Low-orbit satellite communication Ku frequency band antenna

Abstract

The invention relates to the technical field of wireless communication, and discloses a low-orbit satellite communication Ku frequency band antenna, which is characterized by comprising a primary radiation patch, a secondary coupling radiation patch, a radiation aperture surface, a first broadband feed network layer, a coupling matching cavity layer, a second broadband feed network layer and a standard waveguide assembly, the working bandwidth of the antenna is improved based on a new form of combining the broadband feed network and the coupling metal cavity; the antenna can work normally in a Ku frequency band range; through the design of loading, stacking and the like, the antenna radiation layer, the coupling layer and the feed layer are located on the same plane, and the profile of the antenna is reduced; when the design is connected and integrated with other circuit systems, the overall profile of the antenna can be reduced; the antenna is compact in structure, convenient to assemble, excellent in electrical performance, high in antenna gain, wide in bandwidth, high in polarization purity, simple in structure and light in weight.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technology, and more specifically, to a low-orbit satellite communication Ku-band antenna. Background Art

[0002] Most existing satellite communication technologies use dual-polarization and co-aperture design, but this requirement usually increases the complexity of the antenna system. Because microstrip antenna units have the characteristics of low profile, microstrip antennas can generally be selected for array antenna design. For high-gain scenarios, microstrip antennas can be implemented by increasing the number of antenna units or increasing the unit size.

[0003] However, conventional microstrip antennas have disadvantages such as low aperture efficiency, large dielectric loss, and narrow bandwidth. At the same time, the feeding network is relatively complex when forming an array, which is not conducive to system integration and commissioning.

[0004] Therefore, the present invention provides a low-orbit satellite communication Ku-band antenna, which improves the above-mentioned technical problems. Summary of the invention

[0005] The disclosed embodiments aim to address the deficiencies of the prior art and provide a Ku-band antenna for low-orbit satellite communications. The present invention improves the working bandwidth of the antenna through a new form based on the combination of a broadband feeding network and a coupled metal cavity; ensures that this type of antenna can work normally within the Ku-band range; through the design of loading, stacking, etc., the antenna radiation layer, coupling layer and feeding layer are located in the same plane, thereby reducing the antenna profile; when the design is connected and integrated with other circuit systems, the overall profile of the antenna can be reduced, and the antenna unit and its array have lower standing waves, side lobes, and cross polarization, and can have higher aperture efficiency within the entire frequency band.

[0006] The above technical objectives of the present invention are achieved through the following technical solutions: A low-orbit satellite communication Ku-band antenna unit, comprising: a primary radiation patch, a secondary coupled radiation patch, a radiation port, a first broadband feed network layer, a coupled matching cavity layer, a second broadband feed network layer, and a standard waveguide component;

[0007] The radiation aperture surface is composed of 16×16 unit group arrays as antenna units, and a secondary coupling radiation patch is attached to the center of the radiation aperture surface of each unit group; the right side and the bottom side of the secondary coupling radiation patch are attached with primary radiation patches;

[0008] A first broadband feeding network layer is provided on the lower surface of the radiation port surface, and the radiation port surfaces of every two unit groups are connected through the first broadband feeding network layer;

[0009] A coupling matching cavity layer is provided below the first broadband feeding network layer, and the coupling matching cavity layer is used to improve impedance matching;

[0010] A second broadband feeding network layer is arranged below the coupling matching cavity layer, and a standard waveguide component is arranged below the second broadband feeding network layer.

[0011] As a preferred technical solution of the present invention, energy is transferred to the primary radiation patch through the first broadband feeding network layer, the primary radiation patch transfers the microwave signal to the secondary coupling radiation patch by coupling, and finally the radiation port transfers the energy to space or receives the microwave signal from space.

[0012] As a preferred technical solution of the present invention, the secondary coupling radiation patch is composed of a small circular secondary coupling radiation patch located near the primary radiation patch;

[0013] The secondary coupling radiation patch adds a capacitive element to the input impedance, offsetting the inductive characteristics associated with the primary radiation patch; the input impedance can be accurately matched by adjusting the size of the secondary coupling radiation patch and the gap between it and the primary radiation patch.

[0014] As a preferred technical solution of the present invention, two primary radiation patches and a secondary coupling radiation patch are provided in the radiation aperture of each unit group, and the two primary radiation patches and the secondary coupling radiation patch divide the radiation aperture into a stepped gradient horn plus a cross grid structure; by adjusting the aperture size and height of each step of the stepped horn, the impedance matching of the horn antenna can be achieved;

[0015] Among them, the size and length of the waveguide correspond to the wave impedance of the guided mode; the calculation formula is as follows:

[0016]

[0017] Among them, E u 、E v Transverse electric field; H u , H v transverse magnetic field; ε and μ are the dielectric constant and magnetic permeability of the medium respectively; ω is the angular frequency; β and κ are variable constants; λ and λ are c are the operating wavelength and the cut-off wavelength respectively; is the inherent impedance of the medium, and the air impedance

[0018] As a preferred technical solution of the present invention, the conditions for no grating lobe to appear in the radiation aperture array composed of 16×16 units are:

[0019]

[0020] Where d is the spacing between unit antennas, λ is the wavelength in free space corresponding to the antenna operating frequency, and θ is the scanning angle of the antenna. When the antenna is not scanning, θ = 0, and the condition for no grating lobe to appear is:

[0021] d<λ

[0022] For the radiation aperture of the square antenna of the present invention, the conditions for wave transmission are:

[0023] λ<2L

[0024] Where L is the length of the radiation aperture.

[0025] As a preferred technical solution of the present invention, the thickness of the primary radiation patch and the secondary coupling radiation patch is an ideal thickness, and the radius thereof is finite, then the current density J on the secondary coupling radiation patch can be modeled and analyzed by a global sine function:

[0026]

[0027] Among them, f n refers to the basis functions of different vectors, I n It refers to the current density.

[0028] As a preferred technical solution of the present invention, the current density of the primary radiation patch and the current density at the connection of the first broadband feeding network layer can be expressed by a piecewise sine basis function as follows:

[0029]

[0030] in, is the basis function of np on the primary radiation patch.

[0031] As a preferred technical solution of the present invention, the current density of the secondary coupled radiation patch is expressed by a piecewise sine basis function as follows:

[0032]

[0033] in, It refers to the basis function of na on the secondary coupled radiation patch.

[0034] In summary, the present invention has the following beneficial effects:

[0035] First, the bandwidth is wide; it adopts a new form based on the combination of a broadband feeding network and a coupled metal cavity, which is very effective for the impedance matching of the antenna and can effectively improve the working bandwidth of the antenna; ensuring that this type of antenna can work normally within the Ku band range.

[0036] Secondly, the antenna structure is compact. Through the design of loading and stacking, the antenna radiation layer, coupling layer and feeding layer are located in the same plane, which effectively reduces the antenna profile. At the same time, it is convenient to connect and integrate with other circuit systems by placing them on the same layer, which greatly reduces the overall profile of the antenna.

[0037] Third, it is easy to assemble. The main structure of the antenna array is a lightweight alloy structure, which is assembled and installed by stacking and loading. There is no need for welding or debugging, and the assembly is simple and easy.

[0038] Fourthly, the novel antenna structure of the present invention has excellent electrical performance, which enables the antenna to work normally within the Ku-band frequency range. The antenna unit and its array have lower standing waves, side lobes, and cross-polarization, and have higher aperture efficiency within the full frequency band. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 A three-dimensional exploded diagram of the internal structure of a low-orbit satellite communication Ku-band antenna provided by an embodiment of the present invention;

[0040] Figure 2 A schematic structural diagram of a radiation aperture provided by an embodiment of the present invention;

[0041] In the figure: primary radiation patch 1, secondary coupled radiation patch 2, radiation port 3, first broadband feeding network layer 4, coupled matching cavity layer 5, second broadband feeding network layer 6, standard waveguide component 7. DETAILED DESCRIPTION

[0042] The present application is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present application, but do not limit the present application in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements can also be made without departing from the concept of the present application. These all belong to the protection scope of the present application.

[0043] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0044] It should be noted that, if there is no conflict, the various features in the embodiments of the present application can be combined with each other, all within the scope of protection of the present application. In addition, although the functional module division is performed in the device schematic diagram and the logical order is shown in the flow chart, in some cases, the steps shown or described can be performed in a sequence different from the module division in the device or the flow chart. In addition, the words "first", "second", "third", etc. used herein do not limit the data and execution order, but only distinguish the same items or similar items with basically the same functions and effects.

[0045] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in this specification and in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in this specification includes any and all combinations of one or more of the related listed items.

[0046] In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as they do not conflict with each other.

[0047] The embodiments of the present disclosure aim to solve the shortcomings of the microstrip antenna in the prior art, such as low aperture efficiency, large dielectric loss, and narrow bandwidth. At the same time, the feeding network is relatively complex when forming an array, which is not conducive to system integration and commissioning. In view of this, the embodiments of the present disclosure propose a Ku-band antenna for low-orbit satellite communications, and verify the 256-unit array antenna composed of an array of 16×16 radiation aperture units, with an antenna size of 320×320×16mm. The array antenna can cover the Ku band, has 2 ports for transmission and reception, the port standing waves are all within 1.35, the antenna gain is greater than 32.5dB, and the port isolation is greater than 52dB. It can be applied to the communication scenario of low-orbit satellites. The Ku-band antenna unit and its array antenna have high gain, high efficiency, and low surface damage characteristics.

[0048] Please refer to Figure 1-2 , Figure 1-2 The schematic diagram of the structure of the Ku-band antenna for low-orbit satellite communication according to the embodiment of the present disclosure is shown, which includes: a primary radiation patch 1, a secondary coupled radiation patch 2, a radiation aperture 3, a first broadband feed network layer 4, a coupled matching cavity layer 5, a second broadband feed network layer 6, and a standard waveguide component 7;

[0049] The radiation aperture 3 is composed of 16×16 unit group arrays as antenna units, and a secondary coupling radiation patch 2 is attached to the center of the radiation aperture 3 of each unit group; the primary radiation patch 1 is attached to the right side and the bottom side of the secondary coupling radiation patch 2;

[0050] A first broadband feeding network layer 4 is provided on the lower surface of the radiation port surface 3, and the radiation port surfaces 3 of every two unit groups are connected through the first broadband feeding network layer 4; the first broadband feeding network layer 4 is composed of an air cavity and a microstrip suspended strip line, which ensures the purity of electromagnetic waves transmitted inside the cavity, that is, other modes of electromagnetic wave transmission will not be additionally introduced, thereby further reducing the additional loss caused by the feeding network.

[0051] A coupling matching cavity layer 5 is provided below the first broadband feeding network layer 4. The coupling matching cavity layer 5 ensures good impedance matching of the antenna within the Ku band, ensures mode purity, and further reduces the decrease in antenna efficiency and gain caused by impedance mismatch.

[0052] The first broadband feed network layer 4 is the same layer as the primary radiation patch 1 and is enclosed by a metal cavity, so the first broadband feed network layer 4 can be regarded as an independent component of the antenna; there is no coupling energy between the feed network and the antenna unit, and there is no radiation from the broadband feed network. Therefore, in actual calculations, only the antenna unit is simulated without simulating the feed network.

[0053] A second broadband feeding network layer 6 is provided below the coupling matching cavity layer 5, and a standard waveguide component 7 is provided below the second broadband feeding network layer 6;

[0054] Specifically, two primary radiation patches 1 and secondary coupling radiation patches 2 are provided in the radiation aperture 3 of each unit group, and the two primary radiation patches 1 and secondary coupling radiation patches 2 divide the radiation aperture 3 into a stepped gradient horn plus a cross grid structure; by adjusting the aperture size and height of each step of the stepped horn, the impedance matching of the horn antenna can be achieved; wherein, the size and length of the waveguide correspond to the wave impedance of the guided mode. The calculation formula is as follows:

[0055]

[0056] Among them, E u 、E v Transverse electric field; H u , H v transverse magnetic field; ε and μ are the dielectric constant and magnetic permeability of the medium respectively; ω is the angular frequency; β and κ are variable constants; λ and λ are c are the operating wavelength and the cut-off wavelength respectively; is the inherent impedance of the medium, and the air impedance

[0057] The radiation aperture 3 is composed of 16×16 units. The condition for no grating lobe to appear in the array is:

[0058]

[0059] Where d is the spacing between the unit antennas, λ is the wavelength in free space corresponding to the antenna operating frequency (i.e., the antenna operating wavelength), and θ is the scanning angle of the antenna. When the antenna is not scanning, θ = 0, and the condition for no grating lobe to appear is:

[0060] d<λ

[0061] For the radiation aperture 3 of the square antenna of the present invention, the conditions for wave transmission are:

[0062] λ<2L

[0063] Wherein, L is the length of the radiation aperture 3.

[0064] The energy is transferred to the primary radiation patch 1 through the first broadband feeding network layer 4, and the primary radiation patch 1 transfers the microwave signal to the secondary coupling radiation patch 2 by coupling. Finally, the radiation aperture 3 transfers the energy to the space or receives the microwave signal from the space.

[0065] The secondary coupling radiation patch 2 is composed of a small circular secondary coupling radiation patch 2 located near the primary radiation patch 1. The secondary coupling radiation patch 2 adds a capacitive element to the input impedance, which effectively offsets the inductive characteristics associated with the primary radiation patch 1; by adjusting the size of the secondary coupling radiation patch 2 and the gap between it and the primary radiation patch 1, the input impedance can be accurately matched. This distribution can effectively reduce the antenna profile, thereby minimizing the number of substrate layers required. In addition, a relatively wide bandwidth can be achieved, which makes it an effective means of designing Ku-band antenna units and array antennas for communication scenarios of low-orbit satellites.

[0066] The thickness of the primary radiation patch 1 and the secondary coupling radiation patch 2 is ideal, and their radius is finite. Then the current density J on the secondary coupling radiation patch 2 can be modeled and analyzed by the global sine function:

[0067]

[0068] Among them, f n refers to the basis functions of different vectors, I n It refers to the current density.

[0069] The current density of the primary radiation patch 1 and the current density at the connection of the first broadband feeding network layer 4 can be expressed by a piecewise sine basis function as follows:

[0070]

[0071] in, It refers to the basis function of nz of np on the primary radiation patch 1, based on which it can be characterized that the function is similar to a piecewise linear function.

[0072] For the secondary coupled radiation patch 2, the current density is expressed by a piecewise sine basis function:

[0073]

[0074] in, It refers to the basis function of na on the secondary coupled radiation patch 2, based on which it can be characterized that the function is similar to a piecewise linear function.

[0075] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A Ku-band antenna for low-orbit satellite communications, characterized in that: include: A primary radiation patch (1), a secondary coupled radiation patch (2), a radiation port (3), a first broadband feeding network layer (4), a coupled matching cavity layer (5), a second broadband feeding network layer (6), and a standard waveguide component (7); The radiation aperture (3) is composed of an array of 16×16 unit groups as antenna units, and a secondary coupling radiation patch (2) is attached to the center of the radiation aperture (3) of each unit group; the right side and the bottom side of the secondary coupling radiation patch (2) are both attached with a primary radiation patch (1); A first broadband feeding network layer (4) is provided on the lower surface of the radiation port surface (3), and the radiation port surfaces (3) of every two unit groups are connected via the first broadband feeding network layer (4); A coupling matching cavity layer (5) is provided below the first broadband feeding network layer (4), and the coupling matching cavity layer (5) is used to improve impedance matching; A second broadband feeding network layer (6) is provided below the coupling matching cavity layer (5), and a standard waveguide component (7) is provided below the second broadband feeding network layer (6).

2. A low-orbit satellite communication Ku-band antenna according to claim 1, characterized in that: Energy is transferred to the primary radiation patch (1) through the first broadband feeding network layer (4), the primary radiation patch (1) transfers the microwave signal to the secondary coupling radiation patch (2) by coupling, and finally the radiation aperture (3) transfers the energy to space or receives the microwave signal from space.

3. The low-orbit satellite communication Ku-band antenna according to claim 1, characterized in that: The secondary coupling radiation patch (2) is composed of a small circular secondary coupling radiation patch (2) located near the primary radiation patch (1); The secondary coupling radiation patch (2) adds a capacitive element to the input impedance, thereby offsetting the inductive characteristics associated with the primary radiation patch (1); the input impedance can be accurately matched by adjusting the size of the secondary coupling radiation patch (2) and the gap between it and the primary radiation patch (1).

4. The low-orbit satellite communication Ku-band antenna according to claim 1, characterized in that: Two primary radiation patches (1) and a secondary coupling radiation patch (2) are provided in the radiation aperture (3) of each unit group, and the two primary radiation patches (1) and the secondary coupling radiation patch (2) divide the radiation aperture (3) into a stepped gradient horn plus a cross grid structure; by adjusting the aperture size and height of each step of the stepped horn, impedance matching of the horn antenna can be achieved; Among them, the size and length of the waveguide correspond to the wave impedance of the guided mode; the calculation formula is as follows: Among them, E u 、E v Transverse electric field; H u , H v transverse magnetic field; ε and μ are the dielectric constant and magnetic permeability of the medium respectively; ω is the angular frequency; β and κ are variable constants; λ and λ are c are the operating wavelength and the cut-off wavelength respectively; is the inherent impedance of the medium, and the air impedance 5. The low-orbit satellite communication Ku-band antenna according to claim 1, characterized in that: The radiation aperture (3) is composed of 16×16 units. The condition for no grating lobe to appear in the array is: Where d is the spacing between unit antennas, λ is the wavelength in free space corresponding to the antenna operating frequency, and θ is the scanning angle of the antenna. When the antenna is not scanning, θ = 0, and the condition for no grating lobe to appear is: d<λ For the radiation aperture (3) of the square antenna of the present invention, the conditions for satisfying wave transmission are: λ<2L Wherein, L is the length of the radiation aperture (3).

6. The low-orbit satellite communication Ku-band antenna according to claim 1, characterized in that: The thickness of the primary radiation patch (1) and the secondary coupling radiation patch (2) are ideal, and their radius is finite. Then, the current density J on the secondary coupling radiation patch (2) can be modeled and analyzed by a global sine function: Among them, f n refers to the basis functions of different vectors, I n It refers to the current density.

7. The low-orbit satellite communication Ku-band antenna according to claim 1, characterized in that: The current density of the primary radiation patch (1) and the current density at the connection of the first broadband feeding network layer (4) can be expressed by a piecewise sine basis function as follows: in, is the basis function of np on the primary radiation patch (1).

8. The low-orbit satellite communication Ku-band antenna according to claim 1, characterized in that: The current density of the secondary coupled radiation patch (2) is expressed by a piecewise sine basis function: in, It refers to the basis function of na on the secondary coupled radiation patch (2).

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