A broadband dual-polarization multi-beam orbital angular momentum antenna and communication equipment

Abstract

The present invention discloses a broadband dual-polarization multi-beam orbital angular momentum antenna and communication equipment, including a feed source, a dielectric substrate, a metal floor and a metasurface structure, wherein the metal floor is arranged below the dielectric substrate, the metasurface structure is arranged on the upper surface of the dielectric substrate, the feed source is arranged directly above the metasurface structure, and the metasurface structure includes N radiation units arranged in a periodic array, the radiation units include L-shaped patches and parasitic patches, and the sizes of the L-shaped patches and parasitic patches of the N radiation units are different. The planar reflection type orbital angular momentum antenna provided by the present invention has the characteristics of broadband, dual polarization, high gain and multi-beam, and the method used by the present invention can be used to generate vortex waves of any mode, any number of beams and any beam direction.

Description

Technical Field

[0001] The present invention relates to the field of communications, and in particular to a broadband dual-polarization multi-beam orbital angular momentum antenna and communications equipment. Background Art

[0002] In recent years, orbital angular momentum (OAM) has attracted the attention of the academic community because of its infinite orthogonal modes. It can effectively alleviate the shortage of spectrum resources, expand communication capacity and improve communication speed. Since 2007, orbital angular momentum has been introduced into the microwave frequency band, making it possible to apply orbital angular momentum in practice. Orbital angular momentum exists in electromagnetic waves in the form of spiral equiphase surfaces, so it is called vortex wave. The mode of vortex wave is determined by the ratio of the total phase of one revolution to 2π. Theoretically, the number of modes can be any value.

[0003] The core step of generating vortex waves is to transform the traditional planar equiphase surface into a spiral equiphase surface. So far, there are many methods to generate OAM, including single patch, spiral phase plate, dielectric resonator, uniform circular array, artificial electromagnetic metasurface. The orbital angular momentum beam generated by a single patch has the disadvantage of low gain. Spiral dielectric plates and dielectric resonators have the disadvantage of difficult processing. Uniform circular arrays have the disadvantages of complex feeding networks and large antenna losses. Artificial electromagnetic metasurfaces reduce the difficulty of design and easily obtain higher antenna gain by feeding with horns in the form of air feeding.

[0004] At present, the vortex wave antennas of artificial electromagnetic metasurfaces that can be formed are relatively simple, mainly broadband vortex wave antennas, dual-polarization vortex wave antennas, and multi-beam vortex wave antennas. There are few designs that can achieve broadband, dual-polarization, multi-beam, and high-gain integrated multifunctional vortex waves. The combination of OAM mode multiplexing and polarization multiplexing has a very broad application prospect for future large-capacity communications, so the design of multifunctional vortex wave antennas is very necessary. Summary of the invention

[0005] In order to overcome the shortcomings and deficiencies of the prior art, the present invention provides a broadband dual-polarization multi-beam orbital angular momentum antenna and communication equipment, which can simultaneously generate horizontally and vertically polarized broadband high-gain vortex beams.

[0006] The present invention adopts the following technical solution:

[0007] A broadband dual-polarization multi-beam orbital angular momentum antenna comprises a feed source, a dielectric substrate, a metal floor and a metasurface structure, wherein the metal floor is arranged below the dielectric substrate, the metasurface structure is arranged on the upper surface of the dielectric substrate, the feed source is arranged directly above the metasurface structure, the metasurface structure comprises N radiating units arranged in a periodic array, the radiating units comprise L-shaped patches and parasitic patches, and the sizes of the N radiating units are different, that is, the sizes of the L-shaped patches and the parasitic patches are all different.

[0008] Furthermore, the radiation unit includes four L-shaped patches and four parasitic patches, the four L-shaped patches are symmetrical about the center point of the dielectric substrate, and the four parasitic patches are arranged around the four L-shaped patches, specifically including two vertical rectangular patches and two horizontal rectangular patches.

[0009] Furthermore, the feed source is a horn antenna, a microstrip antenna or an array antenna.

[0010] Furthermore, the radiation units arranged in an array form a circular array or a polygonal array.

[0011] Furthermore, the polarization direction of the incident wave of the feed source is 45°.

[0012] Furthermore, an air layer is provided between the metal floor and the dielectric substrate.

[0013] Furthermore, the L-shaped patch includes a horizontal patch and a vertical patch that are perpendicular to each other, and the horizontal patch and the vertical patch have different sizes.

[0014] Furthermore, the four L-shaped patches are equal in size.

[0015] Furthermore, the radiation unit generates at least one beam, and the phase is expressed as in, is represented as the direction of the kth beam, Represents the position vector of the unit to the entire metasurface, the relative coordinates of the radiation unit when the center of the dielectric substrate is the origin, l k represents the mode number of the kth vortex wave generated.

[0016] A communication device comprises the broadband dual-polarization multi-beam orbital angular momentum antenna.

[0017] Beneficial effects of the present invention:

[0018] (1) The antenna metasurface structure can operate in a wide band. The vortex wave antenna of this embodiment can operate in a wide band of 13-15.5 GHz.

[0019] (2) The polarization direction of the spherical wave emitted by the antenna feed is 45° to both the X and Y axes to excite the units in two polarization directions to simultaneously realize dual-polarized beams. The antenna can operate in two polarization directions. The vortex wave antenna of this embodiment operates in horizontal and vertical polarization directions.

[0020] (3) The antenna can realize multiple beams in any direction carrying orbital angular momentum by using N radiating elements of different sizes;

[0021] (4) The antenna has high gain (up to 19.3 dBi in the x-polarization direction at 15 GHz and up to 18.8 dBi in the y-polarization direction) and high aperture efficiency (the aperture efficiency at 15 GHz can be 11.54%). BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a three-dimensional view of embodiment 1 of the present invention;

[0023] Figure 2 is a schematic diagram of the dimensions of the radiation unit of Embodiment 1 of the present invention;

[0024] Figure 3 is a phase shift curve diagram of the radiation unit in the horizontal polarization direction according to Embodiment 1 of the present invention;

[0025] Figure 4 is a phase shift curve diagram of the radiation unit in the vertical polarization direction according to Embodiment 1 of the present invention;

[0026] Figure 5 is a phase compensation diagram of the horizontal size of the electromagnetic metasurface according to embodiment 1 of the present invention;

[0027] Figure 6 is a phase compensation diagram of the vertical dimension of the electromagnetic metasurface according to Embodiment 1 of the present invention;

[0028] Figure 7 is the far-field radiation pattern of the antenna of Example 1 of the present invention at 13 GHz;

[0029] Figure 8 is the far-field radiation pattern of the antenna of Example 1 of the present invention at 14 GHz;

[0030] Fig. 9 is the far-field pattern of the antenna of Example 1 of the present invention at 15 GHz;

[0031] Fig.10 is the far-field pattern of the antenna of Example 1 of the present invention at 15.5 GHz;

[0032] Fig.11 is a near-field phase and amplitude diagram of the antenna of Example 1 of the present invention operating in the x-polarization direction at 13 GHz;

[0033] Fig.12 is a near-field phase and amplitude diagram of the antenna of Example 1 of the present invention operating in the x-polarization direction at 14 GHz;

[0034] Fig.13 is a near-field phase and amplitude diagram of the antenna of Example 1 of the present invention operating in the x-polarization direction at 15 GHz;

[0035] Fig.14 is a near-field phase and amplitude diagram of the antenna of Example 1 of the present invention operating in the x-polarization direction at 15.5 GHz;

[0036] Fig.15 is a near-field phase and amplitude diagram of the antenna of Example 1 of the present invention operating in the y-polarization direction at 13 GHz;

[0037] Fig.16 is a near-field phase and amplitude diagram of the antenna of Example 1 of the present invention operating in the y-polarization direction of 14 GHz;

[0038] Fig.17 is a near-field phase and amplitude diagram of the antenna of Example 1 of the present invention operating in the y-polarization direction of 15 GHz;

[0039] Fig.18 is a near-field phase and amplitude diagram of the antenna of Example 1 of the present invention operating in the y-polarization direction at 15.5 GHz;

[0040] Fig.19 is a phase compensation diagram of the horizontal size of the electromagnetic metasurface according to embodiment 2 of the present invention;

[0041] Fig. 20 is a phase compensation diagram of the vertical dimension of the electromagnetic metasurface according to Embodiment 2 of the present invention;

[0042] Fig.21 is the far-field pattern of the antenna of Example 2 of the present invention at 13 GHz;

[0043] Fig. 22 is the far-field pattern of the antenna of Example 2 of the present invention at 14 GHz;

[0044] Fig.23 is the far-field pattern of the antenna of Embodiment 2 of the present invention at 15 GHz;

[0045] Fig.24 is the far-field pattern of the antenna of Embodiment 2 of the present invention at 15.5 GHz;

[0046] Fig.25 is a phase compensation diagram of the horizontal size of the electromagnetic metasurface according to Embodiment 3 of the present invention;

[0047] Fig.26is a phase compensation diagram of the vertical dimension of the electromagnetic metasurface according to Embodiment 2 of the present invention;

[0048] Fig. 27 is the far-field pattern of the antenna of Example 2 of the present invention at 13 GHz;

[0049] Fig.28 is the far-field pattern of the antenna of Example 2 of the present invention at 14 GHz;

[0050] Fig.29 is the far-field pattern of the antenna of Embodiment 2 of the present invention at 15 GHz;

[0051] Fig.30 This is the far-field radiation pattern of the antenna of Example 2 of the present invention at 15.5 GHz. DETAILED DESCRIPTION

[0052] The present invention will be further described in detail below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0053] Example 1

[0054] A broadband dual-polarization multi-beam orbital angular momentum antenna comprises a feed source 1, a dielectric substrate 2, a metal floor 3 and a metasurface structure. The feed source horn generates a spherical wave 5 to irradiate the metasurface structure, and different reflected electromagnetic waves 6 and 7 are obtained according to different phase compensations of the metasurface structure. The reflected electromagnetic wave is a vortex wave carrying orbital angular momentum.

[0055] The metal floor 3 is arranged below the dielectric substrate 2, and an air layer is spaced between the metal floor and the dielectric substrate, which can reduce the influence of surface waves and the phase shift sensitivity of the metasurface. The metasurface structure is arranged on the upper surface of the dielectric substrate, and the feed source is arranged directly above the metasurface structure. The metasurface structure includes N radiation units 4 arranged in a periodic array, and the array can be a rectangular, circular, polygonal or other structure.

[0056] The radiation unit includes an L-shaped patch and a parasitic patch. The sizes of the L-shaped patches and the parasitic patches of the N radiation units are almost different. The size of each L-shaped patch and the parasitic patch can be adjusted to produce the phase shift required for the position. Due to the orthogonality of the unit structure, the metasurface simultaneously produces electromagnetic responses to two orthogonal polarizations, and can convert a single linearly polarized incident spherical wave into a vortex wave in two polarization directions.

[0057] The radiating elements are of different sizes so as to generate a desired phase over a wide bandwidth.

[0058] In this embodiment, the horizontal direction is based on the center point of the dielectric substrate as the origin, the X-axis direction is the horizontal direction, and the Y-axis direction is the vertical direction.

[0059] Specifically, the radiation unit includes four L-shaped patches and four parasitic patches, and has broadband characteristics. The four L-shaped patches are symmetrical about the center point of the dielectric substrate. The L-shaped patch includes two orthogonal horizontal patches and a vertical patch. The sizes of the horizontal patch and the vertical patch are different, and the sizes of the four L-shaped patches are equal. The intersection of the four L-shaped patches is close to the center of the dielectric substrate. The four L-shaped patches are arranged in groups of two, above and below the horizontal midline of the dielectric substrate. The four parasitic patches are located around the four L-shaped patches. The four parasitic patches include two horizontal rectangular patches and two vertical rectangular patches. The two horizontal rectangular patches are symmetrically arranged about the center of the dielectric substrate, and the two vertical rectangular patches are symmetrically arranged about the center of the dielectric substrate.

[0060] The polarization direction of the spherical wave emitted by the feed source is 45° to both the x-axis and the y-axis to stimulate the units in two polarization directions to simultaneously realize dual-polarization beams; Figure 2 As shown, Figure 1 The radiation unit 4 in the embodiment changes the sizes of Lx, Lm and Ly, Ln respectively, and can independently realize the regulation of x-polarization and y-polarization.

[0061] The feed source 1 is a horn antenna or a microstrip antenna. This embodiment uses a horn antenna.

[0062] The radiation unit is an L-shaped and parasitic patch structure, and its number can be selected according to the specific situation. In this embodiment, there are four L-shaped and parasitic patch structures, which increase the resonance bandwidth and can independently adjust the phase of horizontal and vertical polarization.

[0063] The four L-shaped and four parasitic patches used in this embodiment have equal horizontal dimensions and equal vertical dimensions.

[0064] The horizontal size and vertical size of the radiation unit determine the phases of horizontal polarization and vertical polarization.

[0065] The phase compensation formula of the radiation unit is: in, is represented as the direction of the kth beam, Represents the position vector of the unit to the entire metasurface, the relative coordinates of the radiation unit when the center of the dielectric substrate is the origin, l k represents the mode number of the kth vortex wave generated.

[0066] like Figure 2 As shown, the dimensions selected in this embodiment are:

[0067] The dielectric substrate 2 has a thickness of 0.55 mm, is made of F4B, and has a dielectric constant of 2.25; the dimensions of the radiation unit are P=13 mm, g=0.2 mm, Lm=0.3×Lx+1.2 (mm), Ln=0.3×Ly+1.2 (mm), W0=0.6 mm, W1=1.4 mm, D=0.7 mm, Lx=3~10 mm, Ly=3~10 mm.

[0068] See also Figure 3 In the 13-15.5GHz broadband range, the incident wave is polarized at 45° to the x and y directions respectively. The x-direction dimension of the L-type patch structure changes continuously from 3 to 10mm, and a phase shift coverage range of more than 360° can be achieved. At this time, when Ly is an arbitrary value, the phase shift curve with Lx as a variable is almost unchanged (taking Ly = 4mm, 6mm, 8mm as an example), and the change in the surface y-direction dimension has almost no effect on the change in the x-direction dimension. In addition, the reflection coefficient curves are all close to 1, indicating that the unit has good reflection characteristics in the x direction.

[0069] See also Figure 4 In the 13-15.5GHz broadband range, the incident wave is polarized at 45° to the x and y directions respectively. The y-direction dimension of the L-type patch structure changes continuously from 3 to 10mm, and a phase shift coverage range of more than 360° can be achieved. At this time, when Lx is an arbitrary value, the phase shift curve with Lx as a variable is almost unchanged (taking Lx = 4mm, 6mm, 8mm as an example), and the change in the surface dimension in the x direction has almost no effect on the change in the y direction. In addition, the reflection coefficient curves are all close to 1, indicating that the unit has good reflection characteristics in the y direction.

[0070] like Figure 1 In this embodiment, 16×16 radiation units 4 are used on the upper surface of the dielectric substrate 2 and are arranged periodically. According to the formula in, The phase angle required to compensate for spherical wave to plane wave, the phase angle required for the number of modes, the number of beams and the phase angle required for the radiation direction are calculated to correspond to the size provided by each radiation unit.

[0071] In this embodiment, the length in the x direction is Figure 5 To compensate, the length in the y direction is Figure 6 Compensation is performed to obtain the artificial electromagnetic supersurface of this embodiment.

[0072] like Figure 7 , Figure 8 , Fig. 9 and Fig.10As shown, the corresponding far-field radiation patterns are 13 GHz, 14 GHz, 15 GHz, and 15.5 GHz, respectively. Using a feed horn with a polarization direction of 45° to the x and y directions to illuminate the metasurface, the far-field radiation pattern at 13-15.5 GHz can be obtained. The mode numbers and directions of the x-polarized and y-polarized beams are: like Fig.11 , Fig.12 , Fig.13 and Fig.14 As shown, the corresponding x-polarization near-field phase diagrams are 13GHz, 14GHz, 15GHz, and 15.5GHz respectively. From the far-field and near-field diagrams, it can be seen that the antenna can generate a vortex wave with a mode of -1 in the specified direction in the x-polarization broadband range. Fig.15 , Fig.16 , Fig.17 and Fig.18 As shown, the corresponding y-polarization near-field phase diagrams are 13 GHz, 14 GHz, 15 GHz, and 15.5 GHz respectively. From the far-field and near-field diagrams, it can be seen that the antenna can generate vortex waves in mode 1 in a specified direction within the y-polarization broadband range.

[0073] It can be seen that the broadband dual-polarized multi-beam orbital angular momentum antenna of the present invention can work simultaneously in the broadband of 13-15.5 GHz and in two polarization directions. At the same time, the antenna can realize multi-beam, multi-mode, and vortex waves in any radiation direction.

[0074] Example 2

[0075] The difference between this embodiment and embodiment 1 is that the number of generated beams is different, so the corresponding phase compensation is also different. This embodiment generates two beams in the x-polarization direction and the y-polarization direction, and the phase compensation in the x-polarization direction is calculated according to Fig.19 Compensation is performed, and the phase compensation in the y polarization direction is based on Fig. 20 By performing compensation, the metasurface antenna of this embodiment can be obtained.

[0076] like Fig.21 , Fig. 22 , Fig.23 and Fig.24 , the operating frequency is 13-15.5GHz, the incident wave is polarized at 45° to the x and y directions respectively, and the far-field radiation patterns of 13GHz, 14GHz, 15GHz, and 15.5GHz are obtained. Among them, the mode number and beam direction in the x-polarization direction and the y-polarization direction are:

[0077] Example 3

[0078] The difference between this embodiment and embodiment 1 is that the number of generated beams is different, so the corresponding phase compensation is also different. This embodiment generates four beams in the x-polarization direction and the y-polarization direction, and the phase compensation in the x-polarization direction is calculated according to Fig.25 Compensation is performed, and the phase compensation in the y polarization direction is based on Fig.26 By performing compensation, the metasurface antenna of this embodiment can be obtained.

[0079] like Fig. 27 , Fig.28 , Fig.29 and Fig.30 , the operating frequency is 13-15.5GHz, the incident wave is polarized at 45° to the x and y directions respectively, and the far-field radiation patterns of 13GHz, 14GHz, 15GHz, and 15.5GHz are obtained. Among them, the mode number and beam direction in the x-polarization direction and the y-polarization direction are:

[0080] Example 4

[0081] A communication device comprises the broadband dual-polarization multi-beam orbital angular momentum antenna as described in Example 1.

[0082] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A broadband dual-polarization multi-beam orbital angular momentum antenna, characterized in that: It includes a feed source, a dielectric substrate, a metal floor and a metasurface structure, wherein the metal floor is arranged below the dielectric substrate, the metasurface structure is arranged on the upper surface of the dielectric substrate, the feed source is arranged directly above the metasurface structure, the metasurface structure includes N radiation units arranged in a periodic array, the radiation units include L-shaped patches and parasitic patches, and the sizes of the L-shaped patches and parasitic patches of the N radiation units are all different; The radiation unit generates at least one beam, and the phase is expressed as in, is represented as the direction of the kth beam, represents the position vector from the radiation unit in the mth row and nth column to the center of the entire metasurface structure, x m ,y n are the horizontal and vertical coordinates of the cell in the mth row and nth column, respectively. k represents the mode number of the kth vortex wave generated, is the distance vector from the feed source to the center point of the metasurface structure.

2. A broadband dual-polarization multi-beam orbital angular momentum antenna according to claim 1, characterized in that: The radiation unit includes four L-shaped patches and four parasitic patches. The four L-shaped patches are symmetrical about the center point of the dielectric substrate. The four parasitic patches are arranged around the four L-shaped patches, specifically including two vertical rectangular patches and two horizontal rectangular patches.

3. The broadband dual-polarization multi-beam orbital angular momentum antenna according to claim 1, characterized in that: The feed source is a horn antenna, a microstrip antenna or an array antenna.

4. A broadband dual-polarization multi-beam orbital angular momentum antenna according to any one of claims 1 to 3, characterized in that: The radiation units arranged in an array form a circular array or a polygonal array.

5. The broadband dual-polarization multi-beam orbital angular momentum antenna according to claim 1, characterized in that: The incident wave polarization direction of the feed is 45°.

6. The broadband dual-polarization multi-beam orbital angular momentum antenna according to claim 1, characterized in that: An air layer is spaced between the metal floor and the dielectric substrate.

7. The broadband dual-polarization multi-beam orbital angular momentum antenna according to claim 2, characterized in that: The L-shaped patch includes a horizontal patch and a vertical patch that are perpendicular to each other, and the horizontal patch and the vertical patch have different sizes.

8. The broadband dual-polarization multi-beam orbital angular momentum antenna according to claim 7, characterized in that: The four L-shaped patches are equal in size.

9. A communication device, characterized in that: A broadband dual-polarization multi-beam orbital angular momentum antenna comprising any one of claims 1-8.

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