Low RCS microstrip antenna based on coding metasurface

Abstract

The invention belongs to the technical field of microstrip antennas, and particularly relates to a low RCS microstrip antenna based on a coding metasurface, which solves the technical problem of how to realize RCS reduction of the antenna and ensure radiation performance of the antenna, and comprises a dielectric substrate, the upper surface of the dielectric substrate is printed with the coding metasurface, and the lower surface of the dielectric substrate is printed with a metal ground plane. The coding metasurface is formed by a rectangular array formed by randomly arranging a first coding unit and a second coding unit, and the reflection phase difference of the first coding unit and the second coding unit is 180 degrees; a microstrip patch antenna is printed in the center of the upper surface of the dielectric substrate, a coaxial line feed port is arranged on the lower surface of the dielectric substrate in an embedded mode, and an inner conductor of the coaxial line feed port is connected with the microstrip patch antenna. According to the invention, the bandwidth of the unit reflection phase is expanded; the electromagnetic waves of the coding metasurface are subjected to diffuse reflection, so that RCS reduction is realized; a microstrip patch antenna is printed in the center of the coding metasurface, so that the radiation performance of the antenna is ensured while the RCS is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of microstrip antennas, and in particular to a low RCS microstrip antenna based on a coded metasurface. Background Art

[0002] Antennas are devices that transmit and receive signals in wireless communications and are an important part of wireless communication systems. With the rapid development of wireless communication technology, the performance requirements for antennas are gradually increasing. Radar cross section (RCS) is the most basic parameter in stealth technology. It refers to the physical quantity of the echo intensity of a target under electromagnetic wave irradiation. The key to improving stealth capabilities lies in how to reduce RCS.

[0003] Microstrip antennas are small in size, light in weight, and have a thin planar structure. They can achieve low-profile designs and are suitable for scenarios with limited space. They can be combined with printed circuit board (PCB) technology to facilitate integration in various electronic devices. They are suitable for conformal conformity on the surfaces of carriers such as missiles and satellites, and are widely used in beam control, frequency scanning, and phase control. As a special scatterer, the key point of an antenna is to ensure that the RCS of the antenna is reduced without affecting its radiation performance, and to achieve good RCS reduction. Therefore, achieving RCS reduction of the antenna while ensuring its radiation performance is a problem that must be solved. Summary of the invention

[0004] In order to solve the technical problem of how to achieve RCS reduction of an antenna while ensuring its radiation performance, the present invention provides a low RCS microstrip antenna based on a coded metasurface.

[0005] The present invention provides a low RCS microstrip antenna based on a coding metasurface, comprising a dielectric substrate, wherein the upper surface of the dielectric substrate is printed with a coding metasurface and the lower surface is printed with a metal ground plane, the coding metasurface is formed by a rectangular array in which first coding units and second coding units are randomly arranged, and the reflection phase difference between the first coding units and the second coding units is 180°; a microstrip patch antenna is printed at the center of the upper surface of the dielectric substrate, the microstrip patch antenna and the coding metasurface are located on the same plane, a coaxial line feeding port corresponding to the position of the microstrip patch antenna is embedded on the lower surface of the dielectric substrate, and an inner conductor of the coaxial line feeding port is connected to the microstrip patch antenna.

[0006] Coding metasurface is a new type of two-dimensional artificial electromagnetic material. By designing its unit structure, the metasurface can regulate the wavefront phase, amplitude, polarization and other parameters of electromagnetic waves, thereby realizing many electromagnetic behaviors that do not exist in nature. Due to its flexibility in controlling scattered electromagnetic waves, metasurfaces are widely used to reduce the RCS of antennas. Combining the coding metasurface with the digital bits "0" and "1" introduces the new concept of digital metamaterials. The coding bit consists of 0° and 180° phase responses, which are considered to be "0" and "1" in digital state. The "0" unit and the "1" unit are spatially arranged into a rectangular array, and by changing the coding sequence of the coding metasurface, a digital coding metasurface with a certain regulation function on electromagnetic waves is formed. Among them, the "0" unit is the first coding unit described in the present invention, and the "1" unit is the second coding unit in the present invention.

[0007] The coding metasurface in the present invention is specifically a 1-bit coding metasurface, that is, the first coding unit and the second coding unit are arranged by 1-bit coding through a simulated annealing algorithm. The first coding unit and the second coding unit both adopt a structure of a combination of square rings and cross patches, which expands the bandwidth of the unit reflection phase.

[0008] Preferably, the microstrip patch antenna is a rectangular structure with its long side e 7.95mm, short side d is 7.5 mm, and the distance from the feeding point on the microstrip patch antenna to the upper edge of the microstrip patch antenna f It is 1.9mm.

[0009] Preferably, the microstrip patch antenna adopts a coaxial feeding method.

[0010] Preferably, the dielectric constant of the dielectric substrate is 2.55 and the thickness is 2 mm.

[0011] Preferably, the first encoding unit and the second encoding unit both include a square ring patch and a cross patch located at the center of the square ring patch. The square ring patches of the first encoding unit and the second encoding unit are equal in size, the outer side length a of the square ring patch is 16.7 mm, and the inner side length of the square ring patch is b It is 15.5mm.

[0012] Preferably, the cross patch width of the first coding unit is w 1mm, the length of the cross patch of the first coding unit c 8.8mm; the width of the cross patch of the second coding unit w The cross patch length of the second coding unit is 1mm. c It is 9.6mm.

[0013] Compared with the prior art, the technical solution provided by the present invention has the following technical effects: In the low RCS microstrip antenna described in the present invention, the first coding unit and the second coding unit both adopt a structure of a combination of a square ring and a cross patch, thereby expanding the bandwidth of the unit reflection phase; the two coding units are arranged in a 1-bit random coding manner through a simulated annealing algorithm, and a reflection phase difference of 180° is formed between the first coding unit and the second coding unit by optimizing the size of the unit, thereby achieving a 1-bit phase response; the optimal coding sequence is obtained through a simulated annealing algorithm, so that electromagnetic waves are diffusely reflected, thereby achieving RCS reduction; and a microstrip patch antenna is printed at the center of the coding metasurface, thereby achieving RCS reduction while ensuring the radiation performance of the antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 A schematic diagram of a three-dimensional structure of a low RCS microstrip antenna based on a coding metasurface according to an embodiment of the present invention; Figure 2 A top view of the upper surface of the dielectric substrate in an embodiment of the present invention; Figure 3 A schematic diagram of the structure of the first encoding unit or the second encoding unit in an embodiment of the present invention; Figure 4 is a schematic structural diagram of a microstrip patch antenna according to an embodiment of the present invention; Figure 5 is a reflection phase curve diagram of the first encoding unit and the second encoding unit in a certain embodiment of the present invention when the incident electromagnetic wave is vertically incident; Figure 6 It is a simulation curve diagram of a low RCS microstrip antenna based on a coding metasurface in a radiation state described in an embodiment of the present invention; Figure 7 A single-station RCS and RCS reduction curve simulated by a low RCS microstrip antenna based on a coded metasurface and a reference antenna described in an embodiment of the present invention; Figure 8 A gain curve diagram of a low RCS microstrip antenna based on a coding metasurface described in an embodiment of the present invention; Fig. 9The radiation pattern of a low RCS microstrip antenna based on a coded metasurface at 9.8 GHz described in an embodiment of the present invention; Fig.10 This is the radiation pattern of a low RCS microstrip antenna based on a coded metasurface at 10 GHz described in an embodiment of the present invention.

[0017] In the figure: 1. dielectric substrate; 2. coding metasurface; 3. metal ground plane; 11. microstrip patch antenna; 12. coaxial line feed port; 13. first coding unit; 14. second coding unit; 111. square ring patch; 112. cross patch. DETAILED DESCRIPTION

[0018] In order to more clearly understand the above-mentioned objectives, features and advantages of the present invention, the scheme of the present invention will be further described below. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0019] In the description, it should be noted that the terms "first" and "second" are only used for descriptive purposes and should not be understood as indicating or implying relative importance. It should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internal communication between two components. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0020] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present invention, rather than all of the embodiments.

[0021] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0022] In one embodiment, Figure 1As shown, a low RCS microstrip antenna based on a coding metasurface is disclosed, including a dielectric substrate 1, a coding metasurface 2 is printed on the upper surface of the dielectric substrate 1 and a metal ground plane 3 is printed on the lower surface, the coding metasurface 2 is formed by a rectangular array of first coding units 13 and second coding units 14 arranged randomly, and the reflection phase difference between the first coding unit 13 and the second coding unit 14 is 180°; a microstrip patch antenna 11 is printed in the center of the upper surface of the dielectric substrate 1, the microstrip patch antenna 11 and the coding metasurface 2 are located on the same plane, and a coaxial line feeding port 12 corresponding to the position of the microstrip patch antenna 11 is embedded on the lower surface of the dielectric substrate 1, and the inner conductor of the coaxial line feeding port 12 is connected to the microstrip patch antenna 11.

[0023] The coding metasurface 2 is a new type of two-dimensional artificial electromagnetic material. By designing its unit structure, the metasurface can regulate the wavefront phase, amplitude, polarization and other parameters of electromagnetic waves, thereby realizing many electromagnetic behaviors that do not exist in nature. Due to its flexibility in controlling scattered electromagnetic waves, the metasurface is widely used to reduce the RCS of antennas. Combining the coding metasurface 2 with the digital bits "0" and "1" introduces the new concept of digital metamaterials. The coding bit consists of 0° and 180° phase responses, which are considered to be "0" and "1" in digital state. The "0" unit and the "1" unit are spatially arranged into a rectangular array, and by changing the coding sequence of the coding metasurface 2, a digital coding metasurface 2 with a certain regulating function for electromagnetic waves is formed. Among them, the "0" unit is the first coding unit 13 described in the present invention, and the "1" unit is the second coding unit 14 in the present invention.

[0024] The coding metasurface 2 in the present invention is specifically a 1-bit coding metasurface 2, that is, the first coding unit 13 and the second coding unit 14 are arranged by 1-bit coding through a simulated annealing algorithm. The first coding unit 13 and the second coding unit 14 both adopt a structure of a combination of a square ring and a cross patch 112, which expands the bandwidth of the unit reflection phase.

[0025] Based on the above embodiments, in a preferred embodiment, the microstrip patch antenna 11 is a rectangular structure with a long side e of 7.95 mm and a short side d of 7.5 mm, and a distance f from the feeding point on the microstrip patch antenna 11 to the upper edge of the microstrip patch antenna 11 is 1.9 mm.

[0026] On the basis of the above embodiments, in a preferred embodiment, the microstrip patch antenna 11 adopts a coaxial feeding mode.

[0027] On the basis of the above embodiments, in a preferred embodiment, the dielectric constant of the dielectric substrate 1 is 2.55 and the thickness is 2 mm, and in a specific embodiment, the size of the dielectric substrate 1 is 180×180 mm.

[0028] On the basis of the above embodiments, in a preferred embodiment, the first encoding unit 13 and the second encoding unit 14 both include a square ring patch 111 and a cross patch 112 located at the center of the square ring patch 111. The square ring patches 111 of the first encoding unit 13 and the second encoding unit 14 are equal in size, the outer side length a of the square ring patch 111 is 16.7 mm, and the inner side length b of the square ring patch 111 is 15.5 mm.

[0029] On the basis of the above embodiments, in a preferred embodiment, the width w of the cross patch 112 of the first encoding unit 13 is 1 mm, and the length c of the cross patch 112 of the first encoding unit 13 is 8.8 mm; the width w of the cross patch 112 of the second encoding unit 14 is 1 mm, and the length c of the cross patch 112 of the second encoding unit 14 is 9.6 mm.

[0030] The simulation results of a low RCS microstrip antenna based on a coding metasurface 2 described in the present invention are as follows.

[0031] Among them, except that the reference antenna is not loaded with the coding metasurface 2, the rest of the structure is consistent with the low RCS microstrip antenna structure of the present application.

[0032] like Figure 5 As shown, it is the simulation result of the first coding unit 13 and the second coding unit 14 under the condition of vertical incidence of the incident electromagnetic wave. It can be seen that the first coding unit 13 and the second coding unit 14 in this embodiment have a phase difference of 180° at 10 GHz, which constitutes the design requirement of the 1-bit coding metasurface 2.

[0033] like Figure 6 The figure shows the simulation result of the reflection coefficient of the low RCS microstrip antenna in the radiation state of the present invention. It can be seen from the figure that the antenna resonates at 10 GHz, and the -10 dB impedance bandwidth is 9.54-10.6 GHz.

[0034] like Figure 7 The figure shows the single-station RCS and RCS reduction simulation results of the low RCS microstrip antenna and the reference antenna of the present invention. It can be seen from the figure that the 10dBRCS reduction bandwidth of the antenna is 9.83-10.17GHz.

[0035] like Figure 8 The figure shows the gain simulation result of the low RCS microstrip antenna of the present invention. It can be seen from the figure that the maximum gain of the antenna in the entire working frequency band is 10.68dBi, and the frequency point corresponding to the maximum gain is 10GHz.

[0036] like Fig. 9 and 10The figure shows the radiation pattern simulation results of the low RCS microstrip antenna at 9.8GHz and 10GHz. It can be seen from the figure that the radiation pattern of the antenna on the E plane and H plane is good.

[0037] The above is only a specific implementation of the present invention, which enables those skilled in the art to understand or implement the present invention. Although detailed descriptions are given with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments, and they should all be covered by the protection scope of the claims.

Claims

1. A low RCS microstrip antenna based on a coded metasurface, characterized in that: The invention comprises a dielectric substrate (1), wherein the upper surface of the dielectric substrate (1) is printed with a coding metasurface (2) and the lower surface is printed with a metal ground plane (3), the coding metasurface (2) being formed by a first coding unit (13) and a second coding unit (14) being randomly arranged in a rectangular array, and the reflection phase difference between the first coding unit (13) and the second coding unit (14) is 180°; a microstrip patch antenna (11) is printed in the center of the upper surface of the dielectric substrate (1), the microstrip patch antenna (11) and the coding metasurface (2) are located on the same plane, and a coaxial line feed port (12) corresponding to the position of the microstrip patch antenna (11) is embedded in the lower surface of the dielectric substrate (1), and the inner conductor of the coaxial line feed port (12) is connected to the microstrip patch antenna (11).

2. A low RCS microstrip antenna based on a coded metasurface according to claim 1, characterized in that: The microstrip patch antenna (11) is a rectangular structure, with a long side e of 7.95 mm, a short side d of 7.5 mm, and a distance f from a feeding point on the microstrip patch antenna (11) to an upper edge of the microstrip patch antenna (11) of 1.9 mm.

3. A low RCS microstrip antenna based on a coded metasurface according to claim 2, characterized in that: The microstrip patch antenna (11) adopts a coaxial feeding method.

4. A low RCS microstrip antenna based on a coded metasurface according to any one of claims 1 to 3, characterized in that: The dielectric constant of the dielectric substrate (1) is 2.55 and the thickness is 2 mm.

5. A low RCS microstrip antenna based on a coded metasurface according to claim 4, characterized in that: The first encoding unit (13) and the second encoding unit (14) both comprise a square ring patch (111) and a cross patch (112) located at the center of the square ring patch (111); the square ring patches (111) of the first encoding unit (13) and the second encoding unit (14) are of equal size; the outer side length a of the square ring patch (111) is 16.7 mm, and the inner side length b of the square ring patch (111) is 15.5 mm.

6. A low RCS microstrip antenna based on a coded metasurface according to claim 5, characterized in that: The width w of the cross patch (112) of the first encoding unit (13) is 1 mm, and the length c of the cross patch (112) of the first encoding unit (13) is 8.8 mm; the width w of the cross patch (112) of the second encoding unit (14) is 1 mm, and the length c of the cross patch (112) of the second encoding unit (14) is 9.6 mm.

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