A negative taper wave-absorbing honeycomb
By designing a negative cone-shaped absorbing honeycomb structure and utilizing the decreasing honeycomb aperture and increasing absorber concentration, the scattering and impedance matching of electromagnetic waves are enhanced, solving the problem of insufficient impedance matching in existing absorbing honeycombs over a wide frequency band, and realizing the absorption of electromagnetic waves for low-frequency radar detection.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHENZHEN KUANG CHI GANG DA INNOVATIVE TECH LTD
- Filing Date
- 2025-03-28
- Publication Date
- 2026-05-29
Smart Images
Figure CN224306167U_ABST
Abstract
Description
Technical Field
[0001] This application relates to metamaterials technology, and more specifically, to a negative cone-shaped absorbing honeycomb. Background Technology
[0002] With the widespread use of high-power, high-speed electronic devices and smart appliances, electromagnetic radiation, including both thermal and non-thermal effects, has begun to impact daily life and even endanger human health. Electromagnetic pollution has become the fifth largest form of pollution after air, water, solid waste, and noise. Using electromagnetic absorbing materials to convert electromagnetic radiation energy into heat or other forms of energy is currently one of the most effective methods for solving the problem of electromagnetic radiation pollution. The medical, health, and information security fields also have significant demands for electromagnetic protection and anti-electromagnetic interference. Simultaneously, in the military field, stealth, reconnaissance, and counter-reconnaissance technologies are placing increasingly higher demands on the performance of electromagnetic absorbing materials. To address the urgent needs for electromagnetic protection in both civilian and military fields and to solve electromagnetic pollution, conventional electromagnetic absorbing materials have gradually begun to be used. However, they can only effectively absorb electromagnetic waves in specific frequency bands. The absorption peak value and bandwidth are affected by factors such as the type of absorbing agent, material thickness, and density, preventing industrialization. While simply changing the type, structure, and dosage of the absorbing agent can improve the absorption effect to some extent, it often only achieves effective absorption in a specific and narrow microwave frequency band (above -10dB).
[0003] Currently, the electromagnetic parameters (such as dielectric constant and permeability) of traditional absorbing cellular structures are difficult to achieve impedance matching across a wide frequency range, resulting in a narrow absorption bandwidth. For example, some cellular structures are only effective in the 8-12 GHz frequency band, which cannot cover the detection needs of low-frequency radar. Utility Model Content
[0004] This invention addresses the deficiency of existing absorbing cell structures in meeting the detection requirements of low-frequency radar by providing a negative cone-shaped absorbing cell structure to overcome the aforementioned problems.
[0005] The present invention provides the following solution to the above problems: a negative cone absorbing honeycomb, comprising a negative cone impedance matching layer, an absorption layer and a reflection layer, wherein the negative cone impedance matching layer, the absorption layer and the reflection layer each comprise at least one honeycomb layer, and the honeycomb apertures of the negative cone impedance matching layer, the absorption layer and the reflection layer decrease sequentially; the surface of the negative cone impedance matching layer comprises at least one negative cone groove.
[0006] Preferably, the negative cone impedance matching layer, the absorption layer, and the reflection layer are enriched with a microwave absorbing agent.
[0007] Preferably, the concentration of the absorbing agent added to the negative cone impedance matching layer, the absorption layer, and the reflection layer increases sequentially.
[0008] Preferably, the absorber concentration of the negative cone impedance matching layer is 10% to 15%; the absorber concentration of the absorption layer is 20% to 25%; and the absorber concentration of the reflective layer is 30% to 35%.
[0009] Preferably, the side length of the honeycomb lattice of the negative cone impedance matching layer is 3.67 mm ± 10%;
[0010] Preferably, the side length of the honeycomb pores in the absorbent layer is 2.75 mm ± 10%;
[0011] Preferably, the side length of the honeycomb pores in the reflective layer is 1.83 mm ± 10%;
[0012] Preferably, the thickness of the negative cone impedance matching layer is greater than or equal to the thickness of the absorption layer, and the thickness of the absorption layer is greater than or equal to the thickness of the reflective layer;
[0013] Preferably, the thickness of the negative cone impedance matching layer is 30mm to 40mm, the thickness of the absorption layer is 10mm to 20mm, and the thickness of the reflective layer is 8mm to 10mm.
[0014] Preferably, the negative conical groove is a triangular groove with an opening width of 18–22 mm and a depth of 18–22 mm.
[0015] Preferably, the preparation of the negative cone-shaped absorbing honeycomb includes: adding a carbon-based absorbing agent to a resin solution and grinding it to prepare an absorbing slurry; impregnating an aramid paper honeycomb into the absorbing slurry and baking it for curing.
[0016] Preferably, the carbon-based microwave absorber is acetylene black or conductive carbon black.
[0017] Preferably, the resin solution is prepared by mixing resin and solvent at a ratio of 1:1.5 to 1:3.0.
[0018] Preferably, the resin is phenolic resin or epoxy resin.
[0019] Preferably, the solvent can be an alcohol solvent or a strongly polar solvent.
[0020] By implementing the present invention, when electromagnetic waves are incident on the honeycomb, the negative cone shape design ensures that there are always two surfaces in the oblique incident state of the polarization direction, which enhances the scattering of electromagnetic waves, reduces reflection, strengthens the impedance matching with air waves, and maximizes the incident electromagnetic waves into the interior of the material. It also increases the multiple reflections and refractions of electromagnetic waves in the negative cone structure, effectively reducing the energy of the radiated electromagnetic waves and achieving efficient broadband absorption of electromagnetic waves. Attached Figure Description
[0021] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.
[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0023] Figure 1 This is a perspective view of a preferred embodiment of the present invention;
[0024] Figure 2 This is a cross-sectional schematic diagram of a preferred embodiment of the present invention;
[0025] Figure 3 This is an enlarged schematic diagram of a preferred embodiment of the honeycomb structure of the present invention;
[0026] Figure 4 A schematic diagram showing the cross-sectional dimensions of a negative conical groove;
[0027] Figure 5 This is a schematic diagram of the electromagnetic characteristic curves for Experiment Example 1.
[0028] Figure 6 This is a schematic diagram of the electromagnetic characteristic curves for Experiment Example 2;
[0029] Figure 7 This is a schematic diagram of the electromagnetic characteristic curves for Experiment Example 3. Detailed Implementation
[0030] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.
[0031] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.
[0032] like Figure 1 The diagram shown is a three-dimensional schematic of a preferred embodiment of the negative cone absorbing honeycomb structure of this utility model. The negative cone absorbing honeycomb includes a substrate, which is composed of multiple stacked honeycomb layers. The upper surface of the substrate has multiple negative cone-shaped grooves. The pore size of the multiple honeycomb layers decreases from the upper surface to the substrate surface.
[0033] Functionally, the substrate consists of a negative cone-shaped impedance matching layer, an absorption layer, and a reflection layer stacked sequentially.
[0034] By adopting this negative cone structure, when electromagnetic waves are incident on the honeycomb, the negative cone shape design ensures that there are always two surfaces in the polarization direction of oblique incidence, which enhances the scattering of electromagnetic waves, reduces reflection, strengthens the impedance matching with air waves, and maximizes the incidence of electromagnetic waves into the material. It also increases the number of reflections and refractions of electromagnetic waves in the negative cone structure, effectively reducing the energy of the radiated electromagnetic waves and achieving efficient broadband absorption of electromagnetic waves.
[0035] The approach of transitioning from large to small apertures allows for better absorption of electromagnetic waves. When incident electromagnetic waves first pass through the large-aperture absorbing honeycomb structure, longer wavelengths are lost through multiple reflections within the apertures, which is beneficial for attenuating longer-wavelength, low-frequency electromagnetic waves. Similarly, when shorter-wavelength electromagnetic waves enter the absorption layer, they undergo more reflections within the smaller honeycomb apertures, leading to increased attenuation of high-frequency electromagnetic waves in the smaller aperture structure. When electromagnetic waves enter the reflective layer, they undergo even more reflections within the smallest honeycomb apertures and are affected by the conductivity of this layer, resulting in strong electromagnetic loss. Compared to conventional multi-layer honeycomb structures with the same aperture size, this embodiment effectively utilizes the differences in wavelength across frequency bands to efficiently introduce electromagnetic waves into the honeycomb structure.
[0036] like Figure 2 As shown Figure 1A cross-sectional schematic diagram of the stacked honeycomb layer structure. In this embodiment, the stacked honeycomb layer includes a first honeycomb layer, a second honeycomb layer, and a third honeycomb layer stacked from the incident surface along the incident direction. The first honeycomb layer is a negative cone-shaped impedance matching layer, the second honeycomb layer is an absorption layer, and the third honeycomb layer is a reflection layer. All three honeycomb layers are closely packed hexagonal absorbing honeycombs, with the honeycomb aperture size in the order: first honeycomb layer > second honeycomb layer > third honeycomb layer; the amount of absorbing agent added is in the order: first honeycomb layer < second honeycomb layer < third honeycomb layer.
[0037] exist Figure 2 The embodiment shows a structure where each functional layer is a single honeycomb layer. However, based on the principle of this invention, each functional layer can also be implemented using multiple honeycomb layers.
[0038] exist Figure 2 The embodiment shows that the three-layer honeycomb structure can use honeycomb materials with different dielectric constants to achieve impedance gradient distribution design.
[0039] like Figure 3 As shown Figure 1 , Figure 2 A magnified schematic diagram of the honeycomb structure is shown. In this embodiment, three honeycomb layers are stacked, from top to bottom: a negative cone impedance matching layer 100, an absorption layer 200, and a reflective layer 300. The top negative cone impedance matching layer 100 is first cut to form a negative cone shape, and then all three honeycomb layers are stacked. The dimensions of the negative cone groove are as follows... Figure 4 As shown, 'a' represents the half-width of the opening, and 'b' represents the groove depth. In a feasible example, 'a' is 10 mm and 'b' is 20 mm. The opening width can also be other values; for example, the opening width of a negative tapered groove is 2a = 18–22 mm, and the depth is b = 18–22 mm.
[0040] The process for preparing the above-mentioned honeycomb is as follows: A carbon-based microwave absorbing agent is added to a resin solution, wherein the resin solution is prepared in a ratio of 1:1.5 to 1:3.0, for example, 100 parts resin, 150-300 parts solvent, and the carbon-based microwave absorbing agent is added at 10-35% of the resin parts. The mixture is then ground to prepare an absorbing slurry. Aramid paper honeycomb is impregnated into slurries with different amounts of microwave absorbing agent, and after baking and curing, the desired layers of absorbing honeycomb are obtained. The resin can be phenolic resin, epoxy resin, etc.; the solvent can be an alcohol solvent or a strongly polar solvent, etc.; and the carbon-based microwave absorbing agent can be acetylene black or conductive carbon black, etc.
[0041] Based on the above size requirements and processes, adding different concentrations of absorbing agents can achieve different absorbing characteristics, as shown in the following experimental examples.
[0042] Experimental Example 1
[0043] (1) Slurry preparation: After dispersing epoxy resin in DMF at a ratio of 1:1.5, acetylene black is added at 10%, 20%, and 30% according to the resin content. The mixture is then ground to obtain absorbing slurries for preparing negative cone impedance matching layer honeycomb, absorption layer honeycomb and reflection layer honeycomb, respectively.
[0044] (2) Cellular fabrication:
[0045] The following honeycomb layers are impregnated once to obtain the desired microwave absorbing honeycomb cores:
[0046] Negative cone impedance matching layer honeycomb dimensions: 300mm(L)*300mm(W)*40mm(T), pore side length d1 range: 3.67mm±10%; absorber addition amount 10%; where L and W are the length and width of the honeycomb projection, and T is the thickness. The same meaning applies to the following dimensions, and will not be repeated.
[0047] Absorbing layer honeycomb size: 300mm(L)*300mm(W)*20mm(T), pore side length d2 range: 2.75mm±10%; microwave absorber addition amount: 20%;
[0048] The thickness and dimensions of the reflective layer honeycomb are 300mm (L) * 300mm (W) * 10mm (T), and the pore side length d3 range is 1.83mm ± 10%; the amount of microwave absorbing agent added is 30%.
[0049] (3) Fabrication of stacked honeycomb:
[0050] The negative cone impedance matching layer honeycomb is cut and slotted with a value of 10mm and b value of 20mm, i.e., the opening width is 20mm; the three layers are then bonded together using adhesive.
[0051] The electromagnetic characteristic curve of this experimental example is as follows: Figure 5 As shown. Among them. Figure 5 The left side shows the characteristic diagram of HH polarization (both transmission and reception are horizontally polarized), and the right side shows the characteristic diagram of VV polarization (both transmission and reception are vertically polarized).
[0052] Experimental Example 2
[0053] (1) Slurry preparation: After dispersing epoxy resin in DMF at a ratio of 1:1.5, acetylene black is added at 10%, 20%, and 35% according to the resin content. The mixture is then ground to obtain absorbing slurries for preparing negative cone impedance matching layer honeycomb, absorption layer honeycomb and reflection layer honeycomb, respectively.
[0054] (2) Cellular fabrication:
[0055] The following honeycomb layers are impregnated once to obtain the desired microwave absorbing honeycomb cores:
[0056] Negative cone impedance matching layer honeycomb size: 300mm(L)*300mm(W)*30mm(T), pore side length d1 range: 3.67mm±10%; absorber addition amount: 10%;
[0057] Absorbing layer honeycomb size: 300mm(L)*300mm(W)*20mm(T), pore side length d2 range: 2.75mm±10%; microwave absorber addition amount: 20%;
[0058] The thickness and dimensions of the reflective layer honeycomb are 300mm (L) * 300mm (W) * 10mm (T), and the pore side length d3 range is 1.83mm ± 10%; the amount of microwave absorbing agent added is 35%.
[0059] (3) Fabrication of stacked honeycomb:
[0060] The negative cone impedance matching layer honeycomb is cut and slotted with a value of 10mm and b value of 20mm, i.e., the opening width is 20mm; the three layers are then bonded together using adhesive.
[0061] The electromagnetic characteristic curve of this experimental example is as follows: Figure 6 As shown, the left side is the characteristic diagram of HH polarization, and the right side is the characteristic diagram of VV polarization.
[0062] Experiment Example 3
[0063] (1) Slurry preparation: After dispersing epoxy resin in DMF at a ratio of 1:3.0, acetylene black is added at 15%, 25%, and 35% according to the resin ratio. The mixture is then ground to obtain absorbing slurries for preparing negative cone impedance matching layer honeycomb, absorption layer honeycomb, and reflection layer honeycomb, respectively.
[0064] (2) Cellular fabrication:
[0065] The following honeycomb layers are impregnated once to obtain the desired microwave absorbing honeycomb cores:
[0066] Negative cone impedance matching layer honeycomb size: 300mm(L)*300mm(W)*30mm(T), pore side length d1 range: 3.67mm±10%; microwave absorbing agent addition amount: 15%;
[0067] Absorbing layer honeycomb size: 300mm(L)*300mm(W)*10mm(T), pore side length d2 range: 2.75mm±10%; microwave absorber addition amount: 25%;
[0068] The thickness and dimensions of the reflective layer honeycomb are 300mm (L) * 300mm (W) * 10mm (T), and the pore side length d3 range is 1.83mm ± 10%; the amount of microwave absorbing agent added is 35%.
[0069] (3) Fabrication of stacked honeycomb:
[0070] The negative cone impedance matching layer honeycomb is cut and slotted with a value of 20mm and b value of 20mm, resulting in an opening width of 40mm; the three layers are then bonded together using adhesive.
[0071] The electromagnetic characteristic curve of this experimental example is as follows: Figure 7 As shown, the left side is the characteristic diagram of HH polarization, and the right side is the characteristic diagram of VV polarization.
[0072] As can be seen from the three experimental examples above, when electromagnetic waves are incident on the absorbing honeycomb prepared according to this invention, at least two surfaces are in an oblique incidence state in the polarization direction. This increases the multiple reflections and refractions of electromagnetic waves in the negative cone structure, effectively reducing the energy of the radiated electromagnetic waves and achieving efficient broadband absorption of electromagnetic waves.
[0073] Specific examples in this embodiment can be found in the examples described in the above embodiments and exemplary implementations, and will not be repeated here.
[0074] Obviously, those skilled in the art will understand that the modules or steps of the present invention described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. They can be implemented using computer-executable program code, and thus can be stored in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those presented here, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the present invention is not limited to any particular combination of hardware and software.
[0075] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the principles of this utility model should be included within the protection scope of this utility model.
Claims
1. A negative cone-shaped absorbing honeycomb, characterized in that, It includes a negative conical impedance matching layer (100), an absorption layer (200), and a reflective layer (300), wherein the negative conical impedance matching layer (100), the absorption layer (200), and the reflective layer (300) each include at least one honeycomb layer, and the side length of the honeycomb cells of the negative conical impedance matching layer (100), the absorption layer (200), and the reflective layer (300) decreases sequentially; the surface of the negative conical impedance matching layer (100) includes at least one negative conical groove.
2. The negative cone-shaped absorbing honeycomb according to claim 1, characterized in that, The side length of the honeycomb lattice of the negative conical impedance matching layer (100) is 3.67 mm ± 10%.
3. The negative cone-shaped absorbing honeycomb according to claim 1, characterized in that, The side length of the honeycomb pores in the absorbent layer (200) is 2.75 mm ± 10%.
4. The negative cone-shaped absorbing honeycomb according to claim 1, characterized in that, The side length of the honeycomb lattice of the reflective layer (300) is 1.83 mm ± 10%.
5. The negative cone-shaped absorbing honeycomb according to claim 1, characterized in that, The thickness of the negative cone impedance matching layer (100) is greater than or equal to the thickness of the absorption layer (200), and the thickness of the absorption layer (200) is greater than or equal to the thickness of the reflective layer (300).
6. The negative cone-shaped absorbing honeycomb according to claim 5, characterized in that, The thickness of the negative cone impedance matching layer (100) is 30mm~40mm, the thickness of the absorption layer (200) is 10mm~20mm, and the thickness of the reflective layer (300) is 8mm~10mm.
7. The negative cone-shaped absorbing honeycomb according to claim 1, characterized in that, The negative conical groove is a triangular groove, with an opening width of 18~22mm and a depth of 18~22mm.