Wideband side wall graphical wave-absorbing honeycomb structure

Abstract

The invention belongs to the technical field of electronic materials, and particularly relates to a broadband side wall graphical wave-absorbing honeycomb structure. Through the design mode that the strip-shaped resistive films are arranged at equal intervals according to the width and form the included angle with the honeycomb aperture Z direction to be fully distributed on the inner walls of the honeycomb units in parallel, the spiral-like structure design of resistive film stripes is finally formed on the inner walls of the honeycomb units, and the anisotropy of the effective dielectric constant of the wave-absorbing honeycomb structure is effectively improved; the polarization of the structure is insensitive; in addition, during processing of the structural design, the influence of pattern dislocation caused by process precision is extremely small. And the spiral-like structure design enables alternating impedance to be formed along the aperture direction, so that more times of reflection and absorption are formed on the inner walls of the honeycomb holes due to the arrangement angle of the strip-shaped resistive film after incident waves are incident, the impedance matching with air in a broadband range is effectively improved, and the 2-18GHz ultra-wideband wave-absorbing performance is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of electronic materials, and in particular is a broadband sidewall graphic wave-absorbing honeycomb structure. Background Art

[0002] Nowadays, with the development of science and technology, the popularity of electronic devices has led to increasingly prominent electromagnetic interference problems. Absorbing materials can effectively reduce interference between different devices and improve signal clarity and transmission quality. In the field of communications, especially in 5G and the upcoming 6G technology, absorbing materials play a key role in improving the stability and reliability of signal transmission. As a classic structure in nature, honeycomb structure has been widely used in the design and preparation of absorbing materials. The core material of the honeycomb absorbing structure provides it with excellent mechanical properties, so that it can be used as a design load-bearing component, and the absorbing coating provides it with good electromagnetic loss performance. Therefore, the honeycomb absorbing structure is a dual-function material that integrates load-bearing and absorbing. When electromagnetic waves are incident on the hexagonal honeycomb holes, the absorbing coating on the honeycomb hole wall will cause the electromagnetic waves to be reflected multiple times. This process will cause a large amount of electromagnetic wave energy to be lost to achieve the purpose of absorption.

[0003] At present, the traditional manufacturing process of absorbing honeycomb, such as CN105818453A and CN105297530A, first manufactures aramid paper honeycomb and absorbing slurry, then attaches the absorbing slurry to the aramid paper honeycomb through the impregnation process, and then forms the absorbing honeycomb through steps such as curing. Its advantages are mature technology and simple manufacturing, but its disadvantages are also obvious. Due to the influence of gravity, it is difficult to ensure the uniformity of the absorbing slurry on the honeycomb wall during the impregnation process, and this manufacturing process has a single structure, and it is difficult to carry out pattern design on the honeycomb.

[0004] At present, the non-graphic honeycomb has a relatively simple design method and a low degree of freedom in regulating electromagnetic properties. In order to increase the degree of freedom in regulating electromagnetic properties, a graphic absorbing honeycomb is imperative. The stretched honeycomb manufacturing process solves this problem. Its production process is to first print the absorbing coating on the blank aramid paper through the screen printing process, and then go through the steps of gluing, stacking, stretching, and drying. The product has good uniformity and can be flexibly designed with side wall graphics. However, in the actual manufacturing process of the stretched honeycomb manufacturing process, the aramid paper needs to be stacked accurately. Once the upper and lower papers are not aligned, the designed pattern will be misaligned after being folded into a honeycomb, which will affect the electromagnetic absorbing effect and make it polarization sensitive. Summary of the invention

[0005] In view of the above-mentioned problems or shortcomings, in order to solve the uneven distribution of the absorbing slurry on the honeycomb wall and the problem that the electromagnetic absorbing effect is affected by the inability to accurately align the paper in the stretched honeycomb manufacturing process, a broadband sidewall graphic absorbing honeycomb structure is proposed; this structure achieves more than 90% effective absorption of the incident electromagnetic waves in a broadband range of 2 to 18 GHz, is not affected by the process alignment, and can control the absorbing performance according to the stretching angle, and the structure is insensitive to polarization.

[0006] A broadband sidewall graphic absorbing honeycomb structure comprises an absorbing structure and a metal bottom plate; the absorbing structure is arranged on the metal bottom plate and is composed of a plurality of hexagonal absorbing honeycomb units, the side length of each hexagon is R, and the height of each honeycomb is h.

[0007] The inner walls of the absorbing honeycomb units are loaded with periodic resistance films; the specific loading method is: the strip resistance films are arranged at an angle of 45° with the honeycomb aperture Z direction in their length direction, and adjacent resistance films are parallel to each other and spaced D apart to cover the inner walls of each absorbing honeycomb unit; 0<W<R, 0<D<R.

[0008] The wave-absorbing honeycomb unit is deformed by stretching the hexagon in a diagonal direction to change two angles θ corresponding to the diagonal to achieve polarization insensitivity, θ=132-138°.

[0009] Furthermore, the width of the strip resistor film

[0010] Furthermore, the honeycomb is made of aramid fiber paper, and the real part of its relative dielectric constant ε r is 2.3, the loss tangent tanδ is 0.001, R=2.75mm, h=30mm.

[0011] Furthermore, the θ=136°.

[0012] Furthermore, the resistor film is made on aramid paper by screen printing process, and its square resistance is 900-1100Ω / sq.

[0013] In summary, the present invention has the following outstanding advantages:

[0014] 1. The resistor film is printed on the aramid paper through the screen printing process to ensure the uniformity of the resistor film on the honeycomb side wall.

[0015] 2. Through the design of a quasi-helical structure and the method of controlling the stretching angle θ, the anisotropy of the equivalent dielectric constant of the absorbing honeycomb is effectively improved, thereby making the structure polarization insensitive and the structure is almost not affected by the pattern misalignment.

[0016] 3. The quasi-spiral structure design enables it to form a directional oblique alternating impedance along the aperture direction (Z direction). After the incident wave is incident, the setting angle of the strip resistor film causes it to form more reflection absorption on the inner wall of the honeycomb hole, effectively improving the impedance matching with the air in a broadband range, thereby achieving 2 to 18 GHz ultra-wideband absorbing performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A top view of the bonding method of the honeycomb processing technology of the embodiment;

[0018] Figure 2 This is a schematic diagram of honeycomb stretching angle control in an embodiment;

[0019] Figure 3 It is a structural schematic diagram of Example 1;

[0020] Figure 4 The reflectivity curves of Example 1 at different stretching angles;

[0021] Figure 5 This is the reflectivity curve of Example 2. DETAILED DESCRIPTION

[0022] The technical solution of the present invention is described in detail below in conjunction with the accompanying drawings and embodiments.

[0023] A broadband sidewall patterned wave absorbing honeycomb structure, the specific structure of which is as follows Figure 3 shown.

[0024] In this embodiment, the honeycomb manufacturing process is to first print the resistor film on the blank aramid paper by screen printing, and then go through the steps of gluing, stacking, stretching, drying, etc. Figure 1 As shown in the figure; the arrow points to the glue application location, and then the aramid paper printed with the resistor film is accurately stacked up, and then the honeycomb morphology is controlled by machine stretching, as shown in the figure. Figure 2 In actual processing, the stretching angle θ is controlled by measuring the stretching distance l between the upper and lower sheets of paper.

[0025] Example 1

[0026] like Figure 3 As shown, in the plane printing design of this embodiment, the resistor films are in strip shape (rectangular) and are parallel to each other. The spacing between adjacent resistor films is The angle between the length direction of the resistor film and the honeycomb aperture direction (Z direction) is 45°, and the square resistance of the resistor film is 1000Ω / sq. The honeycomb is made of aramid fiber paper, and its relative dielectric constant real part ε r The value of the loss tangent tanδ is 2.3, and the value of the honeycomb height h is 30 mm, and the honeycomb aperture R is 2.75 mm.

[0027] The honeycomb equivalent electromagnetic parameters are adjusted by adjusting the stretching angle θ to make it tend to be biaxially isotropic. Figure 4 The reflectivity curves at the stretching angles θ = 136° and 120° show that when the stretching angle θ = 120°, the coincidence of the x-polarization and y-polarization reflectivity curves is not very ideal, but when the stretching angle is 136°, the x-polarization and y-polarization curves almost coincide. And the structure achieves 2-18GHz ultra-wideband absorption.

[0028] Example 2

[0029] As mentioned above, in the actual manufacturing process of the honeycomb manufacturing process, the aramid paper needs to be stacked accurately. Once the upper and lower papers are not aligned, the designed pattern will be misaligned after being folded into a honeycomb. However, the structure of the present invention will not be adversely affected by the misalignment of the pattern. In the electromagnetic simulation software CST, this embodiment simulates the situation where the upper and lower papers are not aligned. Figure 5 The reflectivity curves from alignment to misalignment 2R are shown, and it can be seen that the paper misalignment does not cause a significant change in the reflectivity curve.

[0030] It can be seen from the above embodiments that the present invention uses a design method in which the strip resistor film is equally spaced with its width and is parallel to the honeycomb aperture Z direction and is fully distributed on the inner wall of the honeycomb unit, and finally forms a quasi-spiral structure design of resistor film stripes on the inner wall of the honeycomb unit, which effectively improves the anisotropy of the equivalent dielectric constant of the absorbing honeycomb structure, thereby making the structure polarization insensitive; and the structural design is extremely small in the process of processing due to the effect of pattern misalignment caused by process accuracy. Moreover, the quasi-spiral structure design forms alternating impedance along the aperture direction (Z direction), and then after the incident wave is incident, due to the setting angle of the strip resistor film, it forms more reflection absorption on the inner wall of the honeycomb hole, effectively improving the impedance matching with air in a broadband range, thereby achieving 2-18GHz ultra-wideband absorbing performance.

Claims

1. A broadband sidewall patterned microwave absorbing honeycomb structure, characterized in that: It includes an absorbing structure and a metal bottom plate; the absorbing structure is arranged on the metal bottom plate and is composed of a plurality of hexagonal absorbing honeycomb units, the side length of the hexagon is R, and the honeycomb height is h; The inner wall of the absorbing honeycomb unit is loaded with a periodic resistance film; the specific loading method is: the strip resistance film is at an angle of 45° with the honeycomb aperture Z direction in its length direction, and adjacent resistance films are parallel to each other and are spaced D to cover the inner wall of each absorbing honeycomb unit; 0<W<R, 0<D<R; The wave-absorbing honeycomb unit is deformed by stretching the hexagon in a diagonal direction to change two angles θ corresponding to the diagonal to achieve polarization insensitivity, θ=132-138°.

2. The broadband sidewall patterned microwave absorbing honeycomb structure according to claim 1, characterized in that: The width of the strip resistor film 3. The broadband sidewall patterned microwave absorbing honeycomb structure according to claim 1, characterized in that: The honeycomb is made of aramid fiber paper, and its real part of relative dielectric constant ε r is 2.3, the loss tangent tanδ is 0.001, R=2.75mm, h=30mm.

4. The broadband sidewall patterned microwave absorbing honeycomb structure according to claim 1, characterized in that: The θ=136°.

5. The broadband sidewall patterned microwave absorbing honeycomb structure according to claim 1, characterized in that: The resistor film is made on aramid paper by screen printing process, and its square resistance is 900-1100Ω / sq.

6. The broadband sidewall patterned microwave absorbing honeycomb structure according to claim 5, characterized in that: The square resistance is 1000Ω / sq.

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