A Ku-band antenna for low-Earth orbit satellite communication

Abstract

The present invention relates to the field of wireless communication technologies, and discloses a Ku-band antenna for low-orbit satellite communication. The key technical points of its technical solution include: a primary radiation patch, a secondary coupled radiation patch, a radiation aperture surface, a first broadband feeding network layer, a coupled matching cavity layer, a second broadband feeding network layer, and a standard waveguide assembly; based on a new form combining a broadband feeding network with a coupled metal cavity, the operating bandwidth of the antenna is increased; it is ensured that this type of antenna can operate normally within the Ku-band range; through designs such as loading and laminating, the antenna radiation layer, coupling layer, and feeding layer are located on the same plane, reducing the antenna profile; when this design is connected and integrated with other circuit systems, the overall antenna profile can be reduced; it realizes a compact structure, convenient assembly, excellent electrical performance, high antenna gain, wide bandwidth, high polarization purity, and a simple and lightweight structure.

Description

Technical Field

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

[0002] In the existing satellite communication technology, most of them adopt dual linear polarization and common aperture design, but this requirement usually increases the complexity of the antenna system. Due to the low-profile characteristic of the microstrip antenna element, the microstrip form can generally be selected for the array antenna design. For high-gain scenarios, the microstrip antenna can be realized by increasing the number of antenna elements or increasing the element size.

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

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

[0005] The embodiments of the present disclosure aim at the deficiencies of the existing technology and provide a Ku-band antenna for low-earth orbit satellite communication. 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 coupling metal cavity; ensures that this type of antenna can work normally within the Ku-band range; through designs such as loading and stacking, the antenna radiation layer, coupling layer, and feeding layer are located on the same plane, reducing the antenna profile; when connected and integrated with other circuit systems, this design can reduce the overall profile of the antenna, and the antenna element and its array have low standing wave, sidelobe, and cross polarization, and can have high aperture efficiency within the full frequency band range.

[0006] The above technical object of the present invention is achieved through the following technical solutions: A Ku-band antenna element for low-earth orbit satellite communication, comprising: a primary radiation patch, a secondary coupling radiation patch, a radiation aperture, a first broadband feeding network layer, a coupling matching cavity layer, a second broadband feeding network layer, and a standard waveguide component;

[0007] The radiation aperture is formed by arraying 16×16 units as an antenna element, and a secondary coupling radiation patch is pasted at the center position of the radiation aperture of each unit group; the primary radiation patches are pasted on the right side and the lower side of the secondary coupling radiation patch;

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

[0009] The 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 provided below the coupling matching cavity layer, and a standard waveguide component is provided below the second broadband feeding network layer.

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

[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, canceling the inductive characteristics associated with the primary radiation patch; by adjusting the size of the secondary coupling radiation patch and the gap between it and the primary radiation patch, the input impedance can be precisely matched.

[0014] As a preferred technical solution of the present invention, two primary radiation patches and secondary coupling radiation patches are provided in each radiation aperture surface of the unit group, and the two primary radiation patches and secondary coupling radiation patches divide the radiation aperture surface into a stepped tapered 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 waveguide size and length 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 permittivity and permeability of the medium respectively; ω is the angular frequency; β, κ are variable constants; λ, λ c Are the operating wavelength and cut-off wavelength respectively; Is the characteristic impedance of the medium, and for air impedance

[0018] As a preferred technical solution of the present invention, the condition for the radiation aperture surface composed of 16×16 unit groups to form an array without grating lobes is:

[0019]

[0020] In the formula, d is the spacing of the unit antennas, λ is the wavelength in free space corresponding to the operating frequency of the antennas, and θ is the scanning angle of the antennas; when the antennas do not scan, θ = 0, and the condition for no grating lobes to appear is:

[0021] d < λ

[0022] For the radiation aperture of the square antenna of the present invention, the condition for wave transmission to be satisfied is:

[0023] λ < 2L

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

[0025] As a preferred technical solution of the present invention, the thicknesses of the primary radiation patch and the secondary coupled radiation patch are ideal thicknesses, and their radii are finite. Then, the current density J on the secondary coupled radiation patch can be modeled and analyzed through a global sine function:

[0026]

[0027] where f n refers to the basis function of different vectors, and I n 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:

[0029]

[0030] where refers to the basis function of nz on the primary radiation patch for np.

[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:

[0032]

[0033] where 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] Firstly, it has a wide bandwidth; adopting a new form combining a broadband feeding network and a coupled metal cavity is very effective for the impedance matching of the antennas, can effectively improve the operating bandwidth of the antennas; and ensures that this type of antenna can operate normally within the Ku frequency band range.

[0036] Second, the antenna structure is compact. Through designs such as loading and stacking, the antenna radiation layer, coupling layer, and feeding layer are located on the same plane, effectively reducing the antenna profile. At the same time, it is convenient to place them on the same layer when connecting and integrating with other circuit systems, greatly reducing the overall antenna profile.

[0037] Third, it is easy to assemble. The main structures of the antenna array are all lightweight alloy structures, which are assembled by stacking and loading methods without welding, debugging, etc., and the assembly is simple and easy.

[0038] Fourth, excellent electrical performance. The novel antenna structure of the present invention enables this type of antenna to operate normally within the Ku band frequency range. The antenna element and its array have low standing waves, side lobes, and cross polarizations, and have high aperture efficiency within the entire frequency range. Description of the Drawings

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

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

[0041] In the figure: primary radiation patch 1, secondary coupling radiation patch 2, radiation aperture surface 3, first broadband feeding network layer 4, coupling matching cavity layer 5, second broadband feeding network layer 6, standard waveguide component 7. Detailed Embodiments

[0042] The following further elaborates on the present application 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 those of ordinary skill in the art can make several deformations and improvements without departing from the concept of the present application. These all fall within the protection scope of the present application.

[0043] In order to make the purpose, technical solutions, and advantages of the present application clearer, the following further elaborates on the present application 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, and all are within the protection scope of the present application. In addition, although functional module division is carried out in the device schematic diagram and the logical sequence is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order from the module division in the device or the sequence in the flowchart. In addition, the terms "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 commonly understood by those skilled in the technical field to which this application belongs. The terms used in this specification in the description of the present application are only for the purpose of describing specific embodiments and are not used to limit the present 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 the various embodiments 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 problems in the prior art that the microstrip antenna has disadvantages such as low aperture efficiency, large dielectric loss, and narrow bandwidth, and at the same time, the feeding network is relatively complex when forming an array, which is not conducive to system integration and debugging. In view of this, the embodiments of the present disclosure propose a Ku-band antenna for low-orbit satellite communication, and verify a 256-element array antenna composed of 16×16 radiation aperture units. The antenna size is 320×320×16 mm. This array antenna can cover the Ku band, has a total of 2 transceiver ports, the port standing wave is within 1.35, the antenna gain is greater than 32.5 dB, and the port isolation is greater than 52 dB. It can be applied to the communication scenario of low-orbit satellites. The Ku-band antenna unit and its array antenna have the characteristics of high gain, high efficiency, and low profile.

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

[0049] The radiation aperture 3 is formed by an array of 16×16 units as antenna units, and a secondary coupled radiation patch 2 is attached to the center position of the radiation aperture 3 of each unit group; a primary radiation patch 1 is attached to both the right side and the lower side of the secondary coupled radiation patch 2;

[0050] The lower surface of the radiation aperture 3 is provided with a first broadband feeding network layer 4, and the radiation apertures 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 the electromagnetic wave transmission inside the cavity, that is, no additional electromagnetic wave transmission forms of other modes will be introduced, and further reduces the additional loss caused by the feeding network.

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

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

[0053] A second broadband feeding network layer 6 is provided below the coupling and 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 coupled radiation patches 2 are provided in the radiation aperture 3 of each unit group. The two primary radiation patches 1 and secondary coupled 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; among them, the waveguide size and length 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 permittivity and permeability of the medium respectively; ω is the angular frequency; β, κ are variable constants; λ, λ c Are the working wavelength and cut-off wavelength respectively; Is the characteristic impedance of the medium, and for air impedance

[0057] The condition for the array composed of 16×16 unit groups of the radiation aperture 3 not to appear grating lobes is:

[0058]

[0059] In the formula, d is the spacing of 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 lobes to appear is:

[0060] d < λ

[0061] For the radiation aperture 3 of the square antenna of the present invention, the condition for wave transmission to be satisfied is:

[0062] λ < 2L

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

[0064] 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 coupled radiation patch 2 by means of coupling. Finally, the radiation aperture 3 transfers the energy to space or receives the microwave signal from space.

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

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

[0067]

[0068] where f n refers to the basis function of different vectors, and I n 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:

[0070]

[0071] where, refers to the basis function of np on nz of the primary radiation patch 1, and accordingly, this function can be characterized as a piecewise linear function.

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

[0073]

[0074] wherein, refers to the basis function of na on the secondary coupled radiation patch 2, based on which this function can be characterized as a piecewise linear function.

[0075] The above are only the preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the concept of the present invention belong to the protection scope of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications should also be regarded as within the protection scope of the present invention.

Claims

1. A Ku-band antenna for low-earth-orbit satellite communication, characterized in that, Including: Primary radiation patch (1), secondary coupled radiation patch (2), radiation aperture (3), first broadband feeding network layer (4), coupling matching cavity layer (5), second broadband feeding network layer (6), standard waveguide component (7); The radiation aperture (3) is composed of 16×16 unit arrays as antenna units, and a secondary coupled radiation patch (2) is attached to the center position of the radiation aperture (3) of each unit group; the primary radiation patches (1) are attached to both the right side and the lower side of the secondary coupled radiation patch (2); The first broadband feeding network layer (4) is provided on the lower surface of the radiation aperture (3), and the radiation apertures (3) of every two unit groups are connected through the first broadband feeding network layer (4); The 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; The second broadband feeding network layer (6) is provided below the coupling matching cavity layer (5), and the standard waveguide component (7) is provided below the second broadband feeding network layer (6).

2. The Ku-band antenna for low-earth-orbit satellite communication according to claim 1, characterized in that, Energy is transmitted to the primary radiation patch (1) through the first broadband feeding network layer (4), the primary radiation patch (1) transmits the microwave signal to the secondary coupled radiation patch (2) through the coupling method, and finally the radiation aperture (3) transmits the energy to the space or receives the microwave signal from the space.

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

4. A Ku-band antenna for low-earth-orbit satellite communication according to claim 1, characterized in that, Two primary radiation patches (1) and secondary coupled radiation patches (2) are provided in the radiation aperture (3) of each unit group, and the two primary radiation patches (1) and secondary coupled radiation patches (2) divide the inside of 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; Among them, the waveguide size and length correspond to the wave impedance of the guided mode; the calculation formula is as follows: Among them, E u , E v is the transverse electric field; H u , H v is the transverse magnetic field; ε and μ are the permittivity and permeability of the medium respectively; ω is the angular frequency; β and κ are variable constants; λ and λ c are the operating wavelength and the cut-off wavelength respectively; is the characteristic impedance of the medium, and for air impedance 5. A Ku-band antenna for low-earth-orbit satellite communication according to claim 1, characterized in that, The condition for the radiation aperture (3) composed of 16×16 unit groups to form an array without grating lobes is: In the formula, d is the spacing of the 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 does not scan, θ = 0, and the condition for no grating lobes is: d < λ For the radiation aperture (3) of the square antenna, the condition for wave transmission is: λ < 2L Where, L is the length of the radiation aperture (3).

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

7. A Ku-band antenna for low-earth-orbit satellite communication 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 the piecewise sine basis function as: Among them, refers to the basis function of nz on the primary radiation patch (1) of np.

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

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