Broadband wave absorber with adjustable wave-transparent window

Abstract

The utility model discloses a broadband wave-absorbing body with an adjustable wave-transmitting window, relates to the technical field of antennas, and particularly aims to solve the problems that on the basis that out-of-band wave absorption can be realized, a frequency selective surface with an adjustable transmission frequency band needs a via hole in structure and is poor in frequency selection characteristic, and the frequency selection efficiency is high in the prior art. In order to solve the problems that a square ring gap structure can regulate and control a transmission frequency band, but a single-layer frequency selection surface of the square ring gap structure is narrow in transmission frequency band and poor in out-of-band absorption characteristic, the utility model provides a broadband wave absorber with an adjustable wave-transparent window, the broadband wave absorber is composed of an impedance absorption surface, a medium transmission layer and a transmissivity-adjustable surface, and the transmission frequency band can be dynamically switched. Meanwhile, out-of-band absorption is achieved, the structure is simple, corresponding wave transmission and wave absorption adjustment operation is convenient, good out-of-band absorption is guaranteed, and the out-of-band absorption rate is larger than 90%.

Description

Technical Field

[0001] The utility model belongs to the technical field of antennas, and particularly relates to a broadband absorber with an adjustable wave-transmitting window. Background Art

[0002] Frequency selective surface is an important means to achieve the stealth of aircraft radomes. However, the traditional frequency selective surface can only achieve in-band transmission and out-of-band reflection. By loading an absorbing layer, out-of-band absorption can be achieved on the premise of ensuring in-band transmission. However, these solutions are still static and cannot well adapt to the future complex and changing electromagnetic environment. Therefore, a reconfigurable frequency selective surface is realized by loading tunable devices.

[0003] Currently, the main method to realize the reconfigurable frequency selective surface is to load diodes in the structure and achieve the switching of the transmission frequency through voltage regulation. For example, in the paper "Broadband Frequency-Selective Rasorber With Varactor-Tunable Interabsorption Band Transmission Window" published by Lijie Wu, Shuomin Zhong et al. in Volume 67 of IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION in 2019, a frequency selective surface with tunable transmission frequency band based on varactor diodes is proposed, which can also achieve out-of-band absorption at the same time. However, the designed structure requires vias and has poor frequency selection characteristics; in the patent "Absorbing and Transmitting Integrated Tunable Metasurface with Transmission Window Covering C Band and Its Design Method" applied by Ma Yungui et al., a square ring slot structure can be used to regulate the transmission frequency band, but its disadvantages are that the transmission frequency band of the single-layer frequency selective surface is narrow and the out-of-band absorption characteristics are poor. In the existing designs, there is no technology that can achieve adjustable broadband transmission frequency band and good out-of-band absorption at the same time, and the structure performance is improved by multi-layer cascading.

[0004] Therefore, there is an urgent need to design a broadband absorber with an adjustable wave-transmitting window to solve the above problems. Summary of the Utility Model

[0005] Aiming at the problems existing in the above-mentioned prior art, that is, for a frequency selective surface with adjustable transmission frequency band on the basis of achieving out-of-band absorption, its structure requires vias and has poor frequency selection characteristics, and although the square ring slot structure can regulate the transmission frequency band, the transmission frequency band of its single-layer frequency selective surface is narrow and the out-of-band absorption characteristics are poor. The purpose of the utility model is to provide a broadband absorber with an adjustable wave-transmitting window, which is composed of an impedance absorption surface, a dielectric transmission layer and an adjustable transmittance surface, can dynamically switch the transmission frequency band, achieve out-of-band absorption at the same time, has a simple structure, and the corresponding wave-transmitting and absorbing adjustment operations are convenient.

[0006] To achieve the above object, the technical solution adopted by the present utility model is as follows:

[0007] A broadband absorber with an adjustable wave-transmitting window, characterized by comprising, arranged in sequence:

[0008] An impedance absorption surface, comprising impedance absorption units arranged periodically and equidistantly, wherein each impedance absorption unit comprises a plurality of metal structures and a lossy dielectric electrically connected to the metal structures;

[0009] A dielectric transmission layer, with the impedance absorption surface printed on one side and an adjustable transmittance surface arranged on the other side;

[0010] The adjustable transmittance surface, comprising adjustable transmittance units arranged periodically and equidistantly, wherein each adjustable transmittance unit comprises a left transmittance layer, a middle transmittance layer and a right transmittance layer which are arranged in a mutually attached manner.

[0011] Preferably, the left transmittance layer comprises:

[0012] Metal patches one, arranged periodically and equidistantly on one side of a dielectric layer one;

[0013] The dielectric layer one, and varactor diodes, arranged between every two metal patches one in the horizontal direction.

[0014] Preferably, the middle transmittance layer comprises:

[0015] A metal mesh grid, printed on one side of a dielectric layer two;

[0016] The dielectric layer two, with its other side attached to the right transmittance layer.

[0017] Preferably, the right transmittance layer comprises:

[0018] Metal patches two, having the same structure as the metal patches one, arranged periodically and equidistantly on the other side of the dielectric layer two, and arranged at 90° relative to the metal patches one;

[0019] Adjustable devices, arranged between every two metal patches two in the vertical direction.

[0020] Preferably, the material of the lossy dielectric is resistive ink, used to connect two adjacent metal structures.

[0021] Preferably, the materials of the dielectric transmission layer, the dielectric layer one and the dielectric layer two are isotropic dielectric materials, and the thickness of the dielectric transmission layer is 8 mm, and the thicknesses of the dielectric layer one and the dielectric layer two are 0.2 mm.

[0022] Preferably, the area of the lossy dielectric is 0.54 mm 2 , and the resistance value is 80 Ω / m 2 .

[0023] Preferably, the width of the metal line in the metal structure is 0.2 mm.

[0024] The beneficial effects of the present utility model are as follows: The present utility model discloses a broadband absorber with an adjustable wave-transmitting window. Compared with the prior art, the improvements of the present utility model are as follows:

[0025] (1) The broadband absorber with an adjustable wave-transmitting window of the present utility model realizes a large-range movement of the wave-transmitting frequency band, while ensuring absorption outside the band. Moreover, the structure is simple, and the operation of adjusting the wave-transmitting and absorbing effects is simple. In addition, the metamaterial surface of the present utility model can be mass-produced, has good controllability, has a broadband response, and can be used for stealth radomes.

[0026] (2) Through the design of the impedance absorption surface, the present utility model solves the problems of high-efficiency transmission in the wave-transmitting frequency band and high-efficiency absorption outside the wave-transmitting frequency band. Moreover, the structure is simple, and the operation of adjusting the wave-transmitting and absorbing effects is simple.

[0027] (3) Through the design of the adjustable transmittance surface, the present utility model solves the problem of the movement of the wave-transmitting frequency band. Moreover, the structure is simple, and the operation of adjusting the movement effect is simple. The movement of the wave-transmitting frequency band within the absorption band can be realized only by voltage regulation, which can greatly save costs, reduce the adjustment time, and at the same time can adapt to the application of radomes in various complex electromagnetic environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the overall structure of the broadband absorber with an adjustable wave-transmitting window of the present utility model;

[0029] Figure 2 It is a front view schematic diagram of the impedance absorption surface of the present utility model;

[0030] Figure 3 It is a schematic diagram of the structure of the adjustable transmittance surface of the present utility model;

[0031] Figure 4 It is a schematic diagram of the structure of the left transmission layer of the present utility model;

[0032] Figure 5 It is a schematic diagram of the structure of the middle transmission layer of the present utility model;

[0033] Figure 6 It is a schematic diagram of the structure of the right transmission layer of the present utility model;

[0034] Figure 7 It is a transmission simulation performance diagram of the broadband absorber with an adjustable wave-transmitting window of the present utility model under different capacitances of varactor diodes;

[0035] Figure 8Absorption simulation performance diagram of the broadband absorbing metasurface with adjustable transmitting window of the present utility model under different capacitances of varactor diodes;

[0036] Wherein: 1. Impedance absorption surface; 101. Metal structure; 102. Lossy dielectric; 2. Dielectric transmission layer; 3. Adjustable transmittance surface; 301. Left transmission layer; 301-1. Metal patch 1; 301-2. Dielectric layer 1; 301-3. Varactor diode; 302. Middle transmission layer; 302-1. Metal mesh; 302-2. Dielectric layer 2; 303. Right transmission layer; 303-1. Metal patch 2; 303-2. Adjustable device. Specific embodiments

[0037] In order to enable those of ordinary skill in the art to better understand the technical solution of the present utility model, the technical solution of the present utility model will be further described below with reference to the drawings and embodiments.

[0038] Embodiment:

[0039] Referring to Figures 1-6 As shown, a broadband absorber with an adjustable transmitting window includes an impedance absorption surface 1, a dielectric transmission layer 2, and an adjustable transmittance surface 3, and the impedance absorption surface 1 and the adjustable transmittance surface 3 are respectively printed on both sides of the dielectric transmission layer 2; the impedance absorption surface 1 is used for efficient transmission in the transmitting frequency band and efficient absorption outside the transmitting frequency band; the adjustable transmittance surface 3 is used to realize the movement of the transmitting frequency band;

[0040] Specifically referring to Figure 2 As shown, the impedance absorption surface 1 is composed of a plurality of impedance absorption units arranged periodically and equidistantly. Among them, the impedance absorption structure includes a metal structure 101 and a lossy dielectric 102. The material of the metal structure 101 can be selected from low-loss metals such as copper, gold, and silver. The metal structure 101 and the lossy dielectric 102 are electrically connected. The metal structure 101 is composed of metal lines, and the lossy dielectric 102 is formed by printing resistive ink and is used to electrically connect two adjacent metal structures 101. Preferably, in this embodiment, the lossy dielectric 102 is a rectangular structure, an arc structure, or an L-shaped structure. As shown in Figures 7-8 As shown, its function is to connect a plurality of metal structures 101;

[0041] Preferably, in this embodiment, there are 4 metal structures 101, which are symmetrically arranged, and 8 lossy dielectrics 102. One end of each two lossy dielectrics 102 is respectively connected to the output end and the input end of a metal structure 101, and the other end is connected to the end of the adjacent lossy dielectric 102, so that four metal structures 101 and eight lossy dielectrics 102 form a closed-loop circuit;

[0042] By adjusting the width of the metal structure 101, the area of the lossy dielectric 102, and the overlapping area of the width of the metal structure 101 and the lossy dielectric 102, it is possible to achieve high-efficiency transmission in the wave-transmitting frequency band and high-efficiency absorption outside the wave-transmitting frequency band. In this embodiment, the area of the lossy dielectric 102 is 0.54 mm 2 , and the resistance value of the resistive ink is 80 Ω / m 2 , and the width of the metal lines in the metal structure 101 is 0.2 mm;

[0043] Specifically, the dielectric transmission layer 2 is composed of an isotropic dielectric material, and the thickness of the dielectric transmission layer is: 0.1*λ - 0.5*λ, where λ is the center wavelength of the wave-transmitting frequency band, and is selected as 8 mm in this embodiment;

[0044] Specifically, refer to the attached Figure 3 As shown, the adjustable transmittance surface 3 includes adjustable transmittance units arranged at equal intervals periodically. The adjustable transmittance unit includes a left transmittance layer 301, a middle transmittance layer 302, and a right transmittance layer 303 that are bonded together; by changing the capacitance values of the varactor diode 301-3 and the adjustable device 303-2, the movement of the wave-transmitting frequency band can be achieved;

[0045] Refer to the attached Figure 4 As shown, the left transmittance layer 301 includes a metal patch 301-1 and a dielectric layer 301-2. The metal patch 301-1 is a sheet structure, and the material can be selected from low-loss metals such as gold, silver, and copper. The metal patches 301-1 are arranged periodically on the surface of the dielectric layer 301-2, and the other side of the dielectric layer 301-2 is bonded to the middle transmittance layer 302; and there is no electrical connection between every two metal patches 301-1; among them, the dielectric layer 301-2 is composed of an isotropic dielectric material, which can be Rogers 4003C, and the thickness is 0.1*λ - 0.5*λ, where λ is the center wavelength of the wave-transmitting frequency band, and the thickness is preferably 0.2 mm in this embodiment; varactor diodes 301-3 are loaded between every two metal patches 301-1 in the same row horizontally for adjusting the wave-transmitting frequency band of the x-polarized electromagnetic wave;

[0046] Refer to the attached Figure 5 As shown, the middle transmittance layer 302 includes a metal mesh 302-1 and a dielectric layer 302-2. The metal mesh 302-1 is printed on one surface of the dielectric layer 302-2, and the material can be selected from low-loss metals such as gold, silver, and copper; among them, the dielectric layer 302-2 is composed of an isotropic dielectric material, which can be Rogers 4003C, and the thickness is 0.1*λ - 0.5*λ, where λ is the center wavelength of the wave-transmitting frequency band, and the thickness is preferably 0.2 mm in this embodiment;

[0047] Refer to the attached Figure 6As shown in the figure, the right transmission layer 303 includes a second metal patch 303-1 and an adjustable device 303-2. Preferably, the adjustable device 303-2 can be a varactor diode or a switching diode. The second metal patch 303-1 and the adjustable device 303-2 are disposed on the other surface of the second dielectric layer 302-2, and the structure of the second metal patch 303-1 is the same as that of the first metal patch 301-1. It is printed at 90° relative to the first metal patch 301-1, that is, the first metal patch 301-1 is rotated 90° to be the setting state of the second metal patch 303-1. The adjustable device 303-2 is disposed between two second metal patches 303-1 in the same vertical row for adjusting the transmission frequency band of the y-polarized electromagnetic wave; the adjustable device 303-2 is perpendicular to the varactor diode 301-3;

[0048] In the broadband absorber with adjustable wave transmission window of this embodiment, while realizing the movement of the wave transmission frequency band, the mechanism for ensuring out-of-band absorption is as follows: The impedance absorption surface 1 can generate resonance in the resistive dielectric absorption layer to introduce a high-efficiency transmission window, and the dielectric transmission layer 2 provides the necessary isolation; by regulating the capacitance values of the adjustable device 303-2 and the varactor diode 301-3 in the adjustable transmittance surface 3, the structure of the adjustable transmittance surface 3 is changed to match different electromagnetic waves, and at the same time, the movement of the wave transmission frequency band is realized; the broadband absorber with adjustable wave transmission window composed of the impedance absorption surface 1, the dielectric transmission layer 2 and the adjustable transmittance surface 3 realizes a large-range movement of the wave transmission frequency band while ensuring out-of-band absorption.

[0049] Among them, Figure 7 To disclose the relationship curve of the transmittance of the present invention changing with frequency and the capacitance value of the varactor diode, where the abscissa is the frequency. As can be seen from the figure, with the change of the capacitance value, the transmission band moves from 12.2 GHz to 4.8 GHz, and the transmittance is greater than 90%. Here, only a few special capacitance values are selected for illustration. Actually, the wave transmission frequency band can take any value in the range of 4.8 GHz - 12.2 GHz.

[0050] Figure 8 To disclose the relationship curve of the absorption rate of the present invention changing with frequency and the capacitance value of the varactor diode, where the abscissa is the frequency. With the change of the capacitance value, the wave absorption frequency band can change with the wave transmission frequency band to ensure good out-of-band absorption, and the out-of-band absorption rate is greater than 90%. Compared with the disclosed integrated frequency selective surface of wave absorption and wave transmission, the present invention can realize a large-range movement of the wave transmission frequency band while ensuring out-of-band absorption.

[0051] The above has shown and described the basic principles, main features and advantages of the present utility model. Those skilled in the art should understand that the present utility model is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present utility model. Without departing from the spirit and scope of the present utility model, the present utility model will have various changes and improvements, and these changes and improvements all fall within the scope of the present utility model claimed. The scope of protection claimed by the present utility model is defined by the appended claims and their equivalents.

Claims

1. A broadband absorber with adjustable wave-transmitting window, characterized in that: Comprising, successively arranged: An impedance absorption surface (1), comprising impedance absorption units arranged at equal intervals periodically, the impedance absorption units comprising a plurality of metal structures (101) and a lossy dielectric (102) electrically connected to the metal structures (101); A dielectric transmission layer (2), with the impedance absorption surface (1) printed on one side of the dielectric transmission layer (2) and an adjustable transmittance surface (3) provided on the other side; An adjustable transmittance surface (3), comprising adjustable transmittance units arranged at equal intervals periodically, the adjustable transmittance units comprising a left transmittance layer (301), a middle transmittance layer (302), and a right transmittance layer (303) which are arranged in a mutually adhered manner.

2. The broadband absorber with an adjustable wave-transmitting window according to claim 1, characterized in that: The left transmittance layer (301) comprises: Metal patches one (301-1), arranged at equal intervals periodically on one side of a dielectric layer one (301-2); The dielectric layer one (301-2), Varactor diodes (301-3), arranged between every two metal patches one (301-1) in the horizontal direction.

3. The broadband absorber with an adjustable wave-transmitting window according to claim 2, characterized in that: The middle transmittance layer (302) comprises: A metal mesh grid (302-1), printed on one side of a dielectric layer two (302-2); The dielectric layer two (302-2), with the other side thereof adhered to the right transmittance layer (303).

4. The broadband absorber with an adjustable wave-transmitting window according to claim 3, characterized in that: The right transmittance layer (303) comprises: Metal patches two (303-1), having the same structure as the metal patches one (301-1), arranged at equal intervals periodically on the other side of the dielectric layer two (302-2) and arranged at 90° relative to the metal patches one (301-1); Adjustable devices (303-2), arranged between every two metal patches two (303-1) in the vertical direction.

5. The broadband absorber with an adjustable wave-transmitting window according to claim 1, wherein: The material of the lossy dielectric (102) is resistive ink, which is used to connect two adjacent metal structures (101).

6. The broadband absorber with an adjustable wave-transmitting window according to claim 3, characterized in that: The materials of the dielectric transmission layer (2), the dielectric layer one (301-2), and the dielectric layer two (302-2) are isotropic dielectric materials, and the thickness of the dielectric transmission layer (2) is 8 mm, and the thicknesses of the dielectric layer one (301-2) and the dielectric layer two (302-2) are 0.2 mm.

7. The broadband absorber with an adjustable wave-transmitting window according to claim 1, characterized in that: The area of the lossy medium (102) is 0.54 mm 2 , and the resistance value is 80 Ω / m 2 .

8. The broadband absorber with an adjustable wave-transmitting window according to claim 1, wherein: The width of the metal lines in the metal structures (101) is 0.2 mm.

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