High-isolation miniaturized oam antenna array based on defect grooving

Abstract

The application discloses a high-isolation miniaturized OAM antenna array based on defect slotting, which comprises a dielectric substrate arranged on a top layer and a grounding plate arranged below the dielectric substrate; a circular antenna array formed by four identical circular antenna units arranged in a column is arranged on the dielectric substrate; the circular antenna unit comprises a circular patch and n triangular patches uniformly arranged along an outer circle of the circular patch; and a T-shaped power divider is connected with adjacent two triangular patches for feeding, the OAM antenna array can realize reconfiguration of OAM modes, has the advantages of structural miniaturization, low profile, high isolation and easy manufacturing, and can change OAM modes of vortex electromagnetic waves by only changing feeding phases without changing antenna units, array combination modes and defect ground structures.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of full automation products, and relates to a high-isolation miniaturized OAM antenna array based on defect slotting. BACKGROUND

[0002] The importance of an antenna, as an essential component of a wireless communication system, is self-evident. The function of an antenna is to directively radiate or receive electromagnetic wave signals. With the vigorous development of wireless communication, people's requirements for spectrum utilization are getting higher and higher. Expanding the working bandwidth of an antenna can improve the spectrum utilization to a certain extent, but it cannot solve the problem of frequency as a limited resource from the source. The orbital angular momentum carried by a vortex electromagnetic wave opens up a new degree of freedom for electromagnetic waves, thereby providing a new direction for solving the problem of spectrum resource shortage in a wireless communication system. For the research on vortex electromagnetic waves, most of the research focuses on the generation method of OAM and the electromagnetic characteristics of OAM, and there is little research on the reconfigurable OAM mode. SUMMARY

[0003] To solve the above problems, the technical scheme adopted by the application is: a high-isolation miniaturized OAM antenna array based on defect slotting, comprising

[0004] a dielectric substrate placed on the top layer and a ground plate arranged below the dielectric substrate;

[0005] a circular antenna array formed by arranging four identical circular antenna units on the dielectric substrate;

[0006] the circular antenna unit comprises a circular patch and n triangular patches uniformly arranged along the outer circle of the circular patch;

[0007] and a T-shaped power divider connected to the adjacent two triangular patches for feeding.

[0008] Further, the connecting line of the centers of the circular antenna units forms a square.

[0009] Further, the depth of the square slot between the adjacent triangular patches is 1 / 8 of a wavelength.

[0010] Further, the radius of the circular patch is 1 / 2 of a wavelength.

[0011] Further, a cross-shaped defect ground is arranged on the ground plate to form a cross-shaped defect ground array;

[0012] The interval between the adjacent cross-shaped defect grounds is about 1 / 8 of a wavelength.

[0013] The cross-shaped defect ground array is located at the middle position below the circular antenna array.

[0014] Further, the T-shaped power divider comprises a feeding port, a one-way branch and a two-way branch connected to the feeding port, the one-way branch is longer than the two-way branch by a quarter wavelength, and the feeding port is arranged at an edge of the dielectric substrate.

[0015] Further, n is greater than or equal to 2.

[0016] The high-isolation miniaturized OAM antenna array based on defect slot can realize reconfiguration of OAM modes, has the advantages of structure miniaturization, low profile, high isolation and easy manufacturing, and can change OAM modes of vortex electromagnetic waves by only changing feeding phases without changing antenna units, array combination modes and defect ground structures.

[0017] The application has simple structure and low cost, and has wide application prospect.

[0018] The application has high array element isolation and good OAM purity. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0020] Figure 1 It is a schematic diagram of the high-isolation miniaturized OAM antenna array based on defect slot in the present application;

[0021] Figure 2 It is a top view of the high-isolation miniaturized OAM antenna array based on defect slot in the present application;

[0022] Figure 3 It is a distribution diagram of the antenna unit along clockwise feeding in the present application, wherein (a) is in the case of far-field amplitude, and (b) is in the case of phase;

[0023] Figure 4 It is a distribution diagram of the antenna unit along counterclockwise feeding in the present application, wherein (a) is in the case of far-field amplitude, and (b) is in the case of phase;

[0024] Figure 5 It is an OAM mode purity diagram of the antenna unit along clockwise feeding in the present application;

[0025] Figure 6 It is a normalized directivity coefficient diagram of the antenna unit along clockwise feeding in the present application.

[0026] Reference numerals: 1. First power supply port, 2. Second power supply port, 3. Third power supply port, 4. Fourth power supply port, 5. One-way stub, 6. Dielectric substrate, 7. Cross-shaped defect ground, 8. Square slot, 9. Circular patch, 10. Two-way stub, 11. Ground plane. Detailed Implementation

[0027] It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Figure 1 This is a schematic diagram of a high-isolation miniaturized OAM antenna array based on defect slotting, as described in an example of the present invention.

[0030] Figure 2 This is a top view of a high-isolation miniaturized OAM antenna array based on defect slotting, as described in an example of the present invention.

[0031] A miniaturized OAM antenna array with high isolation based on defect slotting, including

[0032] The dielectric substrate 6 is placed on the top layer and the ground plane 11 is disposed below the dielectric substrate 6;

[0033] The dielectric substrate 6 and the ground plane 11 are square;

[0034] A circular antenna array consisting of four identical circular antenna elements is disposed on the dielectric substrate 6; the circular antenna element includes a circular patch 9 and n triangular patches evenly arranged along the outer circumference of the circular patch 9; in this embodiment, n is 9.

[0035] And a T-type power divider that connects to two adjacent triangular patches for power supply.

[0036] The radius of the circular patch 9 is half a wavelength. Too large an array radius will reduce the purity of the OAM modes, while too small an array radius will deteriorate the isolation between array elements.

[0037] The lines connecting the centers of the circular antenna elements form a square.

[0038] The depth of the square slot 8 between adjacent triangular patches is 1 / 8 wavelength. Each antenna element is evolved from a circular patch 9 with a slot 8, thus reducing the operating frequency to 2 / 5 of the original antenna within the same size.

[0039] The grounding plate 11 is provided with uniformly arranged cross-shaped defect ground 7 grooves, forming a cross-shaped defect ground 7 array;

[0040] The interval between adjacent cross-shaped defect sites 7 is approximately 1 / 8 of a wavelength;

[0041] The cross-shaped defect ground 7 array is located in the middle position below the circular antenna array. To improve the isolation between array elements while ensuring OAM mode purity, the spacing between the cross-shaped defect grounds 7 is approximately 1 / 8 wavelength. Too large a spacing will reduce the isolation, while too small a spacing will reduce the antenna gain.

[0042] The T-type power divider includes a power supply port, and one stub 5 and two stubs 10 connected to the power supply port.

[0043] The first stub 5 is a quarter wavelength longer than the second stub 10, resulting in a 90-degree phase difference between the two outputs of the T-type power divider. The feed position is 45 degrees out of phase with the center of the antenna element, thus exciting the higher-order mode TM of the circular patch 9. 21 This allows each antenna element to carry a first-order OAM mode. To ensure input matching for each antenna element, the stub width of the T-type power divider needs to be adjusted. While maintaining manufacturing accuracy, multi-section impedance matching is employed to give the antenna a larger operating bandwidth. Finally, the OAM mode of the vortex electromagnetic wave can be flexibly controlled through the feed ports of the four antenna elements. The feed ports are located at the edge of the dielectric substrate 6.

[0044] A cross-shaped defect 7 with a certain interval exists on the ground plane 11 between adjacent circular antenna elements, thereby ensuring that the isolation between adjacent circular antenna elements is less than -25dB. By feeding the four circular antenna elements with equal amplitude at the first feed port 1, the second feed port 2, the third feed port 3, and the fourth feed port 4 in a certain direction, and maintaining a 90-degree phase difference between adjacent ports, the OAM modes can be superimposed.

[0045] Figure 3This is a schematic diagram of the clockwise feeding distribution of antenna elements in an embodiment of the present invention, where (a) represents the far-field amplitude and (b) represents the phase. By feeding four circular antenna elements with equal amplitude in a clockwise direction and ensuring a 90-degree phase difference between adjacent feed ports, a second-order OAM is obtained. Conversely, if the feeding is counterclockwise, a zero-order OAM is obtained, such as... Figure 4 As shown, Figure 4 This is a schematic diagram of the distribution of the antenna element fed counterclockwise in an example of the present invention, where (a) is the far-field amplitude case and (b) is the phase case;

[0046] To more intuitively observe the OAM modal distribution, the OAM purity was calculated, and the results are as follows: Figure 5 As shown, the purity of the second-order OAM mode reaches 86.9%, indicating that the superimposed OAM mode still has high purity.

[0047] Finally, the normalized directional coefficients of second-order OAM are given, such as... Figure 6 As shown, when the pitch angle is zero degrees, the directional pattern has a significant dip, which is caused by the phase singularity of OAM.

[0048] Keeping all parameters constant, we observe the changes in OAM mode by analyzing two feed phases. Since the antenna element of the invention carries first-order OAM, the feed phases of the four antenna elements are clockwise and counterclockwise, respectively, and the phase difference between adjacent antenna elements is ninety degrees.

[0049] The high-isolation miniaturized OAM antenna array based on defect slotting can obtain vortex electromagnetic waves of different modes without changing the parameters such as antenna elements, array combination method, and defect ground structure. It only needs to perform equal amplitude feeding along different directions and maintain a 90-degree phase difference between adjacent elements.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A miniaturized OAM antenna array with high isolation based on defect slotting, characterized in that: include A dielectric substrate placed on the top layer and a ground plane disposed below the dielectric substrate; A circular antenna array consisting of four identical circular antenna elements is disposed on the dielectric substrate; The circular antenna unit includes a circular patch and n triangular patches evenly arranged along the outer circumference of the circular patch; n=9; And a T-type power divider that connects to two adjacent triangular patches for power supply; The ground plane is provided with uniformly arranged cross-shaped defect grounds, forming a cross-shaped defect ground array; The interval between adjacent cross-shaped defects is approximately 1 / 8 of a wavelength. The cross-shaped defect array is located in the middle position below the circular antenna array; The T-type power divider includes a power supply port, and a first stub and a second stub connected to the power supply port. The first stub is a quarter wavelength longer than the second stub. The power supply port is located at the edge of the dielectric substrate.

2. The high-isolation miniaturized OAM antenna array based on defect slotting according to claim 1, characterized in that: The lines connecting the centers of the circular antenna elements form a square.

3. The high-isolation miniaturized OAM antenna array based on defect slotting according to claim 1, characterized in that: The depth of the square groove between adjacent triangular patches is 1 / 8 wavelength.

4. The high-isolation miniaturized OAM antenna array based on defect slotting according to claim 1, characterized in that: The radius of the circular patch is 1 / 2 wavelength.

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