CN113451781B - Microminiaturized 2.5-dimensional absorption and penetration integrated frequency selection wave absorber - Google Patents

Abstract

The invention relates to an ultra-miniaturized 2.5-dimensional absorption-permeability integrated frequency-selective wave absorber, comprising a plurality of continuous and periodically arranged metamaterial units. The metamaterial unit includes a top resonant layer, a first A dielectric layer, a second dielectric layer, a third dielectric layer and a bottom resonant layer, the top resonant layer includes a first metal patch unit, a thin film resistor and four second metal patch units; the bottom of the first dielectric layer is provided with four Third metal patch units, each third metal patch unit is correspondingly connected to the second metal patch unit through a metallized through hole, and a hollow structure is arranged on the bottom resonant layer. The 2.5-dimensional absorption-permeability integrated frequency-selective wave absorber of the present invention adopts graphene film to replace lumped resistance, which is convenient for plane integration and mass production, and utilizes the design of combining folded metal strips and through holes to achieve superstructure. Miniaturization suppresses the appearance of grating lobes, reduces dual-station RCS under oblique incidence, and improves oblique incidence stealth performance.

Description

An ultra-miniaturized 2.5-dimensional absorption-penetration integrated frequency selective absorber

technical field

The invention belongs to the technical field of antenna stealth, and in particular relates to an ultra-miniaturized 2.5-dimensional absorption-penetration integrated frequency-selective wave absorber.

Background technique

The radome is a protective cover installed on the outside of electromagnetic equipment such as radar antennas on various weapons and aircraft to protect the internal system from external electromagnetic interference. The radar antenna can transmit and receive electromagnetic signals normally.

With the rapid development of antenna stealth technology, the functional requirements of radomes are getting higher and higher, and FSS-type radomes have become a research hotspot. FSS is composed of a large number of periodically arranged metal patch units or slots with the same shape. composed of two-dimensional structures. When the frequency of the incident electromagnetic wave is at the resonant frequency of the unit, the FSS exhibits the characteristics of total reflection (patch type) or total transmission (aperture type), while electromagnetic waves of other frequencies can pass through the FSS (patch type) or be totally reflected (Aperture type). The radome based on the band-pass FSS can achieve in-band wave transmission and out-of-band total reflection. However, this kind of stealth method cannot realize the stealth of dual base station or multi-base station detection. To achieve omnidirectional antenna stealth, the key is not to reflect outside the band. Therefore, the integrated wave absorber is proposed.

In recent years, many researchers have proposed a large number of broadband, low-profile, flexible, and multi-functional integrated absorbers, which provide a solid theoretical basis and design examples for the development of domestic antenna stealth technology. For example: Jianjun Jiang's team proposed two integrated absorbers with double loss layers. This design can improve the absorption bandwidth, but the cost is the improvement of the structural period. The periods of the two designs are 20 mm and 20 mm, respectively. 40 mm, the consequence of such a large period structure is the appearance of grating lobes under oblique incidence, which will lead to the rise of the double-station RCS. Moreover, the absorber with a period of 40 mm will generate grating lobes under normal incidence, which seriously affects the stealth performance. Shaobin Liu's team proposed an integrated absorber with a wide transmission band, but this structure introduces a lumped resistance, which increases the complexity of the process, which is very unfavorable for planar integration and mass production. At the same time, the lumped resistance The reference of this type is limited at high frequencies, which is not conducive to the application of the idea of this structure at high frequencies.

SUMMARY OF THE INVENTION

In order to solve the above problems existing in the prior art, the present invention provides an ultra-miniaturized 2.5-dimensional absorption-permeability integrated frequency-selective wave absorber. The technical problem to be solved by the present invention is realized by the following technical solutions:

The invention provides an ultra-miniaturized 2.5-dimensional absorption-permeability integrated frequency-selective wave absorber, which includes a plurality of continuous and periodically arranged metamaterial units, and the metamaterial units include top resonant layers stacked sequentially from top to bottom. , a first dielectric layer, a second dielectric layer, a third dielectric layer and a bottom resonant layer, the top resonant layer includes a first metal patch unit, a thin film resistor and four second metal patch units, wherein,

The first metal patch unit is a square, the thin film resistor is a cross-shaped structure, and the thin film resistor divides the first metal patch unit into 4 triangular metal patches of equal size. 4 of the triangular metal patches form a square structure;

The second metal patch unit is connected with the triangular metal patch in one-to-one correspondence, and the four second metal patch units form a center-symmetrical pattern, the center of which is the center of the thin film resistor;

The second metal patch unit includes a first folded-shaped metal strip, a first circular metal patch, a second folded-shaped metal strip and a second circular metal patch connected in sequence, the first folded-shaped metal strip One end of the metal strip is connected to the midpoint of the bottom edge of the triangular metal patch, and the centers of the first circular metal patch and the second circular metal patch are both located on the symmetry axis of the triangular metal patch extension line;

The bottom of the first dielectric layer is provided with four third metal patch units, and the four third metal patch units are respectively arranged in parallel with the four sides of the bottom surface of the first dielectric layer. The metal patch unit is connected to the corresponding second metal patch unit through a metallized through hole passing through the first dielectric layer;

The bottom resonant layer is provided with a hollow structure, the hollow structure is square, and the middle of the four sides of the square is recessed toward the center of the square to form a U-shaped recessed groove.

In one embodiment of the present invention, the first folded metal strip includes a first strip portion, a second strip portion, a third strip portion, a fourth strip portion and a fifth strip portion, wherein ,

The first end of the first strip portion is connected to the midpoint of the bottom edge of the triangular metal patch, and the second end is vertically connected to the first end of the second strip portion;

The second end of the second strip portion is vertically connected to the first end of the third strip portion, and the second end of the third strip portion is close to the triangular metal patch;

The first end of the fourth strip portion is vertically connected with the second end of the third strip portion, and the second end of the fourth strip portion is close to the triangular metal patch;

The first end of the fifth strip part is vertically connected with the second end of the fourth strip part, the second end of the fifth strip part is away from the triangular metal patch, and the fifth strip part is The second end of the belt portion is connected to the first circular metal patch.

In one embodiment of the present invention, the second folded metal strip includes a sixth strip portion, a seventh strip portion and an eighth strip portion, wherein,

The first end of the sixth strip portion is connected to the first circular metal patch, the first end of the sixth strip portion is disposed opposite to the second end of the fifth strip portion, and the The second end of the sixth strap portion is vertically connected to the first end of the seventh strap portion;

The second end of the seventh strip portion is away from the triangular metal patch, and the second end of the seventh strip portion is vertically connected to the first end of the eighth strip portion;

The second end of the eighth strip portion is close to the triangular metal patch, and the second end of the eighth strip portion is connected to the second circular metal patch.

In an embodiment of the present invention, the third metal patch unit includes a first rectangular metal patch and a second rectangular metal patch arranged in parallel, wherein,

The length of the first rectangular metal patch is less than the length of the second rectangular metal patch;

the first rectangular metal patch is connected to the first circular metal patch through a first metallized through hole;

the second rectangular metal patch is connected to the second circular metal patch through a second metallized through hole;

The connection point between the first rectangular metal patch and the first metallized through hole is located at the center of the first rectangular metal patch;

The connection point between the second rectangular metal patch and the second metallized through hole is located at the center of the second rectangular metal patch.

In an embodiment of the present invention, the included angle between the side edge and the bottom edge of the U-shaped concave groove is 90°.

In an embodiment of the present invention, the thin film resistor is a graphene resistance film, and the square resistance value ranges from 340 Ohm/sq to 400 Ohm/sq;

The value range of the side length D ₁ of the square structure formed by the thin-film resistor and the four triangular metal patches is 0.052λ _t <D ₁ <0.054λ _t , the four arms of the cross-shaped structure are equal in length, and the arms The value range of the length D ₂ is 0.022λ _t <D ₂ <0.023λ _t , and the value range of the arm width D ₃ of the cross-shaped structure is 0.0143λ _t <D ₃ <0.0146λ _t , where λ _t is The wavelength corresponding to the transmission frequency.

In an embodiment of the present invention, the value range of the bandwidth W ₁ of the first folded metal strip is 0.0038λ _t <D ₁ <0.004λ _t , and the length l ₁ of the first strip portion The value range is 0.0103λ _t <l ₁ <0.0106λ _t , the value range of the length l ₂ of the second strip portion is 0.068λ _t <l ₂ <0.070λ _t , the length of the third strip portion The value range of the length l ₃ is 0.0195λ _t <l ₃ <0.0199λ _t , the value range of the length l ₄ of the fourth strip portion is 0.0142λ _t <l ₄ <0.0147λ _t , the fifth The value range of the length l ₅ of the strip portion is 0.0205λ _t <l ₅ <0.0215λ _t ;

The value range of the bandwidth W ₂ of the second folded metal strip is 0.0052λ _t <W ₂ <0.0054λ _t , and the value range of the length l ₆ of the sixth strip portion is 0.042λ _t <1 ₆ <0.046λ _t , the value range of the length l ₇ of the seventh strip portion is 0.0202λ _t <l ₇ <0.0211λ _t , the value range of the length l ₈ of the eighth strip portion is 0.042 λ _t <l ₆ <0.046λ _t ;

The size of the first circular metal patch and the second circular metal patch are equal, and the value range of the radius R ₁ is 0.0071λ _t <R ₁ <0.00715λ _t , where λ _t is the transmission wave The wavelength corresponding to the frequency.

In an embodiment of the present invention, the widths of the first rectangular metal patch and the second rectangular metal patch are equal, and the value range of the width W ₃ is 0.014λ _t <W ₃ <0.015λ _t , The value range of the length m ₁ of the first rectangular metal patch is 0.052λ _t <m ₁ <0.053λ _t , and the value range of the length m ₂ of the second rectangular metal patch is 0.1037λ _t <m ₂ <0.1046λ _t , the value range of the radius R ₂ of the metallized through hole is 0.0039λ _t <R ₂ <0.0040λ _t , where λ _t is the wavelength corresponding to the transmission frequency.

In an embodiment of the present invention, the materials of the first dielectric layer and the third dielectric layer are both F4B, and the second dielectric layer is an air layer;

The value range of the thickness h ₁ of the first dielectric layer is 0.0523λ _t <h ₁ <0.0529λ _t ;

The value range of the thickness h ₂ of the second dielectric layer is 0.155λ _t <h ₂ <0.159λ _t ;

The value range of the thickness h ₃ of the third dielectric layer is 0.026λ _t <h ₃ <0.0264λ _t , where λ _t is the wavelength corresponding to the transmission frequency.

In an embodiment of the present invention, the value range of the distance b ₁ between the two opposing U-shaped recessed grooves is 0.034λ _t <b ₁ <0.035λ _t , and the groove width of the U-shaped recessed grooves The value range of b ₂ is 0.0155λ _t <b ₂ <0.016λ _t , the value range of the groove depth b ₃ of the U-shaped recessed groove is 0.044λ _t <b ₃ <0.045λ _t , the U-shaped recessed groove has a value range of 0.044λ t <b 3 <0.045λ t . The value range of the distance b ₄ between the side wall of the recessed groove and the vertex of the square hollow structure is 0.064λ _t <b ₄ <0.0648λ _t ;

The value range of the hollow width W ₄ of the hollow structure is 0.0052λ _t <W ₄ <0.0054λ _t , where λ _t is the wavelength corresponding to the transmission frequency.

Compared with the prior art, the beneficial effects of the present invention are:

1. The ultra-miniaturized 2.5-dimensional absorption-penetration integrated frequency-selective wave absorber of the present invention, in each metamaterial unit, adopts a thin-film resistance to replace the lumped resistance, and this thin-film resistance is a graphene resistance film, which only passes through a piece of graphite. The ene resistance film can achieve the effect of omnidirectional resistance without welding multiple lumped resistances, which is convenient for plane integration and mass production.

2. The ultra-miniaturized 2.5-dimensional absorption-permeability integrated frequency selective absorber of the present invention utilizes the design of the combination of folded metal strips and through holes to achieve ultra-miniaturization, thereby suppressing the appearance of grating lobes and reducing oblique incidence Under the dual-station RCS, the oblique incidence stealth performance is greatly improved.

3. The ultra-miniaturized 2.5-dimensional absorption-permeability integrated frequency-selective wave absorber of the present invention adopts a center-symmetric pattern design in each layer structure of the metamaterial unit, so that the frequency-selective wave absorber can absorb the incident electromagnetic waves. Polarization direction is not sensitive.

The above description is only an overview of the technical solution of the present invention, in order to be able to understand the technical means of the present invention more clearly, it can be implemented according to the content of the description, and in order to make the above and other objects, features and advantages of the present invention more obvious and easy to understand , the following specific preferred embodiments, and in conjunction with the accompanying drawings, are described in detail as follows.

Description of drawings

1 is a schematic three-dimensional structure diagram of an ultra-miniaturized 2.5-dimensional absorption-permeability integrated frequency-selective wave absorber provided by an embodiment of the present invention;

2 is a schematic three-dimensional structure diagram of a metamaterial unit provided in an embodiment of the present invention;

3 is a schematic structural diagram of a top resonant layer provided by an embodiment of the present invention;

4 is a schematic structural diagram of a thin film resistor provided by an embodiment of the present invention;

5 is a schematic structural diagram of a top resonant layer with thin film resistors removed according to an embodiment of the present invention;

6 is a schematic structural diagram of a third metal patch unit provided by an embodiment of the present invention;

7 is a schematic structural diagram of a bottom resonance layer provided by an embodiment of the present invention;

8 is a simulation curve diagram of the reflection coefficient of the ultra-miniaturized 2.5-dimensional absorption-permeability integrated frequency-selective wave absorber under different polarizations provided by an embodiment of the present invention;

9 is a simulation graph of the reflection coefficient corresponding to an ultra-miniaturized 2.5-dimensional absorption-transmission integrated frequency selective wave absorber provided by an embodiment of the present invention when the incident angle increases from 0 degrees to 60 degrees under different polarizations.

Icons: 1 - metamaterial unit; 10 - top resonant layer; 20 - first dielectric layer; 30 - second dielectric layer; 40 - third dielectric layer; 50 - bottom resonant layer; 101 - thin film resistor; 102 - second metal patch unit; 103-triangular metal patch; 201-third metal patch unit; 202-metallized through hole; 1021-folded metal strip; 1022-first circular metal patch; 1023-second Folded metal strip; 1024-second circular metal patch; 2011-first rectangular metal patch; 2012-second rectangular metal patch; 2021-first metallized through hole; 2022-second metallized through hole ; 10211 - first strip part; 10212 - second strip part; 10213 - third strip part; 10214 - fourth strip part; 10215 - fifth strip part; 10216 - sixth strip part; 10217 - Seventh strip section; 10218 - Eighth strip section.

Detailed ways

In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the following describes an ultra-miniaturized 2.5-dimensional integrated frequency selective absorber according to the present invention with reference to the accompanying drawings and specific embodiments. Explain in detail.

The foregoing and other technical contents, features and effects of the present invention can be clearly presented in the following detailed description of the specific implementation with the accompanying drawings. Through the description of the specific embodiments, the technical means and effects adopted by the present invention to achieve the predetermined purpose can be more deeply and specifically understood. However, the accompanying drawings are only for reference and description, and are not used for the technical description of the present invention. program is restricted.

Example 1

This embodiment provides an ultra-miniaturized 2.5-dimensional absorption-permeability integrated frequency-selective wave absorber. The wave absorber has a wave-transmitting window at the high frequency of the wave-absorbing band. Waves are equivalent to transparency, and electromagnetic waves can pass through the structure without reflection, so that the antenna system in the absorber can work normally and has good wave absorption and stealth performance outside the working frequency band. Please refer to FIG. 1-FIG. 5. FIG. 1 is a schematic three-dimensional structure diagram of an ultra-miniaturized 2.5-dimensional absorption-permeability integrated frequency selective absorber provided by an embodiment of the present invention; Schematic diagram of the three-dimensional structure of the material unit; FIG. 3 is a schematic structural diagram of the top resonant layer provided by an embodiment of the present invention, FIG. 4 is a schematic structural diagram of a thin film resistor provided by an embodiment of the present invention, and FIG. 5 is an embodiment of the present invention. Schematic diagram of the structure of the top resonant layer. As shown in the figure, the ultra-miniaturized 2.5-dimensional absorption-permeability integrated frequency-selective wave absorber in this embodiment includes a number of metamaterial units 1 that are continuously and periodically arranged. Optionally, the metamaterial units 1 are m*n. A continuous matrix arrangement, where m≥2, n≥2, as shown in FIG. 1 , in this embodiment, the metamaterial units 1 are arranged in a 3*3 continuous matrix. It should be noted that, in this embodiment, the unit period of the metamaterial unit 1 is P=6 mm.

As shown in FIG. 2 , the metamaterial unit 1 includes a top resonant layer 10 , a first dielectric layer 20 , a second dielectric layer 30 , a third dielectric layer 40 and a bottom resonant layer 50 , which are sequentially stacked from top to bottom.

Specifically, as shown in FIG. 3 , the top resonant layer 10 includes a first metal patch unit, a thin film resistor 101 and four second metal patch units 102 . The first metal patch unit is square, and the thin film resistor 101 is a cross-shaped structure. The thin film resistor 101 divides the first metal patch unit into four triangular metal patches 103 of equal size. The thin film resistor 101 and the four triangular metal patches 103 forms a square structure. The second metal patch units 102 are connected to the triangular metal patches 103 in one-to-one correspondence, and the four second metal patch units 102 form a center-symmetrical pattern, and the center of symmetry is the center of the thin film resistor 101 .

Optionally, the material of the first metal patch unit and the second metal patch unit 102 is copper, and the conductivity thereof is 5.8×10 ⁹ S/m. The thin film resistor 101 is a graphene resistor film, and the square resistance value ranges from 340 Ohm/sq to 400 Ohm/sq. As shown in FIG. 4 , the value range of the side length D ₁ of the square structure formed by the thin film resistor 101 and the four triangular metal patches 103 is 0.052λ _t <D ₁ <0.054λ _t , and the four arms of the cross-shaped structure are equal in length , the value range of the arm length D ₂ is 0.022λ _t <D ₂ <0.023λ _t , and the value range of the arm width D ₃ of the cross-shaped structure is 0.0143λ _t <D ₃ <0.0146λ _t , where λ _t is The wavelength corresponding to the transmission frequency.

In this embodiment, the square resistance of the thin film resistor 101 is 360 Ohm/sq, the thin film resistor 101 and the four triangular metal patches 103 form a square structure with a side length D ₁ =2 mm, and the arm length of the cross-shaped structure (that is, the triangular metal The waist length of the patch 103 is D ₂ =0.86 mm, the arm width D ₃ =0.55 mm, the vertex angle of the triangular metal patch 103 is 90°, and the waist length is 0.86 mm.

Further, the second metal patch unit 102 includes a first folded-shaped metal strip 1021, a first circular metal patch 1022, a second folded-shaped metal strip 1023, and a second circular metal patch 1024 connected in sequence, One end of the first folded metal strip 1021 is connected to the midpoint of the bottom edge of the triangular metal patch 103 . on the extension of the shaft.

It should be noted that the centers of the first circular metal patch 1022 and the second circular metal patch 1024 are located on the extension line of the symmetry axis of the adjacent triangular metal patches 103 of the correspondingly connected triangular metal patches 103 .

In each metamaterial unit of the ultra-miniaturized 2.5-dimensional absorption-permeability integrated frequency selective absorber of this embodiment, a thin-film resistor is used to replace the lumped resistance, the thin-film resistance is a graphene resistance film, and the lumped resistance is a two-port The graphene resistive film is a resistive film with impedance characteristics. As long as it is in contact with it, it can be regarded as having an infinite number of ports, and it is a resistor when viewed from every direction. In this implementation, only one graphene resistive film is passed through. The effect of omnidirectional resistance can be realized without welding multiple lumped resistances. Both the price of the resistance itself and the complexity of the processing resistance are much higher than that of the lumped resistance, which is more convenient for plane integration and mass production.

In this embodiment, the first folded metal strip 1021 includes a first strip part 10211 , a second strip part 10212 , a third strip part 10213 , a fourth strip part 10214 and a fifth strip part 10215 . The first end of the first strip portion 10211 is connected to the midpoint of the bottom edge of the triangular metal patch 103, and the second end is vertically connected to the first end of the second strip portion 10212; the second end of the second strip portion 10212 is connected vertically. The end is vertically connected to the first end of the third strip portion 10213, the second end of the third strip portion 10213 is close to the triangular metal patch 103; the first end of the fourth strip portion 10214 is connected to the The second end is connected vertically, the second end of the fourth strip portion 10214 is close to the triangular metal patch 103; the first end of the fifth strip portion 10215 is vertically connected with the second end of the fourth strip portion 10214, the fifth strip The second end of the strip portion 10215 is away from the triangular metal patch 103 , and the second end of the fifth strip portion 10215 is connected to the first circular metal patch 1022 .

Further, the second folded metal strip 1023 includes a sixth strip part 10216 , a seventh strip part 10217 and an eighth strip part 10218 . The first end of the sixth strip portion 10216 is connected to the first circular metal patch 1022, the first end of the sixth strip portion 10216 is disposed opposite to the second end of the fifth strip portion 10215, and the sixth strip The second end of the part 10216 is vertically connected with the first end of the seventh strip part 10217; the second end of the seventh strip part 10217 is far away from the triangular metal patch 103, and the second end of the seventh strip part 10217 The first end of the strip portion 10218 is connected vertically; the second end of the eighth strip portion 10218 is close to the triangular metal patch 103 , and the second end of the eighth strip portion 10218 is connected to the second circular metal patch 1024 .

Optionally, the value range of the bandwidth W ₁ of the first folded metal strip 1021 is 0.0038λ _t <D ₁ <0.004λ _t , and the value range of the length l ₁ of the first strip portion 10211 is 0.0103λ _t <l ₁ <0.0106λ _t , the value range of the length l ₂ of the second strip portion 10212 is 0.068λ _t <l ₂ <0.070λ _t , the value range of the length l ₃ of the third strip portion 10213 is 0.0195 λ _t <l ₃ <0.0199λ _t , the value range of the length l ₄ of the fourth strip portion 10214 is 0.0142λ _t <l ₄ <0.0147λ _t , the value range of the length l ₅ of the fifth strip portion 10215 is 0.0205λ _t <l ₅ <0.0215λ _t , where λ _t is the wavelength corresponding to the transmission frequency.

In this embodiment, the width of the first folded metal strip 1021 is W ₁ =0.15mm, the length of the first strip portion 10211 is l ₁ =0.4mm, and the length of the second strip portion 10212 is l ₂ =2.65mm. The length of the third strip portion 10213 is l ₃ =0.75 mm, the length of the fourth strip portion 10214 is l ₄ =0.55 mm, and the length of the fifth strip portion 10215 is l ₅ =0.75 mm.

Optionally, the value range of the bandwidth W ₂ of the second folded metal strip 1023 is 0.0052λ _t <W ₂ <0.0054λ _t , and the value range of the length l ₆ of the sixth strip portion 10216 is 0.042λ _t <l ₆ <0.046λ _t , the value range of the length l ₇ of the seventh strip portion 10217 is 0.0202λ _t <l ₇ <0.0211λ _t , the value range of the length l ₈ of the eighth strip portion 10218 is 0.042 λ _t <l ₆ <0.046λ _t , where λ _t is the wavelength corresponding to the transmission frequency.

In this embodiment, the length l ₆ of the sixth strip portion 10216 is 1.7 mm, the length of the seventh strip portion 10217 is l ₇ =0.7 mm, and the length of the eighth strip portion 10218 is l ₈ =1.7 mm.

Optionally, the sizes of the first circular metal patch 1022 and the second circular metal patch 1024 are equal, and the value range of the radius R ₁ is 0.0071λ _t <R ₁ <0.00715λ _t , in this embodiment , the radius R ₁ of the first circular metal patch 1022 and the second circular metal patch 1024 is 0.27 mm.

Further, four third metal patch units 201 are disposed at the bottom of the first dielectric layer 20 , and the four third metal patch units 201 are respectively arranged in parallel with the four sides of the bottom surface of the first dielectric layer 20 . The patch unit 201 is connected to the corresponding second metal patch unit 102 through a metallized through hole 202 penetrating the first dielectric layer 20 .

Specifically, please refer to FIG. 6, which is a schematic structural diagram of a third metal patch unit provided by an embodiment of the present invention. As shown in the figure, the third metal patch unit 201 includes a first rectangular metal patch 2011 arranged in parallel and the second rectangular metal patch 2012, wherein the length of the first rectangular metal patch 2011 is smaller than the length of the second rectangular metal patch 2012; the first rectangular metal patch 2011 communicates with the first circular The second rectangular metal patch 2012 is connected to the second circular metal patch 1024 through the second metallized through hole 2022; the first rectangular metal patch 2011 is connected to the first metallized through hole 2021 The point is located at the center of the first rectangular metal patch 2011 ; the connection point of the second rectangular metal patch 2012 and the second metallized through hole 2022 is located at the center of the second rectangular metal patch 2012 .

Optionally, the widths of the first rectangular metal patch 2011 and the second rectangular metal patch 2012 are equal, and the value range of the width W ₃ is 0.014λ _t <W ₃ <0.015λ _t , and the first rectangular metal patch 2011 The value range of the length m ₁ is 0.052λ _t <m ₁ <0.053λ _t , the value range of the length m ₂ of the second rectangular metal patch 2012 is 0.1037λ _t <m ₂ <0.1046λ _t , and the metallization The value range of the radius R ₂ of the hole 202 is 0.0039λ _t <R ₂ <0.0040λ _t , where λ _t is the wavelength corresponding to the transmission frequency.

In this embodiment, the width W ₃ of the first rectangular metal patch 2011 and the second rectangular metal patch 2012 is 0.54 mm, the length m ₁ of the first rectangular metal patch 2011 is 2 mm, and the second rectangular metal patch 2012 The length m ₂ =4mm, and the radius R ₂ =0.15mm of the first metallization through hole 2021 and the second metallization through hole 2022 .

Further, please refer to FIG. 7 , which is a schematic structural diagram of the bottom resonant layer provided by the embodiment of the present invention. As shown in the figure, the bottom resonant layer 50 is provided with a hollow structure, and the hollow structure is a square, and the middle of the four sides of the square is A U-shaped concave groove is formed in the center of the square. In this embodiment, the included angle between the side edge and the bottom edge of the U-shaped concave groove is 90°.

Optionally, the value range of the distance b ₁ between the two opposite U-shaped recessed grooves is 0.034λ _t <b ₁ <0.035λ _t , and the value range of the groove width b ₂ of the U-shaped recessed grooves is 0.0155λ _t <b ₂ <0.016λ _t , the value range of the groove depth b ₃ of the U-shaped concave groove is 0.044λ _t <b ₃ <0.045λ _t , the distance between the side wall of the U-shaped concave groove and the vertex of the square hollow structure is The value range of the distance b ₄ is 0.064λ _t <b ₄ <0.0648λ _t , the value range of the hollow width W ₄ of the hollow structure is 0.0052λ _t <W ₄ <0.0054λ _t , where λ _t is the transparent The wavelength corresponding to the wave frequency.

In this embodiment, the distance between two opposite U-shaped recessed grooves is b ₁ =1.3mm, the groove width of the U-shaped recessed groove is b ₂ =0.6 mm, and the groove depth of the U-shaped recessed groove is b ₃ =1.7 mm , the distance between the side wall of the U-shaped recessed groove and the vertex of the square hollow structure is b ₄ =2.45mm, and the hollow width of the hollow structure is W ₄ =0.2mm.

Further, in this embodiment, the materials of the first dielectric layer 20 and the third dielectric layer 40 are both F4B, and their relative permittivity is 2.2, and the second medium layer 30 is an air layer, and its relative permittivity is 1 . Optionally, the value range of the thickness h ₁ of the first dielectric layer 20 is 0.0523λ _t <h ₁ <0.0529λ _t ; the value range of the thickness h ₂ of the second dielectric layer 30 is 0.155λ _t <h ₂ < 0.159λ _t ; the value range of the thickness h ₃ of the third dielectric layer 40 is 0.026λ _t <h ₃ <0.0264λ _t , where λ _t is the wavelength corresponding to the transmission frequency.

In this embodiment, the thickness of the first dielectric layer 20 is h ₁ =2 mm; the thickness of the second dielectric layer 30 is h ₂ =6 mm; and the thickness of the third dielectric layer 40 is h ₃ =1 mm.

For periodic structures, when the period is too large, the array factor under oblique incidence will also have peaks in addition to the main lobe direction. These peaks are called grating lobes. These grating lobes will lead to the rise of the double-station RCS and increase the Probability of radar detection. The frequency of the grating lobes is inversely proportional to the period p of the structure, that is to say, the smaller the period p of the structure, the higher the frequency of the grating lobes. In this embodiment, a folded metal strip is used to combine with the through hole The design achieves ultra-miniaturization and delays the grating lobes through the miniaturized unit structure, so that no grating lobes appear in the operating frequency band, thereby reducing the dual-station RCS under oblique incidence and greatly improving oblique incidence stealth performance. At the same time, the ultra-miniaturized 2.5-dimensional absorption-permeability integrated frequency-selective wave absorber of this embodiment has a wave-transmitting window at the high frequency of the wave-absorbing band. In the wave-transmitting frequency band, this structure is equivalent to the incident wave. Transparent, electromagnetic waves can pass through the structure without reflection, so that the antenna system in the wave absorber can work normally and has good wave absorption and stealth performance outside the working frequency band.

In addition, the ultra-miniaturized 2.5-dimensional absorption-permeability integrated frequency-selective wave absorber in the embodiment of the present invention adopts a center-symmetric pattern design in each layer structure of the metamaterial unit, so that the frequency-selective wave absorber is suitable for The polarization direction of the incident electromagnetic wave is not sensitive.

Embodiment 2

This embodiment verifies and illustrates the performance of the ultra-miniaturized 2.5-dimensional absorption-permeability integrated frequency-selective wave absorber of the first embodiment through a simulation experiment.

1. Simulation conditions:

In the ultra-miniaturized 2.5-dimensional absorption-penetration integrated frequency selective absorber of this embodiment, the metamaterial units 1 are arranged in a continuous matrix of m*n, and both m and n are infinite. The transmission coefficient and reflection coefficient of the frequency selective absorber are simulated.

2. Simulation content and results:

Simulation 1, under the condition of vertical incidence, electromagnetic simulation is performed on the absorption-transmission integrated wave absorber with TE polarization and TM polarization respectively, and its reflection coefficient curve is obtained, as shown in Figure 8, which is provided by an embodiment of the present invention. Simulation curve of the reflection coefficient of the ultra-miniaturized 2.5-dimensional absorption-transmittance integrated frequency selective absorber under different polarizations. It can be seen from Figure 8 that the absorption band of the integrated absorber is 2.47-8.81GHz, the reflection coefficients in this frequency band are all less than -10dB, the relative bandwidth is 112.4%, and the transmission band is 7.52-8.40GHz. The transmission coefficients are all less than -1dB, and the insertion loss at the 8GHz frequency point is only -0.3dB, indicating that the electromagnetic waves in this frequency band can pass through the structure with low insertion loss, and the antenna system in the radome can operate normally in this frequency band. of sending and receiving work.

Simulation 2, under TE polarization and TM polarization, respectively, when the incident angle increases from 0° to 60°, simulate the absorption-permeability integrated wave absorber, and obtain the reflection coefficient curve, as shown in Figure 9, Figure 9 This is a simulation curve graph of the reflection coefficient corresponding to the incident angle of the ultra-miniaturized 2.5-dimensional absorption-permeability integrated frequency-selective wave absorber provided by the embodiment of the present invention when the incident angle increases from 0 degrees to 60 degrees under different polarizations. Among them, (a) in FIG. 6 is a reflection coefficient curve obtained under TE polarization, and (b) is a reflection coefficient curve obtained under TM polarization. It can be seen from the figure (a) that under the TE polarization, when the incident angle range is 0°<θ<30°, the absorber has a good wave absorption effect, and it still has the wave absorption effect at 45° incidence. From (b) ), it can be seen that: under TM polarization, when the incident angle range is 0°<θ<60°, the wave absorber basically maintains a good wave absorption effect. When the incident angle reaches 60°, there is still a frequency band that can better absorb waves. , only the bandwidth is narrowed, indicating that the absorber has good polarization stability.

The above simulation results show that the ultra-miniature 2.5-dimensional absorption-permeability integrated frequency selective absorber of this example can effectively absorb waves in a wide frequency band, and the relative bandwidth reaches 112.4%. Due to the ultra-miniature design of the structure, the grating lobe is suppressed. The appearance of , reduces the probability of being detected by dual-station RCS under oblique incidence; based on the center-symmetric design of the structure, the structure has polarization stability; the 2.5-dimensional structure design of the absorber also ensures the absorption stability under oblique incidence. sex.

It should be noted that, herein, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any relationship between these entities or operations. any such actual relationship or sequence exists. Moreover, the terms "comprising", "comprising" or any other variation are intended to encompass a non-exclusive inclusion such that an article or device comprising a list of elements includes not only those elements, but also other elements not expressly listed. Without further limitation, an element qualified by the phrase "comprising a..." does not preclude the presence of additional identical elements in the article or device that includes the element. Words like "connected" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The orientation or positional relationship indicated by "up", "bottom", "left", "right", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying The device or element referred to must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as limiting the invention.

The above content is a further detailed description of the present invention in combination with specific preferred embodiments, and it cannot be considered that the specific implementation of the present invention is limited to these descriptions. For those of ordinary skill in the technical field of the present invention, without departing from the concept of the present invention, some simple deductions or substitutions can be made, which should be regarded as belonging to the protection scope of the present invention.

Claims (7)

1. an ultra-miniaturized 2.5-dimensional absorption-penetration integrated frequency-selective wave absorber, characterized in that it comprises several metamaterial units (1) arranged in a continuous period, and the metamaterial unit (1) includes a top-to-bottom The top resonant layer (10), the first dielectric layer (20), the second dielectric layer (30), the third dielectric layer (40) and the bottom resonant layer (50) are stacked in sequence, and the top resonant layer (10) ) includes a first metal patch unit, a thin film resistor (101) and four second metal patch units (102), wherein, The first metal patch unit is square, the thin film resistor (101) has a cross-shaped structure, and the thin film resistor (101) divides the first metal patch unit into four triangular metal patches of equal size (103), the thin film resistor (101) and the four triangular metal patches (103) form a square structure; The second metal patch units (102) are connected to the triangular metal patches (103) in a one-to-one correspondence, and the four second metal patch units (102) form a centrally symmetric figure, and the center of symmetry is the the center of the thin film resistor (101); The second metal patch unit (102) comprises a first folded metal strip (1021), a first circular metal patch (1022), a second folded metal strip (1023) and a second metal strip (1023) connected in sequence A circular metal patch (1024), one end of the first folded metal strip (1021) is connected to the midpoint of the bottom edge of the triangular metal patch (103), and the first circular metal patch (1022) ) and the center of the second circular metal patch (1024) are both located on the extension line of the symmetry axis of the triangular metal patch (103); The bottom of the first dielectric layer (20) is provided with four third metal patch units (201), and the four third metal patch units (201) are respectively connected to the bottom surface of the first dielectric layer (20). The four sides are arranged in parallel, and each of the third metal patch units (201) is connected to the corresponding second metal patch unit through a metallized through hole (202) passing through the first dielectric layer (20). (102) Connect; The bottom resonance layer (50) is provided with a hollow structure, the hollow structure is square, and the middle of the four sides of the square is recessed toward the center of the square to form a U-shaped recessed groove; The first folded metal strip (1021) includes a first strip part (10211), a second strip part (10212), a third strip part (10213), a fourth strip part (10214) and a third strip part (10214) Five strip parts (10215), wherein the first end of the first strip part (10211) is connected to the midpoint of the bottom edge of the triangular metal patch (103), and the second end is connected to the second strip The first end of the part (10212) is connected vertically; the second end of the second strip part (10212) is connected vertically with the first end of the third strip part (10213), the third strip part The second end of (10213) is close to the triangular metal patch (103); the first end of the fourth strip portion (10214) is vertically connected to the second end of the third strip portion (10213), The second end of the fourth strip portion (10214) is close to the triangular metal patch (103); the first end of the fifth strip portion (10215) and the fourth strip portion (10214) The second end of the fifth strip portion (10215) is vertically connected, the second end of the fifth strip portion (10215) is far away from the triangular metal patch (103), and the second end of the fifth strip portion (10215) is connected to the second end of the fifth strip portion (10215). A circular metal patch (1022) is connected; The second folded metal strip (1023) includes a sixth strip part (10216), a seventh strip part (10217) and an eighth strip part (10218), wherein the sixth strip part ( 10216) is connected to the first circular metal patch (1022), and the first end of the sixth strip portion (10216) is opposite to the second end of the fifth strip portion (10215) Arrangement, the second end of the sixth strip portion (10216) is vertically connected with the first end of the seventh strip portion (10217); the second end of the seventh strip portion (10217) is away from the the triangular metal patch (103), the second end of the seventh strip part (10217) is vertically connected with the first end of the eighth strip part (10218); the eighth strip part (10218) ) is close to the triangular metal patch (103), and the second end of the eighth strip portion (10218) is connected to the second circular metal patch (1024); The third metal patch unit (201) includes a first rectangular metal patch (2011) and a second rectangular metal patch (2012) arranged in parallel, wherein the length of the first rectangular metal patch (2011) less than the length of the second rectangular metal patch (2012); the first rectangular metal patch (2011) is connected to the first circular metal patch (1022) through a first metallized through hole (2021) ; the second rectangular metal patch (2012) is connected to the second circular metal patch (1024) through a second metallized through hole (2022); the first rectangular metal patch (2011) is connected to the The connection point of the first metallization through hole (2021) is located at the center of the first rectangular metal patch (2011); the second rectangular metal patch (2012) is connected to the second metallization through hole ( 2022) at the center of the second rectangular metal patch (2012). 2 . The ultra-miniaturized 2.5-dimensional absorption-permeability integrated frequency selective wave absorber according to claim 1 , wherein the angle between the side edge and the bottom edge of the U-shaped recessed groove is 90°. 3 . 3. a kind of ultra-miniaturized 2.5-dimensional absorption-penetration integrated frequency selective wave absorber according to claim 1, is characterized in that, described thin film resistor (101) is graphene resistance film, and square resistance value range is 340Ohm/sq-400Ohm/sq; The value range of the side length D ₁ of the square structure formed by the thin film resistor (101) and the four triangular metal patches (103) is 0.052λ _t <D ₁ <0.054λ _t . The lengths of the arms are equal, the value range of the arm length D ₂ is 0.022λ _t <D ₂ <0.023λ _t , and the value range of the arm width D ₃ of the cross-shaped structure is 0.0143λ _t <D ₃ <0.0146λ _t , where λ _t is the wavelength corresponding to the transmission frequency. 4. The ultra-miniaturized 2.5-dimensional absorption-permeability integrated frequency selective wave absorber according to claim ₁ , wherein the value of the bandwidth W1 of the first folded metal strip (1021) The range is 0.0038λ _t <D ₁ <0.004λ _t , the value range of the length l ₁ of the first strip portion (10211) is 0.0103λ _t <l ₁ <0.0106λ _t , the second strip portion The value range of the length l ₂ of (10212) is 0.068λ _t <l ₂ <0.070λ _t , and the value range of the length l ₃ of the third strip portion (10213) is 0.0195λ _t <l ₃ <0.0199 λ _t , the value range of the length l ₄ of the fourth strip portion (10214) is 0.0142λ _t <l ₄ <0.0147λ _t , the value of the length l ₅ of the fifth strip portion (10215) The range is 0.0205λ _t <l ₅ <0.0215λ _t ; The value range of the bandwidth W ₂ of the second folded metal strip (1023) is 0.0052λ _t <W ₂ <0.0054λ _t , and the value range of the length l ₆ of the sixth strip portion (10216) is 0.042λ _t <l ₆ <0.046λ _t , the value range of the length l ₇ of the seventh strip portion (10217) is 0.0202λ _t <l ₇ <0.0211λ _t , the eighth strip portion ( 10218) the value range of the length l ₈ is 0.042λ _t <l ₆ <0.046λ _t ; The size of the first circular metal patch (1022) and the second circular metal patch (1024) are equal, and the value range of the radius R ₁ is 0.0071λ _t <R ₁ <0.00715λ _t , wherein , λ _t is the wavelength corresponding to the transmission frequency. 5. The ultra-miniaturized 2.5-dimensional absorption-permeability integrated frequency selective wave absorber according to claim 1, characterized in that the first rectangular metal patch (2011) and the second rectangular metal patch The width of the sheet (2012) is equal, the value range of its width W ₃ is 0.014λ _t <W ₃ <0.015λ _t , and the value range of the length m ₁ of the first rectangular metal patch (2011) is 0.052λ _t <m ₁ <0.053λ _t , the value range of the length m ₂ of the second rectangular metal patch (2012) is 0.1037λ _t <m ₂ <0.1046λ _t , and the length of the metallized through hole (202) is The value range of the radius R ₂ is 0.0039λ _t <R ₂ <0.0040λ _t , where λ _t is the wavelength corresponding to the transmission frequency. 6. The ultra-miniaturized 2.5-dimensional absorption-permeability integrated frequency selective wave absorber according to claim 1, characterized in that the first dielectric layer (20) and the third dielectric layer (40) The materials are F4B, and the second dielectric layer (30) is an air layer; The value range of the thickness h ₁ of the first dielectric layer (20) is 0.0523λ _t <h ₁ <0.0529λ _t ; The value range of the thickness h ₂ of the second dielectric layer (30) is 0.155λ _t <h ₂ <0.159λ _t ; The value range of the thickness h ₃ of the third dielectric layer (40) is 0.026λ _t <h ₃ <0.0264λ _t , where λ _t is the wavelength corresponding to the transmission frequency. 7. The ultra-miniaturized 2.5-dimensional absorption-penetration integrated frequency selective wave absorber according to claim 1, characterized in that, the value range of the distance b ₁ between the two relative U-shaped recessed grooves is 0.034λ _t <b ₁ <0.035λ _t , the value range of the groove width b ₂ of the U-shaped recessed groove is 0.0155λ _t <b ₂ <0.016λ _t , the groove depth of the U-shaped recessed groove The value range of b ₃ is 0.044λ _t <b ₃ <0.045λ _t , and the value range of b ₄ between the side wall of the U-shaped recessed groove and the vertex of the square hollow structure is 0.064λ _t <b ₄ <0.0648λ _t ; The value range of the hollow width W ₄ of the hollow structure is 0.0052λ _t <W ₄ <0.0054λ _t , where λ _t is the wavelength corresponding to the transmission frequency.

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