Broadband circular polarization metasurface conformal antenna applied to 5G communication

Abstract

The utility model provides a broadband circularly polarized metasurface conformal antenna applied to 5G communication, comprising a first dielectric plate, the first dielectric plate is crimped with a second dielectric plate, and a metasurface layer is arranged on the surface of one side, separated from the second dielectric plate, of the first dielectric plate; a feed source antenna layer is arranged on the surface of one side, adjacent to the first dielectric plate, of the second dielectric plate, and a microstrip line feed layer is arranged on the surface of one side, away from the first dielectric plate, of the second dielectric plate; the metasurface layer is a circular patch which is arranged in a 4 * 4 periodic array; according to the antenna, a new resonant frequency is successfully excited by loading the metasurface coating, a new axial ratio lowest point is introduced, the-10dB impedance bandwidth and the 3dB axial ratio bandwidth are remarkably expanded, and meanwhile, the main beam gain is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of antennas, in particular to a broadband circularly polarized metasurface conformal antenna applied to 5G communication. Background Art

[0002] Due to its characteristics such as light weight, small volume, and easy integration with microwave circuits, microstrip patch antennas are increasingly widely used in wireless and mobile communication systems, far exceeding other traditional antennas. However, the application of traditional microstrip patch antennas is limited in some wireless systems, mainly due to their narrow bandwidth and low gain. With the rapid development of the fifth-generation mobile communication technology (5G), the performance requirements for communication systems are constantly increasing, especially in terms of high-speed data transmission, low latency, and wide coverage, which pose higher requirements for antenna technology. Traditional antenna designs often struggle to meet the strict requirements of 5G networks in terms of size, performance, and integration, especially in terms of signal quality stability and anti-interference ability in complex environments. To achieve high-speed data transmission, broadband antennas must be used. In addition, in wireless communication systems, when it is necessary to weaken the Faraday rotation effect, suppress multipath interference, or when the directions of the transmitter and receiver are unknown, circularly polarized antennas are required. In the design of single-fed microstrip patch antennas, techniques such as slotting, slitting, and truncating corners are often used to obtain circularly polarized radiation characteristics. However, the impedance bandwidth and axial ratio bandwidth of single-fed circularly polarized microstrip patch antennas are narrow, which is their main defect, and this defect can be overcome by introducing metasurfaces into the antenna design.

[0003] As a two-dimensional planar metamaterial, metasurfaces are widely used to improve the radiation performance of antennas due to their unique electromagnetic properties. The applications of metasurfaces are diverse, including reducing antenna size, increasing impedance bandwidth, increasing the axial ratio bandwidth of circularly polarized antennas, increasing gain, achieving frequency reconfigurability, polarization conversion, and radar cross-section reduction. In recent research results, various forms of metasurfaces have been proposed, such as high-impedance surfaces, photonic bandgap surfaces, reactive impedance surfaces, and artificial ground structures. Reconfigurable intelligent surfaces, as a type of metasurface, have been widely used in the miniaturization, bandwidth increase, and gain improvement of planar antennas, but this method will increase the profile height and structural complexity of the antenna. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a broadband circularly polarized metasurface conformal antenna applied to 5G communication in view of the above-mentioned deficiencies of the prior art, which can be closely combined with the surfaces of various shapes of objects to achieve high gain, low side lobes, and good polarization characteristics.

[0005] To achieve the above purpose, the utility model adopts the following technical solutions:

[0006] The utility model provides a broadband circularly polarized metasurface conformal antenna applied to 5G communication, which comprises a first dielectric plate, the first dielectric plate is pressed against a second dielectric plate, and a metasurface layer is arranged on the surface of the first dielectric plate on the side away from the second dielectric plate;

[0007] A feed antenna layer is arranged on the surface of the second dielectric plate adjacent to the first dielectric plate, and a microstrip line feeding layer is arranged on the surface of the second dielectric plate on the side away from the first dielectric plate;

[0008] The metasurface layer is a circular patch arranged in a 4×4 periodic array.

[0009] Furthermore, the feed antenna layer is an inclined elliptical slot antenna.

[0010] Furthermore, the microstrip line feeding layer is in a T shape.

[0011] Furthermore, both the horizontal part and the vertical part of the microstrip line feeding layer are coated with the second dielectric plate.

[0012] Furthermore, the electromagnetic parameters of the first dielectric plate and the second dielectric plate are ε r =2.2, tan δ =0.0009.

[0013] Furthermore, the thickness of the first dielectric plate is 2.2 mm; the thickness of the second dielectric plate is 0.8 mm.

[0014] The beneficial effects of the utility model are as follows: By loading the metasurface coating, the antenna successfully excites new resonance frequencies and introduces new axial ratio minimum points, significantly expanding the -10dB impedance bandwidth and 3dB axial ratio bandwidth, and at the same time improving the main beam gain;

[0015] Moreover, the circular polarization performance of the antenna is stable, with a small fluctuation range, showing good conformal characteristics;

[0016] In addition, the antenna can closely fit various curved surfaces and maintain stable performance output;

[0017] It is particularly worth mentioning that this conformal metasurface antenna not only has excellent performance, but its bandwidth also covers the 5G frequency band range. This feature enables the antenna to have broad application prospects in the field of 5G communication. Description of the Drawings

[0018] Figure 1 It is an exploded view of a broadband circularly polarized metasurface conformal antenna applied to 5G communication;

[0019] Figure 2 It is a schematic diagram of the metasurface layer structure;

[0020] Figure 3 Schematic diagram of the feed antenna layer structure;

[0021] Figure 4 Schematic diagram of the microstrip line feeding layer structure;

[0022] Figure 5 Relationship curve of return loss varying with frequency;

[0023] Figure 6 Relationship curve of axial ratio varying with frequency;

[0024] Figure 7 Relationship curve of gain varying with frequency;

[0025] Figure 8 is xoz Normalized radiation pattern in the plane;

[0026] Figure 9 is yoz Normalized radiation pattern in the plane;

[0027] Figure 10 Structural diagram of a broadband circularly polarized metasurface conformal antenna applied to 5G communication in a bent state;

[0028] Figure 11 Relationship diagram of return loss varying with frequency under different bending radii;

[0029] Figure 12 Relationship diagram of axial ratio varying with frequency under different bending radii;

[0030] Figure 13 Relationship diagram of main beam gain varying with frequency under different bending radii. Specific embodiments

[0031] In order to make the objectives, technical solutions and advantages of the present utility model clearer and more understandable, the following further elaborates on the present with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present and are not used to limit the present utility model.

[0032] Please refer to Figure 1 , a broadband circularly polarized metasurface conformal antenna applied to 5G communication, comprising a first dielectric plate 1, the first dielectric plate 1 is press-connected to a second dielectric plate 2, and a metasurface layer 101 is provided on the surface of the first dielectric plate 1 away from the second dielectric plate 2;

[0033] A feed antenna layer 201 is provided on the surface of the second dielectric plate 2 adjacent to the first dielectric plate 1, and a microstrip line feeding layer 202 is provided on the surface of the second dielectric plate 2 away from the first dielectric plate 1;

[0034] Please refer to Figure 2 , where the metasurface layer 101 is a circular patch arranged in a 4×4 periodic array.

[0035] Specifically, the metasurface layer provides electromagnetic regulation characteristics for the antenna.

[0036] Please refer to Figure 3 , and the feed antenna layer 201 is an inclined elliptical slot antenna.

[0037] Please refer to Figure 4 , and the microstrip line feeding layer 202 is T-shaped.

[0038] Both the horizontal part and the vertical part of the microstrip line feeding layer 202 are coated with the second dielectric plate 2.

[0039] Specifically, it effectively expands the bandwidth of the antenna.

[0040] Specifically, both the metasurface layer and the microstrip line feeding layer use F4BM as the flexible dielectric plate material;

[0041] The electromagnetic parameters of the first dielectric plate 1 and the second dielectric plate 2 are =2.2, =0.0009.

[0042] The thickness of the first dielectric plate 1 is 2.2 mm, which is used to support the metasurface layer;

[0043] The thickness of the second dielectric plate 2 is 0.8 mm, which bears the feed antenna layer and the microstrip line feeding layer.

[0044] Embodiment 1

[0045] A broadband circularly polarized metasurface conformal antenna applied to 5G communication, from top to bottom in sequence: a metasurface layer 101, that is, the metasurface layer 101 is coated on the front surface of the first dielectric plate 1, and the metasurface layer 101 is formed by arranging circular patch units in a 4×4 periodic array;

[0046] The slot layer 201 is coated on the front of the second dielectric plate 2, and an inclined elliptical slot is etched in the metal coating layer of the second dielectric plate 2, and the center of the ellipse is located at the center of the dielectric plate, and the inclination angle is 40°.

[0047] The microstrip line feeding layer 202 is coated on the back of the second dielectric plate 2, and the microstrip line feeding layer 202 is T-shaped, and the end of the horizontal part of the T-shape is coated on the surface of the second dielectric plate 2, that is, the end is mutated, and broadband matching can be achieved.

[0048] The optimized size parameters are shown in Table 1.

[0049] Table 1 Optimized size parameters

[0050]

[0051] Analysis of simulation results:

[0052] By continuously optimizing the parameters using the high-frequency electronic simulator ANSYS Electronics Desktop, the optimal performance values of the target antenna are obtained. For example, Figure 5 as shown, the return loss is below -10 dB in the frequency range of 4.2 - 7.7 GHz, the center frequency is 5.95 GHz, and the relative bandwidth reaches 58.8%, showing good broadband characteristics and basically covering the entire C-band. Therefore, it greatly meets the communication application requirements within the C-band, such as application scenarios like 5G and WIFI.

[0053] As Figure 6 shown, the 3 dB axial ratio bandwidth is 5.2 - 6.85 GHz, the absolute bandwidth is 1.65 GHz, the relative bandwidth reaches 27.5%, and it is all covered by the impedance bandwidth. The lowest point of the axial ratio is 0.75 dB, which appears at 5.7 GHz, showing excellent circular polarization performance. As Figure 7 shown, the peak gain appears at the frequency point of 6.7 GHz, reaching 7.65 dBic, and the average gain within the circular polarization bandwidth is 6.15 GHz, while the profile height is only 0.06 λ 0. Therefore, the designed antenna has good circular polarization radiation performance.

[0054] As Figure 8 and Figure 9 shown are the normalized radiation patterns of the designed antenna at the 6 GHz frequency point, where Figure 8 is xoz plane, Figure 9 is yoz plane. It can be seen from the figure that the radiation pattern is basically symmetric, the cross-polarization level is below -25 dB within the main beam range, and the 3 dB beam widths in the E-plane and H-plane are 63° and 60° respectively, achieving good broadside circular polarization radiation characteristics. In addition, the back lobe level of the antenna remains below -25 dB, effectively avoiding backward radiation and enhancing the forward directivity of the antenna radiation. In summary, the design of this antenna not only achieves good broadside circular polarization performance but also effectively improves the radiation directivity efficiency through low back lobe design, meeting the strict requirements of high-performance antenna design.

[0055] Conformal simulation analysis: When the antenna is bent, as Figure 10 shown, the coated metal layer and dielectric substrate are bent accordingly, resulting in changes in electromagnetic parameters and field spatial distribution, and thus affecting the radiation performance of the antenna. As Figures 11 - 13As shown, we analyzed the performance of the antenna under different curvature radii through simulation. The analysis results show that the -10dB return loss remains basically the same when the antenna is flat and when the curvature radii are 30mm, 40mm, and 50mm respectively. Meanwhile, the 3dB axial ratio gradually increases with the decrease of the curvature radius at the center frequency, but it only changes within a small frequency range and maintains good stability in the high and low frequency bands, with the overall change amplitude being small.

[0056] In addition, the main beam gain has a roughly 2dB attenuation compared to the flat state under different curvature radii. This is because the main beam direction of the radiating element shifts spatially after bending, resulting in a reduction in the energy focused in the main beam direction. Additionally, with the decrease of the curvature radius, there is a slight attenuation of 0.3dB in the gain. This fluctuation range is small, indicating that the antenna gain has high stability. Thus, it can be seen that the bending of the antenna does not significantly affect its performance. During the process of the curvature radius changing from 30mm to 50mm, the radiation performance of the antenna remains almost unchanged. This shows that the proposed metasurface conformal antenna has good applicability and stability at any curvature radius of 30mm and above, and can be applied to various curved surface carrier platforms and application scenarios with different curvatures.

[0057] Through simulation analysis, the performance stability of the antenna under different curvature radii is verified. The results show that the antenna performance has a small fluctuation range, has good conformal ability, and can adapt to various complex-shaped installation environments;

[0058] In addition, the circular polarization bandwidth of the antenna successfully covers the 5G communication range. This characteristic enables the antenna to have broad application prospects in the 5G communication field and provides strong support for high-speed and stable wireless communication.

[0059] Specifically: The unique oblique elliptical slot design greatly improves the design freedom by flexibly adjusting the tilt angle, and at the same time demonstrates excellent radiation performance;

[0060] The innovative introduction of a periodic circular patch metasurface cladding significantly enhances the circular polarization performance. The high symmetry of the circular patches lays a solid foundation for the stable performance after conformal transformation;

[0061] The two-layer structure stacking technology is adopted, and the dielectric substrate is reasonably selected to successfully achieve high gain and broadband circular polarization, which brings a significant improvement to the radiation performance of the slot antenna.

[0062] The above-described embodiments merely represent the implementation manners of the present invention. Their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the present patent shall be defined by the appended claims.

Claims

1. A broadband circularly polarized metasurface conformal antenna applied to 5G communication, characterized in that: It includes a first dielectric plate (1), the first dielectric plate (1) is press-connected to a second dielectric plate (2), and a metasurface layer (101) is provided on the surface of the first dielectric plate (1) on the side away from the second dielectric plate (2); A feed antenna layer (201) is provided on the surface of the second dielectric plate (2) adjacent to the first dielectric plate (1), and a microstrip line feeding layer (202) is provided on the surface of the second dielectric plate (2) on the side away from the first dielectric plate (1); The metasurface layer (101) is a circular patch arranged in a 4×4 periodic array.

2. The broadband circularly polarized metasurface conformal antenna applied to 5G communication according to claim 1, wherein: The feed antenna layer (201) is an inclined elliptical slot antenna.

3. A broadband circularly polarized metasurface conformal antenna applied to 5G communication according to claim 1, characterized in that: The microstrip line feeding layer (202) is T-shaped.

4. A broadband circularly polarized metasurface conformal antenna applied to 5G communication according to claim 3, characterized in that: Both the horizontal part and the vertical part of the microstrip line feeding layer (202) are coated with the second dielectric plate (2), and the horizontal part is connected to the second dielectric plate (2).

5. A broadband circularly polarized metasurface conformal antenna applied to 5G communication according to claim 1, characterized in that: The electromagnetic parameters of the first dielectric plate (1) and the second dielectric plate (2) are = 2.2, tan = 0.0009.

6. The broadband circularly polarized metasurface conformal antenna applied to 5G communication according to claim 1, wherein: The thickness of the first dielectric plate (1) is 2.2 mm; the thickness of the second dielectric plate (2) is 0.8 mm.

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