Permeation and absorption integrated three-dimensional frequency selection wave absorber based on SSPP structure

Abstract

The invention discloses a transmitting and absorbing integrated three-dimensional frequency selection wave absorber based on an SSPP structure, and belongs to the technical field of microwaves. The invention aims to solve the problems that an existing wave-transmitting and wave-absorbing integrated frequency selection structure cannot meet the characteristics of good permeability and wide wave-absorbing band at the same time, a large number of lumped resistors need to be installed on a wave-absorbing layer to increase the wave-absorbing band width, and the manufacturing difficulty and the total cost are increased. The transmission and absorption integrated three-dimensional frequency selection wave absorber is formed by periodically arranging wave absorber units; the wave absorber unit is composed of an FSS structure unit and a three-dimensional wave absorbing structure unit. The FSS structure unit sequentially comprises a first substrate and a metal pattern layer from bottom to top; the three-dimensional wave-absorbing structure unit is vertically arranged on the upper surface of the FSS structure unit; the three-dimensional wave-absorbing structure unit is formed by two second substrates which are arranged in a crossed manner along two diagonals of the FSS structure unit, and metal strip-shaped groups are symmetrically arranged on the surfaces of the two sides of the second substrates. The invention is used for the transmitting and absorbing integrated three-dimensional frequency selection wave absorber based on the SSPP structure.

Description

Technical Field

[0001] The invention belongs to the field of microwave technology. Background Art

[0002] With the rapid development of 5G communication technology, the transmission and shielding of electromagnetic waves has become an important research field. 5G communication requires a wider spectrum, higher capacity and lower latency, which makes the millimeter wave band widely used. However, with the establishment of a large number of 5G base stations, the problem of electromagnetic radiation has become increasingly prominent, which may not only cause information leakage, but also pose a threat to human health. Therefore, it is particularly important to develop a frequency selection structure that can transmit waves at low frequencies and absorb waves at high frequencies. Low-frequency wave transmission technology aims to meet the needs of 5G communication and ensure the effective transmission of electromagnetic waves in low frequency bands to maintain the transmission quality and stability of communication signals. High-frequency wave absorption technology aims to reduce electromagnetic pollution, protect human health and daily life, and achieve green electromagnetic shielding by absorbing high-frequency electromagnetic waves, reducing the potential impact on the environment and health. In summary, the research and development of this metamaterial structure is crucial to the green development of 5G communication technology. It not only supports the advancement of 5G communication technology, but also protects the environment and human health by reducing electromagnetic pollution.

[0003] However, most of the current wave-transmitting and wave-absorbing integrated frequency-selective structures cannot simultaneously meet the characteristics of good transmittance and wide wave-absorbing band. In addition, most of the current wave-transmitting and wave-absorbing integrated frequency-selective structures require a large number of lumped resistors to be installed on the wave-absorbing layer to increase the wave-absorbing bandwidth, which increases the manufacturing difficulty and total cost. Summary of the invention

[0004] The present invention aims to solve the problem that the existing integrated wave-transmitting and wave-absorbing frequency selective structure cannot simultaneously meet the characteristics of good transmittance and wide wave-absorbing band, and a large number of lumped resistors need to be installed on the wave-absorbing layer to increase the wave-absorbing bandwidth, which increases the manufacturing difficulty and total cost, and further proposes a three-dimensional frequency selective absorber with integrated wave-transmitting and wave-absorbing based on the SSPP structure.

[0005] A three-dimensional frequency selective absorber based on SSPP structure, which is composed of absorber units periodically arranged into N columns×M rows, wherein N≥5 and M≥5;

[0006] The absorber unit is composed of an FSS structural unit and a three-dimensional absorber structural unit;

[0007] The FSS structural unit is arranged horizontally, and the FSS structural unit is sequentially composed of a first substrate and a metal pattern layer from bottom to top; the metal pattern layer is in the shape of a Jerusalem cross;

[0008] The three-dimensional absorbing structure unit is vertically arranged on the upper surface of the FSS structure unit; the three-dimensional absorbing structure unit is formed by two second substrates arranged crosswise along the two diagonals of the FSS structure unit, and metal strip groups are symmetrically arranged on both side surfaces of the second substrates, and the metal strip group arranged on one side is composed of a first metal strip structure and a second metal strip structure that are symmetrical along the intersection line of the two second substrates; the first metal strip structure and the second metal strip structure are both composed of K metal strips.

[0009] The beneficial effects of the present invention are:

[0010] The advantage of the present invention is that it uses a simple metal strip group printed on the substrate to replace the traditional lumped resistor to achieve excellent wave absorption effect, greatly simplifies the processing technology, and the assembly process is more flexible and the structure is more variable. The wave absorbing layer is designed based on the SSPP structure, so that the wave absorption performance of the structure is greatly enhanced, and it has high transmittance below the cutoff frequency. By twisting the three-dimensional wave absorbing structure by 45°, the wave absorption performance is further improved, so that the overall structure takes into account both high transmittance and good wave absorption performance.

[0011] The invention is used for a three-dimensional frequency selective absorber with integrated penetration and absorption based on SSPP structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic structural diagram of a three-dimensional frequency selective absorber based on a SSPP structure according to the first embodiment;

[0013] Figure 2 This is a schematic structural diagram of an FSS structural unit in Example 1;

[0014] Figure 3 This is a schematic structural diagram of a three-dimensional wave absorbing structural unit in accordance with the first embodiment;

[0015] Figure 4 This is a simulation result diagram of a three-dimensional frequency selective absorber based on a SSPP structure in Example 1;

[0016] Figure 5 This is a simulation result diagram of the three-dimensional frequency selective absorber based on the SSPP structure under dual polarization conditions in Example 1;

[0017] Figure 6 The S of the three-dimensional frequency selective absorber based on the SSPP structure under different oblique incident angles of electromagnetic waves in Example 1 11 Simulation result diagram;

[0018] Figure 7 The S of the three-dimensional frequency selective absorber based on the SSPP structure under different oblique incident angles of electromagnetic waves in Example 1 21Simulation result diagram;

[0019] Figure 8 This is a schematic structural diagram of a three-dimensional frequency selective absorber based on a SSPP structure according to Example 2;

[0020] Fig. 9 This is a schematic structural diagram of a three-dimensional wave absorbing structural unit in Example 2;

[0021] Fig.10 This is a simulation result diagram of the three-dimensional frequency selective absorber based on the SSPP structure of Example 2;

[0022] Fig.11 This is a simulation result diagram of the three-dimensional frequency selective absorber based on the SSPP structure under dual polarization conditions in Example 2;

[0023] Fig.12 The S of the three-dimensional frequency selective absorber based on the SSPP structure under different oblique incident angles of electromagnetic waves in Example 2 11 Simulation result diagram;

[0024] Fig.13 The S of the three-dimensional frequency selective absorber based on the SSPP structure under different oblique incident angles of electromagnetic waves in Example 2 21 Simulation result diagram;

[0025] Fig.14 This is a schematic diagram of the structure of a three-dimensional frequency selective absorber based on the SSPP structure according to Example 3;

[0026] Fig.15 This is a schematic structural diagram of a three-dimensional wave absorbing structure unit in Example 3;

[0027] Fig.16 This is a simulation result diagram of the three-dimensional frequency selective absorber based on the SSPP structure of Example 3;

[0028] Fig.17 This is a simulation result diagram of the three-dimensional frequency selective absorber based on the SSPP structure under dual polarization conditions in Example 3;

[0029] Fig.18 This is a schematic structural diagram of a three-dimensional frequency selective absorber based on a SSPP structure according to the fourth embodiment;

[0030] Fig.19 This is a schematic structural diagram of a three-dimensional wave absorbing structure unit in Example 4;

[0031] Fig. 20 This is a simulation result diagram of the integrated three-dimensional frequency selective absorber based on the SSPP structure in Example 4;

[0032] Fig.21 This is a simulation result diagram of the integrated three-dimensional frequency selective absorber based on the SSPP structure under dual polarization conditions in Example 4;

[0033] Fig. 22 This is a schematic structural diagram of a three-dimensional frequency selective absorber based on a SSPP structure according to Example 5;

[0034] Fig.23 This is a schematic structural diagram of a three-dimensional wave absorbing structural unit in Example 5;

[0035] Fig.24 This is a simulation result diagram of the three-dimensional frequency selective absorber based on the SSPP structure of Example 5;

[0036] Fig.25 This is a simulation result diagram of the three-dimensional frequency selective absorber based on the SSPP structure under dual polarization conditions in Example 5;

[0037] Fig.26 The S of the three-dimensional frequency selective absorber based on the SSPP structure under different oblique incident angles of electromagnetic waves in Example 5 11 Simulation result diagram;

[0038] Fig. 27 The S of the three-dimensional frequency selective absorber based on the SSPP structure under different oblique incident angles of electromagnetic waves in Example 5 21 Simulation result diagram;

[0039] Fig.28 This is a schematic diagram of the structure of a three-dimensional frequency selective absorber based on the SSPP structure according to Example 6;

[0040] Fig.29 This is a schematic structural diagram of a three-dimensional wave absorbing structural unit of Example 6;

[0041] Fig.30 This is a simulation result diagram of the integrated three-dimensional frequency selective absorber based on the SSPP structure in Example 6;

[0042] Fig.31 This is a simulation result diagram of the integrated three-dimensional frequency selective absorber based on the SSPP structure under dual polarization conditions in Example 6;

[0043] Fig.32 This is a schematic diagram of the structure of a three-dimensional frequency selective absorber based on the SSPP structure for comparative experiment 1;

[0044] Fig.33 This is the simulation result of the three-dimensional frequency selective absorber based on the SSPP structure for comparative experiment 1;

[0045] Fig.34 This is a schematic diagram of the structure of the three-dimensional frequency selective absorber based on the SSPP structure for comparison experiment 2;

[0046] Fig.35 It is a schematic diagram of the structure of the two-dimensional and three-dimensional absorbing structure unit for comparison experiment;

[0047] Fig.36 This is the simulation result diagram of the comparative experiment 2, which is a three-dimensional frequency selective absorber based on the SSPP structure. DETAILED DESCRIPTION

[0048] The technical solution of the present invention is not limited to the specific implementation modes listed below, but also includes any combination of the specific implementation modes.

[0049] Specific implementation method 1: This implementation method is a three-dimensional frequency selective absorber based on the SSPP structure, which is composed of absorber units periodically arranged into N columns×M rows, where N≥5 and M≥5;

[0050] The absorber unit is composed of an FSS structural unit and a three-dimensional absorber structural unit;

[0051] The FSS structural unit is arranged horizontally, and the FSS structural unit is sequentially composed of a first substrate and a metal pattern layer from bottom to top; the metal pattern layer is in the shape of a Jerusalem cross;

[0052] The three-dimensional absorbing structure unit is vertically arranged on the upper surface of the FSS structure unit; the three-dimensional absorbing structure unit is formed by two second substrates arranged crosswise along the two diagonals of the FSS structure unit, and metal strip groups are symmetrically arranged on both side surfaces of the second substrates, and the metal strip group arranged on one side is composed of a first metal strip structure and a second metal strip structure that are symmetrical along the intersection line of the two second substrates; the first metal strip structure and the second metal strip structure are both composed of K metal strips.

[0053] In this embodiment, the material of the metal stripe group and the metal pattern layer is a highly conductive metal, such as copper, aluminum, silver paste, silver nanowires, or a highly conductive semiconductor material ITO (indium tin oxide).

[0054] The three-dimensional absorbing structure described in this embodiment is arranged directly above the FSS structural unit, and there is no gap between the two.

[0055] This embodiment provides a three-dimensional frequency selective surface absorber (FSR) that transmits waves in a wide band at low frequencies and absorbs waves in an ultra-wide band at high frequencies. It consists of a three-dimensional absorbing structure based on the SSPP structure design on the top and a two-dimensional frequency selective surface (FSS) on the bottom. Symmetrical metal strips are printed on the front and back of the substrate of the three-dimensional absorbing structure on the top, replacing a large number of lumped resistors in the traditional absorbing layer. The three-dimensional absorbing structure is twisted 45° as a whole to improve the absorbing performance of the absorbing layer, broaden the absorbing frequency band, and improve the absorbing performance of the overall structure. The bottom achieves low insertion loss within the working frequency band by cooperating with the three-dimensional absorbing structure on the upper layer through the two-dimensional frequency selective surface structure. Compared with the prior art, this embodiment has a wider absorbing bandwidth and a smaller insertion loss, so that the structure has both good transmittance and absorbing performance. In addition, the structure is small in size and simple in process. In order to facilitate processing, the middle part of the metal strip array of the upper absorbing layer is removed, making the assembly process simpler and more flexible, and having good angular stability.

[0056] The beneficial effects of this embodiment are:

[0057] The advantage of this embodiment is that it uses a simple metal strip group printed on the substrate instead of the traditional lumped resistor to achieve excellent wave absorption effect, which greatly simplifies the processing technology, and the assembly process is more flexible and the structure is more variable. The wave absorbing layer is designed based on the SSPP structure, which greatly enhances the wave absorption performance of the structure and has high transmittance below the cutoff frequency. By twisting the three-dimensional wave absorbing structure by 45°, the wave absorption performance is further improved, so that the overall structure takes into account both high transmittance and good wave absorption performance.

[0058] Specific implementation method 2: This implementation method is different from specific implementation method 1 in that: the shape of the first substrate is square, the thickness h1 is 0.1mm-0.5mm, and the side length a is 10mm-20mm; the first substrate is F4BM substrate, the dielectric constant is 2.2±0.05, and the loss tangent tanδ is 0.001-0.002; the shape of the second substrate is rectangular, the thickness is 0.1mm-0.3mm, and the width h2 is 8mm-12mm; the second substrate is FR-4 substrate, the dielectric constant is 4.3±0.05, and the loss tangent tanδ is 0.5±0.001; the thickness of the metal pattern layer and the metal strip group is 0.035mm. Others are the same as specific implementation method 1.

[0059] Specific implementation method three: This implementation method is different from specific implementation method one or two in that: the first metal strip structure and the second metal strip structure are spliced ​​to form a polygon or a circle. The rest is the same as specific implementation method one or two.

[0060] Specific embodiment 4: This embodiment differs from any one of specific embodiments 1 to 3 in that: the splicing edges of the first metal strip structure and the second metal strip structure are located on both sides of the intersection line of the two second substrates or at the edge of the second substrate;

[0061] When the splicing edges of the first metal strip structure and the second metal strip structure are located on both sides of the intersection line of the two second substrates, a gap b is provided between the splicing edges of the first metal strip structure and the second metal strip structure in the horizontal direction; when the splicing edges of the first metal strip structure and the second metal strip structure are located at the edge of the second substrate, the vertical distance between the splicing edges of the first metal strip structure and the second metal strip structure in the horizontal direction and the edge of the second substrate is b / 2;

[0062] When the first metal strip structure and the second metal strip structure are joined together to form a hexagon or rectangle, or when the first metal strip structure, the second metal strip structure and the gap b are joined together to form a circle, b=0.5mm-1.5mm; when the first metal strip structure and the second metal strip structure are joined together to form a triangle or a pentagon, b=0.3mm-0.5mm. Others are the same as the first to third embodiments.

[0063] In this specific embodiment, if the first metal strip structure and the second metal strip structure can be spliced ​​to form a hexagon, triangle, rectangle or pentagon after being attached, that is, when forming a hexagon, triangle, rectangle or pentagon, the gap between the two is not included.

[0064] In this specific implementation manner, the first metal strip structure, the second metal strip structure and the gap form a circle, that is, when forming a circle, the gap between the two is included.

[0065] Specific embodiment 5: This embodiment is different from specific embodiments 1 to 4 in that: when the first metal strip structure and the second metal strip structure are bonded and spliced ​​to form a hexagon, the length l0 of the longest metal strip in the first metal strip structure and the second metal strip structure is 2.25mm to 3.75mm, and the length of the metal strips on both sides of the longest metal strip decreases by 0.1mm to 0.3mm; K=17 to 25. Others are the same as specific embodiments 1 to 4.

[0066] Specific embodiment 6: This embodiment is different from specific embodiments 1 to 5 in that: when the first metal strip structure and the second metal strip structure are bonded and spliced ​​to form a triangle, the length l0 of the bottom metal strip of the first metal strip structure and the second metal strip structure is 2.35mm to 3.25mm, and the length of the metal strip above the bottom metal strip decreases gradually by 0.1mm to 0.2mm; K=18 to 26. Others are the same as specific embodiments 1 to 5.

[0067] Specific embodiment 7: This embodiment differs from specific embodiments 1 to 6 in that: when the first metal strip structure and the second metal strip structure are bonded and spliced ​​to form a rectangle, the length l0 of the metal strips of the first metal strip structure and the second metal strip structure is equal, and l0 is 2.25 mm to 3.75 mm; K is 17 to 25. The rest is the same as specific embodiments 1 to 6.

[0068] Specific embodiment 8: This embodiment is different from specific embodiments 1 to 7 in that: when the first metal strip structure and the second metal strip structure are bonded and spliced ​​to form a pentagon, the length l0 of the longest metal strip in the first metal strip structure and the second metal strip structure is 2.25mm to 3.75mm, the length of the metal strip above the longest metal strip decreases by 0.2mm to 0.4mm, and the length of the metal strip below the longest metal strip decreases by 0.1mm to 0.3mm; K=18 to 26. Others are the same as specific embodiments 1 to 7.

[0069] Specific embodiment 9: This embodiment differs from specific embodiments 1 to 8 in that: when the first metal strip structure, the second metal strip structure and the gap b are spliced ​​to form a circle, the circle radius r is 3.5 mm to 4.5 mm; K is 17 to 22. Others are the same as specific embodiments 1 to 8.

[0070] Specific embodiment 10: This embodiment differs from specific embodiments 1 to 9 in that: the sides of the cross arm and the end arm of the Jerusalem cross are parallel to the edge of the first substrate; the width W1 of the cross arm is 0.5mm-3mm, and the length L2 is 5mm-9mm; the width W2 of the end arm is 0.1mm-1mm, and the length L1 is 2mm-5mm. Other features are the same as specific embodiments 1 to 9.

[0071] The following examples are used to verify the beneficial effects of the present invention:

[0072] Embodiment 1, combined with Figures 1 to 3 Specific instructions:

[0073] A three-dimensional frequency selective absorber based on SSPP structure, which is composed of absorber units periodically arranged into N columns×M rows, wherein N=5 and M=5;

[0074] The absorber unit is composed of an FSS structural unit and a three-dimensional absorber structural unit;

[0075] Taking the XOY plane as the horizontal plane, the FSS structural unit is horizontally arranged, and the FSS structural unit is sequentially a first substrate and a copper metal graphic layer from bottom to top; the copper metal graphic layer is in the shape of a Jerusalem cross;

[0076] The three-dimensional absorbing structure unit is vertically arranged on the upper surface of the FSS structure unit; the three-dimensional absorbing structure unit is formed by two second substrates arranged crosswise along the two diagonals of the FSS structure unit, and copper metal strip groups are symmetrically arranged on both side surfaces of the second substrates, and the copper metal strip group arranged on one side is composed of a first copper metal strip structure and a second copper metal strip structure that are symmetrical along the intersection line of the two second substrates; the first copper metal strip structure and the second copper metal strip structure are both composed of K metal strips, the spacing between adjacent metal strips is 0.2 mm, and the width of each metal strip is 0.2 mm.

[0077] The first substrate is square in shape, with a thickness h1 of 0.127 mm and a side length a of 10 mm; the first substrate is an F4BM substrate with a dielectric constant of 2.2 and a loss tangent tanδ of 0.001; the second substrate is rectangular in shape, with a thickness of 0.25 mm and a width h2 of 10 mm; the second substrate is an FR-4 substrate with a dielectric constant of 4.3 and a loss tangent tanδ of 0.5; the thickness of the copper metal graphic layer and the copper metal strip group is 0.035 mm.

[0078] The first copper metal strip structure and the second copper metal strip structure are bonded and spliced ​​to form a hexagon, and the splicing edges of the first copper metal strip structure and the second copper metal strip structure are located on both sides of the intersection line of the two second substrates; a gap b is provided between the splicing edges of the first copper metal strip structure and the second copper metal strip structure in the horizontal direction; the longest metal strip length l0 in the first copper metal strip structure and the second copper metal strip structure is 3.25 mm, and the longest metal strip is located in the middle, and the lengths of the metal strips on both sides of the longest metal strip decrease by 0.2 mm; b is 1.5 mm; K=21;

[0079] The sides of the cross arm and the end arm of the Jerusalem cross are parallel to the edge of the first substrate; the width W1 of the cross arm is 1 mm, and the length L2 is 6 mm; the width W2 of the end arm is 0.5 mm, and the length L1 is 3 mm.

[0080] In the following simulation results, S 11 is the reflection coefficient. The lower its value is, the smaller the reflection is during the transmission process. 21 is the transmission coefficient. The closer its value is to 0dB, the smaller the signal loss is during the transmission process.

[0081] Figure 4This is a simulation result diagram of a three-dimensional frequency selective absorber based on a SSPP structure in Example 1; Figure 5 This is a simulation result diagram of the integrated three-dimensional frequency selective absorber with SSPP structure under dual polarization conditions in Example 1; the integrated three-dimensional frequency selective absorber with SSPP structure designed in the embodiment transmits waves in the range of 0GHz to 8.39GHz, and absorbs waves in the range of 23.48GHz to 61.1GHz; the insertion loss of the normally incident TE and TM electromagnetic waves in the 0GHz to 8.39GHz band is less than 1dB, the absorption rate in the 23.48GHz to 61.1GHz band is more than 80%, and the reflection coefficient in this frequency band is less than -10dB.

[0082] Figure 6 The S of the three-dimensional frequency selective absorber based on the SSPP structure under different oblique incident angles of electromagnetic waves in Example 1 11 Simulation result diagram; Figure 7 The S of the three-dimensional frequency selective absorber based on the SSPP structure under different oblique incident angles of electromagnetic waves in Example 1 21 Simulation result diagram: The structure designed in this embodiment is a symmetrical structure, which makes the absorber insensitive to the polarization direction of the incident electromagnetic wave and has good angular stability. For electromagnetic waves with an incident angle range of 0-45°, it can still maintain good absorption rate and transmittance in the above band.

[0083] Embodiment 2, combined with Figures 8 to 9 Specific description: The difference between this embodiment and the first embodiment is that the first copper metal strip structure and the second copper metal strip structure are joined and spliced ​​to form a triangle, the length l0 of the bottom metal strip of the first copper metal strip structure and the second copper metal strip structure is 2.35mm, and the length of the metal strip above the bottom metal strip decreases by 0.1mm; b=0.5mm; K=24. Others are the same as the first embodiment.

[0084] Fig.10 This is a simulation result diagram of the three-dimensional frequency selective absorber based on the SSPP structure of Example 2; Fig.11 This is a simulation result diagram of the three-dimensional frequency selective absorber with integrated penetration and absorption based on the SSPP structure under dual polarization conditions in Example 2; the three-dimensional frequency selective absorber with integrated penetration and absorption designed in the embodiment transmits waves in the range of 0GHz to 8.41GHz, and absorbs waves in the range of 26.2GHz to 31.2GHz and 33.3GHz to 69.6GHz; the insertion loss of the normally incident TE and TM electromagnetic waves in the 0GHz to 8.41GHz band is less than 1dB, the absorption rate in the 26.2GHz to 31.2GHz and 33.3GHz to 69.6GHz bands is more than 80%, and the reflection coefficient in this band is less than -10dB.

[0085] Fig.12 The S of the three-dimensional frequency selective absorber based on the SSPP structure under different oblique incident angles of electromagnetic waves in Example 2 11 Simulation result diagram; Fig.13 The S of the three-dimensional frequency selective absorber based on the SSPP structure under different oblique incident angles of electromagnetic waves in Example 2 21 Simulation result diagram; The structure designed in this embodiment is a symmetrical structure, which makes the absorber insensitive to the polarization direction of the incident electromagnetic wave. The structure has good angular stability and can maintain good absorption rate and transmittance for electromagnetic waves with an incident angle range of 0-45° in the above band.

[0086] Embodiment 3, combined with Figures 14 to 15 Specific description: The difference between this embodiment and the first embodiment is that the first copper metal strip structure and the second copper metal strip structure are joined and spliced ​​to form a rectangle, the length of the metal strips of the first copper metal strip structure and the second copper metal strip structure are equal, l0 is 2.75mm; b=1.5mm; K=23. Others are the same as the first embodiment.

[0087] Fig.16 This is a simulation result diagram of the three-dimensional frequency selective absorber based on the SSPP structure of Example 3; Fig.17 This is a simulation result diagram of the three-dimensional frequency selective absorber with integrated penetration and absorption based on the SSPP structure under dual polarization conditions in Example 3; the three-dimensional frequency selective absorber with integrated penetration and absorption designed in the embodiment transmits waves in the range of 0GHz to 7.61GHz, and absorbs waves in the range of 22.39GHz to 46.01GHz and 48.4GHz to 60.4GHz; the insertion loss of the normally incident TE and TM electromagnetic waves in the 0GHz to 7.61GHz band is less than 1dB, the absorption rate in the 22.39GHz to 46.01GHz and 48.4GHz to 60.4GHz bands is more than 80%, and the reflection coefficient in this band is less than -10dB.

[0088] The structure designed in this embodiment is a symmetrical structure, so that the absorber is insensitive to the polarization direction of the incident electromagnetic wave. The structure has good angular stability and can still maintain good absorption rate and transmittance for electromagnetic waves with an incident angle range of 0-45° in the above band.

[0089] Embodiment 4, combined with Figures 18 to 19Specific description: The difference between this embodiment and the first embodiment is that the first copper metal strip structure and the second copper metal strip structure are spliced ​​to form a pentagon, the longest metal strip length l0 of the first copper metal strip structure and the second copper metal strip structure is 3.75mm, there are 9 metal strip lengths above the longest metal strip and they decrease in length by 0.4mm, and there are 10 metal strip lengths below the longest metal strip and they decrease in length by 0.2mm; b=0.5mm; K=20. Others are the same as the first embodiment.

[0090] Fig. 20 This is a simulation result diagram of the integrated three-dimensional frequency selective absorber based on the SSPP structure in Example 4; Fig.21 This is a simulation result diagram of the integrated three-dimensional frequency selective absorber of the SSPP structure under dual polarization conditions in Example 4; the integrated three-dimensional frequency selective absorber designed in the embodiment transmits waves in the range of 0GHz to 7.1GHz, and absorbs waves in the ranges of 19.79GHz to 27.03GHz and 33.2GHz to 60.94GHz; the designed integrated three-dimensional frequency selective surface absorber has an insertion loss of less than 1dB for normally incident TE and TM electromagnetic waves in the 0GHz to 7.1GHz band, and an absorptivity of more than 80% in the 19.79GHz to 27.03GHz and 33.2GHz to 60.94GHz bands, and the reflection coefficient in this band is less than -10dB.

[0091] The structure designed in this embodiment is a symmetrical structure, so that the absorber is insensitive to the polarization direction of the incident electromagnetic wave, and the structure has good angular stability and is resistant to electromagnetic waves with an incident angle range of 0-45°.

[0092] Embodiment 5, combined with Figures 22 to 23 Specific description: The difference between this embodiment and the first embodiment is that the first copper metal strip structure, the second copper metal strip structure and the gap b are spliced ​​to form a circle, and the radius r of the circle is 4.25mm; b=1.5mm; K=22; except for the top and bottom metal strips, the width of the remaining metal strips is 0.2mm. The rest is the same as the first embodiment.

[0093] Fig.24 This is a simulation result diagram of the three-dimensional frequency selective absorber based on the SSPP structure of Example 5; Fig.25This is a simulation result diagram of the fifth embodiment of the three-dimensional frequency selective absorber with integrated penetration and absorption based on the SSPP structure under dual polarization conditions; the three-dimensional frequency selective absorber with integrated penetration and absorption designed in the embodiment transmits waves in the range of 0GHz to 7.52GHz, and absorbs waves in the range of 21.43GHz to 60.33GHz; the insertion loss of the normally incident TE and TM electromagnetic waves in the 0GHz to 7.52GHz band is less than 1dB, the absorption rate in the 21.43GHz to 60.33GHz band is more than 80%, and the reflection coefficient in this band is less than -10dB.

[0094] Fig.26 The S of the three-dimensional frequency selective absorber based on the SSPP structure under different oblique incident angles of electromagnetic waves in Example 5 11 Simulation result diagram; Fig. 27 The S of the three-dimensional frequency selective absorber based on the SSPP structure under different oblique incident angles of electromagnetic waves in Example 5 21 Simulation result diagram; The structure designed in this embodiment is a symmetrical structure, which makes the absorber insensitive to the polarization direction of the incident electromagnetic wave. The structure has good angular stability and can maintain good absorption rate and transmittance for electromagnetic waves with an incident angle range of 0-45° in the above band.

[0095] Embodiment 6, combined Figures 28 to 29 Specific description: This embodiment is different from the first embodiment in that the splicing edge of the first copper metal strip structure and the second copper metal strip structure is located at the edge of the second substrate, and the vertical distance between the splicing edge of the first copper metal strip structure and the second copper metal strip structure and the edge of the second substrate in the horizontal direction is b / 2. Others are the same as the first embodiment.

[0096] Fig.30 This is a simulation result diagram of the integrated three-dimensional frequency selective absorber based on the SSPP structure in Example 6; Fig.31 This is a simulation result diagram of the six embodiment of the three-dimensional frequency selective absorber with integrated penetration and absorption based on the SSPP structure under dual polarization conditions; the three-dimensional frequency selective absorber with integrated penetration and absorption designed in the embodiment transmits waves in the range of 0GHz to 7.64GHz, and absorbs waves in the range of 21.82GHz to 60.26GHz; the insertion loss of the normally incident TE and TM electromagnetic waves in the 0GHz to 7.64GHz band is less than 1dB, the absorption rate in the 21.82GHz to 60.26GHz band is more than 80%, and the reflection coefficient in this band is less than -10dB.

[0097] The structure designed in this embodiment is a symmetrical structure, so that the absorber is insensitive to the polarization direction of the incident electromagnetic wave. The structure has good angular stability and can still maintain good absorption rate and transmittance for electromagnetic waves with an incident angle range of 0-45° in the above band.

[0098] Comparative experiment 1, combined with Fig.32 Specific description: The difference between this comparative experiment and the first embodiment is that the three-dimensional wave absorbing structure unit is formed by two second substrates arranged crosswise along the cross arms of the Jerusalem cross shape. The rest is the same as the first embodiment.

[0099] Fig.33 This is a simulation result diagram of the three-dimensional frequency selective absorber based on the SSPP structure for comparison experiment 1; it can be seen from the simulation result diagram that when the three-dimensional absorbing structure of the upper layer is arranged in a right cross relative to the FSS structure of the lower layer, it transmits waves in the range of 0GHz to 7.65GHz and absorbs waves in the range of 21.57GHz to 28.4GHz and 42.1GHz to 45.3GHz; compared with Example 1, the transmission band and the absorption band of the overall structure are shortened, especially the absorption band, the bandwidth is shortened by nearly half. This shows that when the three-dimensional absorbing structure of the upper layer is twisted by 45°, the resonance effect is enhanced, and the absorption performance and transmission performance of the overall structure are improved.

[0100] Comparative experiment 2, combined with Figures 34 to 35 Specific description: The difference between this comparative experiment and Example 1 is that the three-dimensional absorbing structure unit is composed of four second substrates arranged perpendicularly to each other on the four sides of the upper surface of the FSS structure unit, and copper metal strip groups are symmetrically arranged on both sides of the second substrate, and the copper metal strip group arranged on one side is composed of a hexagonal copper metal strip structure and a vertical copper metal strip symmetrically arranged along the central axis of the second substrate, and the vertical copper metal strip is arranged in the middle of the hexagonal copper metal strip structure; the longest metal strip in the hexagonal copper metal strip structure is 8mm (including the width of the vertical copper metal strip); the width of the vertical copper metal strip is 0.2mm and the length is 10mm; the longest metal strip is located in the middle, and the length of the metal strips on both sides of the longest metal strip decreases by 0.4mm; the hexagonal copper metal strip structure is composed of 21 metal strips. The rest is the same as Example 1.

[0101] Fig.36 The simulation result diagram of the three-dimensional frequency selective absorber based on the SSPP structure for comparison experiment 2; it can be seen from the simulation result diagram that when the three-dimensional absorber structure of the upper layer is surrounded by a square relative to the FSS structure of the lower layer, it transmits waves in the range of 0GHz to 2.48GHz and absorbs waves in the range of 11.4GHz to 22.93GHz and 49.27GHz to 51.76GHz; compared with the first embodiment, the transmission band and the absorption band of the overall structure are greatly shortened. In addition, there is a blank space in the middle of the metal strip in the first embodiment, which is conducive to processing, making the process simpler and the assembly more flexible.

Claims

1. A three-dimensional frequency selective absorber based on SSPP structure, characterized in that It is composed of absorber units periodically arranged into N columns×M rows, wherein N≥5 and M≥5; The absorber unit is composed of an FSS structural unit and a three-dimensional absorber structural unit; The FSS structural unit is arranged horizontally, and the FSS structural unit is sequentially composed of a first substrate and a metal pattern layer from bottom to top; the metal pattern layer is in the shape of a Jerusalem cross; The three-dimensional absorbing structure unit is vertically arranged on the upper surface of the FSS structure unit; the three-dimensional absorbing structure unit is formed by two second substrates arranged crosswise along the two diagonals of the FSS structure unit, and metal strip groups are symmetrically arranged on both side surfaces of the second substrates, and the metal strip group arranged on one side is composed of a first metal strip structure and a second metal strip structure that are symmetrical along the intersection line of the two second substrates; the first metal strip structure and the second metal strip structure are both composed of K metal strips.

2. The three-dimensional frequency selective absorber based on the SSPP structure according to claim 1, characterized in that The first substrate is square in shape, with a thickness h1 of 0.1mm to 0.5mm and a side length a of 10mm to 20mm; the first substrate is an F4BM substrate with a dielectric constant of 2.2±0.05 and a loss tangent tanδ of 0.001 to 0.002; the second substrate is rectangular in shape, with a thickness of 0.1mm to 0.3mm and a width h2 of 8mm to 12mm; the second substrate is an FR-4 substrate with a dielectric constant of 4.3±0.05 and a loss tangent tanδ of 0.5±0.001; the thickness of the metal graphic layer and the metal strip group is 0.035mm.

3. The three-dimensional frequency selective absorber based on the SSPP structure according to claim 1, characterized in that The first metal strip structure and the second metal strip structure are spliced ​​to form a polygon or a circle.

4. The three-dimensional frequency selective absorber based on the SSPP structure according to claim 3 is characterized in that The splicing edges of the first metal strip structure and the second metal strip structure are located on both sides of the intersection line of the two second substrates or at the edge of the second substrate; When the splicing edges of the first metal strip structure and the second metal strip structure are located on both sides of the intersection line of the two second substrates, a gap b is provided between the splicing edges of the first metal strip structure and the second metal strip structure in the horizontal direction; when the splicing edges of the first metal strip structure and the second metal strip structure are located at the edge of the second substrate, the vertical distance between the splicing edges of the first metal strip structure and the second metal strip structure in the horizontal direction and the edge of the second substrate is b / 2; When the first metal strip structure and the second metal strip structure are bonded together to form a hexagon or a rectangle, or when the first metal strip structure, the second metal strip structure and the gap b are bonded together to form a circle, b=0.5mm~1.5mm; when the first metal strip structure and the second metal strip structure are bonded together to form a triangle or a pentagon, b=0.3mm~0.5mm.

5. The three-dimensional frequency selective absorber based on the SSPP structure according to claim 3 is characterized in that When the first metal strip structure and the second metal strip structure are bonded and spliced ​​to form a hexagon, the longest metal strip length l0 in the first metal strip structure and the second metal strip structure is 2.25mm~3.75mm, and the length of the metal strips on both sides of the longest metal strip decreases gradually by 0.1mm~0.3mm; K=17~25.

6. The three-dimensional frequency selective absorber based on the SSPP structure according to claim 3, characterized in that When the first metal strip structure and the second metal strip structure are bonded and spliced ​​to form a triangle, the bottom metal strip length l0 of the first metal strip structure and the second metal strip structure is 2.35mm~3.25mm, and the length of the metal strip above the bottom metal strip decreases gradually by 0.1mm~0.2mm; K=18~26.

7. The three-dimensional frequency selective absorber based on the SSPP structure according to claim 3, characterized in that When the first metal strip structure and the second metal strip structure are bonded and spliced ​​to form a rectangle, the length l0 of the metal strips of the first metal strip structure and the second metal strip structure is equal, and l0 is 2.25mm-3.75mm; K=17-25.

8. The three-dimensional frequency selective absorber based on the SSPP structure according to claim 3, characterized in that When the first metal strip structure and the second metal strip structure are bonded and spliced ​​to form a pentagon, the length l0 of the longest metal strip in the first metal strip structure and the second metal strip structure is 2.25mm~3.75mm, the length of the metal strip above the longest metal strip decreases gradually by 0.2mm~0.4mm, and the length of the metal strip below the longest metal strip decreases gradually by 0.1mm~0.3mm; K=18~26.

9. The three-dimensional frequency selective absorber based on the SSPP structure according to claim 3, characterized in that When the first metal strip structure, the second metal strip structure and the gap b are spliced ​​to form a circle, the radius r of the circle is 3.5 mm to 4.5 mm; and K=17 to 22.

10. The three-dimensional frequency selective absorber based on the SSPP structure according to claim 1, characterized in that The sides of the cross arm and the end arm of the Jerusalem cross are parallel to the edge of the first substrate; the width W1 of the cross arm is 0.5mm-3mm, and the length L2 is 5mm-9mm; the width W2 of the end arm is 0.1mm-1mm, and the length L1 is 2mm-5mm.

Images