RCS in-band reduction circular polarization metasurface antenna based on C-band satellite communication

Abstract

The invention belongs to the technical field of electromagnetic metasurfaces, and particularly discloses an RCS (radar cross section) in-band reduction circularly polarized metasurface antenna based on C-band satellite communication, which comprises a first metasurface layer, a first dielectric layer, a second metasurface layer, a second dielectric layer, a slotted metal plate, a third dielectric layer and a feed antenna layer which are stacked from top to bottom, wherein the first metasurface layer is formed by arranging four groups of unit structures in a mirror image mode in the two-dimensional direction, and two kinds of square chamfered patches in each group of unit structures are arranged in a non-contact mode; the second metasurface layer is formed by arranging four groups of unit structures in a mirror image mode in the two-dimensional direction, and the L-shaped resonance rings in each group of unit structures are arranged in an array mode; the total number of the square chamfered patches is the same as that of the L-shaped resonant rings, and one L-shaped resonant ring is arranged below each square chamfered patch. The antenna can be suitable for satellite communication, can realize reduction of a radar cross section at 4-10.5 GHz, and has a huge application value in the aspect of an electromagnetic stealth technology.

Description

Technical Field

[0001] The present invention belongs to the technical field of electromagnetic metamaterials and relates to an RCS in-band reduced circular polarization metasurface antenna based on C-band satellite communication. Background Art

[0002] Metasurface, as an innovative two-dimensional material structure, has sub-wavelength-scale artificial electromagnetic resonance units as its core elements. It has shown extraordinary potential in the field of electromagnetic wave manipulation and has attracted much attention. This type of metasurface antenna has become a frontier of scientific research and exploration due to its low mass density, compact space occupancy, high integration compatibility and great flexibility in design. With the rapid development of satellite communication technology, the performance optimization of antenna systems has become one of the key factors to promote technological development. The C-band (frequency range between 4 GHz and 8 GHz) occupies an important position in the field of satellite communications due to its excellent signal propagation characteristics and relatively low environmental interference level, and is widely used in various communication tasks. However, with the rapid increase in the demand for satellite communications, more stringent performance challenges have been posed to antenna systems, including but not limited to higher gain, wider bandwidth, stronger directivity and better anti-interference ability. These requirements drive the continuous innovation and breakthrough of antenna design technology.

[0003] Antennas, as core equipment for signal transmission and information exchange, play a pivotal role in the communications industry. They are widely used in many fields such as satellites, drones, aircraft, radars, etc. Especially in aircraft, antennas are like their "eyes", collecting key information by transmitting and receiving electromagnetic waves. In order to prevent our aircraft and other weapon platforms from being accurately locked by enemy radars, stealth technology has become crucial. This technology requires reducing the radar cross section (RCS) of the weapon platform, which is essentially to reduce the target reflected electromagnetic energy received by the enemy radar, thereby shortening the detection range of the radar detection system. By ensuring that the electromagnetic power of the scattered echo is lower than the receiving accuracy of the radar, the risk of our aircraft and other weapon platforms being destroyed by the enemy can be effectively avoided, thereby improving the effectiveness of our weapons.

[0004] At present, the traditional methods for reducing the radar cross section of antennas are: (1) Using specific shapes, materials or structures can reduce the reflection of radar waves by the antenna. For example, designing antennas with special shapes, such as curved, wavy or inclined surfaces, can change the scattering direction of electromagnetic waves. However, in some cases, in order to reduce RCS, it may be necessary to sacrifice the performance of the antenna, such as reducing the antenna gain or increasing the beam width, which will affect the communication or detection distance. Antennas with specific shapes are often complex in structure, which increases the manufacturing cost and maintenance difficulty. (2) Radar wave absorbing materials (RAM): Special materials are used in the structure of the antenna. These materials can absorb radar waves instead of reflecting them. However, these materials usually have changes in dielectric constant and magnetic permeability, so they can only achieve absorption effects at specific frequencies. And in order to achieve better wave absorption effects, RAM usually requires a certain thickness, which increases the weight and volume of the structure. The performance of RAM may be affected by the environment, such as humidity, temperature, etc., and high-quality RAM is expensive. (3) Loading frequency selective surface (FSS): A frequency selective surface is a periodic structure that allows electromagnetic waves to pass only at specific frequencies and reflects or absorbs electromagnetic waves at other frequencies. When FSS is used as a radome or floor, the detection wave can be reflected in other directions to achieve antenna RCS reduction, but due to the characteristics of frequency selection, only the RCS outside the antenna band can be reduced. Compared with out-of-band RCS reduction, in-band RCS reduction is more difficult. In-band RCS is closely related to the radiation performance of the antenna itself, and it is necessary to reduce its radar cross-section while maintaining the antenna performance. In modern warfare, the enemy may use radars in multiple frequency bands for detection. Through in-band RCS reduction technology, we can ensure that our antenna has good performance in its own operating frequency band, while reducing the detectability in the enemy radar band, thereby dealing with multi-band threats.

[0005] The above traditional RCS reduction methods can reduce the radar cross section of the antenna, but they all have some defects. In recent years, the application of two-dimensional electromagnetic metamaterials (electromagnetic metasurfaces) to reduce the radar cross section of the antenna has become a popular research direction. The electromagnetic unit of the electromagnetic metasurface has design flexibility. By artificially controlling its electromagnetic properties, the phase and amplitude of the reflected wave can be precisely controlled, thereby effectively reducing the RCS. The unit structure of the electromagnetic metasurface is usually very thin and light. The integration of electrical energy with traditional materials or structures can achieve RCS reduction without adding too much weight and volume, which is particularly important for weight-sensitive carriers such as aircraft. The electromagnetic metasurface can be designed to respond to electromagnetic waves of specific frequencies or frequency bands, so that the RCS can be significantly reduced in the required frequency band while maintaining normal performance in other frequency bands. The maintenance of the electromagnetic metasurface is relatively simple. Due to its stable structure, it is not easily affected by the environment and is easy to replace after damage. At the same time, due to the advantages of low profile, low cost and flexible and changeable electromagnetic properties, the metasurface has been deeply explored and studied by many scholars in the design of low RCS antennas. Summary of the invention

[0006] The present invention provides an RCS in-band reduced circularly polarized metasurface antenna based on C-band satellite communication, with an impedance bandwidth (IBW) of 74.6% (3.7GHz-8.1GHz) and an axial ratio bandwidth (ARBW) of 29% (5.6GHz-7.5GHz) at a center frequency of 6GHz, and a maximum gain of 9.2dBic at 6GHz, making the proposed array antenna suitable for satellite communication. In addition, since the mirror image of the metasurface structure can weaken the reflected wave, this antenna array can achieve a reduction in the radar cross section at 4-10.5GHz, with the maximum reduction in the in-band RCS being 26.8dB, which has great application value in electromagnetic stealth technology.

[0007] In order to achieve the above objectives, the present invention adopts the following technical scheme: an RCS-band reduced circularly polarized metasurface antenna based on C-band satellite communication, comprising a first metasurface layer, a first dielectric layer, a second metasurface layer, a second dielectric layer, a slotted metal plate, a third dielectric layer and a feeding antenna layer stacked from top to bottom; wherein the first metasurface layer is formed by four groups of unit structures arranged in a mirror image with each other in a two-dimensional direction, and two types of square cut-corner patches are arranged non-contact in each group of unit structures; the second metasurface layer is formed by four groups of unit structures arranged in a mirror image with each other in a two-dimensional direction, and L-shaped resonant rings are arranged in an array in each group of unit structures; the total number of square cut-corner patches is the same as that of L-shaped resonant rings, and an L-shaped resonant ring is provided under each square cut-corner patch.

[0008] In some embodiments, the first super surface layer, the second super surface layer, the slotted metal plate and the feed antenna layer are made of metal copper material with a thickness of 0.03-0.04 mm.

[0009] In some embodiments, the first dielectric layer and the second dielectric layer are both FR-4 dielectric layers, with a dielectric constant of 4.3, a loss tangent of 0.025, a thickness of 2.8-3 mm, a length of 71-72 mm, and a width of 71-72 mm. In some embodiments, the third dielectric layer is a F4B dielectric layer with a dielectric constant of 2.2, a loss tangent of 0.001, a thickness of 0.7-0.8 mm, a length of 71-72 mm, and a width of 71-72 mm.

[0010] In some embodiments, the side length of the square cut corner patches in the unit structure of the first metasurface layer is 5.1-5.2 mm, and each patch has two cut corners in the diagonal direction; the two types of square cut corner patches are specifically large square cut corner patches with a projected cut corner length of 3.0-3.1 mm and small square cut corner patches with a cut corner length of 2.1-2.2 mm.

[0011] In some embodiments, after the four groups of unit structures of the first metasurface layer are mirrored to each other in the two-dimensional direction, seven layers are arranged from the center to the outside, the innermost layer is 4 large square cut corner patches, the second layer is 8 small square cut corner patches, the third layer is 8 small square cut corner patches and 4 large square cut corner patches, the fourth layer is 16 large square cut corner patches, the fifth layer is 8 small square cut corner patches and 4 large square cut corner patches, the sixth layer is 8 small square cut corner patches, and the seventh layer is 4 large square cut corner patches.

[0012] In some embodiments, the outer side length and the inner side length of the L-shaped resonant ring are 7.4-7.5 mm and 5.2-5.3 mm respectively.

[0013] In some embodiments, the slotted metal plate is composed of four groups of unit structures, each group of unit structures has a slot, and the slots of two adjacent groups of unit structures are perpendicular to each other; the length of the slot lf=23mm, wf=2.6mm.

[0014] In some embodiments, the feeding antenna layer adopts a sequential feeding network, including four groups of microstrip lines, two adjacent groups of microstrip lines are perpendicular to each other, and one ends of the four groups of microstrip lines are respectively connected and set with side feeding waveguide ports.

[0015] The present invention also relates to the application of the antenna in the fields of satellite communication, circular polarization transmission signals and / or electromagnetic stealth.

[0016] The present invention has the following beneficial effects: The present invention designs a new metasurface structure, and applies the metasurface to the antenna array design. The 4*4 metasurface is arranged on the slot antenna array, which can achieve good circular polarization radiation performance and effectively reduce RCS within the antenna working frequency band. After loading the 4*4 metasurface structure, at a center frequency of 6GHz, the impedance bandwidth with a reflection coefficient lower than -10dB is 3.7GHz-8.1GHz (74.6%), the bandwidth with an axial ratio lower than 3dB is 5.6GHz-7.5GHz (29%), and the gain is a maximum of 9.2dBic at 6GHz. At the same time, the measured results of the antenna are well consistent with the simulation results, verifying that the proposed array antenna is suitable for satellite communications. In addition, when the plane electromagnetic wave is irradiated vertically, the mirror image of the metasurface structure can weaken the reflected wave. Compared with the metal floor of the same size, the RCS reduction of the designed antenna is up to 26.8dB, of which the RCS reduction band above 6dB is 4GHz-10.5GHz.

[0017] The antenna provided by the present invention can effectively reduce the radar detectability within its working frequency band, thereby improving the stealth performance of the entire system, making our equipment more difficult to be discovered and tracked by the enemy. This is particularly important in military applications and has great application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 (a) and (b) are schematic diagrams of the unit structures of the L-shaped supersurface and the rectangular cut-corner supersurface of Example 1, respectively.

[0019] Figure 2 (a) and (b) are schematic diagrams of the two overall structures of the electromagnetic supersurface rectangular cut-corner top layer and the L-shaped supersurface of Example 1, respectively.

[0020] Figure 3 (a), (b) and (c) are respectively the back, front and side of the overall structure diagram of the RCS-band reduced circularly polarized metasurface antenna for C-band satellite communication of Example 1.

[0021] Figure 4 (a) and (b) are respectively the back and front sides of the actual images of the RCS-band reduced circular polarization metasurface antenna for C-band satellite communication of Example 2.

[0022] Figure 5 (a) and (b) are respectively the S of the sequential feeding antenna in Example 3. 11 Curve and axis ratio curve simulation diagram.

[0023] Figure 6 (a) is an RCS-band reduced circularly polarized metasurface antenna S for C-band satellite communication of Example 3 11Curve simulation and actual measurement comparison experiment diagram, (b) is the RCS band reduced circular polarization metasurface antenna axial ratio and gain curve simulation diagram for C-band satellite communication.

[0024] Figure 7 (a) and (b) are respectively the E-plane and H-plane of the simulated and measured far-field radiation patterns of the RCS-band reduced circularly polarized metasurface antenna for C-band satellite communication of Example 3 at 6 GHz.

[0025] Figure 8 (a) and (b) are the axial ratio curves and gain curves of different la lengths of the RCS-band reduced circularly polarized metasurface antenna for mid-C-band satellite communication in Example 3.

[0026] Fig. 9 : In the figure are the axial ratio curves of different lf lengths of the RCS-band reduced circularly polarized metasurface antenna for mid-C-band satellite communication in Example 3.

[0027] Fig.10 The figure in the middle is a comparison diagram of RCS reduction of the antenna in Example 3 when loaded with a metasurface structure and a metal plate.

[0028] Fig.11 (a) and (b) are the three-dimensional scattering patterns of the antenna in Example 3 loaded with a metasurface structure and a metal plate at 7 GHz. DETAILED DESCRIPTION

[0029] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0030] Example 1 like Figure 1~Figure 3As shown, the RCS-band reduced circular polarization metasurface antenna for C-band satellite communication provided in this embodiment is composed of four metal structures and three dielectric layers, specifically, the first metasurface layer (square cut-angle metasurface), the first dielectric layer, the second metasurface layer (L-shaped metasurface), the second dielectric layer, the slotted metal plate, the third dielectric layer and the feed antenna layer stacked from top to bottom; the first metasurface layer is a square cut-angle patch metasurface layer, specifically, the first metasurface layer is formed by four groups of unit structures arranged in a mirror image in a two-dimensional direction, and two types of square cut-angle patches are arranged in a non-contact manner in each group of unit structures (4*4); the second metasurface layer is an L-shaped resonant ring metasurface layer, and the second metasurface layer is formed by four groups of unit structures arranged in a mirror image in a two-dimensional direction, and the L-shaped resonant rings in each group of unit structures are arranged in an array (4*4). The total number of square cut-angle patches is the same as that of L-shaped resonant rings, and an L-shaped resonant ring is arranged under each square cut-angle patch. The period of the unit structure w=8.5mm. Multiple unit structures are periodically arranged closely with a spacing of g=1mm, and the overall structure is shown as Figure 2 As shown in (a)(b).

[0031] The side length of the square cut corner patch in the unit structure of the first super surface layer is 5.1-5.2mm, and the preferred embodiment of this invention is l3=5.2mm. Each patch has two cut corners in the diagonal direction, and the diagonal cut angle is 45°; the two types of square cut corner patches are specifically a large square cut corner patch with a cut corner length projection of 3.0-3.1mm (the preferred cut corner length projection in this embodiment is b=3mm) and a small square cut corner patch with a cut corner length projection of 2.1-2.2mm (the preferred cut corner length projection in this embodiment is a=2.2mm).

[0032] Preferably, after the four groups of unit structures of the first supersurface layer are mirror-arranged to each other in the two-dimensional direction, seven layers are arranged from the center to the outside, the innermost layer is 4 large square cut corner patches, the second layer is 8 small square cut corner patches, the third layer is 8 small square cut corner patches and 4 large square cut corner patches, the fourth layer is 16 large square cut corner patches, the fifth layer is 8 small square cut corner patches and 4 large square cut corner patches, the sixth layer is 8 small square cut corner patches, and the seventh layer is 4 large square cut corner patches.

[0033] In some embodiments, the outer side length and inner side length of the L-shaped resonant ring are 7.4-7.5 mm and 5.2-5.3 mm respectively. In this embodiment, the outer side length l1=7.5 mm and the inner side length l2=5.3 mm are preferred.

[0034] Preferably, the first super surface layer, the second super surface layer, the slit metal plate and the feed antenna layer are made of metal copper material with a thickness of 0.03-0.04mm; more preferably ts=0.035mm. The first dielectric layer and the second dielectric layer are both FR-4 dielectric layers with a dielectric constant of 4.3, a loss tangent of 0.025, and a thickness of 2.8-3mm, and more preferably h1=h2=3mm. The third dielectric layer is an F4B dielectric layer with a dielectric constant of 2.2, a loss tangent of 0.001, and a thickness of 0.7-0.8mm, and more preferably h3=0.8mm. The lengths of the first dielectric layer, the second dielectric layer and the third dielectric layer are all 71-72mm, and in this embodiment, wsub=72mm. The width is 71-72mm, and in this embodiment, wsub=72mm. The total thickness of the super surface antenna as a whole in this embodiment is 6.94mm.

[0035] In some embodiments, the slotted metal plate is composed of four groups of unit structures, each group of unit structures has a slot, and the slots of two adjacent groups of unit structures are perpendicular to each other; the length of the slot lf=23mm, wf=2.6mm.

[0036] Preferably, the electromagnetic waves output by the sequentially rotating feed antenna at the four output ports are radiated from the gaps between the slotted metal plates and coupled to the metasurface through the gaps. These electromagnetic waves are regulated by the double-layer metasurface structure to further optimize the radiation performance of the antenna, improve the gain, and reduce the sidelobe level.

[0037] In some embodiments, the feeding antenna layer adopts a sequential feeding network, including four groups of microstrip lines, two adjacent groups of microstrip lines are perpendicular to each other, and one ends of the four groups of microstrip lines are respectively connected and set with side feeding waveguide ports.

[0038] Figure 3 (a) shows the specific dimensions of the slot coupling layer and sequentially fed microstrip line on the back of the antenna. Figure 3 (b) is the front perspective view of the antenna, and the side structure is as follows Figure 3 (c) is shown in Table 1.

[0039] Table 1

[0040] Example 2 A 72mm×72mm experimental sample was made using printed circuit board manufacturing technology. The actual pictures of the back and front are as follows: Figure 4 (a)(b) is shown. And by Figure 6The comparison chart of the experimental results and simulation results of the reflection curve data is obtained. It is easy to see that the actual experimental data curve and the simulation data curve are similar, and the experimental effect is better than the simulation effect. The simulated antenna has an impedance bandwidth below -10dB of 3.7GHz-8.1GHz and a maximum gain of 9.2dBic. Similarly, the simulated antenna has a 3 dB axial ratio bandwidth of 5.6GHz-7.5GHz. The measurement results prove the feasibility of the proposed circularly polarized metasurface antenna design method. Figure 7 (a) and (b) show the E-plane and H-plane of the antenna at 6 GHz after simulation and actual measurement of the metasurface. It can be seen that the E-plane and H-plane have good symmetry at this time, and the radiation characteristics in the two main planes are similar, which can achieve relatively uniform radiation coverage.

[0041] Example 3 In order to analyze the influence of metamaterial surface structure on impedance matching, the present invention analyzes the sequential feeding structure with and without metasurface, i.e., the first metasurface layer, the first dielectric layer, the second metasurface layer, and the second dielectric layer. When the metasurface is not loaded, the reflection coefficient curve of the sequential feeding antenna has a potential downward trend in 4-8GHz, but the impedance bandwidth at -10dB has three frequency bands, namely 5.7-6GHz, 6.4-7.2GHz and 7.5-7.9GHz. Figure 5 (a) As shown. After loading the metasurface, the impedance bandwidth below -10dB can be increased to 3.7GHz-8.1GHz. Figure 6 (a) As shown. Similarly, sequentially fed antennas have potential circular polarization performance advantages, such as Figure 5 The axial ratio curve shown in (b) shows a downward trend after 5 GHz, but it does not fall below 3 dB. After loading the metasurface, the 3 dB axial ratio bandwidth can reach 5.6 GHz-7.5 GHz. Figure 6 (b) shows the AR curve. It can be seen that the impedance bandwidth and axial ratio bandwidth of the antenna are significantly improved after loading the metasurface.

[0042] Example 4 To study the antenna |S 11 |≤−10dB and AR≤3 dB vary with the feeder size parameters. The control variable method is used to simulate the metasurface antenna, such as Figure 8 (a)(b) is shown. Parameter la represents the length of the feeder. Figure 8It can be seen that as la increases in steps of 2 mm. Using CST simulation software, it was found that when la=28mm and 32mm, the IBW and ARBW axial ratio bandwidths (ARBW) were 5.4-7.1GHz, 4.2-6.9GHz and 2.7-6.2GHz, 6.9-7.5GHz respectively. For la=30mm, the impedance bandwidth is 74.6% (3.7GHz-8.1GHz) and the axial ratio bandwidth is 29% (5.6GHz-7.5GHz), which is wider in comparison. And when la=28mm and 32mm, the gain of the antenna is less than that of the antenna at 6GHz when la=30mm, which is 9.2dBic. Considering the above impedance bandwidth, axial ratio bandwidth and gain, the optimal feed line length la is 30mm.

[0043] Example 5 The effect of the metal floor gap length lf on the reflection coefficient of this antenna model is studied. When wf=2.6mm is selected, lf increases from 21mm to 25mm with a step size of 2mm. Fig. 9 It can be seen that the axial ratio curves of the three different parameters all have a downward trend. In order to ensure better circular polarization performance, the axial ratio is required to be below 3dB. The simulated curve only meets the requirements when lf=23mm. At this time, the axial ratio bandwidth reaches 29% (5.6GHz-7.5GHz), so the optimal metal floor gap length lf is selected as 23mm.

[0044] Example 6 The proposed metasurface antenna model is analyzed to have the function of RCS reduction, and the simulation effects of single-station RCS of the metal plate and this model without metasurface loading are compared. Fig.11 The three-dimensional scattering field images with and without the metasurface structure at 4.5 GHz are shown. Fig.10 The RCS reduction is shown. Under plane electromagnetic wave incidence, the average reduction is more than 6dB at 4-10.5GHz, and the reductions are 26.8dB and 26.7dB at 4.5GHz and 7GHz respectively. It can be seen that the antenna has the best RCS reduction effect at 4-10.5GHz.

[0045] In summary, the present invention proposes an RCS in-band reduced circular polarization metasurface antenna based on C-band satellite communication. The device can be used for C-band satellite communication, can show good circular polarization performance, and the antenna can achieve RCS reduction in the band, reduce the detectability of radar waves, and thus improve its own stealth effect.

[0046] The above embodiments describe the preferred implementation of the present invention, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An RCS-band reduced circularly polarized metasurface antenna based on C-band satellite communication, characterized in that: It includes a first supersurface layer, a first dielectric layer, a second supersurface layer, a second dielectric layer, a slotted metal plate, a third dielectric layer and a feeding antenna layer stacked from top to bottom; wherein the first supersurface layer is composed of four groups of unit structures arranged in a mirror image with each other in a two-dimensional direction, and two types of square cut-corner patches are arranged in a non-contact manner in each group of unit structures; the second supersurface layer is composed of four groups of unit structures arranged in a mirror image with each other in a two-dimensional direction, and L-shaped resonant rings are arranged in an array in each group of unit structures; the total number of square cut-corner patches is the same as that of L-shaped resonant rings, and an L-shaped resonant ring is arranged under each square cut-corner patch.

2. The antenna according to claim 1, characterized in that: The first super surface layer, the second super surface layer, the slotted metal plate and the feeding antenna layer are made of metal copper material with a thickness of 0.03-0.04 mm.

3. The antenna according to claim 1, characterized in that: The first dielectric layer and the second dielectric layer are both FR-4 dielectric layers, with a dielectric constant of 4.3, a loss tangent of 0.025, a thickness of 2.8-3 mm, a length of 71-72 mm, and a width of 71-72 mm.

4. The antenna according to claim 1, characterized in that: The third dielectric layer is an F4B dielectric layer, with a dielectric constant of 2.2, a loss tangent of 0.001, a thickness of 0.7-0.8 mm, a length of 71-72 mm, and a width of 71-72 mm.

5. The antenna according to any one of claims 1 to 4, characterized in that: The side length of the square cut corner patches in the unit structure of the first metasurface layer is 5.1-5.2 mm, and each patch has two cut corners in the diagonal direction; the two types of square cut corner patches are specifically a large square cut corner patch with a cut corner projection length of 3.0-3.1 mm and a small square cut corner patch with a cut corner projection length of 2.1-2.2 mm.

6. The antenna according to claim 5, characterized in that: After the four groups of unit structures of the first metasurface layer are mirrored to each other in the two-dimensional direction, seven layers are arranged from the center to the outside, the innermost layer is 4 large square cut corner patches, the second layer is 8 small square cut corner patches, the third layer is 8 small square cut corner patches and 4 large square cut corner patches, the fourth layer is 16 large square cut corner patches, the fifth layer is 8 small square cut corner patches and 4 large square cut corner patches, the sixth layer is 8 small square cut corner patches, and the seventh layer is 4 large square cut corner patches.

7. The antenna according to claim 1, characterized in that: The outer side length and inner side length of the L-shaped resonant ring are 7.4-7.5 mm and 5.2-5.3 mm respectively.

8. The antenna according to claim 1, characterized in that: The slotted metal plate is composed of four groups of unit structures, each group of unit structures has a slot, and the slots of two adjacent groups of unit structures are perpendicular to each other; the length of the slot is lf=23mm, wf=2.6mm.

9. The antenna according to claim 1, characterized in that: The feeding antenna layer adopts a sequential feeding network, including four groups of microstrip lines, two adjacent groups of microstrip lines are perpendicular to each other, and one ends of the four groups of microstrip lines are respectively connected and set with side feeding waveguide ports.

10. Application of the antenna according to any one of claims 1 to 9 in the fields of satellite communications, circularly polarized signal transmission and / or electromagnetic stealth.

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