Low-density low-cost luneberg lens antenna based on high-dielectric mixed material

Abstract

The invention discloses a low-density and low-cost Longboer lens antenna based on a high-dielectric mixed material, and belongs to the field of antennae, and the antenna comprises a plurality of nested spherical layer structures which are segmented along the radial direction based on the spherical center of the Longboer antenna; wherein the spherical layer structure is formed by stacking and cutting a plurality of layers of same lens main body supporting structures in a multi-layer manner; the lens main body supporting structure is made of a low-density flat plate material with an extremely low dielectric constant; aiming at the single ball layer structure, opening structures which are uniformly distributed are arranged on different lens main body supporting structures, the opening structures are uniformly distributed in the ball layer structure, and the diameters and the depths of the opening structures are the same; a dielectric constant modulation material is arranged in the opening structure; according to the invention, the Lunberg lens antenna which is light in weight and low in cost can be provided.

Description

Technical Field

[0001] The present invention belongs to the field of antenna technology, and in particular relates to a low-density and low-cost Luneburg lens antenna based on a high-dielectric hybrid material. Background Art

[0002] The Luneburg lens antenna is a widely used antenna type that uses the continuous refraction characteristics of a sphere to achieve electromagnetic wave convergence. Common Luneburg lens antennas usually use a multi-layer concentric spherical shell structure, with each layer filled with a different dielectric constant (ε r ) dielectric materials or metamaterials to obtain a gradient dielectric constant distribution to achieve an effect close to a continuous dielectric distribution. The Luneburg lens can converge the waves radiated by a single feed source into high-gain, narrow-beam waves, and is mostly used in the field of wireless communications. At present, the low-altitude economic field is gradually becoming hot, and there is a demand for the integration of communication and perception. Therefore, mobile communication base stations are required to be gradually rebuilt into equipment that is compatible with both communication and perception modes and their respective frequency bands. The Sub-6G mobile communication frequency band is low, requiring a larger antenna aperture, and the challenges of weight and cost are becoming increasingly prominent. Therefore, the research and design of a low-density, low-cost Luneburg lens antenna is an urgent need at present.

[0003] Some existing Luneburg lens antennas utilize high-density materials such as metal or ceramics as dielectric materials to determine the dielectric constant of each layer. A patent application has been filed (Application No. 202210672766.9) reporting a method for preparing Luneburg lenses from low-dielectric-loss ceramic materials. This method involves high-temperature sintering of the formulated material followed by compression molding, resulting in a Luneburg lens with a continuously variable relative dielectric constant. However, this method is heavy, costly, and involves numerous complex processes.

[0004] In response to the above problems, the present invention provides a low-density, low-cost Luneburg lens antenna based on a mixed material with a high dielectric constant. By using low-density foam as a supporting material and a liquid mixed with antifreeze as a dielectric constant modulation material, this mixed liquid has low cost and is suitable for the high and low temperature (-30℃-70℃) requirements of outdoor communication equipment in most areas of my country. In addition, since the mixed liquid still has a high dielectric constant (approximately ε according to the mixing ratio), the dielectric constant of the antenna is about ε. r =48-60), so the dielectric distribution (ε) required for the Luneburg lens can be achieved in a very small volume. r =1-2), compared with solid media, the density and overall weight of the lens can be greatly reduced, ultimately achieving low density and low cost of the Luneburg lens antenna. Summary of the Invention

[0005] In order to solve the technical problems of the above-mentioned existing large-aperture Luneburg lens antenna such as heavy weight, great difficulty in manufacturing and high cost, the present invention proposes a low-density and low-cost Luneburg lens antenna based on high-dielectric mixed materials. By periodically adding a mixed liquid with a high dielectric constant to the sphere, a light-weight and low-cost Luneburg lens antenna is realized, which meets the dielectric constant distribution required by the Luneburg lens and the performance consistency of incident waves at different angles after passing through the lens, so as to solve the problems existing in the above-mentioned prior art.

[0006] To achieve the above objectives, the present invention provides a low-density, low-cost Luneburg lens antenna based on a high-dielectric hybrid material, comprising:

[0007] A plurality of spherical layer structures, wherein the spherical layer structure is a structure divided along the radial direction based on the spherical center of the Luneburg antenna;

[0008] The spherical layer structure is formed by stacking and cutting multiple layers of the same lens main body support structure; the lens main body support structure is made of a low-density flat plate material with an extremely low dielectric constant;

[0009] For a single spherical layer structure, different lens body support structures are provided with evenly distributed open hole structures and the open hole structures are evenly distributed in the spherical layer structure, and the diameter and depth of the open hole structures are the same; a dielectric constant modulation material is provided in the open hole structure.

[0010] Optionally, the dielectric constant of the low-density flat plate material in the lens body support structure is less than 1.1.

[0011] Optionally, the dielectric constant modulation material is a mixed liquid of water and ethylene glycol or a solid dielectric material.

[0012] Optionally, the open hole structure is a circular hole structure or an ellipsoidal hole structure.

[0013] Optionally, the opening structure evenly distributed on the same layer of the lens main body support structure satisfies:

[0014]

[0015] Among them, ε rp is the dielectric constant of the foam material, ε rq is the dielectric constant of the mixed liquid, ε is the target dielectric constant, and p is the volume ratio of the mixed liquid to the low-density flat material in the lens body.

[0016] Optionally, the low-density flat panel material is foam.

[0017] Optionally, the dual-polarization feed sources are symmetrically placed in a direction perpendicular to the radial direction.

[0018] Optionally, the thickness of the lens body support structure is less than 15% of the antenna operating wavelength.

[0019] Compared with the prior art, the present invention has the following advantages and technical effects:

[0020] Compared to existing Luneburg lens antennas, which use solid materials for dielectric constant modulation, the present invention's high-dielectric hybrid, low-density, and low-cost Luneburg lens antenna uses a liquid as the dielectric constant modulation material. The mixed liquid still has a very high dielectric constant, comparable to other materials such as metal fillers and ceramics. Compared to solid dielectric materials, liquid dielectric materials can significantly reduce the density and weight of the lens, ultimately achieving the low density and low cost of the Luneburg lens. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of this application. The exemplary embodiments and descriptions of this application are intended to explain this application and do not constitute an improper limitation on this application. In the accompanying drawings:

[0022] Figure 1 A cross-sectional structural diagram of an embodiment of the present invention;

[0023] Figure 2 This is the 2690 MHz directional pattern of an embodiment of the present invention;

[0024] Figure 3 Schematic diagram of the internal structure of the Luneburg lens according to an embodiment of the present invention; DETAILED DESCRIPTION

[0025] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0026] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0027] In response to the technical problems of existing large-aperture Luneburg lens antennas, such as heavy weight, difficulty in production, and high cost, the present invention provides a light-weight and low-cost Luneburg lens antenna based on a mixed material with a high dielectric constant. By using low-density foam as a supporting material and a liquid mixed with antifreeze as a dielectric constant modulation material, this mixed liquid is low in cost and suitable for the high and low temperature (-30℃-70℃) requirements of outdoor communication equipment in most areas. In addition, since the mixed liquid still has a high dielectric constant (approximately ε according to the mixing ratio), the dielectric constant of the mixed liquid is about ε. r=48-60), so the dielectric distribution (ε) required for the Luneburg lens can be achieved in a very small volume. r =1-2), compared with solid media, the density and overall weight of the lens can be greatly reduced, ultimately achieving the light weight and low cost of the Luneburg lens antenna.

[0028] The above technical solution is described in detail:

[0029] The main purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art, and to achieve the advantages of light weight and low cost while meeting the equivalent dielectric distribution required by the Luneburg lens. Due to the symmetry of the structure, the advantage of good beam consistency for multi-beam feed can also be obtained.

[0030] The object of the present invention is achieved through the following technical solution: a low-density, low-cost Luneburg lens antenna made of a high-dielectric mixed material, in the above antenna structure, comprising:

[0031] Several spherical layer structures, wherein the spherical layer structure is a structure divided along the radial direction based on the spherical center of the Luneburg antenna,

[0032] The spherical layer structure is formed by stacking and cutting multiple layers of the same lens main body support structure;

[0033] The lens body support structure is made of low-density flat material with extremely low dielectric constant;

[0034] For a single spherical layer structure, cylindrical holes are evenly distributed on different lens body support structures, and the diameter and depth of the cylindrical holes are the same;

[0035] The spacing between the cylindrical holes is much smaller than the working wavelength;

[0036] A mixed liquid of water and ethylene glycol is provided in the cylindrical hole;

[0037] The uniform distribution of the cylindrical holes satisfies the dielectric requirement formula:

[0038]

[0039] Among them, ε rp is the dielectric constant of the foam material, ε rq is the dielectric constant of the mixed liquid, ε is the target dielectric constant, and p is the volume ratio of the mixed liquid to the foam medium material in the lens body.

[0040] In view of the above, the present invention also provides a design method for the low-density, low-cost Luneburg lens antenna. The specific design steps are as follows:

[0041] Step 1: Divide the spherical Luneburg lens antenna into N (N≥1) spherical layers along the radial direction. The outer contour radius of each spherical layer from the outside to the inside is recorded as R1, R2,...R N (where R1 is exactly the radius of the entire Luneburg lens and is generally several times the size of the working wavelength), and then it is horizontally cut (coplanar with the XOZ plane) into several horizontal layers with the same thickness h (much smaller than the working wavelength λ, generally h<0.15λ);

[0042] Step 2: Select a material with a very low dielectric constant (generally, ε r <1.1) as the main support structure of the lens, and the spherical contour structure of the entire lens is achieved by multi-layer stacking and cutting (taking foam as an example, the dielectric constant ε r =1.05), a number of densely distributed cylindrical holes are opened downward from the upper surface of any foam plate (the spacing between adjacent holes is much smaller than the working wavelength λ), among which all holes located in the Nth sphere layer are evenly distributed, and their diameters are equal and are recorded as d N , the depth and diameter are equal and are also d N All the holes in the spherical layer of the plate evenly distribute the volume of the surrounding foam board and distribute it completely (the volume allocated to each hole is recorded as V N );

[0043] Step 3: According to this method, make a number of densely distributed cylindrical holes on the upper surface of any foam plate downwards, and pour the prepared mixed liquid of water and ethylene glycol (the dielectric constant of the mixed liquid is ε rq ), inject the mixed liquid into a N The hollow spheres are placed in multiple thin hollow sphere cavities with negligible wall thickness. The hollow sphere cavities are then placed in a number of densely distributed cylindrical holes opened downward from the upper surface of any foam flat plate. The distribution of the cylindrical holes must satisfy the following formula:

[0044] The cylindrical hole distribution of the Luneburg lens antenna satisfies the following formula (the wall thickness of the hollow spherical cavity is very thin and can be ignored, and the gap between the liquid and the cylindrical hole is ignored):

[0045]

[0046] Among them, ε rp is the dielectric constant of the foam material, ε rq is the dielectric constant of the mixed liquid, ε is the target dielectric constant, and p is the volume ratio of the mixed liquid to the foam medium material in the lens body.

[0047] Furthermore, the relative dielectric constant of the foam dielectric material used in the lens antenna is 1.05, and the loss tangent is 0.002. The following are three different cases.

[0048] Case 1: Follow the above steps to make a three-layer Luneburg lens antenna with a diameter of R = 750mm, in which several layers have a diameter of d N The cylindrical hole contains a thin cavity filled with mixed liquid. The local structure of the Luneburg lens antenna is as follows: Figure 1 Shown, schematic Figure 1 Only three layers of the structure are shown in the figure. There are several layers of this structure in the entire sphere of the Luneburg lens antenna. The operating frequency band is 1427-2690MHz. The volume ratio factor of the outermost layer of foam dielectric material and the mixed liquid is p1=0.047, and the dielectric constant ε1=1.2; the volume ratio factor of the middle layer is p2=0.141, ε2=1.6; the volume ratio factor of the innermost layer is p3=0.194, ε3=1.9. By optimizing the radius parameters of the two inner layers, the dimensions for maximum gain are: outer layer radius r1=375mm, middle layer r2=255mm, innermost layer r3=130mm. The entire sphere of the Luneburg lens antenna weighs 20kg, achieving the goal of lightweight and low cost. The simulated typical frequency band gain of this scheme is 24.83dBi (2690MHz). The dual-polarization feed is symmetrically placed on the X-axis. The simulated gain pattern results are shown as follows Figure 2 As shown in the figure, 6 beams can cover the typical beam requirement of 120°, which can meet the commercial requirements of base stations in this frequency band.

[0049] Case 2: Follow the above steps to make a three-layer Luneburg lens antenna. The cylindrical hole is opened as follows Figure 3 As shown, a number of densely distributed cylindrical holes are opened downward from the upper surface of any foam plate (the spacing between adjacent holes is much smaller than the working wavelength λ), among which all holes located in the Nth sphere are evenly distributed, and their side length and depth dimensions are equal and are recorded as d N All the holes in each ball layer area of ​​the flat plate evenly share the volume of the surrounding foam boards and distribute it completely.

[0050] Case 3: By way of comparison, replacing the mixed liquid dielectric material used in Case 1 with a solid polypropylene material to design a Luneburg lens with the same operating frequency, dimensions, and equivalent dielectric distribution, the resulting Luneburg lens antenna weighs 126 kg, approximately six times the weight of the Luneburg lens antenna in Case 1. This directly demonstrates the lightweight advantage of this invention. Therefore, using a mixed liquid as the dielectric material significantly reduces the weight and cost of the Luneburg lens antenna, foreseeably bringing conveniences in terms of mounting loads, etc.

[0051] The present invention introduces the key points related to the above:

[0052] (1) The Luneburg lens antenna of the present invention uses a high dielectric constant mixed material as a dielectric material instead of a traditional solid dielectric material, which greatly reduces the volume ratio and average density of the required filling medium, thereby achieving a lighter and lower-cost Luneburg lens antenna.

[0053] (2) An implementation case of the present invention's low-density, low-cost Luneburg lens antenna made of a high-dielectric hybrid material is to dig out a plurality of cylindrical holes with rectangular cross-sections in a sphere, and the cylindrical holes are compactly connected and spread over the entire sphere, so that the antenna beam emitted after the incident waves of the feed source placed at different positions on the entire sphere are refracted by the lens has good consistency.

[0054] (3) The dielectric constant modulation materials of this antenna product include but are not limited to liquid and solid dielectric materials.

[0055] (4) The low-density and low-cost Luneburg lens antenna made of a high-dielectric hybrid material of the present invention is not limited to an open hole structure with a rectangular cross section.

[0056] (5) The low-density and low-cost Luneburg lens antenna made of a high-dielectric hybrid material of the present invention is not limited to a cylindrical opening structure, and can be a circular hole, an ellipsoidal hole, etc.

[0057] (6) The diameter d of each circle of foam cells in this antenna structure N It can be the same or different.

[0058] The above are merely preferred embodiments of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A low-density, low-cost Luneburg lens antenna based on a high-dielectric hybrid material, characterized in that: include: A plurality of nested spherical layer structures, wherein the spherical layer structure is a structure divided along the radial direction based on the spherical center of the Luneburg antenna; The spherical layer structure is formed by stacking and cutting multiple layers of the same lens main body support structure; the lens main body support structure is made of a low-density flat plate material with an extremely low dielectric constant; For a single spherical layer structure, different lens body support structures are provided with evenly distributed open hole structures and the open hole structures are evenly distributed in the spherical layer structure, and the diameter and depth of the open hole structures are the same; a dielectric constant modulation material is provided in the open hole structure.

2. The antenna according to claim 1, wherein The dielectric constant of the low-density flat plate material in the lens body support structure is less than 1.

1.

3. The antenna according to claim 1, wherein The dielectric constant modulation material is a mixed liquid of water and ethylene glycol or a solid dielectric material.

4. The antenna according to claim 1, wherein The open hole structure is a circular hole structure or an ellipsoidal hole structure.

5. The antenna according to claim 1, wherein The evenly distributed opening structure of the lens main support structure on the same layer satisfies the following requirements: Among them, ε rp is the dielectric constant of the foam material, ε rq is the dielectric constant of the mixed liquid, ε is the target dielectric constant, and p is the volume ratio of the mixed liquid to the low-density flat material in the lens body.

6. The antenna according to claim 1, wherein The low-density flat panel material is foam.

7. The antenna according to claim 1, wherein The dual-polarization feed sources are symmetrically placed in a direction perpendicular to the radial direction.

8. The antenna according to claim 1, wherein The thickness of the lens main support structure is less than 15% of the antenna's operating wavelength.

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