6 percent, 1.7 to 2.3 percent and 2.4 to 3 percent. And five layers: 1 to 1.4 percent, 1.4 to 1.8 percent, 1.8 to 2.2 percent, 2.2 to 2.6 percent and 2.6 to 3 percent. The impedance matching component can be selected from porous materials such as foamed glass particles, foamed polystyrene, expanded perlite and the like to improve the impedance matching between the wave-absorbing material and the free space. The electromagnetic wave absorbing plate structure is prepared in a mode of reverse molding, an upper super-surface structure is required to be prepared at first, and then each layer of structure in the lower multilayer structure is prepared, the upper super-surface structure is made of the same material as the first layer of structure in the lower multilayer structure, and the upper super-surface structure and the lower multilayer structure both have good impedance matching and certain electromagnetic loss characteristics. The total thickness of the electromagnetic wave absorbing plate structure is 40-60 mm, and the length and the width can be flexibly regulated and controlled according to the transportation and construction requirements.

Example 1

This embodiment quickly assembled electromagnetism wave-absorbing plate structure for emergent protection fast. The cement-based material is prepared by adding acetylene black wave absorbing agent and impedance matching component expanded perlite into the cement-based material, the content of the wave absorbing agent in the surface layer bulge is the same as that in the first layer of the lower multilayer structure, and the content of the wave absorbing agent in each layer of the lower multilayer structure is uniformly and gradiently changed at 1-3 percent according to the number of layers.

The preparation method of the fast assembly type electromagnetic wave absorbing plate structure comprises the following steps:

1. according to the 3D model, printing the template by using acrylonitrile-butadiene-styrene plastic through a 3D printer, putting the prepared plastic template into steel maintenance for preparing a silica gel mold, and coating vaseline on the surface layer of the plastic template.

2. And uniformly mixing the weighed silica gel and a curing agent (100), paving the mixture on a plastic mold, and taking out the mixture after curing to obtain the soft silica gel mold for preparing cement mortar.

3. The preparation process of the cement mortar comprises the following steps: dissolving a carbon black dispersing agent and a high-efficiency water reducing agent (the mass ratio of the carbon black dispersing agent to the cement is 0.2%) in water, adding weighed acetylene black, wherein the mass ratio of the dispersing agent to the acetylene black is 1: and 5, after uniformly stirring, ultrasonically dispersing for 10min, wherein the standard sand content is 50 percent, and the water cement ratio is 0.35, and pouring the weighed materials into a stirrer to prepare cement mortar.

4. Inverting the soft silica gel mold, pouring the uniformly stirred cement mortar into the soft silica gel mold, and preparing a first layer with a surface 3D structure and a multilayer structure;

5. performing layered pouring on the first layer of foundation, wherein the interval time of each layer of pouring is one hour, vibrating on a vibration table for 1min to eliminate bubbles after each layer of pouring is finished, scraping the surface, and then performing next layer of pouring, namely performing next layer of pouring after the previous layer of cement reaches initial setting; not only guarantees the flatness between layers, but also keeps the better bonding capability of cement;

and (3) after 6.24h, performing demolding treatment on the structure prepared in the step 2), wherein the integrity of the convex form needs to be preserved during demolding, and maintaining for 28d at 20 ℃.

Before the reflectance test, the samples were dried at 60 ℃ to constant weight to reduce the effect of free water. The following table shows the test data for different bump shapes and heights and the number of base layer layers.

FIG. 2 corresponds to the front view of the surface unit of pyramid type, cone type, wedge type; FIG. 3 is a front view of a corresponding regular quadrangular prism-shaped, cylindrical surface unit; in fig. 3, a and 2a are widths of regular quadrangular prism type and cylindrical unit protrusions and corresponding substrate widths, which are parameters for determining the number of surface protrusions.

1) Compared with the tests 1, 2 and 3, when the number of the layers of the cement substrate is taken as the only variable, the wave absorbing effect is increased along with the increase of the number of the layers under the condition of the same thickness.

2) In comparison tests 2, 4 and 5, when the height of the pyramid on the surface layer is taken as the only variable, the height of the pyramid is increased, an absorption peak appears in a low-frequency band region, and the maximum absorption peak value is correspondingly increased.

3) Compared with experiments 5, 6, 7 and 8, when the height of the surface layer bulge is taken as the only variable and the surface layer bulge structure is in the form of a pyramid, the wave-absorbing bandwidth, the maximum absorption peak value and the number of absorption peaks are all better than those of other types of bulge structures.

4) Comparison tests 3 and 4 show that the height of the surface layer protrusion structure can be reduced by increasing the number of the bottom layers to achieve the same wave absorbing effect. Similarly, the number of layers of the substrate can be reduced by increasing the height of the surface layer protrusions.

The invention is applicable to the prior art where nothing is said.

Claims (4)

1. The utility model provides a rapid Assembly formula electromagnetism wave-absorbing plate structure which characterized in that: the wave-absorbing plate structure achieves the purpose of flexibly regulating and controlling high electromagnetic loss of different frequency bands by regulating the protruding height of the surface layer and the number of the base layers in a 'multi-layer + super-surface' structure; the structure of the multilayer and the super surface is an upper part and a lower part: the lower part of the wave absorber is of a multilayer structure, the overall thickness is 25-30mm, layered pouring is carried out according to the wave absorber content, and the purpose of optimal absorption of electromagnetic waves is achieved according to different layer impedance gradient design; the upper part of the structure is a super-surface structure, and a surface convex periodic structure is formed by arranging units with different shapes and is marked as a surface layer 3D structure;

the material ratio of the surface layer 3D structure is the same as that of the first layer of the lower multilayer structure, and the surface layer 3D structure and the first layer of the lower multilayer structure are cast simultaneously during manufacturing;

the thicknesses of all layers of the lower multi-layer structure are the same, and all layers control the electromagnetic parameters of the cement-based material by changing the concentration of the wave absorbing agent, so that good impedance matching between the free space and the wave absorbing material and between layers is realized;

the multilayer structure is a cement-based electromagnetic wave-absorbing material, acetylene black is used as a wave-absorbing agent, the particle size of the acetylene black is 30nm, the mixing amount range is 1-3%, and the mixing amount of each layer is distributed in a gradient manner according to the number of layers; when the multilayer structure is three layers, the wave absorbing agent content of each layer is respectively as follows: 1% -1.6%, 1.7% -2.3% and 2.4% -3%; when the multilayer structure is five layers, the wave absorbing agent content of each layer is respectively as follows: 1% -1.4%, 1.4% -1.8%, 1.8% -2.2%, 2.2% -2.6% and 2.6% -3%; the impedance matching component is at least one of foamed glass particles, foamed polystyrene or expanded perlite;

the optimized absorption of microwaves of different frequency bands is realized by controlling the gradient change of the surface layer protrusion height, the number of cement substrate layers and the wave absorbing agent content, and the effective wave absorbing bandwidth can be expanded to a low frequency by increasing the protrusion height; the number of layers of the lower multilayer structure is 3, 4 or 5; when the height of the bulge of the surface layer 3D structure is 15-20mm, the reflectivity is lower than-10 dB in the wave band of 2.0-18.0 GHz, the average reflectivity is lower than-30 dB, the maximum reflection loss is lower than-45 dB, and 3 strong absorption peaks are formed; when the height of the bulge is 20 to 25mm, the reflectivity is less than minus 10dB in the wave band of 1.0 to 18.0GHz, the average reflectivity is less than minus 35.0dB, and the maximum reflection loss is less than minus 52 dB; when the protrusion height of the surface layer 3D structure is 25 to 30mm, the reflectivity is below-10 dB in the wave band of 0.1 to 18.0GHz, the average reflectivity is below-39 dB, the maximum reflection loss is below-58 dB, and 5 strong absorption peaks exist;

the total thickness of the electromagnetic wave absorbing plate structure is 40 to 60mm, the length and the width are flexibly regulated according to transportation and construction requirements, and the electromagnetic wave absorbing plate structure is set to be different specifications of 800mm, 900mm, 400mm 1200mm and 1000mm, and is convenient to assemble quickly.

2. The structure of a fast assembling electromagnetic wave absorbing plate of claim 1, wherein: the upper super-surface unit structure is in a pyramid shape, a wedge shape, a cylinder shape, a cone shape or a regular quadrangular prism shape;

the angle of the pyramid-shaped structure is 40-50 degrees, and the height is 15-30mm; the top angle of the wedge-shaped structure is 40-50 degrees, and the length is two times of the width; the diameter of the cylindrical structure is 15 to 20mm; the vertex angle of the conical structure is 40-50 degrees, and the diameter is 15-20mm; the length of the regular quadrangular side is 15 to 20mm.

3. The structure of a fast assembling electromagnetic wave absorbing plate of claim 1, wherein: when the height of the protrusion of the surface layer 3D structure is 25mm, the number of layers of the lower multilayer structure is 5, and the reflectivity of the lower multilayer structure in the wave band of 0.1GHz to 18GHz is less than-15 dB, the free regulation and control of the reflection loss in the microwave frequency band of 0.1GHz to 18GHz is realized; by controlling the protruding height of the surface layer 3D structure, the optimized absorption of low-frequency-band electromagnetic waves can be improved, and the effective wave-absorbing bandwidth is increased;

the height of the surface layer protrusion can be reduced by adjusting the number of the bottom layers, and the reflection loss effect of-10 dB can be achieved by reasonably coordinating the height of the surface layer protrusion and the number of the base layers within 0.1-18 GHz.

4. A method for preparing the fast assembling electromagnetic wave absorbing plate structure of claim 1, which is characterized in that: the electromagnetic wave absorbing plate structure is prepared in a mode of reverse molding, an upper super-surface structure is firstly prepared, and then each layer structure in a lower multilayer structure is prepared, wherein the upper super-surface structure is made of the same material as a first layer structure in the lower multilayer structure; the method comprises the following specific steps:

1) Preparing a soft silica gel mold for preparing cement mortar, inverting the soft silica gel mold, pouring the uniformly stirred cement mortar into the soft silica gel mold, and preparing a first layer of a surface 3D structure and a multilayer structure at the same time;

2) Performing layered pouring on the first layer of foundation, wherein the pouring interval time of each layer is one hour, after each layer of pouring is finished, vibrating on a vibration table for 1min to eliminate bubbles, then scraping the surface, and performing next layer of pouring, namely performing next layer of pouring after the upper layer of cement reaches initial setting; not only guarantees the flatness between layers, but also keeps the better bonding capability of cement;

3) And (3) after 24h, carrying out mould removal treatment on the structure prepared in the step 2), wherein the integrity of the convex form needs to be preserved when the mould is removed, and maintaining for 28d at the temperature of 20 ℃.

Images