Metasurface wave absorber based on square and round multi-nested structure

Abstract

The invention discloses a metasurface wave absorber based on a square and round multi-nested structure. The structure is composed of a top metal resonance layer, a dielectric layer and a bottom metal layer. The wave absorber is composed of a periodic unit structure, and a resonance layer of the wave absorber is composed of a split circular ring, a split square ring, a metal wafer and eight chip resistors. The split circular ring is distributed on the outermost periphery of the resonance layer, a certain distance is kept between the split circular ring and the boundary of the resonance unit, and chip resistors with the resistance value of 250 ohms are welded to the four split positions of the circular ring; the split square ring is arranged on the inner side of the circular ring and keeps a certain distance from the circular ring, and 300-ohm chip resistors are welded at four split positions; the inner side of the split circular ring is provided with a metal disc and keeps a certain distance from the square ring. The metasurface wave absorber is low in manufacturing cost and simple in structure, the electromagnetic wave absorption rate can reach 90% or above at 10.15 GHz-20.91 GHz, and the metasurface wave absorber has the very good broadband 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 and round multi-nested structure. Background Art

[0002] A metasurface is an artificial surface with a subwavelength structure that achieves precise control of electromagnetic waves by controlling the phase, amplitude, and polarization of electromagnetic waves. By designing its geometry, material properties, and arrangement, the metasurface absorber can achieve functions such as absorption, reflection, and scattering of electromagnetic waves in an ultra-thin form. It breaks through the limitations of traditional absorbing materials and can achieve strong absorption of electromagnetic waves in a specific frequency band in a thinner structure, and can even achieve broadband absorbing effects. This feature makes it have great application potential in the fields of electromagnetic stealth, radio waves, and communication interference suppression.

[0003] When electromagnetic waves are shot into a metasurface absorber, three main phenomena will occur: part of the electromagnetic waves are reflected, part of the electromagnetic waves are transmitted through the metasurface absorber, and the other part is lost in the form of energy in the dielectric layer. Due to the existence of the metal reflective layer, only a very small part of the electromagnetic waves can pass through. Therefore, through the structural design of the metasurface absorber, the electromagnetic waves can be converted into other forms of energy in a specific frequency band, thereby achieving the absorption of electromagnetic waves. Summary of the invention

[0004] In view of the prior art, the present invention provides a metasurface absorber based on a square and circle multi-nested structure, which includes 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 includes a split ring structure, a split square ring structure, a metal disc structure, and 8 patch resistors; the split ring is distributed at the outermost periphery of the resonance layer and keeps a certain distance from the unit boundary, and the four splits of the ring are welded with a 250Ω patch resistor; the split square ring is distributed inside the ring and keeps a certain distance from the ring, and the four splits are welded with a 300Ω patch resistor; the metal disc is arranged inside the split ring and keeps a certain distance from the square ring. The metasurface absorber has low production cost and simple structure, and can achieve an electromagnetic wave absorption rate of more than 90% at 10.15GHz-20.91GHz, and has very good broadband 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 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 plurality of unit periodic resonance arrays, and the resonance unit comprises a split circular ring structure, a split square ring, a metal disc and 8 chip resistors; the metal disc is distributed on the innermost side of the metasurface absorber resonance layer, the split square ring is distributed on the outer side of the metal disc and the outer boundary is kept at a distance of 3 mm from the unit boundary, each split square ring is composed of four "L"-shaped metal structures of the same size and symmetry, and 4 chip resistors are also respectively welded at the four splits of the square ring structure; each split circular ring structure is composed of four arc structures of the same size, an open split circular ring structure is distributed on the outermost side of the unit resonance structure and the outer boundary of the circular ring is kept at a distance of 1.3 mm from the midpoint of the unit boundary, and 4 chip resistors are respectively welded at the four splits of the circular ring structure.

[0007] Furthermore, the thickness of the top metal resonance layer and the bottom metal reflection layer of the absorber are both 0.035 mm, and the radius r1 of the metal disc of each unit structure metal resonance layer is 0.7 mm; the inner and outer side lengths a and b of the split square ring are 3.0 mm and 4.0 mm respectively, the distance between the inner and outer edges of a single side is 0.5 mm, and the width c of the split openings of the four square rings is 1 mm; the inner diameter r2 and outer diameter r3 of the split circular ring are 3.2 mm and 3.7 mm respectively, and the width d of the four split openings of the circular ring is 0.5 mm; the dielectric layer and the metal reflection layer of the absorber are both squares with equal side lengths, and the side length L is 10 mm, and the thickness X1 of the dielectric layer is 2.3 mm.

[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 split opening of the split square ring is 300Ω; the resistance of the chip resistor at the split opening of the split circular ring is 250Ω.

[0010] Compared with the prior art, the present invention has the following beneficial effects:

[0011] 1. The structure of the resonance layer of the present invention is formed by the nesting of simple patterns. When the electromagnetic wave is incident on the metasurface absorber, the absorber and the external medium have a perfect impedance matching effect. In the frequency band of 10.15GHz-20.91GHz, obvious resonance peaks are generated near the three frequency points of 12.24GHz, 18.40GHz and 20.16GHz, 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 10.76GHz, and the relative bandwidth is 69%, which has a better broadband effect. The structure of the absorber is a nesting of simple structures such as square and circular rings, and the manufacturing process is simple.

[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 is composed of a structure of multiple periodic unit arrays, and the top metal resonance unit includes a split circular ring structure, a split square ring structure, a metal disc, 4 250Ω chip resistors and 4 300Ω chip resistors, and the absorption rate in the 10.15GHz-20.91GHz frequency band reaches more than 90%, which is better than similar The metamaterial absorber has a very wide absorption bandwidth; the lowest resonance point electromagnetic wave frequency band corresponding to the absorber of the present invention is 12.24 GHz, and the wavelength of the electromagnetic wave in this frequency band is 0.25 m. However, when designing a traditional absorber, the thickness is usually designed to be one-fourth of the wavelength of the electromagnetic wave corresponding to the absorbed frequency band. Therefore, the thickness of the absorber designed for absorbing 12.24 GHz electromagnetic waves by a traditional absorber is about 0.063 m, while the overall thickness of the absorber of the present invention is about 2.37 mm, which is about 27 times the thickness of the metasurface absorber of the present invention.

[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 The overall structure diagram of a metasurface absorber based on a square and circle multi-nested structure is invented;

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

[0016] Figure 3 This is a schematic diagram of the top metal resonance layer chip resistor of the present invention;

[0017] Figure 4 It is a combined structural diagram of the dielectric layer and the bottom metal reflective layer of the present invention;

[0018] Figure 5 is an absorption characteristic curve diagram of the 7-24 GHz frequency band of the present invention;

[0019] Description of reference numerals:

[0020] In the figure: 1. Top metal resonant layer; 2. Dielectric layer; 3. Bottom metal reflective layer. DETAILED DESCRIPTION

[0021] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0022] like Figure 1 As shown, a metasurface absorber based on a square-circle 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 proposed absorber metal resonance layer 1 is composed of a plurality of unit periodic resonance arrays, and the resonance unit comprises a split circular ring structure, a split square ring, a metal disc and 8 chip resistors; the metal discs are distributed on the innermost side of the metasurface absorber resonance layer, the split square rings are distributed on the outer side of the metal discs and maintain a certain distance, each split square ring is composed of four "L"-shaped metal structures of the same size and symmetry, and four 300Ω chip resistors are also welded at the four splits of the square ring structure, as shown in FIG. Figure 3 As shown by dotted lines; each split annular structure is composed of four arc-shaped structures of the same size. The open split annular structure is distributed on the outermost side of the unit resonant structure and maintains a certain margin from the boundary. Four 250Ω chip resistors are respectively welded at the four splits of the annular structure, as shown in FIG. Figure 3 Shown by the dashed line.

[0023] 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.

[0024] like Figure 2 As shown, the radius of the metal disc of each unit structure metal resonance layer 1 is r1=0.7mm; the inner and outer side lengths of the split square ring are a=3.0mm and b=4.0mm respectively, the distance between the inner and outer sides of one side is 0.5mm, and the width of the split openings of the four square rings is c=1mm; the inner and outer diameters of the split circular ring are r2=3.2mm and r3=3.7mm respectively, and the width of the four split openings of the circular ring is d=0.5mm;

[0025] 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, and the side length is L=10mm. The dielectric layer 2 has a thickness X1=2.3mm, and the metal reflective layer 3 has a thickness X2=0.035mm.

[0026] like Figure 4As shown, a metasurface absorber based on a square-circle multi-nested structure of the present embodiment is simulated by using relevant simulation software, and the simulation adopts the boundary conditions of unit cell in both the length and width directions and the open boundary conditions in the vertical direction. The incident direction of the electromagnetic wave adopts the vertical incidence mode. Figure 4 is the absorption characteristic curve of the periodic array absorber in the 7-24GHz frequency band, Figure 4 It can be seen that the absorption rate of the absorber in the frequency band of 10.15GHz-20.91GHz reaches more than 90%, and the three resonant frequency bands are near 12.24GHz, 18.40GHz and 20.16GHz respectively. The highest absorption rate in the frequency band reaches 99.9%, meeting the characteristics of wide band and high absorption rate.

[0027] The present invention also provides a method for manufacturing a metasurface absorber based on a square and round 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 and round multi-nested structure.

[0028] 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 multi-nested structure, characterized in that: From top to bottom, it includes a metal resonance layer, a dielectric layer and a metal reflection layer; the proposed absorber metal resonance layer is composed of multiple unit periodic resonance arrays, and the resonance unit includes a split circular ring structure, a split square ring, a metal disc and 8 chip resistors; the split circular ring structure of each resonance unit is composed of four arc structures, the center of the split circular ring coincides with the intersection of the diagonal of the square of the dielectric layer, the open split circular ring structure is distributed around the unit resonance structure, and the outer boundary is kept at a distance of 1.3 mm from the midpoint of the unit boundary, and the 4 chip resistors are respectively welded on the circular ring At the four splits of the square ring structure, the split square rings are distributed on the inner side of the split circular rings and the outer boundary keeps a distance of 3 mm from the unit boundary, each split square ring is composed of four "L"-shaped metal structures of the same size, and the four chip resistors are also welded on the four splits of the square ring structure, the metal discs are distributed on the inner side of the split square rings and the outer boundary keeps a distance of 4.3 mm from the midpoint of the unit boundary; 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 multi-nested structure according to claim 1, characterized in that: The dielectric layer and the metal reflective layer of the absorber are both squares with equal sides, each of which is 10 mm long. The dielectric layer is 2.3 mm thick, and the top metal resonance layer and the bottom metal reflective layer are 0.035 mm thick. The inner and outer diameters of the split circular rings of each unit structure metal resonance layer are 3.2 mm and 3.7 mm respectively, and the widths of the four split openings of the circular ring are 0.5 mm. The inner and outer side lengths of the split square rings are 3.0 mm and 4.0 mm respectively, the distance between the inner and outer edges of a single side is 0.5 mm, the width of the split openings of the four square rings is 1 mm, and the radius of the metal disc is 0.7 mm.

3. According to claim 1, a metasurface absorber based on a square-circle 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 multi-nested structure is characterized in that: The resistance value of the chip resistor at the split opening of the split circular ring in the metal resonance layer is 250Ω, and the resistance value of the chip resistor at the split opening of the split square ring is 300Ω.

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