Wide angle beam scanning luneberg lens antenna and method with linearly arranged feeds

Abstract

The application discloses a wide-angle beam scanning Luneberg lens antenna with linearly arranged feed sources and a method thereof, wherein the antenna comprises: a first metal plate, the shape of the first metal plate is a truncated circular truncated cone, and the cutting surface is perpendicular to the upper and lower bottom surfaces of the circular truncated cone; a second metal plate, the shape of the second metal plate is the same as that of the first metal plate; a cutting surface is formed between the cutting surfaces of the two metal plates; a Luneberg lens is arranged between the first metal plate and the second metal plate, and the shape of the Luneberg lens matches the shape of the upper bottom surface; two metal nails are symmetrically arranged on the two sides of the cutting surface; and the feed source of the Luneberg lens antenna is arranged on the cutting surface and can move between the two metal nails. The wide-angle beam scanning Luneberg lens with stable gain is obtained by the Luneberg lens with the focal point being shifted to the inside of the lens, the feed source being arranged on the two sides of the focal arc and the two metal nails being introduced outside the cutting lens edge, and can be widely applied to the technical field of antenna engineering.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of antenna engineering, and particularly relates to a wide-angle beam scanning Luneberg lens antenna with linearly arranged feed sources and a method. BACKGROUND

[0002] With the development of mobile communication technology, people's requirements for the capacity and rate of wireless communication are also getting higher and higher, and the antenna is required to have high gain and wide-angle beam scanning capability. Phased array antennas, reflector antennas and lens antennas can usually meet the above requirements. Phased array antennas are widely used due to their flexible and rapid beam scanning capability and stable radiation characteristics, but they require a large and complex feed network and a large number of high-cost T / R components, and the antenna bandwidth is limited by the feed network, unit spacing, etc., making it difficult to achieve wideband and ultra-wideband. The structure of the reflector antenna is simple, mature in technology, and has high gain, but its aperture is large, the feed source blocks the antenna, and the beam scanning speed is slow. The lens antenna, especially the gradient refractive index lens antenna, can achieve stable high gain and wide-angle beam scanning without complex feed network and expensive T / R components, and has gradually become one of the types of antennas that researchers focus on in recent years.

[0003] Luneberg lens is a typical gradient refractive index lens that can convert spherical waves on the surface of the lens into plane waves, has excellent beam focusing and beam consistency, and is considered to be the most attractive candidate for wide-angle beam scanning antennas. Although the Luneberg lens has the advantages of high gain, wide-angle beam scanning range and wideband, the curved feed surface and the manufacturing of non-uniform dielectric materials limit its wide application.

[0004] In order to better integrate planar feed antennas and Luneberg lenses, researchers have done a lot of work to partially flatten the feed surface of the Luneberg lens. The design methods of these works can be roughly divided into approximation method, transformation optics method and quasi-conformal transformation optics method. The Luneberg lens with linear / planar feed based on the approximation method is limited by the approximation accuracy and cannot achieve stable wide-angle beam scanning and large off-axis aberration. The transformation optics method and the quasi-conformal transformation optics method can achieve wide-angle beam scanning, but the complex dielectric constant extraction and modeling process, wide dielectric constant range and irregular dielectric constant distribution limit the design and preparation of the lens. Therefore, it is still a challenge to design a linear / planar feed Luneberg lens with stable wide-angle beam scanning capability and simple dielectric constant distribution profile.

[0005] In addition, another practical challenge for the Luneburg lens is the gradient variation of the permittivity required for the lens. For this purpose, researchers have proposed a large number of methods to construct the lens, such as: double or multi-layer spherical shells with different materials, compressed foam, parallel plate waveguide and periodic structure, among which the periodic structure is the most commonly used method, which includes drilling, printed circuit board and 3D printing processing technology. 3D printing has the advantages of low cost and easy preparation and has attracted widespread attention. However, in the current existing literature, the periodic structure unit of the Luneburg lens prepared based on the 3D printing technology mostly uses the same structure, which makes the coverage range of the permittivity that can be achieved very limited. SUMMARY

[0006] In order to at least partially solve one of the technical problems existing in the prior art, the purpose of the present application is to provide a wide-angle beam scanning Luneburg lens antenna with linearly arranged feed sources and a method thereof.

[0007] The technical scheme adopted by the present application is:

[0008] A wide-angle beam scanning Luneburg lens antenna with linearly arranged feed sources comprises:

[0009] A first metal plate, the shape of the first metal plate is a truncated circular cone, and the cutting surface is perpendicular to the upper and lower bases of the circular cone, wherein the volume of the truncated part is smaller than that of the remaining part;

[0010] A second metal plate, the shape of the second metal plate is the same as that of the first metal plate, the two metal plates are parallel and symmetrical, forming a parallel metal plate waveguide structure; a cutting surface is formed between the truncated parts of the two metal plates;

[0011] A Luneburg lens is arranged between the first metal plate and the second metal plate, one end of the Luneburg lens is connected to the upper base of the first metal plate, the other end of the Luneburg lens is connected to the upper base of the second metal plate, and the shape of the Luneburg lens matches the shape of the upper base;

[0012] Two metal nails are symmetrically arranged on both sides of the cutting surface and perpendicular to the metal plate;

[0013] The feed source of the Luneburg lens antenna is arranged on the cutting surface and can move between the two metal nails.

[0014] Further, the Luneburg lens is composed of transparent photosensitive resin containing air through holes and transparent photosensitive resin columns with complementary structures, and the transparent photosensitive resin columns are perpendicular to the metal plate.

[0015] Further, the lens is composed of 9 layers of air apertures with gradually increasing diameters and 4 layers of transparent photosensitive resin columns with gradually decreasing diameters from the lens center to the lens surface.

[0016] Further, the truncated columnar lens is provided with a thin layer of transparent photosensitive resin support plate under the outermost 4 layers of transparent photosensitive resin columns, which is used to support and fix the relative positions of the transparent photosensitive resin columns.

[0017] Further, the upper bottom surfaces of the two metal plates are tightly attached to the upper and lower surfaces of the lens, and the centers of the metal plates and the lens coincide; the upper bottom surfaces of the two metal plates are larger than the surface size of the lens;

[0018] The cutting surface of the metal plate is parallel to the truncated surface of the lens, and the distance from the lens center to the cutting surface of the metal plate is greater than the distance to the truncated surface of the lens;

[0019] The ends of the two parallel metal plates are conical opening structures, which are used to adjust the impedance matching between the lens and the air.

[0020] Further, the lengths of the two metal nails are the same as the spacing of the parallel metal plates; the two metal nails are in contact with the truncated surface of the lens and are located on the two side edges of the truncated lens, which are used to fine-tune the radiation electric field of the edge feed source, and further improve the radiation characteristics of the wide-angle beam.

[0021] Further, the radiator of the feed source of the lens antenna is clamped in the middle of the parallel metal plates, and the radiation direction is perpendicular to the cutting surface of the metal plate and towards the lens.

[0022] Further, the feed source antenna is a patch antenna, a rectangular waveguide, a horn antenna or an array antenna, and the wide-angle beam scanning is realized by switching the feed source antennas in the linear array or moving a single feed source antenna.

[0023] Further, the feed source antenna is a patch antenna, and the patch antenna is moved along the cutting surface of the parallel metal plate to realize wide-angle beam scanning.

[0024] Another technical solution adopted by the present application is:

[0025] A design method of a lens, comprising the following steps:

[0026] S1, by means of Hamiltonian transformation optics, the focal point of a lens with a radius of R is transferred from the surface of the lens to a circle with a distance of x×R from the center of the lens;

[0027] S2, a straight line with a distance of y×R from the center of the lens is used to truncate the lens obtained in step S1; wherein the value range of x is: 0.5 xIf y < 0.8, the range of y is: 0.3 < y <0.6, and x > y ;

[0028] S3: Discretize the truncated Luneburg lens from the lens center to the lens surface into n concentric circles (rings) of equal thickness, and calculate the required relative permittivity value of each layer based on Hamiltonian transform optics; n is a positive integer, n≥10;

[0029] S4: A Luneburg lens is constructed by using transparent photosensitive resin with air holes and transparent photosensitive resin pillars with complementary structures as the unit for extracting the relative permittivity. The size of the air holes / transparent photosensitive resin pillars corresponding to the required relative permittivity values ​​of each layer is calculated based on the A-BG equivalent medium theory. The Luneburg lens is constructed by filling each layer with the air holes / transparent photosensitive resin pillars in a way that rotates around the central axis of the lens.

[0030] Furthermore, the truncated cylindrical Luneburg lens is designed with the following dimensions: R=32.5 mm, x=0.75, y=0.41, n=13, and a relative permittivity range of 1-2.78.

[0031] The beneficial effects of the present invention are: the present invention obtains a wide-angle beam scanning Luneburg lens with stable gain by cutting off the Luneburg lens whose focus is transferred to the inside of the lens, placing the feed source on both sides of the focal arc, and introducing two metal pins on the outer side of the cut-off lens edge. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following description is provided with accompanying drawings of the relevant technical solutions in the embodiments of the present invention or the prior art. It should be understood that the accompanying drawings described below are only for the purpose of clearly illustrating some embodiments of the technical solutions of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a structural diagram of a wide-angle beam scanning Luneburg lens antenna with feed sources arranged in a straight line according to an embodiment of the present invention;

[0034] Figure 2 yes Figure 1 Top and side views of a wide-angle beam-scanning Luneburg lens antenna with feeds arranged in a straight line;

[0035] Figure 3 This is a ray tracing simulation diagram of parallel light rays incident perpendicular to the Luneburg lens section in an embodiment of the present invention;

[0036] Figure 4 This is a schematic diagram showing the relative positional relationship between the feed source and the truncated focal arc of the Luneburg lens in an embodiment of the present invention;

[0037] Figure 5 is a function curve diagram of equivalent relative dielectric constant changing with air via hole / photoreactive resin column radius in the embodiment of the present application;

[0038] Figure 6 is a 30 GHz simulation radiation pattern diagram of the patch antenna loaded with the Luneberg lens under the condition that the feed source is offset from the symmetry axis of the Luneberg lens in the embodiment of the present application; d y is a 30 GHz simulation radiation pattern diagram of the patch antenna loaded with the Luneberg lens under the condition that the feed source is offset from the symmetry axis of the Luneberg lens in the embodiment of the present application;

[0039] Figure 7 is a 30 GHz simulation radiation pattern diagram of the patch antenna loaded with the Luneberg lens under the condition that the feed source is offset from the symmetry axis of the Luneberg lens in the embodiment of the present application; d y is a 30 GHz simulation electric field distribution diagram before introducing the metal nail under the condition that the feed source is offset from the symmetry axis of the Luneberg lens by 24 mm in the embodiment of the present application;

[0040] Figure 8 is a 30 GHz simulation electric field distribution diagram after introducing the metal nail under the condition that the feed source is offset from the symmetry axis of the Luneberg lens by 24 mm in the embodiment of the present application; d y is a 30 GHz simulation electric field distribution diagram before introducing the metal nail under the condition that the feed source is offset from the symmetry axis of the Luneberg lens by 24 mm in the embodiment of the present application;

[0041] Figure 9 is a 30 GHz simulation radiation pattern diagram of the patch antenna loaded with the Luneberg lens under the condition that the feed source is offset from the symmetry axis of the Luneberg lens in the embodiment of the present application; d y is a 30 GHz simulation radiation pattern diagram of the patch antenna loaded with the Luneberg lens under the condition that the feed source is offset from the symmetry axis of the Luneberg lens in the embodiment of the present application;

[0042] Figure 10 is a 30 GHz simulation radiation pattern diagram of the patch antenna loaded with the Luneberg lens under the condition that the feed source is offset from the symmetry axis of the Luneberg lens in the embodiment of the present application; d y is a 30 GHz simulation radiation pattern diagram of the patch antenna loaded with the Luneberg lens under the condition that the feed source is offset from the symmetry axis of the Luneberg lens in the embodiment of the present application;

[0043] Figure 11 is a 30 GHz simulation radiation pattern diagram of the patch antenna loaded with the Luneberg lens under the condition that the feed source is offset from the symmetry axis of the Luneberg lens in the embodiment of the present application; d y is a 30 GHz simulation radiation pattern diagram of the patch antenna loaded with the Luneberg lens under the condition that the feed source is offset from the symmetry axis of the Luneberg lens in the embodiment of the present application;

[0044] Figure 12 is a 30 GHz simulation radiation pattern diagram of the patch antenna loaded with the Luneberg lens under the condition that the feed source is offset from the symmetry axis of the Luneberg lens in the embodiment of the present application; d y is a 30 GHz simulation radiation pattern diagram of the patch antenna loaded with the Luneberg lens under the condition that the feed source is offset from the symmetry axis of the Luneberg lens in the embodiment of the present application. DETAILED DESCRIPTION

[0045] Embodiments of the present application are described below in detail with reference to the accompanying drawings, wherein the same or similar components or components having the same or similar functions are denoted by the same or similar reference numerals throughout the drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation of the present application. For the step numbers in the following embodiments, they are only set for the convenience of explanation, and the order between the steps is not limited in any way, and the execution order of each step in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0046] In the description of the present application, it should be understood that the orientation description, such as the orientation or position relationship indicated by the upper, lower, front, rear, left, right, etc. is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or component referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0047] In the description of the present application, the meaning of several is one or more, and the meaning of multiple is more than two, greater than, less than, more than, etc. are understood as not including the number, and above, below, etc. are understood as including the number. If it is described as first, second, it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or the order of indicated technical features.

[0048] In the description of the present application, unless otherwise explicitly limited, the words such as setting, installing, connecting, etc. should be broadly understood, and those skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical solution.

[0049] As shown in the drawings, the present embodiment provides a wide-angle beam scanning Luneberg lens antenna with linearly arranged feed sources, comprising: Figure 1 A first metal plate 21, the shape of the first metal plate is a truncated circular cone, and the cutting surface is perpendicular to the upper and lower bases of the circular cone, wherein the volume of the truncated part is less than the volume of the remaining part;

[0050] A second metal plate 22, the shape of the second metal plate is the same as that of the first metal plate, the two metal plates are parallel and symmetrical, forming a parallel metal plate waveguide structure; a cutting surface is formed between the cutting parts of the two metal plates;

[0051]

[0052] ​A dragon lens 1 is arranged between the first metal plate and the second metal plate, one end of the dragon lens is connected to the upper bottom surface of the first metal plate, the other end of the dragon lens is connected to the upper bottom surface of the second metal plate, and the shape of the dragon lens matches the shape of the upper bottom surface;

[0053] Two metal nails (including the first metal nail 41 and the second metal nail 42) are symmetrically arranged on both sides of the cut surface and are perpendicular to the metal plate;

[0054] A feed source 3 of the dragon lens antenna is arranged on the cut surface and can move between the two metal nails.

[0055] In this embodiment, in order to design a linear / planar feed dragon lens with stable wide-angle beam scanning capability, by cutting the dragon lens whose focal point is shifted to the inside of the lens, a focal arc with a larger curvature radius is obtained at the cut surface, and a patch antenna as a feed source is placed on both sides of the focal arc to obtain a minimum feed source-focal arc distance. Further, two metal nails are introduced outside the edge of the cut lens to fine-tune the electric field of the edge feed source and improve the radiation characteristics of the edge beam, so as to obtain a wide-angle beam scanning dragon lens with stable gain. The dragon lens designed based on this technology has simple design and modeling, narrow relative dielectric constant range, and regular relative dielectric constant distribution profile. In addition, the relative dielectric constant required for the design of the cut dragon lens is constructed by two complementary periodic structure units, which widens the available range of the relative dielectric constant of the unit material and avoids the high complexity caused by using multiple materials to construct and process the dragon lens.

[0056] As a further optional implementation, the cut cylindrical dragon lens has, in sequence from the lens center to the lens surface, 9 layers of transparent photosensitive resin with gradually increasing air apertures and 4 layers of transparent photosensitive resin columns with gradually decreasing diameters.

[0057] As a further optional implementation, the cut cylindrical dragon lens has, in sequence from the lens center to the lens surface, 9 layers of transparent photosensitive resin with gradually increasing air apertures and 4 layers of transparent photosensitive resin columns with gradually decreasing diameters.

[0058] As a further optional implementation, the upper bottom surfaces of the two cut circular truncated cone-shaped parallel metal plates are tightly attached to the upper and lower surfaces of the dragon lens, the centers of the metal plates coincide with the center of the dragon lens, the upper bottom surfaces of the two cut circular truncated cone-shaped parallel metal plates are slightly larger than the surface size of the dragon lens, the cut surfaces of the metal plates are parallel to the cut surface of the dragon lens, and the distance from the center of the lens to the cut surface of the metal plate is greater than the distance to the cut surface of the dragon lens, and the ends of the two parallel metal plates are conical opening structures for adjusting the impedance matching between the lens and the air.

[0059] Further, as an optional embodiment, the lengths of the two metal pins are the same as the interval of the parallel metal plates and are placed perpendicularly to the parallel metal plates, the two metal pins are in contact with the cross section of the Luneberg lens and are respectively located at the two side edges of the truncated Luneberg lens, for fine tuning the radiation electric field of the edge feed, further improving the radiation characteristics of the wide-angle beam.

[0060] Further, as an optional embodiment, the radiator of the feed is clamped in the middle of the parallel metal plates and the radiation direction is perpendicular to the cross section of the metal plates and towards the Luneberg lens.

[0061] The feed antenna includes patch antennas, rectangular waveguides, horn antennas, array antennas, etc., and the wide-angle beam scanning is achieved by switching the feed antennas in the linear array or moving a single feed antenna.

[0062] The following will be explained in detail Figures 1-12 The structure and performance of the wide-angle beam scanning Luneberg lens antenna with the feed arranged in a straight line.

[0063] Referring to Figure 1 and Figure 2 , the wide-angle beam scanning Luneberg lens antenna with the feed arranged in a straight line provided by the embodiment includes a truncated Luneberg lens 1, two truncated circular cone-shaped parallel metal plates 21 and 22, a feed patch antenna 3 moving along the cross section of the metal plates, and two metal pins 41 and 42 outside the edges of the cross section of the Luneberg lens. The truncated cylindrical Luneberg lens 1 is constructed by a transparent photosensitive resin column containing air holes and a transparent photosensitive resin column with a complementary structure, the relative dielectric constant of the transparent photosensitive resin is 2.9, the radius R is 32.5 mm, the truncation depth is 13.2 mm, and the height H is 4.5 mm. The sizes of the two truncated circular cone-shaped parallel metal plates 21 and 22 are the same, the lower base radius r 1 is 37.65 mm, the upper base radius r 2 is 34.5 mm, the truncation depth is 15.2 mm, the thickness h 1- H ) / 2 is 3 mm, and the metal material is aluminum. The feed 3 is a common patch antenna, the radiation patch size is 2.9 mm x 2.5 mm, the relative dielectric constant of the dielectric substrate is 2.2, the height is 0.787 mm, the size is 7 mm x 10.5 mm, the metal ground plane size is the same as the dielectric substrate, and the feed offset from the symmetry axis of the Luneberg lens is d y The radius of the metal pin 41 and 42 is 0.6 mm, the height is 4.5 mm, and the offset from the symmetry axis of the Luneberg lens is d 26.2 mm.

[0064] Figure 3 The ray tracing simulation schematic diagram of the embodiment of the application under the condition that parallel light is perpendicular to the cross section of the Luneburg lens is shown in the figure, the focal arc of the Luneburg lens before being cut off is a dashed line 51, and the focal arc after being cut off is a solid line 52, the larger refractive index difference on both sides of the cross section of the Luneburg lens causes the parallel light to converge in advance, which further causes the focal arc of the cut Luneburg lens to present a phenomenon of moving up to different degrees compared with that before being cut off, and the cut Luneburg lens provides a focal arc with a larger curvature radius.

[0065] Figure 4 The relative position relationship between the feed source and the focal arc of the cut Luneburg lens is shown in the figure, the feed sources P1-P5 are located on both sides of the focal arc to obtain the minimum distance difference between the feed source and the focal arc, and further make the Luneburg lens antenna maintain stable directivity in the wide-angle beam scanning process.

[0066] It is difficult to find a material with a continuous change in relative dielectric constant in nature, therefore, in the embodiment of the application, the Luneburg lens is discretely divided into 13 layers (each layer has a thickness of 2.5 mm), and the relative dielectric constant of each layer is calculated, and then the photosensitive resin containing air through holes and the photosensitive resin column with a complementary structure are used to realize the relative dielectric constant required by the design. Figure 5 The function curve diagram of the equivalent relative dielectric constant changing with the air through hole / photosensitive resin column radius in the embodiment of the application can be observed, it can be observed that the photosensitive resin containing air through holes or the photosensitive resin column alone cannot cover the relative dielectric constant range of 1-2.78 required by the design, therefore, the combination of the two kinds of periodic structure units with complementary structures can perfectly realize the relative dielectric constant required by the design and avoid the increase in complexity caused by using multiple materials to construct and process the Luneburg lens.

[0067] Table 1 is the relative dielectric constant required by the design of each layer of the Luneburg lens and the radius size of the air through hole / photosensitive resin column of each layer in the embodiment of the application.

[0068] Table 1

[0069]

[0070] Figure 6 The figure shows the embodiment of the application in which the feed source is offset from the symmetry axis of the Luneburg lens d yThe 30 GHz simulation radiation patterns of the feed patch antenna with or without loading the dragon lens under the condition that the offset is 0 mm, the beam width of the feed patch antenna after loading the dragon lens is obviously narrowed, the gain is increased by 6 dB, the cross-polarization field is 30 dB weaker than the main polarization field, and the radiation pattern of the dragon lens antenna is in a pencil shape, which shows that the dragon lens antenna has good radiation characteristics of high gain, narrow beam and low side lobe under the premise of greatly reducing the processing difficulty.

[0071] Figure 7 、 Figure 8 The embodiment of the application is in the case that the feed is offset from the symmetry axis of the dragon lens d y The 30 GHz simulation electric field distribution diagrams before and after introducing the metal nail under the condition that the offset is 0 mm, 6 mm, 12 mm, 18 mm and 24 mm, since the polarization direction of the electric field radiated by the feed patch antenna is parallel to the axis of the metal nail, the loading of the metal nail produces perturbation to the near-field radiation electric field, the radiation direction of the electric field is deflected towards the center of the lens, the distance between the feed antenna and the focal point of the dragon lens is shortened, and the radiation intensity is enhanced.

[0072] In order to further illustrate the influence of introducing the metal nail on the dragon lens antenna, Figure 9 The embodiment of the application is in the case that the feed is offset from the symmetry axis of the dragon lens d y The 30 GHz simulation radiation patterns before and after introducing the metal nail under the condition that the offset is 0 mm, 6 mm, 12 mm, 18 mm and 24 mm, it can be observed that the radiation intensity of the edge beam (the feed is offset from the symmetry axis of the dragon lens d y =24 mm) is improved, the radiation intensity of the non-radiation direction, especially the direction of-60 degrees to 0 degrees, is obviously inhibited, and the radiation characteristics of other beams are basically not affected.

[0073] Figure 10 The embodiment of the application is in the case that the feed is offset from the symmetry axis of the dragon lens d y The simulation diagrams of the reflection coefficients under the condition that the offset is 0 mm, 6 mm, 12 mm, 18 mm and 24 mm, since there is a certain difference between the impedances of the feed antenna and the dragon lens at different feed positions, this leads to a slight offset phenomenon of |S 11 |, the overlapping impedance bandwidth of the wide-angle beam scanning dragon lens antenna with the feed arranged along a straight line is-10 dB when the feed is offset from the symmetry axis of the dragon lens 11 | is 28.43-30.78 GHz, the absolute bandwidth is 2.35 GHz, and the relative bandwidth is 7.9%, and the bandwidth of the dragon lens antenna is mainly limited by the bandwidth of the feed.

[0074] Figure 11For the embodiment of the application, the feed source is offset from the symmetry axis of the Luneberg lens d y From the simulation radiation pattern of 30 GHz under the condition of 0 mm, ±6 mm, ±12 mm, ±18 mm, ±24 mm, it can be observed that the wide-angle beam scanning of ±60 degrees is achieved by moving the feed source antenna along the parallel metal plate section, the gain difference between the center beam and the edge is 0.1 dBi, and the highest gain during the beam scanning process is 12.9 dBi, the lowest gain is 12.2 dBi, and the maximum gain fluctuation is only 0.7 dB, which indicates that the gain is relatively stable during the wide-angle beam scanning process.

[0075] Figure 12 For the embodiment of the application, the feed source is offset from the symmetry axis of the Luneberg lens d y The simulation diagram of the directivity, actual gain and actual gain of the feed source under the condition of 0 mm, 6 mm, 12 mm, 18 mm, 24 mm. It can be observed that the actual gain of the Luneberg lens antenna is about 6 dB higher than the actual gain of the feed source, and the gain curve in the passband of the Luneberg lens antenna at each feed position is flat.

[0076] In summary, the wide-angle beam scanning Luneberg lens antenna with the feed source arranged along a straight line has at least the following beneficial effects relative to the prior art:

[0077] (1) By cutting the focal point to the inside of the Luneberg lens to obtain a focal arc with a larger curvature radius, placing the feed source on both sides of the focal arc to obtain a smaller feed source-focal arc distance, and introducing two metal nails outside the edge of the cut lens to fine-tune the edge electric field to achieve stable gain wide-angle beam scanning performance, the design and modeling are simple, the dielectric constant range is narrow and the distribution profile is regular.

[0078] (2) The relative dielectric constant required for Luneberg lens design is achieved by using two complementary periodic structure units, which widens the available range of unit material dielectric constant and avoids the complexity of using multiple materials to construct and process the Luneberg lens.

[0079] (3) The beam scanning performance is good, and by moving the feed source patch antenna along a straight line, the Luneberg lens antenna can achieve a wide-angle beam scanning range of 120 degrees, and the gain of each beam remains relatively constant during the scanning process, with a maximum gain fluctuation of only 0.7 dB.

[0080] (4) Compared with previous quasi-conformal transformation optical work, the wide-angle beam scanning Luneberg lens antenna with the feed source arranged along a straight line has the advantages of simple design / modeling, narrow dielectric constant range and regular distribution profile, small longitudinal size, easy to process and manufacture, etc.

[0081] For the above-mentioned Luneburg lens, the embodiment further provides a design method of the Luneburg lens, comprising the following steps:

[0082] S1, by means of Hamiltonian transformation optics, the focal point of the Luneburg lens with a radius of R is transferred from the surface of the Luneburg lens to a circle with a distance of x×R from the center of the Luneburg lens;

[0083] S2, the Luneburg lens obtained in step S1 is truncated by a straight line with a distance of y×R from the center of the lens; wherein the value range of x is: 0.5 x <0.8, the value range of y is: 0.3 y <0.6, and x > y ;

[0084] S3: the truncated Luneburg lens is discretized into n layers of concentric circles (rings) from the center of the lens to the surface of the lens, and the required relative permittivity value of each layer is calculated based on Hamiltonian transformation optics; n is a positive integer, n≥10;

[0085] S4: the transparent photosensitive resin containing air holes and the transparent photosensitive resin column with complementary structure are used as the unit for extracting the relative permittivity, the size of the air hole / transparent photosensitive resin column corresponding to the required relative permittivity value of each layer is calculated based on A-BG equivalent medium theory, and the Luneburg lens is constructed by filling each layer in the form of rotating around the center axis of the lens.

[0086] As an optional implementation, the design size of the truncated Luneburg lens is: R=32.5 mm, x=0.75, y=0.41, n=13, and the relative permittivity range is 1-2.78.

[0087] In the above description of the present specification, the description of the terms "one embodiment / one example", "another embodiment / another example", or "some embodiments / some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiments or examples are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0088] Although the embodiments of the present application have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and purposes of the present application, and the scope of the present application is defined by the claims and their equivalents.

[0089] The above is a specific description of the preferred embodiment of the present application, but the present application is not limited to the above-described embodiments, and those skilled in the art can make various equivalent modifications or replacements without departing from the spirit of the present application, and these equivalent modifications or replacements are all included in the scope defined by the claims of the present application.

Claims

1. A wide angle beam scanning Leaky Lens antenna with linearly arranged feeds, characterized in that, Comprising: A first metal plate, the shape of the first metal plate being a truncated frustum of a cone, and the cut surface being perpendicular to the upper and lower bases of the frustum of the cone; A second metal plate, the shape of the second metal plate being the same as that of the first metal plate, the two metal plates being parallel and symmetric to each other, forming a parallel metal plate waveguide structure; a cut surface is formed between the cut-off portions of the two metal plates; A Luneburg lens, disposed between the first metal plate and the second metal plate, one end of the Luneburg lens being connected to the upper base surface of the first metal plate, the other end of the Luneburg lens being connected to the upper base surface of the second metal plate, and the shape of the Luneburg lens matching the shape of the upper base surface; Two metal pins, the two metal pins being disposed on both sides of the cut surface and perpendicular to the metal plates; A feed source of the Luneburg lens antenna, disposed on the cut surface and movable between the two metal pins.

2. A wide-angle beam scanning Leaky Lens antenna with linearly arranged feeds according to claim 1, characterized in that, The Luneburg lens is composed of a transparent photosensitive resin containing air through holes and transparent photosensitive resin columns with complementary structures, and the transparent photosensitive resin columns are perpendicular to the metal plates.

3. The wide-angle beam scanning Luneburg lens antenna with feed arranged in a straight line according to claim 2, characterized in that, The Luneburg lens consists of 9 layers of drilled transparent photosensitive resins with gradually increasing air hole diameters and 4 layers of transparent photosensitive resin columns with gradually decreasing diameters from the center of the lens to the lens surface.

4. The wide-angle beam scanning Luneburg lens antenna with feed arranged in a straight line according to claim 3, characterized in that, Below the outermost 4 layers of transparent photosensitive resin columns of the truncated columnar Luneburg lens is a thin layer of transparent photosensitive resin support plate for supporting and fixing the relative positions of the transparent photosensitive resin columns.

5. A wide-angle beam scanning Luneburg lens antenna with feed arranged in a straight line according to claim 1, characterized in that, The upper base surfaces of the two metal plates are closely adhered to the upper and lower surfaces of the Luneburg lens respectively, and the centers of the metal plates coincide with the center of the Luneburg lens; the sizes of the upper base surfaces of the two metal plates are larger than the surface size of the Luneburg lens; The cut surface of the metal plate is parallel to the cut-off surface of the Luneburg lens, and the distance from the center of the lens to the cut surface of the metal plate is greater than the distance to the cut-off surface of the Luneburg lens; The ends of the two parallel metal plates are of a tapered opening structure for adjusting the impedance matching between the lens and the air.

6. A wide-angle beam scanning Luneburg lens antenna with feed arranged in a straight line according to claim 1, characterized in that, The lengths of the two metal pins are the same as the interval of the parallel metal plates; the two metal pins contact the cut-off surface of the Luneburg lens and are respectively located on both side edges of the truncated Luneburg lens, for finely adjusting the radiation electric field of the edge feed source, and further improving the radiation characteristics of the large-angle beam.

7. A wide-angle beam scanning Luneburg lens antenna with feed arranged in a straight line according to claim 1, characterized in that, The radiator of the feed source of the Luneburg lens antenna is sandwiched in the middle of the parallel metal plates, and the radiation direction is perpendicular to the cut surface of the metal plate and towards the Luneburg lens.

8. A wide-angle beam scanning Luneburg lens antenna with feed arranged in a straight line according to claim 1, characterized in that, The feed source antenna is a patch antenna, a rectangular waveguide, a horn antenna or a dipole antenna, and wide-angle beam scanning is achieved by switching the feed source antenna in the linear array or moving a single feed source antenna.

9. A wide-angle beam scanning Luneburg lens antenna with feed sources arranged in a straight line according to claim 8, characterized in that, The feed source antenna is a patch antenna, and the patch antenna moves along the cut surface of the parallel metal plates to achieve wide-angle beam scanning.

10. A method for designing a Luneburg lens, characterized in that, Including the following steps: S1. Transfer the focus of the Luneburg lens with a radius of R from the surface of the Luneburg lens to a circle at a distance of x×R from the center of the Luneburg lens by means of Hamiltonian transformation optics; S2. Cut the Luneburg lens obtained in step S1 with a straight line at a distance of y×R from the center of the lens; where the value range of x is: 0.5 < x < 0.8, the value range of y is: 0.3 < y < 0.6, and x > y; S3: Discretize the truncated Luneburg lens from the lens center to the lens surface into n concentric circles of equal thickness, and calculate the required relative permittivity value of each layer based on Hamiltonian transform optics; n is a positive integer; S4: A Luneburg lens is constructed by using transparent photosensitive resin with air holes and transparent photosensitive resin pillars with complementary structures as the unit for extracting the relative permittivity. The size of the air holes / transparent photosensitive resin pillars corresponding to the required relative permittivity values ​​of each layer is calculated and filled into each layer by rotating around the lens's central axis.

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