Metasurface wave absorber based on square-round cross-shaped multi-nested structure

Abstract

The invention designs a metasurface wave absorber based on a square-round cross-shaped multi-nested structure. The structure is composed of a top metal resonance layer, a dielectric layer and a bottom metal layer. A metal resonance layer of the wave absorber is composed of a multi-period unit resonance array, and each resonance unit comprises an open circular ring structure, an open square ring, a crisscross patch and four patch resistors. The open circular ring is distributed on the outermost side of the resonance layer, a certain distance is kept between the open circular ring and the boundary of the unit, and chip resistors with the resistance value of 370 ohms are welded to four openings of the circular ring; the open square rings are distributed on the inner side of the circular ring, and outer ring diagonal lines are open circle inner diameters; and the cross-shaped patch is positioned at the inner diagonal line of the open square ring. The metasurface wave absorber structure is simple in manufacturing structure, the electromagnetic wave absorption rate reaches 90% or above at 7.35-18.18 GHz, and the metasurface wave absorber structure has the good bandwidth absorption characteristic.

Description

Technical Field

[0001] The invention belongs to electromagnetic wave absorption technology, and in particular relates to a super surface absorber based on a square, circle and cross multi-nested structure. Background Art

[0002] Metasurface absorbers are artificial periodic composite materials with special electromagnetic properties, and their structural dimensions are generally much smaller than the working wavelength. Metasurface absorbers have attracted much attention due to their excellent electromagnetic control performance. In recent years, they have broad application prospects in the fields of electromagnetic compatibility, electromagnetic protection, and military stealth. At present, traditional absorbing materials have problems such as large structural thickness, difficult low-frequency design, and narrow absorbing frequency band, which makes it difficult to meet the current broadband and lightweight absorbing needs.

[0003] Metasurface absorbers mainly rely on the electromagnetic resonance of the metal structure in the unit to create absorbing frequencies. Since single-frequency and multi-frequency metasurface absorbers can only reduce reflected waves at a specific frequency, their application scenarios are limited. Therefore, the research on broadband metasurface absorbers is particularly important. Summary of the invention

[0004] In view of the prior art, the present invention provides a metasurface absorber based on a square, circle and cross multi-nested structure, which comprises a top metal resonance layer, a dielectric layer and a bottom metal reflection layer; the metal resonance layer is composed of a plurality of periodic unit array structures, and the resonance unit comprises an open ring circular structure, an open square ring, a cross patch and four patch resistors; the open ring is distributed on the outermost side of the resonance layer and keeps a certain distance from the unit boundary, and the four openings of the ring are welded with a patch resistor with a resistance of 370Ω; the open square ring is distributed on the inner side of the ring, and the outer ring diagonal is the inner diameter of the open circle; the cross patch is located at the inner diagonal of the open square ring. The metasurface absorber has a simple manufacturing structure, achieves an electromagnetic wave absorption rate of more than 90% at 7.35-18.18GHz, and has good bandwidth absorption characteristics.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A metasurface absorber based on a square-circle-cross multi-nested structure comprises a metal resonance layer, a dielectric layer and a metal reflection layer from top to bottom; the metal resonance layer of the proposed absorber is composed of a multi-periodic unit resonance array, and the resonance unit includes an open circular ring structure, an open square ring, a cross-cross patch and four patch resistors; the open circular ring structure of each resonance unit is composed of four arc-shaped closed structures with equal inner and outer diameters and an arc angle of 80°, the center of the open ring coincides with the intersection of the diagonal of the square of the dielectric layer, and the outer ring of the open circular ring structure coincides with the unit resonance edge. The vertical distance between the midpoints is 1.7 mm, and the four chip resistors are respectively welded at the opening of the circular ring structure. The diagonal length of the outer side of the open square ring is the inner diameter of the open circular ring. Each split square ring is composed of four "L"-shaped metal structures with equal length and width. The cross-cross patch is located at the inner diagonal of the open square ring, and the cross intersection coincides with the intersection of the inner diagonal of the open square ring. The metal resonance layer, the dielectric layer and the metal reflection layer constitute the absorber unit structure, the metal resonance layer is attached to the top layer of the dielectric layer, and the metal reflection layer is attached to the bottom layer of the dielectric layer.

[0007] Furthermore, the thickness of the metal resonance layer and the bottom metal reflection layer of the absorber is 2 Both are 0.035mm, the dielectric layer thickness is X 1 2.6mm; the metal reflective layer and dielectric layer at the bottom of the absorber have equal side lengths, both of which are 9.4mm; the inner and outer diameters of the open ring r 1 and r 2 The inner angle θ of the circular ring opening is 10°; the inner and outer side lengths a and b of the open square ring are 3.42mm and 3.82mm respectively, and the distances c of the four openings are all 0.89mm; the cross patch is a vertical combination of two rectangles with a length d and a width e of 5.12mm×0.28mm.

[0008] Furthermore, the dielectric layer is made of FR-4 material to form a dielectric substrate, and the dielectric constant of the FR-4 epoxy resin material substrate used in the dielectric layer is 4.3. The top metal resonance layer and the bottom metal reflection layer are both made of metal copper.

[0009] Furthermore, the resistance of the chip resistor at the opening of the open circular ring in the metal resonance layer is 370Ω.

[0010] Compared with the prior art, the metasurface absorber based on the square, circle and cross multi-nested structure of the present invention has the following advantages:

[0011] 1. The structure of the resonance layer of the present invention is formed by nesting simple patterns. When electromagnetic waves are incident on the metasurface absorber, the absorber and the external medium have a perfect impedance matching effect. In the frequency band of 7.35-18.18 GHz, obvious resonance peaks are generated near three frequency points of 7.9 GHz, 13.1 GHz and 17.85 GHz, respectively, and superimposed, so that the resonance layer can have broadband absorption performance. Compared with the same type of metasurface absorbers, the actual absorption bandwidth of the absorber is 10.83 GHz, and the relative bandwidth is 84.84%, which has better broadband effect, and the manufacturing process of the absorber is simple and cost-saving.

[0012] 2. The absorber of the present invention has both simple resonance layer structure and good performance of wide absorption band. The unit structure of the absorber only includes three parts, namely the top metal resonance layer, the dielectric layer and the metal reflection layer; the metal resonance layer of the proposed absorber is composed of a multi-period unit resonance array, and the resonance unit includes an open circular ring structure, an open square ring, a cross-cross patch and 4 patch resistors; the absorption rate in the 7.35-18.18GHz frequency band is more than 90%, which has a wider absorption bandwidth compared with other absorbers of the same type.

[0013] The following is a detailed description with reference to the accompanying drawings in conjunction with embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is an overall structural diagram of a metasurface absorber based on a square-circle-cross multi-nested structure of the present invention;

[0015] Figure 2 It is a schematic diagram of the top metal resonance layer of the present invention;

[0016] Figure 3 A combined structural diagram of the dielectric layer and the bottom metal reflective layer of the present invention;

[0017] Figure 4 is an absorption characteristic curve diagram of the 0-30 GHz frequency band of the present invention;

[0018] Description of reference numerals:

[0019] In the figure: 1. Top metal resonant layer; 2. Dielectric layer; 3. Bottom metal reflective layer. DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0021] like Figure 1As shown, a metasurface absorber based on a square-circle-cross multi-nested structure of the present invention comprises a metal resonance layer 1, a dielectric layer 2, and a metal reflection layer 3 from top to bottom; the metal resonance layer 1 of the proposed absorber is composed of a plurality of unit periodic resonance arrays, and the resonance unit comprises an open circular ring structure, an open square ring, a cross-cross patch and four patch resistors; the open circular ring structure of each resonance unit is composed of four arc-shaped closed structures with equal inner and outer diameters and an arc angle of 80°, the center of the open ring coincides with the intersection of the diagonal of the square of the dielectric layer, the outer ring of the open circular ring structure is 1.7 mm vertically away from the midpoint of the unit resonance boundary, and the four patch resistors are respectively welded at the opening of the circular ring structure, as shown in FIG. Figure 2 As shown in the blue resistor pattern; the diagonal length of the outer side of the open square ring is the inner diameter of the open circular ring, and each open square ring is composed of 4 "L"-shaped metal structures with equal length and width; the cross-shaped patch is located at the inner diagonal of the open square ring, and its cross intersection coincides with the intersection of the inner diagonal of the open square ring.

[0022] In this embodiment, the top metal resonance layer 1 and the bottom metal reflection layer 3 of the absorber are both made of metal copper with a thickness of 0.035 mm, and the matrix layer 2 is made of FR-4 epoxy resin with a dielectric constant of 4.3.

[0023] like Figure 2 As shown, the inner and outer diameters r of the open ring of each unit structure metal resonance layer 1 are 1 and r 2 The inner angle θ of the circular ring opening is 10°; the inner and outer side lengths a and b of the open square ring are 3.42mm and 3.82mm respectively, and the distances c of the four openings are all 0.89mm; the cross patch is a vertical combination of two rectangles with a length d and a width e of 5.12mm×0.28mm.

[0024] like Figure 3 As shown, the dielectric layer 2 and the metal reflective layer 3 of the absorber of the present invention are both squares with equal sides, each with a side length of L=9.4 mm. The dielectric layer 2 has a thickness of X 1 =2.6mm, thickness of metal reflective layer 3 X 2 =0.035mm.

[0025] like Figure 4 As shown, the CST simulation software is used to simulate the metasurface absorber based on the square circle cross multi-nested structure of the present embodiment, using open boundary conditions in the vertical direction and unit structure boundary conditions in the horizontal direction. Electromagnetic waves are incident vertically. Figure 4This is the absorption characteristic curve of the periodic unit array absorber in the 0-30GHz frequency band. It can be seen from the figure that the absorber has an absorption rate of more than 90% in the 7.35-18.18GHz frequency band, and the three resonance points are near 7.9GHz, 13.1GHz and 17.85GHz respectively. The highest absorption rate in the band reaches 99.9%, meeting the characteristics of wide bandwidth and high absorption rate.

[0026] The present invention also provides a method for manufacturing a metasurface absorber based on a square, circle, and cross multi-nested structure: using a PCB process, metal printing is performed on a designed resonance structure on a dielectric layer 2 to obtain a metal resonance layer; the dielectric layer 2 and the metal reflection layer 3 are adhesively printed, and finally, a chip resistor of a corresponding resistance value is soldered to a designated position on the top layer by soldering, thereby obtaining a metasurface absorber based on a square, circle, and cross multi-nested structure.

[0027] Working principle of the present invention: The metasurface absorber utilizes the electromagnetic resonance effect, designs the geometric structure of the metal resonance layer 1 and selects specific material parameters to achieve efficient absorption of electromagnetic waves. Its working principle lies in the resonance characteristics of the metasurface unit. When an electromagnetic wave is incident on the metasurface, the structural unit of the metal resonance layer 1 will produce electromagnetic resonance, so that the energy of the electromagnetic wave is locally concentrated and absorbed. This local resonance effect greatly improves the response to electromagnetic waves of a specific frequency, allowing the absorber to effectively capture and dissipate electromagnetic wave energy. When the electromagnetic wave enters the absorber, due to the presence of the metal reflective layer 3, the amount of the reflected part of the electromagnetic wave is almost zero, so most of the energy of the electromagnetic wave is consumed in the form of dielectric loss and resistance loss in the material through the matrix layer 3, thereby achieving the absorbing effect.

Claims

1. A metasurface absorber based on a square-circle-cross multi-nested structure, characterized by: From top to bottom, the invention comprises a metal resonance layer, a dielectric layer and a metal reflection layer in sequence; the metal resonance layer of the proposed absorber is composed of a multi-period unit resonance array, and the resonance unit comprises an open circular ring structure, an open square ring, a cross patch and four chip resistors; the open circular ring structure of each resonance unit is composed of four arc-shaped closed structures with equal inner and outer diameters and an arc angle of 80°, the center of the open ring coincides with the intersection of the diagonal of the square of the dielectric layer, and the four chip resistors are respectively welded at the opening of the circular ring structure, the diagonal length of the outer side of the open square ring is the inner diameter of the open circular ring, and each open square ring is composed of four "L"-shaped metal structures with equal length and width, and the cross patch is located at the inner diagonal of the open square ring, and its cross intersection coincides with the intersection of the inner diagonal of the open square ring; the metal resonance layer, the dielectric layer and the metal reflection layer constitute the absorber unit structure, the metal resonance layer is attached to the top layer of the dielectric layer, and the metal reflection layer is attached to the bottom layer of the dielectric layer.

2. The metasurface absorber based on the square-circle-cross multi-nested structure according to claim 1, characterized in that: The metal reflection layer and dielectric layer of the absorber are both squares with equal sides, each with a side length of 9.4 mm. The thickness of the metal resonance layer and the bottom metal reflection layer is 0.035 mm, and the thickness of the dielectric layer is 2.6 mm. The inner and outer diameters of the open circular ring of each unit structure metal resonance layer are 2.7 mm and 3.0 mm respectively, the arc angle is 80 degrees, the four arcs are arranged axially symmetrically, and the vertical distance between the outer ring of the open circular ring structure and the midpoint of the unit resonance boundary is 1.7 mm; the inner and outer side lengths of the open square ring are 3.42 mm and 3.82 mm respectively, and the distance between the four openings of the open square ring is 0.89 mm; the cross patch is a vertical combination of two 5.12 mm×0.28 mm rectangles.

3. According to claim 1, a metasurface absorber based on a square-circle-cross multi-nested structure is characterized in that: The metal resonance layer and the metal reflection layer are both made of copper with a thickness of 0.035 mm. The dielectric layer is made of FR-4 epoxy resin. The dielectric constant of the FR-4 epoxy resin board is 4.

3.

4. According to claim 1, a metasurface absorber based on a square-circle-cross multi-nested structure is characterized in that: The resistance of the chip resistor at the opening of the open circular ring in the metal resonance layer is 370Ω.

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