A high-isolation, wideband, low-profile dual-polarized antenna and its usage method

Abstract

This invention discloses a high-isolation, wideband, low-profile dual-polarized antenna and its usage method, comprising a stacked upper dielectric substrate, a middle dielectric substrate, and a lower dielectric substrate; the upper dielectric substrate has a rectangular patch; a differential coaxial line is disposed below the rectangular patch; the differential coaxial line is used to input energy to the rectangular patch; the rectangular patch radiates the energy input from the differential coaxial line outward; a metasurface structure is disposed between the upper and middle dielectric substrates; a metal ground plane is disposed between the middle and lower dielectric substrates; the metal ground plane has coupling slots; a feed network is disposed at the bottom of the lower dielectric substrate; the feed network inputs energy to the coupling slots and then radiates it outward through the metasurface structure; the dual polarization employs slot-coupled feeding and differential coaxial feeding respectively, enabling the antenna to achieve high isolation over a wide frequency range.

Description

Technical Field

[0001] This invention belongs to the field of antenna technology, specifically relating to a high-isolation, broadband, low-profile dual-polarized antenna with metasurface multiplexing and its usage method. Background Technology

[0002] With the rapid development of communication technology, antennas with low profile, wide bandwidth, high gain, and small size have increasingly become a research hotspot in the field of wireless communication. Traditional antennas can generally be divided into single-polarized antennas and dual-polarized antennas. Single-polarized antennas can only transmit or receive electromagnetic waves in one polarization direction, while dual-polarized antennas can transmit or receive electromagnetic waves in two polarization directions simultaneously. In practical applications, dual-polarized antennas have advantages such as improved communication reliability and reduced signal attenuation and distortion, therefore, dual-polarization technology has been widely used. Although crossed dipole antennas, slot antennas, and patch antennas have been developed to achieve dual polarization and improve bandwidth, simultaneously achieving high isolation, low profile, and wide bandwidth operation remains a challenge.

[0003] Furthermore, in recent years, metasurface (MS) structures have been widely used in antennas to improve performance due to their unique electromagnetic properties that allow for the manipulation of electromagnetic waves. Therefore, metasurface structures are also commonly used to increase antenna gain, bandwidth, and reduce profile. For example, stacking and reusing metasurface structures can improve impedance bandwidth or increase gain to varying degrees while maintaining a low profile, showing great promise. However, these methods cannot achieve high isolation over a wide frequency range, which remains a technical challenge for dual-polarized metasurface antennas. Summary of the Invention

[0004] The purpose of this invention is to provide a high-isolation, wideband, low-profile dual-polarized antenna and its usage method. The dual polarization employs slot-coupled feeding and differential coaxial feeding respectively, enabling the antenna to achieve high isolation over a wide frequency range.

[0005] To achieve the above objectives, the technical solution adopted by the present invention in the first aspect is as follows:

[0006] A high-isolation, wideband, low-profile dual-polarized antenna includes a stacked upper dielectric substrate, a middle dielectric substrate, and a lower dielectric substrate. A rectangular patch is disposed on the side of the upper dielectric substrate away from the middle dielectric substrate. A differential coaxial line is disposed below the rectangular patch. The differential coaxial line is used to input energy to the rectangular patch. The differential coaxial line perpendicularly penetrates the upper dielectric substrate, the middle dielectric substrate, and the lower dielectric substrate. The rectangular patch radiates the energy input from the differential coaxial line outward.

[0007] A metasurface structure is provided between the upper dielectric substrate and the middle dielectric substrate; a metal ground plane is provided between the middle dielectric substrate and the lower dielectric substrate; the metal ground plane is provided with coupling gaps; a power supply network is provided at the bottom of the lower dielectric substrate; the power supply network inputs energy to the coupling gaps and then radiates it outward through the metasurface structure.

[0008] Preferably, the metasurface structure includes a plurality of square metal patches, which are arranged in a matrix, and an etched gap is provided between two adjacent square metal patches.

[0009] Preferably, the square metal patch is divided into square metal patch A and square metal patch B; a plurality of square metal patches A are distributed in a matrix to form a matrix unit, the matrix unit having the same size as the square metal patch B, and the plurality of matrix units and the plurality of square metal patches B are combined to form a metasurface structure; the rectangular patch is distributed on one side of the coupling gap, and the matrix unit is distributed on the other side of the coupling gap.

[0010] Preferably, the matrix unit is set as four square metal patches A distributed in a 2×2 matrix; the metasurface structure is set as a 4×4 matrix composed of the matrix unit and the square metal patches B; the center of the coupling gap corresponds to the center of the metasurface structure.

[0011] Preferably, a plurality of differential coaxial lines are disposed below the rectangular patch; the differential coaxial lines are electrically connected to the rectangular patch.

[0012] Preferably, the input end of the power supply network is configured as a microstrip line; the output end of the power supply network is configured as a rectangle, a Y, or a fan shape; the vertical projection of the microstrip line intersects with the vertical projection of the coupling gap.

[0013] Preferably, the width at both ends of the coupling gap is greater than the width at the middle of the coupling gap.

[0014] Preferably, the dielectric constants of the upper dielectric substrate, the middle dielectric substrate, and the lower dielectric substrate are in the range of [1, 10], and the thicknesses h1, h2, and h3 of the upper dielectric substrate are in the range of [0.001λ0, 0.1λ0]; where λ0 is the free space wavelength.

[0015] Preferably, the length a of the rectangular patch ranges from [0.08λ0, 0.3λ0], and the width b ranges from [0.03λ0, 0.2λ0].

[0016] Preferably, the gap width g between two adjacent square metal patches in the metasurface structure ranges from [0.01λ]. g ,0.05λ gThe side length d of the square metal patch B ranges from [0.2λ]. g ,0.4λ g ], where λ g This refers to the effective wavelength of the dielectric substrate in the upper layer.

[0017] Preferably, the metal floor is square; the side length G of the metal floor is... L The range is [0.9λ0, 1.2λ0]; the total length of the coupling gap ranges from [0.1λ0]. g1 0.6λ g1 The width range of the coupling gap is [0.03λ]. g1 ,0.4λ g1 ], where λ g1 This refers to the effective wavelength of the dielectric substrate in the middle layer.

[0018] Preferably, the width w of the microstrip line f The range is [0.1λ] g2 ,0.5λ g2 The length S of the output terminal of the feeder network along the coupling gap direction ranges from [0.1λ]. g2 ,0.4λ g2 The output terminal of the feed network has a length l along the microstrip line in the range of [0.1λ]. g2 ,0.5λ g2 ], where λ g2 This represents the effective wavelength of the dielectric substrate in the lower layer.

[0019] In a second aspect, the present invention provides a method of using a high-isolation, wideband, low-profile dual-polarized antenna, comprising:

[0020] In horizontal polarization, energy is input to the rectangular patch through the differential coaxial line; the rectangular patch radiates the energy input through the differential coaxial line outward; the metasurface structure reflects the energy radiated by the rectangular patch upward.

[0021] In vertical polarization, energy is input to the coupling gap through the feeding network and then radiated outward through the metasurface structure.

[0022] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0023] The differential coaxial cable of this invention is used to input energy to a rectangular patch; the rectangular patch radiates the energy input from the differential coaxial cable outward; a metasurface structure is provided between the upper dielectric substrate and the middle dielectric substrate; a metal ground plane is provided between the middle dielectric substrate and the lower dielectric substrate; the metal ground plane has coupling gaps; a power supply network is provided at the bottom of the lower dielectric substrate; the power supply network inputs energy to the coupling gaps and then radiates it outward through the metasurface structure; by using gap coupling power supply and differential coaxial power supply, high isolation can be achieved over a wide frequency range.

[0024] In this invention, several square metal patches A are distributed in a matrix to form a matrix unit, and several matrix units and several square metal patches B are combined to form a metasurface structure; the rectangular patches are distributed on one side of the coupling gap, and the matrix unit is distributed on the other side of the coupling gap; the reverse current is disrupted by the matrix unit, while maintaining the symmetry of the radiation pattern.

[0025] In horizontal polarization, the present invention inputs energy to a rectangular patch through the differential coaxial line; the rectangular patch radiates the energy input through the differential coaxial line outward; the metasurface structure reflects the energy radiated by the rectangular patch upward; in vertical polarization, energy is input to the coupling slot through the feed network and then radiated outward through the metasurface structure. The metasurface structure is reused, reducing the antenna profile. It features compact size, simple structure, and low processing cost, which is beneficial for mass production. Attached Figure Description

[0026] Figure 1 This is a top view of the dual-polarized antenna provided in Embodiment 1 of the present invention;

[0027] Figure 2 This is a cross-sectional view of the dual-polarized antenna provided in Embodiment 1 of the present invention;

[0028] Figure 3 This is a structural diagram of the metal base plate and coupling gap provided in Embodiment 1 of the present invention;

[0029] Figure 4 This is a structural diagram of the power supply structure provided in Embodiment 1 of the present invention;

[0030] Figure 5 The E-plane radiation pattern of the dual-polarized metasurface antenna at 5.5 GHz is shown in Embodiment 1 of this invention.

[0031] Figure 6 The H-plane radiation pattern of the dual-polarized metasurface antenna at 5.5 GHz is shown in Embodiment 1 of this invention.

[0032] Figure 7 The E-plane radiation pattern of the dual-polarized metasurface antenna at 6.2 GHz provided in Embodiment 1 of the present invention;

[0033] Figure 8 The H-plane radiation pattern of the dual-polarized metasurface antenna at 6.2 GHz provided in Embodiment 1 of the present invention;

[0034] Figure 9 The S-parameter characteristic diagram of the dual-polarized metasurface antenna provided in Embodiment 1 of the present invention is shown.

[0035] Figure 10 This is a dual-polarization gain diagram of the dual-polarized metasurface antenna provided in Embodiment 1 of the present invention.

[0036] In the figure: 1 Upper dielectric substrate, 2 Middle dielectric substrate, 3 Lower dielectric substrate, 4 Rectangular patch, 5 Differential coaxial line, 6 Metasurface structure, 7 Square metal patch, 71 Square metal patch A, 72 Square metal patch B, 8 Etched gap, 9 Metal ground plane, 10 Coupling gap, 11 Microstrip line. Detailed Implementation

[0037] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0038] It should be noted that in the description of this invention, the terms "front," "rear," "left," "right," "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used only for the convenience of describing the invention and do not require the invention to be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. The terms "front," "rear," "left," "right," "upper," and "lower" used in the description of this invention refer to the directions shown in the accompanying drawings, while the terms "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

[0039] Example 1

[0040] like Figures 1 to 4 As shown, a high-isolation, wideband, low-profile dual-polarized antenna includes an upper dielectric substrate 1, a middle dielectric substrate 2, and a lower dielectric substrate 3 stacked together. A rectangular patch 4 is disposed on the side of the upper dielectric substrate 1 away from the middle dielectric substrate 2. A plurality of differential coaxial lines 5 are disposed below the rectangular patch 4. The differential coaxial lines 5 are electrically connected to the rectangular patch 4. The differential coaxial lines 5 are used to input energy to the rectangular patch 4. The differential coaxial lines 5 perpendicularly penetrate the upper dielectric substrate 1, the middle dielectric substrate 2, and the lower dielectric substrate 3. The rectangular patch 4 radiates the energy input by the differential coaxial lines 5 outward.

[0041] A metasurface structure 6 is provided between the upper dielectric substrate 1 and the middle dielectric substrate 2; the metasurface structure includes several square metal patches 7, and an etching gap 8 is provided between two adjacent square metal patches 7; the square metal patches 7 are divided into square metal patches A71 and square metal patches B72; four square metal patches A71 distributed in a 2×2 matrix are set as matrix units, the size of the matrix unit is equal to that of the square metal patch B72, and the length d of the square metal patch B72 is equal to the length of the two square metal patches A71 plus the width of the etching gap 8. The four matrix units and twelve square metal patches B72 are combined to form a 4×4 matrix metasurface structure 6.

[0042] A metal ground plane 9 is disposed between the middle dielectric substrate 2 and the lower dielectric substrate 3; the metal ground plane 9 is provided with a coupling gap 10, the rectangular patch 4 is distributed on one side of the coupling gap 10, and the matrix unit is distributed on the other side of the coupling gap 10; the center of the coupling gap 10 corresponds to the center of the metasurface structure, and the reverse current is disrupted by the matrix unit while maintaining the symmetry of the radiation pattern; the width at both ends of the coupling gap 10 is greater than the width in the middle of the coupling gap 10.

[0043] A power feeding network is disposed at the bottom of the lower dielectric substrate 3; the input end of the power feeding network is configured as a microstrip line 11; the output end of the power feeding network is configured as a rectangle, a Y, or a fan shape; the vertical projection of the microstrip line 11 intersects with the vertical projection of the coupling gap 10, and the microstrip line 11 and the coupling gap 10 are perpendicular to each other. After the power feeding network inputs energy to the coupling gap 10, it radiates outward through the metasurface structure 6.

[0044] The dielectric constants of the upper dielectric substrate 1, the middle dielectric substrate 2, and the upper dielectric substrate 3 range from [1, 10]. The thickness h1 of the upper dielectric substrate 1, the thickness h2 of the middle dielectric substrate 2, and the thickness h3 of the lower dielectric substrate 3 range from [0.001λ0, 0.1λ0]; λ0 is the free space wavelength. The length a of the rectangular patch 4 ranges from [0.08λ0, 0.3λ0], and the width b ranges from [0.03λ0, 0.2λ0].

[0045] The width g of the elongated etched gap 8 between two adjacent square metal patches 7 ranges from [0.01λ]. g ,0.05λ g The side length d of the square metal patch B72 ranges from [0.2λ]. g ,0.4λ g ]. λ g The effective wavelength of the dielectric substrate 1 is denoted as .

[0046] The side length G of metal floor 9 LThe range is [0.9λ0, 1.2λ0]; the total length of the coupling gap 10 is 2×(L s1 +L S2 The total length of the coupling gap 10 ranges from [0.1λ]. g1 0.6λ g1 The width Ws1 at the widest point of the coupling gap 10 ranges from [0.05λ]. g1 ,0.4λ g1 The width Ws2 at its narrowest point ranges from [0.03λ]. g1 ,0.3λ g1 ], where λ g1 Where is the effective wavelength of the dielectric in the middle dielectric substrate 2, and n is the number of coupling gaps 10 in the metal ground plane; L s1 This represents the length corresponding to the widest point of a single coupling gap of 10, 2 s2 This represents the length corresponding to the narrowest point of a single coupling gap 10.

[0047] The width w of the Y-shaped microstrip line 11 f [0.1λ] g2 ,0.5λ g2 The length S of the output end of the feed network along the coupling gap 10 ranges from [0.1λ]. g2 ,0.4λ g2 The output terminal of the feed network has a length l along the microstrip line 11 ranging from [0.1λ]. g2 ,0.5λ g2 ], where λ g2 This is the effective wavelength of the dielectric substrate 3 in the lower layer.

[0048] In this embodiment, the specific parameters are set as follows: the thickness h1 of the upper dielectric substrate 1 is 0.254 mm, the thickness h2 of the middle dielectric substrate 2 is 3.25 mm, and the thickness h3 of the lower dielectric substrate 3 is 0.813 mm; the length a of the rectangular patch 4 is 15.5 mm, and the width b is 6 mm; the width g of the elongated etched gap 8 between two adjacent square metal patches 7 is 1.1 mm, and the side length d of the square metal patch B72 is 8.1 mm; the side length G of the metal ground plate 9 is... L The length is 60mm; the total length of the coupling gap 10 opened on the metal floor is 28.9mm, the width Ws1 at the widest point is 1.6mm, and the corresponding length L is 60mm. S1 The width at its narrowest point, Ws2, is 13.2mm, and the corresponding length, L, is 1.4mm. S2 The width w of the Y-shaped microstrip line 11 is 1.25mm. f The length of the output end of the power supply network is 1.85mm, the length of the output end of the power supply network is 7.5mm, and the length of the output end of the power supply network is 10mm.

[0049] like Figures 5 to 8 As shown, the radiation patterns of the dual-polarized metasurface antenna provided in this embodiment are displayed at different frequencies. Observations were conducted at 5.5 GHz and 6.2 GHz within the bandwidth range, revealing that the radiation direction remains symmetrical and the dominant polarization is significantly higher than the cross-polarization. The dual-polarized metasurface antenna provided in this embodiment exhibits high gain and strong anti-interference capability over a wide frequency band.

[0050] like Figure 9 As shown in the figure, the S-parameter characteristics of the dual-polarized metasurface antenna provided in this embodiment are illustrated; it can be seen that |S 11 The operating impedance bandwidth of approximately -10dB exhibits a vertical polarization of approximately 28.4% (4.84–6.44 GHz) and a horizontal polarization of approximately 38.7% (4.83–7.15 GHz). The achieved isolation profile is very high across the entire operating impedance bandwidth, with a minimum isolation exceeding 51dB. Therefore, the metasurface antenna provided in this embodiment can effectively achieve both wide bandwidth and high isolation characteristics.

[0051] like Figure 10 As shown in the diagram, this embodiment provides a dual-polarization gain diagram. The gain is high across the entire operating impedance bandwidth, with a peak gain of approximately 9.6 dBi for vertical polarization and approximately 9.1 dBi for horizontal polarization. Therefore, it can be seen that the metasurface antenna provided in this embodiment can effectively achieve high-gain characteristics.

[0052] Example 2

[0053] This embodiment provides a method for using a high-isolation, wideband, low-profile dual-polarized antenna. This method can be applied to the dual-polarized antenna described in Embodiment 1. The method includes:

[0054] In horizontal polarization, energy is input to the rectangular patch through the differential coaxial line; the rectangular patch radiates the energy input through the differential coaxial line outward; the metasurface structure reflects the energy radiated by the rectangular patch upward.

[0055] In vertical polarization, energy is input to the coupling gap through the feeding network and then radiated outward through the metasurface structure.

[0056] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A high-isolation, wideband, low-profile dual-polarized antenna, characterized in that, The device includes a stacked upper dielectric substrate, a middle dielectric substrate, and a lower dielectric substrate; a rectangular patch is disposed on the side of the upper dielectric substrate away from the middle dielectric substrate; a differential coaxial line is disposed below the rectangular patch; the differential coaxial line is used to input energy to the rectangular patch; the differential coaxial line perpendicularly penetrates the upper dielectric substrate, the middle dielectric substrate, and the lower dielectric substrate. The rectangular patch radiates energy input via the differential coaxial line outwards; A metasurface structure is provided between the upper dielectric substrate and the middle dielectric substrate; a metal ground plane is provided between the middle dielectric substrate and the lower dielectric substrate; the metal ground plane is provided with coupling gaps; a power supply network is provided at the bottom of the lower dielectric substrate; the power supply network inputs energy to the coupling gaps and then radiates it outward through the metasurface structure; The metasurface structure includes several square metal patches, which are arranged in a matrix, and an etched gap is provided between two adjacent square metal patches. The square metal patch is divided into square metal patch A and square metal patch B; several square metal patches A are distributed in a matrix to form a matrix unit, and the matrix unit has the same size as the square metal patch B. Several matrix units and several square metal patches B are combined to form a metasurface structure; the rectangular patch is distributed on one side of the coupling gap, and the matrix unit is distributed on the other side of the coupling gap. In horizontal polarization, energy is input to the rectangular patch through the differential coaxial line; the rectangular patch radiates the energy input through the differential coaxial line outward; the metasurface structure reflects the energy radiated by the rectangular patch upward. In vertical polarization, energy is input to the coupling gap through the feeding network and then radiated outward through the metasurface structure.

2. The high-isolation, wideband, low-profile dual-polarized antenna according to claim 1, characterized in that, The input end of the power supply network is configured as a microstrip line; the output end of the power supply network is configured as a rectangle, a Y, or a fan shape; the vertical projection of the microstrip line intersects with the vertical projection of the coupling gap.

3. The high-isolation, wideband, low-profile dual-polarized antenna according to claim 1, characterized in that, The dielectric constants of the upper dielectric substrate, the middle dielectric substrate, and the lower dielectric substrate are in the range of [1, 10], and the thicknesses h1, h2, and h3 of the upper dielectric substrate are in the range of [0.001λ0, 0.1λ0]; λ0 is the free space wavelength.

4. The high-isolation, wideband, low-profile dual-polarized antenna according to claim 1, characterized in that, The length 'a' of the rectangular patch ranges from [0.08λ0, 0.3λ0], and the width 'b' ranges from [0.03λ0, 0.2λ0], where λ0 is the free-space wavelength.

5. A high-isolation, wideband, low-profile dual-polarized antenna according to claim 1, characterized in that, The gap width g between two adjacent square metal patches in the metasurface structure ranges from [0.01λ]. g ,0.05λ g The side length d of the square metal patch B ranges from [0.2λ]. g ,0.4λ g ], where λ g This refers to the effective wavelength of the dielectric substrate in the upper layer.

6. A high-isolation, wideband, low-profile dual-polarized antenna according to claim 1, characterized in that, The metal floor is square; the side length G of the metal floor is... L The range is [0.9λ0, 1.2λ0]; the total length of the coupling gap ranges from [0.1λ0]. g1 0.6λ g1 The width range of the coupling gap is [0.03λ]. g1 ,0.4λ g1 ], where λ g1 λ is the effective wavelength of the dielectric substrate in the middle layer, and λ0 is the free space wavelength.

7. A high-isolation, wideband, low-profile dual-polarized antenna according to claim 2, characterized in that, The width w of the microstrip line f The range is [0.1λ] g2 ,0.5λ g2 The length S of the output terminal of the feeder network along the coupling gap direction ranges from [0.1λ]. g2 ,0.4λ g2 The output terminal of the feed network has a length l along the microstrip line in the range of [0.1λ]. g2 ,0.5λ g2 ], where λ g2 This represents the effective wavelength of the dielectric substrate in the lower layer.

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