WO2024140214A1

WO2024140214A1 - Luneburg lens and manufacturing method therefor, and luneburg lens antenna

Info

Publication number: WO2024140214A1
Application number: PCT/CN2023/138414
Authority: WO
Inventors: 谢勇锋; 陈泽峰; 赵春雨; 季魁文; 刘玥
Original assignee: 华为技术有限公司
Priority date: 2022-12-30
Filing date: 2023-12-13
Publication date: 2024-07-04
Also published as: CN118281577A

Abstract

The present application provides a Luneburg lens and a manufacturing method therefor, and a Luneburg lens antenna. The method comprises: preparing a core; mixing a first material with a second material according to a first proportion and coating the surface of the core with the mixture to form a first dielectric layer; processing the first dielectric layer to form a first lens layer; mixing the first material with the second material according to an i-th proportion and coating the surface of an (i-1)-th lens layer with the mixture to form an i-th dielectric layer; and processing the i-th dielectric layer to form an i-th lens layer, i being any integer from 2 to N in sequence, N being an integer and N being greater than or equal to 2, so as to obtain a Luneburg lens comprising the core and N lens layers covering the core. According to the method, the first material can be mixed with the second material according to parameters of each lens layer to manufacture the lens layers layer by layer, so that the manufacturing steps of the Luneburg lens are simplified, and the manufacturing process difficulty and the manufacturing costs of the Luneburg lens are reduced.

Description

Luneburg lens and its manufacturing method, and Luneburg lens antenna

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to the Chinese patent application filed with the China Patent Office on December 30, 2022, with application number 202211736116.2 and application name “Luneburg lens and its manufacturing method, and Luneburg lens antenna”, all contents of which are incorporated by reference in this application.

Technical Field

The present application relates to the field of communication technology, and in particular to a Luneburg lens and a manufacturing method thereof, and a Luneburg lens antenna.

Background technique

As a special lens antenna, the Luneburg lens antenna is a centrally symmetrical sphere made of a gradient dielectric material. The Luneburg lens antenna adopts the focusing principle of an optical lens and utilizes the refractive characteristics of a multi-layer dielectric sphere to converge incident electromagnetic waves of a specific wavelength to a certain point on the spherical surface, and vice versa, it can also reflect the electromagnetic waves back in the original direction. Since the Luneburg lens antenna can reduce the low gain of a single antenna unit and can converge wide-beam electromagnetic wave signals into high-gain, narrow-beam electromagnetic wave signals, it has broad application prospects in communications, radar, astronomy, imaging and other fields. In recent years, with the large-scale construction of 5G antennas, the high gain and strong beam directivity of the Luneburg lens have achieved good performance in scenarios covered by tracks such as high-speed rail lines, and have once again attracted people's attention. However, due to the difficulty in processing and production of the Luneburg lens antenna, the high cost and heavy weight, the application of the Luneburg lens antenna is subject to certain restrictions.

Summary of the invention

The present application provides a Luneburg lens and a manufacturing method thereof, as well as a Luneburg lens antenna, so as to simplify the manufacturing steps of the Luneburg lens, thereby reducing the manufacturing process difficulty and manufacturing cost of the Luneburg lens.

In a first aspect, the present application provides a method for making a Luneburg lens. Specifically, the method for making a Luneburg lens may include: preparing a core; mixing a first material and a second material in a first ratio and coating them on the surface of the core to form a first dielectric layer; and processing the first dielectric layer to form a first lens layer; mixing the first material and the second material in an i-th ratio and coating them on the surface of an i-1 lens layer to form an i-th dielectric layer; and processing the i-th dielectric layer to form an i-th lens layer, wherein i is sequentially any integer from 2 to N, N is an integer and N is greater than or equal to 2, so as to obtain a Luneburg lens including a core and N lens layers covering the core.

When making a Luneburg lens, the above method can make N lens layers layer by layer. Specifically, according to the dielectric constant requirements of the target lens layer, the first material and the second material can be directly mixed in a corresponding proportion and coated on the surface of the core or the lens layer to form a dielectric layer, and then the target lens layer can be formed after processing, thereby simplifying the production steps of the Luneburg lens, and further reducing the difficulty and cost of the Luneburg lens production process. In addition, this layer-by-layer production method can more accurately control the production of each lens layer, thereby improving the performance of the Luneburg lens.

In the present application, the manner in which the first material and the second material are mixed and coated on the surface of the inner core or the lens layer is not limited. For example, mixing the first material and the second material in a first ratio and coating the inner core surface may specifically include: spraying, applying, molding or cavity forming the first material and the second material in a first ratio on the inner core surface. Similarly, mixing the first material and the second material in an i-th ratio and coating the surface of the i-1 lens layer may specifically include: spraying, applying, molding or cavity forming the first material and the second material in an i-th ratio and coating the surface of the i-1 lens layer, which is not specifically limited here.

Accordingly, after the first material and the second material are coated on the surface of the inner core or the lens layer, different methods can be used to form a dielectric layer. For example, forming the first dielectric layer can specifically include: forming the first dielectric layer by foaming, molding, cavity forming, heating, drying or dehydrating the first material and the second material coated on the surface of the inner core. Similarly, forming the i-th dielectric layer can specifically include: forming the i-th dielectric layer by foaming, molding, cavity forming, heating, drying or dehydrating the first material and the second material coated on the surface of the i-1th lens layer. In a possible technical solution, the first material and the second material can be mixed and sprayed on the surface of the inner core in a first ratio, and left to stand for a first period of time to foam to form the first dielectric layer; the first material and the second material can be mixed and sprayed on the surface of the i-1th lens layer, and left to stand for an i-1 period of time to foam to form the i-1th dielectric layer. This technical solution does not require temperature and pressure, thereby further reducing the difficulty of the manufacturing process of the Luneburg lens.

In some technical solutions of the present application, the i-1th lens layer has the i-1th dielectric constant, the i-th lens layer has the i-th dielectric constant, and the i-1th dielectric constant may be greater than the i-th dielectric constant. In this way, the dielectric constant gradually decreases from the 1st lens layer to the Nth lens layer, forming a gradient change. Of course, according to the actual application scenario, the dielectric constants of two adjacent lens layers in the above-mentioned N lens layers may also be equal, and no specific limitation is made here.

When separately manufacturing the i-1th dielectric layer and the i-th dielectric layer, by making the mixing ratio of the first material and the second material different, that is, making the i-1th ratio different from the i-th ratio, the dielectric constants of two adjacent lens layers can be different, which can further simplify the manufacturing difficulty.

In the technical solution of the present application, processing the first dielectric layer or the i-th dielectric layer may specifically include: shaping the surface of the first dielectric layer or the i-th dielectric layer; smoothing the surface of the shaped first dielectric layer or the i-th dielectric layer to form a lens layer. During processing, shaping the dielectric layer can control the weight of the lens layer to a target weight. The surface of the dielectric layer is smoothed to form a lens layer, which can not only improve the surface accuracy of the lens layer, but also provide a smooth manufacturing surface for the first material and the second material of the next lens layer.

When manufacturing the lens layer, the thickness of two adjacent lens layers can be equal, or the thickness of two adjacent lens layers can be unequal. It can be specifically designed according to the performance requirements of the Luneburg lens, and no specific restrictions are made here. For example, in some technical solutions, the thickness of each lens layer can be equal. In this technical solution, the thickness of each lens layer is controlled by controlling the surface shaping amount of the dielectric layer, so that the difficulty of the Luneburg lens manufacturing process can be further reduced.

When making a Luneburg lens, since the shape of the core and the lens layer are different, and the dielectric constant of the core is different from that of the lens layer, the core can be prepared separately before making the lens layer. Specifically, the preparation of the core can include: placing the core material into a mold and forming it; processing the formed core material to form the core. In the mold, the core material can be formed by any one of foaming, extrusion, and injection molding, which is not specifically limited here. In addition, the core material can be a polypropylene material or polypropylene.

In the present application, the parameters of the Luneburg lens can be designed according to different application scenarios and different size requirements and performance requirements. For example, before preparing the core, the above method can also include obtaining the size of the core, and the thickness and dielectric constant of each lens layer. In this way, the core and lens layers can be manufactured layer by layer using the above method according to these parameters, thereby improving the manufacturing accuracy.

The first material in the present application may include one or more of polyurethane, phenolic resin, ethylene-vinyl acetate copolymer, polyamide, polyamic acid, polyimide, polypropylene, polyethylene and polystyrene. That is to say, the first material may be selected from one of polyurethane, phenolic resin, ethylene-vinyl acetate copolymer, polyamide, polyamic acid, polyimide, polypropylene, polyethylene and polystyrene; or, the first material may be a mixture of multiple materials of polyurethane, phenolic resin, ethylene-vinyl acetate copolymer, polyamide, polyamic acid, polyimide, polypropylene, polyethylene and polystyrene, and no specific limitation is made here.

In order to change the dielectric constant of the lens layer, the dielectric constant of the second material may be greater than 10, thereby achieving the change in the dielectric constant by mixing the first material and the second material.

In addition, the second material may be a dielectric constant additive, and may specifically include one or more of barium strontium titanate, barium copper titanate, ceramic powder, aluminum powder or silver powder. By changing the mixing ratio of the first material and the second material, the dielectric constant of the formed lens layer may be different, thereby more accurately controlling the dielectric constant change of the N lens layers of the Luneburg lens. Specifically, when a poorly soluble solid material is selected, the solid material may be made into a solvent to form a second material solvent, which is convenient for mixing with the first material.

In a second aspect, the present application also provides a system for manufacturing a Luneburg lens antenna. The system is used to execute the method of the first aspect above. The system may specifically include a controller, a spraying device, and a surface treatment device. The spraying device and the surface treatment device are electrically connected to the controller respectively. The spraying device is used to mix the first material and the second material and coat them on the surface of the inner core or the surface of the lens layer. The surface treatment device is used to process the first dielectric layer or the i-th dielectric layer. The controller is used to control the spraying device to absorb the first material and the second material according to the first ratio or the i-th ratio when manufacturing the first lens layer or the i-th lens layer.

The above system can produce N lens layers layer by layer. Specifically, according to the dielectric constant requirements of the target lens layer, the first material and the second material can be directly mixed in a corresponding proportion by a spraying device and coated on the surface of the inner core or the lens layer to form a dielectric layer, and then processed by a surface treatment device to form the target lens layer, thereby simplifying the production steps of the Luneburg lens, and further reducing the production process difficulty and production cost of the Luneburg lens. In addition, the system adopts a layer-by-layer production method to produce lens layers, which can more accurately control the production of each lens layer, thereby improving the performance of the Luneburg lens.

In a third aspect, the present application also provides a Luneburg lens. The Luneburg lens is manufactured using the method of the first aspect, and the manufacturing process difficulty and manufacturing cost are relatively low. In addition, the size and dielectric constant of each lens layer are relatively precise, which can improve the performance of the Luneburg lens.

In a fourth aspect, the present application also provides a Luneburg lens antenna. The Luneburg lens antenna comprises a bracket, a feed source, a circuit board, and the Luneburg lens of the third aspect, wherein the feed source, the circuit board, and the Luneburg lens are arranged on the bracket. The feed source is electrically connected to the circuit board and is arranged on one side of the Luneburg lens. The manufacturing steps of the Luneburg lens of the Luneburg lens antenna are relatively simple, thereby reducing the manufacturing process difficulty and manufacturing cost of the Luneburg lens antenna.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the structure of a Luneburg lens;

FIG2 is a schematic flow chart of a method for manufacturing a Luneburg lens in an embodiment of the present application;

FIG3 is another schematic flow chart of a method for manufacturing a Luneburg lens in an embodiment of the present application;

FIG4 is another schematic flow chart of the method for manufacturing a Luneburg lens in an embodiment of the present application;

FIG5 is a schematic diagram of a structure of a Luneburg lens antenna in an embodiment of the present application;

FIG6 is a schematic diagram of a system for manufacturing a Luneburg lens antenna in an embodiment of the present application;

FIG. 7 is a schematic diagram of manufacturing a Luneburg lens in an embodiment of the present application.

Reference numerals:

current technology:
10-Luneburg lens antenna; 11-feed source; 12-Luneburg lens;

This application:
50-Luneburg lens antenna; 51-feed source; 52-Luneburg lens;
53- bracket; 54- circuit board; 60- system; 61- spraying device;
62- surface treatment device; 71- inner core; 72- lens layer.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present application more clear, the present application will be further described in detail below in conjunction with the accompanying drawings.

References to "one embodiment" or "some embodiments" etc. described in this specification mean that a particular feature, structure or characteristic described in conjunction with the embodiment is included in one or more embodiments of the present application. Thus, the phrases "in one embodiment", "in another embodiment", "in some other embodiments", "in some other embodiments", etc. that appear at different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

FIG1 is a schematic diagram of a structure of a Luneburg lens. As shown in FIG1 , the Luneburg lens antenna 10 includes a feed source 11 and a Luneburg lens 12. The Luneburg lens 12 is an onion-shaped central symmetrical sphere, and the Luneburg lens 12 specifically includes a core and a plurality of lens layers covering the core. When used, the feed source 11 is arranged on one side of the Luneburg lens 12, so that the Luneburg lens 12 can refract and amplify the signal radiated by the feed source 11, and radiate in a specified direction, thereby producing a good gain effect.

At present, mixed materials containing expanded beads can be used to make Luneburg lenses. During production, the expanded bead material is usually mixed with other materials and then foamed at high temperature, and the change in dielectric constant is achieved by adjusting the apparent density of each lens layer. However, in the actual foaming process, it is difficult to control the inner layer structure and outer layer structure formed by the bead foaming to be consistent, resulting in difficulty in controlling the dielectric constant of each lens layer, thereby affecting the performance of the Luneburg lens.

In addition, 3D printing technology is currently used to make Luneburg lenses. Specifically, before printing, it is necessary to configure a printing substrate, and then use the fused deposition modeling method to print the printing substrate into a spherical structure to obtain a spherical blank mold. Subsequently, it is necessary to use a supercritical fluid to impregnate the spherical blank mold, and then form a Luneburg lens after foaming. However, when using the above method to make Luneburg lenses, on the one hand, the cost of 3D printing is high and the printing time is long; on the other hand, the foaming supercritical environment process has high requirements for the manufacturing environment, and requires precise control of temperature and pressure changes. The process is relatively complicated, which makes the Luneburg lens more difficult to make.

In view of the technical problems described above, the present application provides a Luneburg lens and a manufacturing method thereof, as well as a Luneburg lens antenna to simplify the manufacturing steps of the Luneburg lens, thereby reducing the manufacturing process difficulty and manufacturing cost of the Luneburg lens.

FIG2 is a flow chart of a method for making a Luneburg lens in an embodiment of the present application. In an embodiment of the present application, the Luneburg lens includes a core and N lens layers covering the core, wherein N=2, 3, 4, ..., that is, N can be a positive integer greater than or equal to 2. The Luneburg lens can be a sphere, an ellipsoid, a column or other shapes. As shown in FIG2, the method for making the Luneburg lens can specifically include:

Step S101, preparing a kernel.

FIG3 is another schematic flow diagram of the method for making a Luneburg lens in an embodiment of the present application. When making a Luneburg lens, since the shape of the core is different from the shape of the lens layer, and the dielectric constant of the core and the dielectric constant of the lens layer are usually different, the core can be prepared separately before making the lens layer. As shown in FIG3, step S101 may specifically include:

Step S201, placing the core material into a mold and forming it. In step S201, the core material can be made of polypropylene or polypropylene. In the mold, the core material can be formed by foaming, extrusion, injection molding, etc., which are not specifically limited here.

Step S202, processing the formed core material to form a core. In step S202, after processing the surface of the formed core material, a smooth surface can be obtained, so as to facilitate the subsequent production of a lens layer on the surface of the core.

Please continue to refer to FIG. 2 . After step S101 , the method may further include:

Step S102: Mix the first material and the second material in a first ratio and coat them on the surface of the inner core to form a first dielectric layer; and process the first dielectric layer to form a first lens layer.

Step S103, when i takes the values of 2, 3, 4, 5 ... N in sequence, repeatedly perform the following steps, where N is the number of lens layers required to prepare the Luneburg lens:

The first material and the second material are mixed in an i-th ratio and coated on the surface of the i-1th lens layer to form an i-th dielectric layer; the i-th dielectric layer is processed to form an i-th lens layer.

In the present application, the method of mixing the first material and the second material and coating them on the surface of the inner core and the lens layer may include spraying, painting, molding or cavity molding. One method may be selected according to actual needs, and no specific limitation is made here. After the first material and the second material are coated on the surface of the inner core or the lens layer, different methods may be used to form a dielectric layer, for example, it may be achieved by any one of foaming, molding, cavity molding, heating, drying or dewatering. For example, in a specific embodiment, step S102 may specifically be: spraying the first material and the second material on the surface of the inner core in a first ratio, and letting it stand for a first time to foam to form a first dielectric layer; spraying the first material and the second material on the surface of the i-1th lens layer, and letting it stand for an i-1th time to foam to form an i-1th dielectric layer. In this embodiment, there is no need to require temperature and pressure, thereby further reducing the difficulty of the manufacturing process of the Luneburg lens. In another specific embodiment, step S102 may specifically be: placing the core in a mold, and mixing the first material and the second material in a first ratio and filling them between the core and the mold, and forming them by compression molding technology, so that the first material and the second material are attached to the surface of the core or the surface of the lens layer. In another specific embodiment, step S102 may specifically be: placing the core in a mold, and mixing the first material and the second material in a first ratio and filling them between the core and the mold, and forming them by compression molding technology, so that the first material and the second material are attached to the surface of the core or the surface of the lens layer, and then drying the first material and the second material to form a dielectric layer.

When making the first material, one or more of polyurethane, phenolic resin, ethylene-vinyl acetate copolymer, polyamide, polyamic acid, polyimide, polypropylene, polyethylene and polystyrene can be used. That is to say, the first material can be one of polyurethane, phenolic resin, ethylene-vinyl acetate copolymer, polyamide, polyamic acid, polyimide, polypropylene, polyethylene and polystyrene; or, the first material can be a mixture of multiple materials of polyurethane, phenolic resin, ethylene-vinyl acetate copolymer, polyamide, polyamic acid, polyimide, polypropylene, polyethylene and polystyrene, and no specific limitation is made here.

In order to change the dielectric constant of the lens layer, the dielectric constant of the second material can be greater than 10, so that the dielectric constant can be changed by changing the mixing ratio of the second material during the mixing of the first material and the second material. Specifically, the second material can be a dielectric constant additive, for example, it can include one or more of strontium barium titanate, copper barium titanate, ceramic powder, aluminum powder or silver powder. That is to say, the second material can be one of strontium barium titanate, copper barium titanate, ceramic powder, aluminum powder or silver powder; or, the second material can be a mixture of multiple materials of strontium barium titanate, copper barium titanate, ceramic powder, aluminum powder or silver powder, and no specific restrictions are made here. Specifically, when a poorly soluble solid material is selected, the solid material can be made into a solvent to form a second material, which facilitates mixing the first material with the solvent-type second material.

By changing the mixing ratio of the first material and the second material, the dielectric constant of the formed lens layer can be made different, thereby more accurately controlling the dielectric constant change of the N lens layers of the Luneburg lens. For example, in a specific embodiment, by increasing the mixing ratio of the second material, the dielectric constant of the first material before foaming can be increased, thereby increasing the foaming ratio, reducing the density of the dielectric layer formed after foaming, and thus reducing the weight of the Luneburg lens.

FIG4 is another schematic flow chart of the method for making a Luneburg lens in an embodiment of the present application. In an embodiment of the present application, the processing performed on the surface of the core, the surface of the first dielectric layer or the surface of the i-th dielectric layer may specifically include shaping and surface smoothing. As shown in FIG4 , taking the processing of the surface of the dielectric layer as an example, the processing specifically includes:

Step S301: shaping the surface of the j-th dielectric layer, wherein j is 1, 2, 3, 4, ..., N in sequence.

Step S302: performing surface smoothing treatment on the shaped j-th medium layer to form a j-th lens layer.

During processing, shaping the dielectric layer can control the final weight of the lens layer within the designed weight range. The surface of the dielectric layer is smoothed to form a lens layer. On the one hand, the surface accuracy of the lens layer can be improved, thereby improving the performance of the Luneburg lens. On the other hand, it can also provide a smooth manufacturing surface for the next lens layer and attach to the first material and the second material. Among them, shaping can be performed by polishing and/or cutting, and surface smoothing can also be performed by polishing and/or cutting, which is not specifically limited here.

In some embodiments of the present application, the i-1th lens layer has the i-1th dielectric constant, the i-th lens layer has the i-th dielectric constant, and the i-1th dielectric constant is greater than the i-th dielectric constant. In this way, from the 1st lens layer to the Nth lens layer, the dielectric constant gradually decreases, forming a gradient change. Of course, according to the actual application scenario, the dielectric constant of at least one lens layer among the N lens layers may also be different from the dielectric constant of the lens layer adjacent to it. They can be equal, and no specific limitation is given here.

When manufacturing the lens layer, the thickness of two adjacent lens layers can be equal, or the thickness of two adjacent lens layers can be unequal, which can be specifically designed according to the performance requirements of the Luneburg lens, and is not specifically limited here. For example, in some embodiments, the thickness of each lens layer can be equal, and the thickness of each lens layer can be controlled by controlling the surface shaping amount of the dielectric layer, thereby further reducing the difficulty of the Luneburg lens manufacturing process.

In the above method, the N lens layers of the Luneburg lens are manufactured layer by layer. Specifically, according to the dielectric constant of the lens layer to be manufactured, the first material and the second material can be directly mixed in a corresponding proportion, and then coated on the surface of the inner core or the surface of the lens layer to form a dielectric layer. This process does not require high temperature and pressure requirements. Subsequently, the dielectric layer is processed to form a lens layer to obtain a smooth lens layer surface. This method can simplify the manufacturing steps of the Luneburg lens, thereby reducing the manufacturing process difficulty and manufacturing cost of the Luneburg lens. Moreover, this layer-by-layer manufacturing method can more accurately control the size and dielectric constant of each lens layer, thereby improving the performance of the Luneburg lens.

In the present application, the parameters of the Luneburg lens can be designed according to different size requirements and performance requirements according to different application scenarios. For example, before step S101, the size of the core, and the thickness and dielectric constant of each lens layer can also be obtained. In this way, according to these parameters, the core and lens layers can be manufactured layer by layer using the method shown in Figures 2, 3 and 4 above.

Based on the same technical concept, the present application also provides a Luneburg lens. The Luneburg lens is prepared by the method of the above embodiment, and the manufacturing process difficulty and manufacturing cost are relatively low. In addition, the size and dielectric constant of each lens layer are relatively precise, which can improve the performance of the Luneburg lens.

Based on the same technical concept, the present application also provides a Luneburg lens antenna. FIG. 5 is a schematic diagram of the structure of the Luneburg lens antenna in the embodiment of the present application. As shown in FIG. 5 , the Luneburg lens antenna 50 includes a feed source 51, a Luneburg lens 52 prepared in the above embodiment, a bracket 53 and a circuit board 54. Among them, the feed source 51, the circuit board 54 and the Luneburg lens 52 can be fixed to the bracket 53. The feed source 51 is electrically connected to the circuit board 54 and is arranged on one side of the Luneburg lens 52. In actual application, the Luneburg lens 52 can refract and amplify the signal radiated by the feed source 51, and radiate in a specified direction, thereby producing a good gain effect. The manufacturing steps of the Luneburg lens 52 of the Luneburg lens antenna 50 are relatively simple, thereby reducing the manufacturing process difficulty and manufacturing cost of the Luneburg lens antenna 50.

Based on the same technical concept, the present application provides a system for making a Luneburg lens antenna. FIG. 6 is a schematic diagram of a system for making a Luneburg lens antenna in an embodiment of the present application. As shown in FIG. 6 , the system 60 is used to execute the method of the above embodiment. Among them, the system 60 may specifically include a controller (not shown in the figure), a spraying device 61 and a surface treatment device 62. The spraying device 61 and the surface treatment device 62 are electrically connected to the controller respectively. Among them, the spraying device 61 is used to mix the first material and the second material and coat them on the surface of the inner core or the surface of the lens layer. The surface treatment device 62 is used to process the first dielectric layer or the i-th dielectric layer. The controller is used to control the spraying device 61 to absorb the first material and the second material according to the first ratio or the i-th ratio when making the first lens layer or the i-th lens layer.

The above system 60 can produce N lens layers layer by layer. Specifically, according to the dielectric constant requirements of the target lens layer, the first material and the second material can be directly mixed in proportion by using a spraying device 61 and coated on the surface of the inner core or the lens layer; then the lens layer can be formed after processing by a surface treatment device 62, thereby simplifying the production steps of the Luneburg lens, and further reducing the production process difficulty and production cost of the Luneburg lens. In addition, the system can more accurately control the production of each lens layer, thereby improving the performance of the Luneburg lens.

In a specific embodiment, the spraying device 61 can spray the first material and the second material mixed in a first ratio on the surface of the inner core, and keep it still for a first time to foam and form a first dielectric layer. Then, the spraying device 61 sprays the first material and the second material mixed on the surface of the i-1th lens layer, and keeps it still for an i-1th time to foam and form an i-1th dielectric layer. In this embodiment, the controller can also be used to control the surface treatment device 62 to stop for a jth time after the spraying device 61 sprays, so as to wait for the first material and the second material to foam and form a dielectric layer.

Fig. 7 is a schematic diagram of manufacturing a Luneburg lens in an embodiment of the present application. As shown in Fig. 7, the method of the present application is described below by taking a complete manufacturing process as an example.

First, a Luneburg lens with a radius of R = 150 mm is designed. According to the size of the Luneburg lens, the radius of the core of the Luneburg lens is designed to be R1 = 20 mm, the number of lens layers is 26, and the thickness of each lens layer is 5 mm. As shown in Table 1 below, according to the size of the core and lens layer, the dielectric constants of the core and lens layer of the Luneburg lens are calculated:

Table 1

Then, the core is prepared according to step S201 to step S202. In this embodiment, polypropylene material can be used, and after the volume of the polypropylene material is foamed to 1.25 times, it is machined into a spherical shape to form the core 71. Subsequently, the core 71 is placed at the nozzle position of the spray device 61.

According to the dielectric constants of each lens layer in Table 1, the controller controls the spraying device 61 to mix the first material and the second material in a first ratio. Then, the first material is sprayed evenly onto the surface of the core 71; the mixture of the first material and the second material is kept still for several minutes to foam evenly to form a first dielectric layer. After that, the controller adjusts the position of the cutting blade of the surface treatment device 62 and cuts the surface of the first dielectric layer. After processing, the thickness of the first lens layer 72 is 5 mm, and the radius of the processed sphere R2 = 25 mm.

Next, the controller controls the spraying device 61 to mix the first material and the second material in a second ratio. Then, the first lens layer 72 is uniformly sprayed on the surface; it is kept still for several minutes, waiting for the mixture of the first material and the second material to foam uniformly, so as to form a second dielectric layer. The controller adjusts the position of the cutting blade of the surface treatment device 62, and cuts the surface of the second dielectric layer. After processing, the thickness of the second lens layer is 5 mm, and the radius of the processed sphere R2 = 30 mm.

Repeat the above steps to produce the third lens layer to the twenty-sixth lens layer. Finally, the spherical radius R of the Luneburg lens 52 is 150 mm, and the dielectric constant of the lens layer is distributed according to the dielectric constant of Table 1.

The terms used in the above embodiments are only for the purpose of describing specific embodiments and are not intended to be used as limitations on the present application. As used in the specification and appended claims of the present application, the singular expressions "a", "an", "said", "above", "the" and "this" are intended to also include expressions such as "one or more", unless there is a clear contrary indication in the context.

The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

A method for manufacturing a Luneburg lens, characterized in that the method comprises:

preparing the kernel;

Mixing a first material and a second material in a first ratio and coating the mixture on the surface of the inner core to form a first dielectric layer; and processing the first dielectric layer to form a first lens layer;

The first material and the second material are mixed in an i-th ratio and coated on the surface of the i-1th lens layer to form an i-th dielectric layer; and the i-th dielectric layer is processed to form an i-th lens layer, wherein i is any integer from 2 to N in sequence, and N is an integer greater than or equal to 2, so as to obtain a Luneburg lens including the core and N lens layers covering the core.
The method according to claim 1, characterized in that the first material and the second material are mixed in a first ratio and coated on the surface of the core, comprising:

Mixing the first material and the second material in the first ratio and spraying, applying, pressing or cavity forming the mixture on the surface of the core;

The first material and the second material are mixed in an i-th ratio and coated on the surface of the i-1-th lens layer, comprising:

The first material and the second material are mixed in the i-th ratio and sprayed, applied, molded or cavity-formed on the surface of the i-1th lens layer.
The method according to claim 1 or 2, characterized in that forming the first dielectric layer comprises:

The first material and the second material covering the surface of the inner core are foamed, molded, cavity formed, heated, dried or dehydrated to form the first dielectric layer;

Forming an i-th dielectric layer, comprising:

The first material and the second material covering the surface of the (i-1)th lens layer are foamed, molded, cavity formed, heated, dried or dehydrated to form the (i)th dielectric layer.
The method according to any one of claims 1 to 3, characterized in that the (i-1)th lens layer has an (i-1)th dielectric constant, the (i)th lens layer has an (i)th dielectric constant, and the (i-1)th dielectric constant is greater than the (i)th dielectric constant.
The method according to any one of claims 1 to 4, characterized in that the (i-1)th ratio is different from the (i)th ratio.
The method according to any one of claims 1 to 5, characterized in that processing the first dielectric layer or the i-th dielectric layer comprises:

shaping a surface of the first dielectric layer or the i-th dielectric layer;

The first dielectric layer or the i-th dielectric layer after shaping is subjected to surface smoothing treatment to form the first lens layer or the i-th lens layer.
The method according to any one of claims 1 to 6, characterized in that the preparation of the kernel comprises:

placing the core material into a mold and forming it;

The formed core material is processed to form the core.
The method according to any one of claims 1 to 7, characterized in that, before preparing the kernel, the method further comprises:

The size of the core, and the thickness and dielectric constant of each of the lens layers are obtained.
The method according to any one of claims 1 to 8, characterized in that the dielectric constant of the second material is greater than 10.
The method according to claim 9, characterized in that the second material comprises one or more of barium strontium titanate, barium copper titanate, ceramic powder, aluminum powder and silver powder.
The method according to any one of claims 1 to 10, characterized in that the first material comprises one or more of polyurethane, phenolic resin, ethylene-vinyl acetate copolymer, polyamide, polyamic acid, polyimide, polypropylene, polyethylene and polystyrene.
A Luneburg lens, characterized in that the Luneburg lens is manufactured using the method described in any one of claims 1 to 11.
A Luneburg lens antenna, characterized in that the Luneburg lens antenna comprises a bracket, a feed source, a circuit board, and the Luneburg lens as described in claim 12, wherein the feed source, the circuit board and the Luneburg lens are arranged on the bracket, and the feed source is electrically connected to the circuit board and is arranged on one side of the Luneburg lens.