A liquid-based low-scattering reconfigurable slot antenna

Abstract

The embodiment of the present invention discloses a liquid-based low-scattering reconfigurable slot antenna, which relates to the field of radar detection technology. Specifically, the front of the dielectric substrate is a slot antenna array, the back of the dielectric substrate is a feeding network, and the surface of the slot antenna array is periodically arranged with block-shaped water-based absorbers. The upper container is consistent with the water-based absorbers arranged on the upper surface of the slot antenna array, and the two constitute a closed structure; the water layer is filled in the closed structure, and the back of the antenna is a metal backplane. The present invention combines the slot array antenna with the water-based absorber, utilizes the high loss and fluidity of water, constructs a liquid-based low-scattering reconfigurable antenna, and achieves good impedance matching. Under the premise of ensuring the radiation performance of the slot array antenna, the antenna achieves low scattering and RCS reconfigurable performance. The present invention takes the dispersion characteristics of water as the research basis, and obtains the low scattering and RCS reconfigurable performance of the antenna by pumping in and out water.

Description

Technical Field

[0001] The invention relates to the field of radar detection technology, and in particular to a liquid-based low-scattering reconfigurable slot antenna. Background Art

[0002] With the development of detection technology and stealth technology, the reduction of the radar cross section (RCS) of platform targets has great military significance. The RCS reduction of the antenna system on the platform has become a bottleneck restricting the stealth of the platform. Compared with the platform itself, the scattering characteristics of the platform itself can be significantly improved by changing its own shape and mounting absorbing materials on the surface. As a special scatterer, the antenna must meet its radiation performance requirements while reducing the RCS.

[0003] In recent years, artificial metamaterials have been used to reduce the RCS of antennas. For example, a bandpass frequency selective absorber is used as a radome, which can radiate electromagnetic waves within the antenna band and absorb electromagnetic waves outside the band, thereby reducing the antenna RCS. However, this method can easily cause the radome to heat up, thus affecting the working performance of the antenna. By utilizing the zero reflection phase characteristics of artificial magnetic conductors (AMCs), by properly arranging AMCs around the antenna, the phase difference of the reflected waves is 180 degrees, thereby achieving the purpose of cancellation.

[0004] The drawback of this method is that it can only reduce the RCS of a single station in a certain direction, which will increase the RCS in other directions. Although the RCS reduction of most antennas can achieve stealth for enemy detection, it is also difficult for self-detection. Summary of the invention

[0005] The embodiment of the present invention provides a water-based low-scattering reconfigurable slot antenna, wherein the middle water layer of the unit structure is interconnected everywhere, thereby forming a high-loss resonant cavity, thereby achieving liquid-based wide-band wave absorbing performance.

[0006] To achieve the above object, the embodiments of the present invention adopt the following technical solutions:

[0007] The invention comprises, in descending order of hierarchy, an upper container (1), a slot antenna array (3), a dielectric substrate (4) and a metal back plate (6), wherein the slot antenna array (3) is laid on the front of the dielectric substrate (4), and a feeding network (5) is laid on the back of the dielectric substrate (4); a slot structure is opened on the back of the upper container (1), and the slot structures are arranged in a matrix; the upper container (1) and the slot antenna array (3) are installed and bonded, and each slot structure forms a cavity with the bonded slot antenna array (3); a guide hole is opened between a slot structure and at least another adjacent slot structure, so that liquid can flow between the slot structure and at least another adjacent slot structure; when the liquid fills all the cavities, block water is formed in each cavity to obtain an intermediate block water layer (2), and all the block water in the intermediate block water layer (2) are arranged according to the matrix. The liquid material used in the middle water layer (2) is pure water whose electromagnetic parameters satisfy the Debye model.

[0008] The length and width of the cavity l w Both are 5mm, thickness h w The slot antenna array (3) has a slot length I of 33.2 mm, a width w of 3 mm, an array element spacing d of 30 mm, and an operating frequency band of close to 3.1 GHz.

[0009] The dielectric substrate (4) is made of FR4 dielectric material with a relative dielectric constant of 4.3 and a loss tangent of 0.025. The length L of the dielectric substrate (4) is 220 mm, the width W is 110 mm, and the thickness is 1 mm. The upper container (1) is made of acrylic material with a dielectric constant of 2.67 and a loss tangent of 0.01.

[0010] The water-based low-scattering reconfigurable slot antenna provided by the embodiment of the present invention has a slot antenna array on the front of the dielectric substrate, a feed network on the back of the dielectric substrate, block-shaped water-based absorbers arranged periodically on the surface of the slot antenna array, and the upper container is consistent with the water-based absorbers arranged on the upper surface of the slot antenna array, and the two form a closed structure; the water layer is filled in the closed structure, and the antenna is behind a metal backplane. The present invention combines the slot array antenna with the water-based absorber, utilizes the high loss and fluidity of water, constructs a liquid-based low-scattering reconfigurable antenna, and achieves good impedance matching, and achieves low scattering and RCS reconfigurable performance of the antenna while ensuring the radiation performance of the slot array antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments provided by the embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0012] Figure 1 A schematic diagram of the back-facing layering of a liquid-based low-scattering RCS reconfigurable antenna provided in an embodiment of the present invention;

[0013] Figure 2 A structural diagram of a feed network provided in an embodiment of the present invention;

[0014] Figure 3 A water-based absorber unit structure provided by an embodiment of the present invention;

[0015] Figure 4 A schematic diagram of the forward layering of a liquid-based low-scattering RCS reconfigurable antenna provided in an embodiment of the present invention;

[0016] Figure 5 A single-station RCS diagram of a liquid-based low-scattering antenna provided in an embodiment of the present invention;

[0017] Figure 6 A bistatic RCS diagram of a liquid-based low-scattering antenna provided by an embodiment of the present invention;

[0018] Figure 7 The E-plane radiation pattern of the liquid-based low-scattering antenna provided in an embodiment of the present invention;

[0019] Figure 8 H-plane radiation pattern of a liquid-based low-scattering antenna provided in an embodiment of the present invention.

[0020] Fig. 9 The Debye model curve of water provided by the embodiment of the present invention.

[0021] Fig.10 This is an S parameter curve of the antenna provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments of the present invention will be described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be interpreted as limiting the present invention. It can be understood by those skilled in the art that, unless specifically stated, the singular forms "one", "one", "said" and "the" used herein may also include plural forms. It should be further understood that the term "including" used in the specification of the present invention refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or their groups. It should be understood that when we say that an element is "connected" or "coupled" to another element, it can be directly connected or coupled to other elements, or there may also be intermediate elements. In addition, the "connection" or "coupling" used here may include wireless connection or coupling. The term "and / or" used herein includes any unit and all combinations of one or more associated listed items. It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as generally understood by those of ordinary skill in the art to which the present invention belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.

[0023] Radar cross-section (RCS) is a physical quantity that defines the scattering characteristics of a target, which is the equivalent scattering area presented by the target when it is illuminated by an incident radar wave. The more traditional RCS reduction includes four methods: shaping technology, coating with absorbing materials, passive cancellation, and active cancellation. Among them, shaping technology often competes with the RCS characteristics of the platform itself. Since the antenna needs to ensure its own radiation characteristics, it is difficult to change its shape. The problem with coating with absorbing materials is that after the absorbing material absorbs energy, its own temperature rises. If the scattering cannot keep up, the temperature change will change the electrical performance of the device. Due to technical difficulties and costs, passive cancellation and active cancellation are not as widely used as the previous two.

[0024] The existing defect is that it can only achieve a single-station RCS reduction in a certain direction, which will lead to an increase in RCS in other directions. Although the RCS reduction of most antennas achieves stealth for enemy detection, it is also difficult for one's own detection. The present invention aims to provide a low-scattering, RCS-reconfigurable slot antenna to overcome the problems existing in the above-mentioned prior art, and relates to a water-based low-scattering reconfigurable slot antenna, specifically, a low-scattering reconfigurable slot antenna composed of a high-loss medium that can be used for stealth detection.

[0025] The specific design idea is to use the most extensive resource on earth - water, taking advantage of its high loss, fluidity and its own heat dissipation performance, to provide a low-scattering reconfigurable slot antenna. Compared with traditional structures, it saves costs, is simple to prepare, and achieves low-scattering and RCS reconfigurable performance.

[0026] The embodiment of the present invention provides a liquid-based low-scattering reconfigurable slot antenna, such as Figure 1 , 4 As shown, the structure includes, in descending order of levels: an upper container (1), a slot antenna array (3), a dielectric substrate (4) and a metal backplane (6), wherein the slot antenna array (3) is laid on the front of the dielectric substrate (4), and a feed network (5) is laid on the back of the dielectric substrate (4). The specific layout structure of the feed network (5) can be as follows: Figure 2 As shown, the feed network (5) is composed of H-shaped wires and wires connected to the H-shaped structure. Behind the feed network (5) is the metal back plate (6) of the antenna.

[0027] like Figure 1 As shown, a slot-shaped structure is opened at the back of the upper container (1), and the slot-shaped structures are arranged in a matrix. The upper container (1) is installed and attached to the slot antenna array (3), and each slot-shaped structure forms a cavity with the attached slot antenna array (3). A guide hole is opened between a slot-shaped structure and at least another adjacent slot-shaped structure, so that liquid can flow between the slot-shaped structure and at least another adjacent slot-shaped structure. When the liquid fills all the cavities, block water is formed in each cavity to obtain an intermediate block water layer (2), and all the block water in the intermediate block water layer (2) is arranged according to the matrix.

[0028] In the preferred embodiment of this embodiment, Figure 3 As shown, the length and width lw of the cavity are both 5 mm, the thickness hw is 5 mm, and the spacing between adjacent cavities in the matrix is ​​4 mm. The slot length I of the slot antenna array (3) is 33.2 mm, the width w is 3 mm, the array element spacing d is 30 mm, and the operating frequency band of the slot antenna array (3) is close to 3.1 GHz.

[0029] In the preferred solution of this embodiment, the dielectric substrate (4) is made of FR4 dielectric material with a relative dielectric constant of 4.3 and a loss tangent of 0.025. The length L of the dielectric substrate (4) is 220 mm, the width W is 110 mm, and the thickness is 1 mm. The upper container (1) is made of acrylic material with a dielectric constant of 2.67 and a loss tangent of 0.01.

[0030] In the preferred embodiment of this embodiment, Fig. 9 The liquid material used in the intermediate water layer (2) is pure water whose electromagnetic parameters satisfy the Debye model. The liquid material used in this embodiment is not limited thereto, and other liquid materials such as alcohol and acetone may also be used. The intermediate water layer (2) is filled between the upper containers (1); due to the unique electromagnetic properties of water, when the water is filled and drained, the low-scattering reconfigurable slot antenna presents a unique electromagnetic performance of "unchanged radiation performance and reconfigurable RCS", which is more in line with the "intelligent" choice in the stealth system.

[0031] The present invention designs a low-scattering, RCS-reconfigurable slot antenna, wherein the unit structure comprises an upper container (1), an intermediate water layer (2), a dielectric substrate (4), a slot antenna array (3) on the front of the dielectric substrate, a feeding network (5) on the back of the dielectric substrate, and a metal back plate (6), thereby achieving consistency between the upper container (1) and the arranged water-accumulated absorbers, thereby forming a closed structure, and the intermediate block-shaped water layer (2) is filled in the closed structure.

[0032] This embodiment designs a low-scattering reconfigurable slot antenna based on liquid. The slot antenna array is on the front of the dielectric substrate, the feeding network is on the back of the dielectric substrate, and block-shaped water-based absorbers are periodically arranged on the surface of the slot antenna array. The upper container is consistent with the water-based absorbers arranged on the upper surface of the slot antenna array, and the two constitute a closed structure; the water layer is filled in the closed structure, and the metal backplane is behind the antenna. The present invention combines the slot array antenna with the water-based absorber, utilizes the high loss and fluidity of water, constructs a low-scattering reconfigurable antenna based on liquid, and achieves good impedance matching. Under the premise of ensuring the radiation performance of the slot array antenna, the antenna achieves low scattering and RCS reconfigurable performance. The present invention takes the dispersion characteristics of water as the research basis, and obtains the low scattering and RCS reconfigurable performance of the antenna by pumping in and out water.

[0033] In this embodiment, the radiation pattern of the antenna is referenced Figure 7-8 , the single-station RCS of the antenna is Figure 5 As shown in Figure 2, a broadband RCS reduction from 4 GHz to 18 GHz is achieved, and the bistatic RCS of the antenna is as follows: Figure 6As shown in the figure, the overall structural design achieves low scattering and RCS reconfigurable performance of the antenna, while meeting the requirements of good impedance matching and antenna radiation performance.

[0034] comprehensive Figure 5-10 It can be seen from the experimental results that in this embodiment, by periodically arranging the liquid-based broadband absorber in the horizontal and vertical directions and utilizing the fluidity of water, it is ensured that the middle block water layer (2) of the unit structure is connected everywhere to form a high-loss resonant cavity, thereby achieving liquid-based broadband absorber performance. Among them, the upper container (1) is provided with four slots that are consistent with the slot positions of the slot antenna array (3) to ensure its radiation performance.

[0035] The main advantages in practical applications are: through the high loss performance of water, a broadband absorber is formed, and combined with the slot antenna, the out-of-band RCS reduction of the antenna single station and dual stations is achieved. Through the flow performance of water and the process of pumping water in and out, the reconfigurable performance of the antenna RCS is achieved. In addition, the frequency band performance can be met, and the out-of-band broadband RCS reduction from 4GHz to 18GHz can be achieved, and good radiation performance in the band is guaranteed.

[0036] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. The above is only a specific implementation method of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or replacements that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A liquid-based low-scattering reconfigurable slot antenna, characterized in that: The device comprises, in descending order of levels, an upper container (1), a slot antenna array (3), a dielectric substrate (4) and a metal back plate (6), wherein the slot antenna array (3) is laid on the front surface of the dielectric substrate (4), and a feeding network (5) is laid on the back surface of the dielectric substrate (4); A slot-shaped structure is provided on the back of the upper container (1), and the slot-shaped structures are arranged in a matrix. The upper container (1) and the slot antenna array (3) are installed and attached to each other, and each slot-shaped structure and the attached slot antenna array (3) form a cavity. A flow guide hole is provided between a groove structure and at least another adjacent groove structure, so that liquid can flow between the groove structure and at least another adjacent groove structure. When the liquid fills all the cavities, block water is formed in each cavity to obtain an intermediate block water layer (2), and all the block water in the intermediate block water layer (2) is arranged according to the matrix. The feed network (5) is composed of H-shaped wires and wires connected to the H-shaped structure; behind the feed network (5) is a metal back plate (6) of the antenna; The liquid material used in the middle water layer (2) is alcohol or acetone whose electromagnetic parameters satisfy the Debye model.

2. The liquid-based low-scattering reconfigurable slot antenna according to claim 1, characterized in that: The length and width of the cavity l w Both are 5mm, thickness h w The spacing between adjacent cavities in the matrix is ​​4 mm.

3. The liquid-based low-scattering reconfigurable slot antenna according to claim 1, characterized in that: The slot antenna array (3) has a slot length I of 33.2 mm, a width w of 3 mm, an array element spacing d of 30 mm, and an operating frequency band of the slot antenna array (3) close to 3.1 GHz.

4. The liquid-based low-scattering reconfigurable slot antenna according to claim 1, characterized in that: The dielectric substrate (4) adopts FR4 dielectric material with a relative dielectric constant of 4.3 and a loss tangent of 0.

025.

5. The liquid-based low-scattering reconfigurable slot antenna according to claim 4, characterized in that: The dielectric substrate (4) has a length L of 220 mm, a width W of 110 mm and a thickness of 1 mm.

6. The liquid-based low-scattering reconfigurable slot antenna according to claim 1, characterized in that: The upper container (1) is made of acrylic material with a dielectric constant of 2.67 and a loss tangent of 0.01.

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