An integrated high-gain metal lens horn antenna and a manufacturing method thereof

Abstract

The present invention discloses an integrated high-gain metal lens horn antenna, comprising a metal feed horn and a metal lens; the metal feed horn comprises a horn-shaped metal wall and a feed waveguide arranged at the feed end of the horn-shaped metal wall; the radiation aperture end of the metal feed horn and the metal lens form an integrated structure to completely confine the electric field distribution of the transmitted electromagnetic wave within the integrated structure. Compared with other dielectric horn antennas, the present invention can have a higher power capacity and effectively improve the aperture efficiency of the antenna.

Description

Technical Field

[0001] The present invention relates to the technical field of horn antennas, and in particular to an integrated high-gain metal lens horn antenna and a manufacturing method thereof. Background Art

[0002] With the development of communication technology, high-gain millimeter-wave antennas with high power capacity play an increasingly important role in applications such as satellite communications (SATCOM), 5G point-to-point communications, and radar systems. Horn antennas have the advantages of simple structure, stable performance, large power capacity, and low cost, and are widely used in microwave and millimeter-wave systems. Horn antennas are aperture antennas. The simplest way to achieve a high-gain horn antenna is to increase the aperture area of ​​the horn. However, in order to reduce the phase deviation in the aperture plane, the length of the high-gain horn antenna needs to be very long. Lens technology is widely used to reduce the length of high-gain horn antennas, such as dielectric lenses, metal lenses, metamaterial lenses (metalens), and transmission arrays.

[0003] Existing lens horn antennas mainly include three types: dielectric lens horn antenna, metamaterial lens horn antenna and metal lens horn antenna. Dielectric lens horn antenna is a deceleration lens (convex lens). The dielectric loss is large in the millimeter wave frequency band, and the dielectric loss of the dielectric lens horn antenna will reduce the overall efficiency of the antenna. The higher the frequency, the higher the processing accuracy of the lens, and the higher the dielectric material cost and processing cost. Metamaterial lenses have the advantages of low profile and low cost. Metamaterial technology can also realize the characteristics of some materials that do not exist in nature, but most metamaterials are realized based on periodic resonant structures, which will make the working bandwidth of lens horn antenna very narrow and not suitable for broadband application scenarios. In addition, the realization of metamaterials is generally based on periodic structures that are much smaller than the wavelength to equivalently simulate materials that do not exist in reality, which will result in a low power capacity of the antenna and is not suitable for application scenarios with high power capacity requirements. Metal lens horn antennas have the advantages of wide bandwidth and high power capacity, but the metal lens itself is large in size. According to previous research, the focal ratio of traditional metal lenses has a minimum value (for example, when the equivalent refractive index of the lens is 0.71@30GHz, it is about 1.21). Therefore, after the aperture size and lens unit of the traditional metal lens horn antenna are determined, the minimum focal ratio is determined, and the minimum length of the antenna is also determined. Therefore, the length reduction of the traditional metal lens horn antenna is limited. When the focal ratio is forcibly reduced, the gain bandwidth and aperture efficiency of the traditional metal lens horn antenna will drop sharply. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention provides an integrated high-gain metal lens horn antenna and a manufacturing method thereof.

[0005] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0006] In the first aspect, the present invention proposes an integrated high-gain metal lens horn antenna, comprising a metal feed horn and a metal lens; the metal feed horn comprises a horn-shaped metal wall and a feed waveguide arranged at the feed end of the horn-shaped metal wall; the radiation aperture end of the metal feed horn forms an integrated structure with the metal lens to completely confine the electric field distribution of the transmitted electromagnetic wave within the integrated structure.

[0007] Optionally, the metal lens is a metal lens based on the Fresnel lens principle.

[0008] Optionally, the metal lens is composed of a plurality of Ka-band square waveguides.

[0009] Optionally, a Ka-band orthogonal mode coupler is further included; the Ka-band orthogonal mode coupler is connected to the input end of the feed waveguide to achieve dual-linear polarization radiation.

[0010] Optionally, a circular polarizer is also included; the circular polarizer is arranged between the Ka-band orthogonal mode coupler and the input end of the feed waveguide to achieve dual circular polarization radiation.

[0011] In a second aspect, the present invention proposes a method for manufacturing the above-mentioned integrated high-gain metal lens horn antenna, comprising the following steps:

[0012] S1. Determine antenna gain and focal diameter ratio according to antenna design requirements;

[0013] S2. calculating the area of ​​the metal lens and the size of the square waveguide in the metal lens according to the determined antenna gain;

[0014] S3, calculating the length of the square waveguide in the metal lens according to the determined focal diameter ratio, and determining the thickness of the metal lens based on the Fresnel lens principle;

[0015] S4. Determine the size of the feed waveguide according to the operating frequency band of the metal feed horn;

[0016] S5. Determine the structure of the horn antenna according to the size of the feed waveguide and the size of the metal lens;

[0017] S6. According to the determined structure of the horn antenna, an integrated molding method is used for processing.

[0018] The present invention has the following beneficial effects:

[0019] The all-metal lens horn antenna of the present invention is an integrated structure formed by a metal feed horn and a metal lens, which completely confines the electric field distribution of the transmitted electromagnetic wave inside the integrated structure. Compared with other dielectric horn antennas, it can have a higher power capacity and effectively improve the aperture efficiency of the antenna. Since air is filled inside the integrated structure, a wider impedance bandwidth and gain bandwidth, as well as a shorter antenna length, can be achieved at a small focal diameter ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic structural diagram of an integrated high-gain metal lens horn antenna in Example 1 of the present invention;

[0021] Figure 2 This is a side view comparison diagram of the lens when the Fresnel lens principle is adopted and not adopted in Example 2 of the present invention;

[0022] Figure 3 Schematic diagram of a lens unit of a metal lens in Example 3 of the present invention;

[0023] Figure 4 It is a schematic structural diagram of a dual-polarized horn antenna in Embodiment 4 of the present invention;

[0024] Figure 5 Schematic diagram of the structure of the dual circularly polarized horn antenna in Example 5 of the present invention;

[0025] Figure 6 Schematic diagram of the comparison between the metal lens horn antenna of the present invention and the traditional metal lens horn antenna; (a) is the traditional metal lens horn antenna, (b) is the metal lens horn antenna of the present invention;

[0026] Figure 7 It is a schematic diagram of the reflection coefficient simulated and tested in the present invention;

[0027] Figure 8 It is a schematic diagram of the segment peak gain simulated and tested in the present invention;

[0028] Fig. 9 It is a schematic diagram of the radiation pattern simulated and tested in the present invention.

[0029] The accompanying drawings are marked as follows: 1. Metal feed horn; 2. Metal lens. DETAILED DESCRIPTION

[0030] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0031] Example 1

[0032] like Figure 1 As shown, this embodiment proposes an integrated high-gain metal lens horn antenna, including a metal feed horn 1 and a metal lens 2; the metal feed horn 1 includes a horn-shaped metal wall and a feed waveguide arranged at the feed end of the horn-shaped metal wall; the radiation aperture end of the metal feed horn and the metal lens 2 form an integrated structure to completely confine the electric field distribution of the transmitted electromagnetic wave within the integrated structure.

[0033] It should be understood that the full metal lens horn antenna of the present invention is an integrated structure formed by a metal feed horn 1 and a metal lens 2, and the interior of the integrated structure is filled with air. Since the air-filled antenna has a lower Q value, the full metal lens horn antenna of the present invention can achieve a wider impedance bandwidth and gain bandwidth, as well as a shorter antenna length at a small focal ratio.

[0034] In addition, the all-metal lens horn antenna of the present invention is made of all-metal material. Compared with other dielectrics, the breakdown electric field strength of metal is higher (generally up to 1MV / cm), so the all-metal lens horn antenna of the present invention is less likely to be broken down and has a higher power capacity than other dielectric horn antennas. According to a certain margin, the antenna port power of the present invention can reach 14MW when the breakdown electric field strength is 0.5MV / cm.

[0035] More importantly, those skilled in the art should know that the aperture efficiency of the lens horn antenna is the product of the spill-over efficiency and the taper efficiency. The spill-over efficiency describes the degree to which the power radiated by the focal source is captured by the lens, and the taper efficiency describes the amplitude unevenness of the radiation aperture. Therefore, due to the spatial feeding method adopted by the traditional lens horn antenna, a large part of the electric field distribution of the lens antenna overflows, so it is inevitable that the aperture efficiency will be low due to the existence of spill-over loss; and the all-metal lens horn antenna of the present invention uses a metal feed horn 1 and a metal lens 2 to form an integrated structure to completely confine the electric field distribution of the transmitted electromagnetic wave inside the integrated structure, which can effectively suppress the spill-over loss, so that the aperture efficiency mainly depends on the lighting loss, thereby effectively improving the aperture efficiency of the antenna.

[0036] In addition, the all-metal lens horn antenna of the present invention utilizes a metal feed horn and a metal lens to form an integrated structure, so that the overall structure of the antenna is more stable and has a higher degree of integration, which can largely avoid the problem of feed deviation that exists in the traditional lens horn antenna using a space feeding method.

[0037] In order to enable those skilled in the art to more clearly understand the working mechanism of the all-metal lens horn antenna of the present invention, a specific analysis is made below:

[0038] For horn antennas without lenses, to increase the gain of the horn antenna, the radiation aperture of the horn antenna is generally increased; in this case, in order to optimize the phase distribution of the larger radiation aperture, it is generally necessary to increase the length of the horn antenna or the focal length of the lens antenna. The gain of the aperture antenna can be calculated according to the following formula:

[0039]

[0040] Where A is the aperture area of ​​the aperture antenna, λ is the free space wavelength, and AE is the aperture efficiency.

[0041] As the aperture size increases, the horn length must be increased to avoid phase errors due to the distribution of the electromagnetic field at a large aperture. This phase deviation is caused by the path difference between the feed source to the center of the aperture and the edge of the aperture. The length of the horn antenna can be calculated according to the following formula:

[0042]

[0043] Where D is the diameter of the aperture antenna.

[0044] Therefore, the length of the lens horn antenna of the present invention can be greatly reduced compared to that of an ordinary horn antenna, especially in the case of high gain. Taking the embodiment of the present invention as an example, when the gain is 30.8dBi@31.5GHz, the length of the lens horn antenna of the present invention can be reduced by 68% compared to the horn antenna without adding a lens (assuming that the aperture efficiency of the ordinary horn antenna is 70%).

[0045] Example 2

[0046] like Figure 2 As shown, based on the integrated high-gain metal lens horn antenna described in Example 1, due to the large lens aperture, in order to further reduce processing costs, this embodiment uses a metal lens based on the Fresnel lens principle for the metal lens 2, thereby reducing the lens thickness and achieving a wider gain bandwidth. Figure 2Here, Side view of lens is the side view of the lens, Side view of Fresnel lens is the side view of the Fresnel lens, Lens Diameter is the lens diameter, Lens Height is the lens height, and the thickness T of the lens after the Fresnel lens principle is 34.48 mm.

[0047] Example 3

[0048] like Figure 3 As shown, based on an integrated high-gain metal lens horn antenna described in Example 2, in order to realize a dual-polarized lens horn antenna, this embodiment uses a combination of multiple Ka-band square waveguides to form the metal lens 2, that is, the lens unit of the metal lens 2 is a Ka-band square waveguide, thereby realizing dual-polarized radiation, including dual linear polarized radiation or dual circularly polarized radiation. Figure 3 Medium u is the cross-sectional width of the waveguide.

[0049] Example 4

[0050] like Figure 4 As shown, based on an integrated high-gain metal lens horn antenna described in Example 1, in order to realize a lens horn antenna with dual-linear polarization radiation, this embodiment adds a Ka-band orthogonal mode coupler at the input end of the feed waveguide to realize dual-linear polarization radiation, that is, one linear polarization when Port1 is excited and another orthogonal linear polarization when Port2 is excited. Figure 4 In the figure, OMT (Orthomode Transducer) is an orthogonal mode coupler, Horn is a metal feed horn, and Lens is a metal lens.

[0051] Example 5

[0052] like Figure 5 As shown, based on an integrated high-gain metal lens horn antenna described in Example 4, in order to realize a lens horn antenna with dual circular polarization radiation, this embodiment adds a circular polarizer between the Ka-band orthogonal mode coupler and the input end of the feed waveguide, thereby realizing dual circular polarization radiation, that is, one circular polarization when Port1 is excited, and another orthogonal circular polarization when Port2 is excited. Figure 5 In the figure, OMT (Orthomode Transducer) is an orthogonal mode coupler, Circularly polarizer is a circular polarizer, Horn is a metal feed horn, and Lens is a metal lens.

[0053] Example 6

[0054] This embodiment proposes a method for manufacturing an integrated high-gain metal lens horn antenna as described in the above embodiments 1 to 6, comprising the following steps S1 to S6:

[0055] S1. Determine antenna gain and focal diameter ratio according to antenna design requirements;

[0056] S2. Calculate the area of ​​the metal lens 2 and the size of the square waveguide in the metal lens 2 according to the determined antenna gain;

[0057] S3, calculating the length of the square waveguide in the metal lens 2 according to the determined focal diameter ratio, and determining the thickness of the metal lens 2 based on the Fresnel lens principle;

[0058] S4, determining the size of the feed waveguide according to the working frequency band of the metal feed horn 1;

[0059] S5, determining the structure of the horn antenna according to the size of the feed waveguide and the size of the metal lens 2;

[0060] S6. According to the determined structure of the horn antenna, an integrated molding method is used for processing.

[0061] Specifically, in order to realize the dual-polarization lens horn antenna, the unit of the lens adopts a square waveguide. When the waveguide transmits the main mode (TE10 and TE01), the width of the waveguide determines the equivalent refractive index of the lens. The equivalent refractive index can be calculated according to the following formula:

[0062]

[0063]

[0064] Where v is the phase velocity of propagation in the waveguide, v0 is the phase velocity of propagation in free space, λ is the wavelength in free space, n is the equivalent refractive index of the equivalent medium of the metal lens, and w u is the cross-sectional width of the waveguide.

[0065] In order to achieve a high-gain beam, the lens needs to convert the spherical wave of the feed horn into a plane wave. The curved surface of the traditional metal lens adopts an ellipsoidal surface, and the curve equation is expressed as:

[0066]

[0067] Among them, (y0,z0) is the coordinate value of the cross section of the metal lens surface, and F1 is the focal length of the traditional metal lens horn antenna; Figure 6 As shown in (a), Horn is a metal feed horn, Lens is a metal lens, and Air is air.

[0068] When the size of the lens is determined, assuming that the radius of the lens is R, simplifying the equivalent refractive index calculation formula and using the root determination formula of the quadratic equation group, the range of focal diameter ratios of the two lenses can be obtained:

[0069]

[0070] Therefore, the curved surface of traditional metal lenses is unsolvable under the condition of smaller focal ratio.

[0071] The curved surface of the metal lens of the present application is a hyperbolic surface, and the curve equation is expressed as:

[0072]

[0073] Wherein, (y0, z0) is the coordinate value of the cross section of the metal lens curved surface, and F2 is the focal length of the metal lens horn antenna of the present invention. Figure 6 As shown in (b), Horn is a metal feed horn, Lens is a metal lens, and Air is air.

[0074] It can be concluded that the focal diameter ratio of the metal lens of the present application can be any value, that is, F2 can theoretically take any positive number (in practice, considering the aperture efficiency, generally F2 / 2R≥0.4).

[0075] In order to realize a shorter lens horn antenna, the Fresnel lens principle can also be applied to the lens horn antenna of the present invention, so that the thickness of the lens can be kept at a fixed thickness T:

[0076]

[0077] If the Fresnel lens principle is not adopted in this embodiment, the thickness of the lens reaches more than 100 mm. After adopting the Fresnel lens principle, the thickness of the lens is 34.48 mm.

[0078] This embodiment can be produced and processed by mechanical processing or metal 3D printing technology. 3D printing technology can reduce processing difficulty and cost, so the embodiment of the present invention adopts 3D printing technology.

[0079] like Figure 7 , Figure 8 , Fig. 9 As shown, Figure 7 Where S parameters is s parameters, Simulated is simulation data, Measured is test data, and Frequency / GHz is frequency / GHz; Figure 8Where Peak Gain is the peak gain, MeasuredAperture Efficiency (Pol.1) is the aperture efficiency tested when radiating polarization 1, MeasuredApertureEfficiency (Pol.2) is the aperture efficiency tested when radiating polarization 2, Sim.Peak Gain is the simulated peak gain, Mea.Peak Gain (Pol.1) is the peak gain of the tested polarization 1, Mea.Peak Gain (Pol.2) is the peak gain of the tested polarization 2, and Aperture Efficiency is the aperture efficiency; Fig. 9 In the figure, Pol.2E-Plane is the E-plane radiation pattern of polarization 2, Pol.1E-Plane is the E-plane radiation pattern of polarization 1, Mea.Pol.1 is the tested polarization 1, Mea.Pol.2 is the tested polarization 2, Sim.Pol.1 is the simulated polarization 1, and Sim.Pol2 is the simulated polarization 2.

[0080] pass Figure 7 , Figure 8 , Fig. 9 It can be seen that the reflection coefficient of the lens horn antenna of the present invention in the working frequency band is all below -14dB, the test peak gain is 30.8dBi, the 3dB gain bandwidth can cover 28.4-34.5GHz (relative bandwidth is 22.5%), and the peak aperture efficiency of the two polarizations is 34.1% and 26.5% respectively. The radiation patterns of simulation and test are in good agreement, the sidelobe level is below -15dB, and the cross-polarization isolation is above 25dB. Overall, the test results are in good agreement with the simulation results, proving that the antenna proposed in this application has good performance.

[0081] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0082] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0083] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0084] The present invention uses specific embodiments to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

[0085] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific variations and combinations that do not deviate from the essence of the present invention based on the technical revelations disclosed by the present invention, and these variations and combinations are still within the protection scope of the present invention.

Claims

1. An integrated high-gain metal lens horn antenna, characterized in that: The invention comprises a metal feed horn (1) and a metal lens (2); the metal feed horn (1) comprises a horn-shaped metal wall and a feed waveguide arranged at the feed end of the horn-shaped metal wall; the radiation aperture end of the metal feed horn (1) and the metal lens (2) form an integrated structure so as to completely confine the electric field distribution of the transmitted electromagnetic wave within the integrated structure.

2. The integrated high-gain metal lens horn antenna according to claim 1, characterized in that: The metal lens (2) is a metal lens based on the Fresnel lens principle.

3. The integrated high-gain metal lens horn antenna according to claim 1 or 2, characterized in that: The metal lens (2) is composed of a plurality of Ka-band square waveguides.

4. The integrated high-gain metal lens horn antenna according to claim 1, characterized in that: It also includes a Ka-band orthogonal mode coupler; the Ka-band orthogonal mode coupler is connected to the input end of the feed waveguide to achieve dual-linear polarization radiation.

5. The integrated high-gain metal lens horn antenna according to claim 4, characterized in that: It also includes a circular polarizer; the circular polarizer is arranged between the Ka-band orthogonal mode coupler and the input end of the feed waveguide to achieve dual circular polarization radiation.

6. A method for manufacturing an integrated high-gain metal lens horn antenna according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. Determine antenna gain and focal diameter ratio according to antenna design requirements; S2. calculating the area of ​​the metal lens (2) and the size of the square waveguide in the metal lens (2) according to the determined antenna gain; S3, calculating the length of the square waveguide in the metal lens (2) according to the determined focal diameter ratio, and determining the thickness of the metal lens (2) based on the Fresnel lens principle; S4, determining the size of the feed waveguide according to the operating frequency band of the metal feed horn (1); S5, determining the structure of the horn antenna according to the size of the feed waveguide and the size of the metal lens (2); S6. According to the determined structure of the horn antenna, an integrated molding method is used for processing.

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