Interlayer luneberg lens antenna with double-frequency radiation characteristic independent adjustment capability

Abstract

The invention discloses an interlayer luneberg lens antenna with double-frequency radiation characteristic independent adjustment capability, which comprises a first plane luneberg lens, a second plane luneberg lens and a third plane luneberg lens, and is characterized in that the first plane luneberg lens is positioned on the upper side of the second plane luneberg lens; the third plane luneberg lens is located on the lower side of the second plane luneberg lens, and the structure of the first plane luneberg lens is the same as that of the third plane luneberg lens and different from that of the second plane luneberg lens. According to the invention, by using the planar luneberg lenses with two different structures, the dual-frequency radiation characteristic and the independent adjustment capability on dual frequency bands are realized, the heterogeneous design is beneficial to realizing structure simplification, the design and processing difficulty is effectively reduced, and the influence caused by dimension errors brought by manufacturing tolerance is reduced. The antenna is widely applied to the technical field of antennas.

Description

Technical Field

[0001] The present invention relates to the field of antenna technology, and in particular to a sandwich Luneburg lens antenna with the ability to independently adjust dual-frequency radiation characteristics. Background Art

[0002] With the rapid development of wireless communication technology, dual-frequency communication plays an increasingly important role in future communication systems. The lower operating frequency band has good coverage, while the high frequency band is responsible for providing broadband, high-speed, and low-latency communication services. In order to reduce the impact of propagation path loss and improve signal coverage flexibility, antennas that can achieve high-gain, wide-angle scanning multi-beam radiation characteristics in two frequency bands have become an ideal choice for future communication equipment.

[0003] The current dual-band antennas generally have the disadvantages of both bands being relatively low in frequency and not being able to independently adjust the dual-band radiation characteristics. The lower frequency band is not conducive to high-speed communication, and the dual-band radiation characteristics cannot be independently adjusted, which limits the flexibility of the dual-band antenna. Summary of the invention

[0004] In view of the technical problems that current dual-frequency antennas have relatively low frequencies in both bands and lack the ability to independently adjust dual-frequency radiation characteristics, the purpose of the present invention is to provide a sandwich Luneburg lens antenna with the ability to independently adjust dual-frequency radiation characteristics.

[0005] An embodiment of the present invention includes a sandwich Luneburg lens antenna having the ability to independently adjust dual-frequency radiation characteristics. The sandwich Luneburg lens antenna having the ability to independently adjust dual-frequency radiation characteristics includes:

[0006] A first plane Luneburg lens, a second plane Luneburg lens and a third plane Luneburg lens; the first plane Luneburg lens is located on the upper side of the second plane Luneburg lens, the third plane Luneburg lens is located on the lower side of the second plane Luneburg lens, the structure of the first plane Luneburg lens is the same as that of the third plane Luneburg lens, and different from the structure of the second plane Luneburg lens.

[0007] Further, the first plane Luneburg lens and the third plane Luneburg lens are both woodpile structures;

[0008] The second plane Luneburg lens comprises a plurality of cubic structural units;

[0009] The edges of the first plane Luneburg lens, the second plane Luneburg lens and the third plane Luneburg lens are respectively provided with a dielectric protrusion fixing structure, and the dielectric protrusion fixing structure is provided with a through hole;

[0010] The sandwich Luneburg lens antenna with the ability to independently adjust dual-frequency radiation characteristics also includes a nylon screw, a nylon nut and a nylon gasket; the nylon gasket is placed between two corresponding dielectric protrusion fixing structures, the nylon screw passes through the through hole of the dielectric protrusion fixing structure and the nylon gasket, and the nylon nut fixes the nylon screw.

[0011] Furthermore, the first planar Luneburg lens and the third planar Luneburg lens respectively include a plurality of dielectric rods with rectangular cross-sections, each of the dielectric rods is located in a corresponding layer, and each layer of the dielectric rods is stacked;

[0012] The dielectric rods in the same layer are parallel to each other and are periodically arranged according to a horizontal period;

[0013] The dielectric rods in any layer are vertical to the dielectric rods in an adjacent layer;

[0014] The dielectric rods in any layer are relatively offset from the dielectric rods in an alternate layer by half a horizontal period.

[0015] Further, the first plane Luneburg lens, the second plane Luneburg lens and the third plane Luneburg lens are all disc-shaped; the first plane Luneburg lens, the second plane Luneburg lens and the third plane Luneburg lens have the same radius and their centers are aligned;

[0016] The cubic structural units in the second plane Luneburg lens are arranged around a multi-layer circular ring formed by the center of the circular disk.

[0017] Further, each of the dielectric rods located in the inner cylindrical region has a first size parameter, and each of the dielectric rods located in the outer annular region has a second size parameter;

[0018] Each of the cubic structural units located in the inner cylindrical region is solid, and each of the cubic structural units located in the outer annular region is provided with a cylindrical air hole, and the cylindrical air hole is perpendicular to the plane where the second plane Luneburg lens is located;

[0019] Among them, the inner cylindrical area is the spatial area extending from the central axis of the cylinder to the edge of the cylinder in the cylinder formed by the superposition of the first plane Luneburg lens, the second plane Luneburg lens and the third plane Luneburg lens, and the outer annular area is the spatial area in the cylinder except the inner cylindrical area.

[0020] Furthermore, the sandwich Luneburg lens antenna with the ability to independently adjust dual-frequency radiation characteristics also includes:

[0021] Multiple dual-frequency feed antennas; each of the dual-frequency feed antennas is distributed on the edge of the second planar Luneburg lens and is mechanically connected to the second planar Luneburg lens.

[0022] Furthermore, the dual-frequency feed antenna includes a patch antenna and a metal open waveguide antenna; the operating frequency of the metal open waveguide antenna is in a first frequency band, and the operating frequency of the patch antenna is in a second frequency band, and the first frequency band is higher than the second frequency band;

[0023] The patch antenna is provided with an opening;

[0024] The metal open waveguide antenna passes through the opening of the patch antenna, thereby being nested in the patch antenna.

[0025] Furthermore, the edge of the second plane Luneburg lens is provided with a plurality of slots; the shape and size of the slots match one end of the metal open waveguide antenna;

[0026] One end of the metal open waveguide antenna is an opening, and the other end is a metal short-circuit wall;

[0027] The end of the metal open waveguide antenna where the opening is located is embedded in the slot, thereby forming a mechanical connection with the second planar Luneburg lens;

[0028] A first SMA connector is installed at the other end of the metal open waveguide antenna.

[0029] Further, a pair of trapezoidal metal ridges are provided inside the metal open waveguide antenna;

[0030] The longer bottom side of the trapezoidal metal ridge faces the outside of the metal open waveguide antenna, and the oblique waist of the trapezoidal metal ridge extends from the opening of the metal open waveguide antenna to the inside of the metal open waveguide antenna; the right-angle waist of the trapezoidal metal ridge is connected to the metal short-circuit wall of the metal open waveguide antenna; and the upper part of the right-angle waist of the trapezoidal metal ridge has two-level stepped grooves;

[0031] The shorter bottom sides of the two trapezoidal metal ridges are opposite to each other;

[0032] One of the trapezoidal metal ridges is provided with a through hole perpendicular to the bottom edge, the inner conductor of the first SMA connector passes through the through hole of the trapezoidal metal ridge and forms electrical contact with the other trapezoidal metal ridge, and the outer conductor of the first SMA connector is connected to the outside of the metal open waveguide antenna.

[0033] Further, the patch antenna includes a substrate, a metal patch, a metal ground and a second SMA connector;

[0034] The metal patch is arranged on one side of the substrate, and the metal ground is arranged on the other side of the substrate;

[0035] The inner conductor of the second SMA connector is in electrical contact with the metal patch, and the outer conductor of the second SMA connector is in electrical contact with the metal ground.

[0036] The beneficial effects of the present invention are: the sandwich Luneburg lens antenna in the embodiment, by using two planar Luneburg lenses with different structures, has dual-frequency radiation characteristics and independent adjustment capabilities for dual frequency bands. This heterogeneous design is conducive to achieving structural simplification, effectively reducing the difficulty of design and processing, and reducing the impact of dimensional errors caused by manufacturing tolerances. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 Schematic diagram of the overall structure of the sandwich Luneburg lens antenna in the embodiment;

[0038] Figure 2 Schematic diagram of the structure of the first plane Luneburg lens, the second plane Luneburg lens and the third plane Luneburg lens in the embodiment;

[0039] Figure 3 A schematic diagram of a woodpile structure formed by dielectric rods in an embodiment;

[0040] Figure 4 A schematic diagram of a cubic structural unit in an embodiment;

[0041] Figure 5 Schematic diagram of the inner cylindrical area and the outer annular area in the embodiment;

[0042] Figure 6 Schematic diagram of the installation position of the dual-frequency feed antenna in the embodiment;

[0043] Figure 7 It is a structural schematic diagram of a dual-frequency feed antenna in an embodiment;

[0044] Figure 8 It is a schematic diagram of the structure of the patch antenna and the metal open waveguide antenna in the embodiment;

[0045] Fig. 9 Schematic diagram comparing the propagation of electromagnetic waves of different frequencies inside the sandwich Luneburg lens antenna in this embodiment and the existing broadband metamaterial planar Luneburg lens;

[0046] Fig.10 It is a schematic diagram of the simulation and measured results of the return loss-operating frequency of the sandwich Luneburg lens antenna in this embodiment;

[0047] Fig.11 Schematic diagram of the isolation coefficient between the ports of the sandwich Luneburg lens antenna in this embodiment;

[0048] Fig.12: is the radiation pattern of ports 6-10 of the sandwich Luneburg lens antenna in this embodiment on the XoY plane when the operating frequency is 5.8 GHz;

[0049] Fig.13 and Fig.14 Schematic diagram of measured results and simulation data of stable high-gain multi-beam radiation generated by the sandwich Luneburg lens antenna in this embodiment at 24 GHz and 27 GHz;

[0050] Fig.15 and Fig.16 It is a schematic diagram of the ability of the sandwich Luneburg lens antenna in this embodiment to independently adjust the dual-frequency radiation characteristics;

[0051] Fig.17 The electric field distribution diagrams on the XoZ plane at different frequencies obtained by simulating the sandwich Luneburg lens antenna in this embodiment;

[0052] Fig.18 Schematic diagram of the gain-frequency relationship of all ports of the sandwich Luneburg lens antenna in this embodiment. DETAILED DESCRIPTION

[0053] The Luneburg lens antenna has the following important properties: 1. It can generate a high-gain narrow radiation beam; 2. It can generate multiple approximately uniform radiation beams, and can achieve wide-angle multi-beam scanning effects by switching the feed antenna excitation; 3. It does not require a more complex feeding and phase shifting network to achieve wide-angle beam scanning.

[0054] The dual-band Luneburg lens antenna can be composed of multiple layers of uniform dielectric materials or a broadband metamaterial structure covering two working frequency bands. The solution using uniform dielectric materials is limited by the inherent properties of the material itself and is difficult to meet the design requirements. The dual-band Luneburg lens based on a broadband metamaterial structure has two defects: 1. When the frequency is relatively large, the overall size of the lens and the unit size are significantly different, which will lead to a complex structure; 2. The two-band electromagnetic waves have the same propagation area in the lens. Adjusting any design parameter will affect the radiation characteristics in the two frequency bands at the same time, and it is difficult to adjust the radiation characteristics of the two frequency bands independently.

[0055] Based on the above principle, this embodiment provides a sandwich Luneburg lens antenna with the ability to independently adjust dual-frequency radiation characteristics. Figure 1 The sandwich Luneburg lens antenna with the ability to independently adjust dual-frequency radiation characteristics includes a first plane Luneburg lens, a second plane Luneburg lens and a third plane Luneburg lens.

[0056] In this embodiment, the first plane Luneburg lens, the second plane Luneburg lens and the third plane Luneburg lens have a certain thickness, but they extend to a relatively large size on a plane perpendicular to the thickness direction, for example Figure 1The first plane Luneburg lens, the second plane Luneburg lens and the third plane Luneburg lens are all cylinders with a base radius greater than the height, and their base radii are equal, and the centers of the bases are located on the same straight line. After the three plane Luneburg lenses are assembled, the overall shape is still a cylinder, that is, the first plane Luneburg lens, the second plane Luneburg lens and the third plane Luneburg lens are all disc-shaped. Therefore, from a macroscopic perspective, the thickness of the first plane Luneburg lens, the second plane Luneburg lens and the third plane Luneburg lens can be ignored, and they can be regarded as figures on the plane.

[0057] Figure 1 The “missing” part shown by the dotted line is used to show the internal structure of the sandwich Luneburg lens antenna, and does not mean that the actual sandwich Luneburg lens antenna must have such a “missing” part.

[0058] In this embodiment, refer to Figure 1 , establish the X-axis and Y-axis with the plane where the second plane Luneburg lens is located, establish the Z-axis perpendicular to the plane where the second plane Luneburg lens is located, the first plane Luneburg lens is located on the side of the direction in which the Z-axis of the second plane Luneburg lens increases, and the third plane Luneburg lens is located on the side of the direction in which the Z-axis of the second plane Luneburg lens decreases, that is, the first plane Luneburg lens and the third plane Luneburg lens are distributed on the upper and lower sides of the second plane Luneburg lens, thereby forming a sandwich structure.

[0059] In this embodiment, the first plane Luneburg lens and the second plane Luneburg lens can be connected by glue or a special connecting structure, the second plane Luneburg lens and the third plane Luneburg lens can be connected by glue or a special connecting structure, or the first plane Luneburg lens, the second plane Luneburg lens and the third plane Luneburg lens can be manufactured by an integrated molding process, so that the sandwich Luneburg lens antenna with the ability to independently adjust dual-frequency radiation characteristics forms a whole.

[0060] Reference Figure 1 An air gap layer is provided between the first plane Luneburg lens and the second plane Luneburg lens, and between the second plane Luneburg lens and the third plane Luneburg lens, that is, the first plane Luneburg lens and the second plane Luneburg lens, and between the second plane Luneburg lens and the third plane Luneburg lens may not be completely tightly fitted.

[0061] In this embodiment, refer to Figure 1, the structure of the first plane Luneburg lens is the same as that of the third plane Luneburg lens, the structure of the first plane Luneburg lens is different from that of the second plane Luneburg lens, and the structure of the third plane Luneburg lens is also different from that of the second plane Luneburg lens. Since the first plane Luneburg lens, the second plane Luneburg lens and the third plane Luneburg lens are all Luneburg lenses, they all have the function of converting the incident spherical wave into an outgoing plane wave, thereby increasing the beam gain and narrowing the beam width; the first plane Luneburg lens and the third plane Luneburg lens with the same structure can be used to propagate low-frequency electromagnetic waves and limit the propagation of high-frequency electromagnetic waves. The second plane Luneburg lens with different structures can be used to simultaneously support the propagation of high and low frequency electromagnetic waves, so the sandwich Luneburg lens antenna composed of them has dual-frequency radiation characteristics as a whole; since the first plane Luneburg lens and the third plane Luneburg lens are of one structure and the second plane Luneburg lens is of another structure, it is convenient to adjust the parameters of the first plane Luneburg lens and the third plane Luneburg lens of the same structure to adjust the radiation characteristics of the corresponding frequency band (such as low-frequency electromagnetic waves) without affecting the radiation characteristics of the sandwich Luneburg lens antenna as a whole for other frequency bands (such as high-frequency electromagnetic waves). Similarly, the parameters of the second plane Luneburg lens of another structure can be adjusted to adjust the radiation characteristics of the corresponding frequency band (such as high-frequency electromagnetic waves) without affecting the radiation characteristics of the sandwich Luneburg lens antenna as a whole for other frequency bands (such as low-frequency electromagnetic waves), thereby achieving independent adjustment capabilities for dual frequency bands; and this heterogeneous design is conducive to simplification of the structure, effectively reducing the difficulty of design and processing, and reducing the impact of dimensional errors caused by manufacturing tolerances.

[0062] In this embodiment, refer to Figure 2 The first plane Luneburg lens and the third plane Luneburg lens have the same structure, both of which are woodpile structures composed of dielectric rods. The second plane Luneburg lens is a structure composed of multiple cubic structural units.

[0063] In this embodiment, taking the first plane Luneberg lens as an example, a part of the structure is as follows: Figure 3 See Figure 3 The first plane Luneburg lens includes a plurality of dielectric rods, which are distributed on each layer ( Figure 3 4 layers are shown in the figure), and these layers are parallel to the XoY plane. Multiple dielectric rods in the same layer are parallel to each other and arranged periodically, wherein the periodic arrangement means that the distance between any two dielectric rods in the same layer is the same. In this embodiment, this distance is called a horizontal period, and the specific size of the horizontal period can be p=6.25 mm.

[0064] Reference Figure 3 , the dielectric rods of different layers are stacked together to form a three-dimensional orthogonal rectangular grid-shaped woodpile structure. The dielectric rods in any layer are perpendicular to the dielectric rods in the adjacent layer, for example, Figure 3 The dielectric rods in the bottom layer are adjacent to the dielectric rods in the second layer from the bottom, and the dielectric rods in these two layers are perpendicular to each other in space, that is, when the dielectric rods in these two layers are projected onto a plane parallel to them (such as the XoY plane), the resulting projections are perpendicular.

[0065] Reference Figure 3 , each dielectric rod in any layer is relatively offset by half a horizontal period from each dielectric rod in the alternate layer. There is another layer between a layer and the alternate layer. For example, Figure 3 The dielectric rods in the bottom layer are not directly adjacent to the dielectric rods in the third layer from the bottom (the second layer from the top). There is another layer between them, which is the second layer from the bottom. Figure 3 For the dielectric rods in the bottom layer, the dielectric rods in the third layer from the bottom (the second layer from the top) are the dielectric rods in the alternate layer. Figure 3 , the dielectric rods of the third layer from the bottom (the second layer from the top) are offset by half a horizontal period relative to the dielectric rods in the bottom layer. For example, if the dielectric rods of these two layers are projected onto a plane parallel to them (such as the XoY plane), the resulting projection is still periodic, but the corresponding period becomes half of the horizontal period of a single layer. That is to say, if observed from a direction perpendicular to the XoY plane, it will be seen Figure 3 The dielectric rods in the third layer from the bottom (the second layer from the top) just fill the gaps between the dielectric rods in the bottom layer.

[0066] In this embodiment, refer to Figure 2 The first plane Luneburg lens and the third plane Luneburg lens with a woodpile structure are also periodic in the thickness direction (or height direction, that is, the direction of the Z axis). Figure 3 The top layer of dielectric rods, the layer of dielectric rods above it ( Figure 3 The arrangement and direction of the Figure 3 The dielectric rods at the bottom are the same, so from the thickness direction, the woodpile structure has 4 layers as a period. In this embodiment, this period, that is, the total height of the 4 layers of dielectric rods, is called a vertical period. The specific size of the vertical period can be h=8.84mm. In this embodiment, the heights of the dielectric rods are the same, so the height of a dielectric rod is equal to one quarter of the vertical period, for example, the height of a dielectric rod is 2.21mm.

[0067] In this embodiment, the first plane Luneburg lens and the third plane Luneburg lens are respectively formed by stacking 18 layers of dielectric rods, so the thickness (height) of the first plane Luneburg lens and the third plane Luneburg lens is 39.78 mm. The first plane Luneburg lens and the third plane Luneburg lens can be manufactured by 3D printing integrated molding and other technologies, wherein the dielectric rods in the first plane Luneburg lens and the third plane Luneburg lens are made of nylon.

[0068] In this embodiment, the firewood pile structure units of the first plane Luneburg lens and the third plane Luneburg lens have frequency selection characteristics, which can be equivalent to a uniform medium in the low frequency band, thereby realizing their own low-frequency band transmission function; they show a certain band-stop effect in the high frequency band, thereby not affecting the high-frequency band transmission function of the second plane Luneburg lens, which is conducive to realizing dual-frequency independent adjustment.

[0069] In this embodiment, the structure of a part of the second plane Luneberg lens, that is, the cubic structure unit is as follows: Figure 4 See Figure 2 The disc-shaped second plane Luneburg lens has a central axis, and the second plane Luneburg lens can be divided into multiple layers, and the center of each layer is on the central axis. When manufacturing the second plane Luneburg lens, multiple independent cubic structural units can be manufactured first, and then a single layer in the second plane Luneburg lens can be manufactured. Specifically, multiple cubic structural units are arranged in layers around the center of the circle, and each cubic structural unit is located on a ring. The steps of manufacturing a single layer are repeated multiple times to manufacture multiple layers in the second plane Luneburg lens, and the centers of these layers are aligned and assembled together to obtain the second plane Luneburg lens.

[0070] In this embodiment, a PCB material with a relative dielectric constant of 2.2 (such as Wangling F4B) can be used to manufacture the second plane Luneburg lens. Specifically, a single layer in the second plane Luneburg lens can be obtained by using a piece of PCB substrate and making a plurality of cubic structural units on it; multiple pieces of PCB substrates are manufactured in this way to obtain multiple layers in the second plane Luneburg lens; multiple layers are stacked together to obtain the second plane Luneburg lens.

[0071] In this embodiment, for a single layer in the second plane Luneburg lens, the number of structural units contained in each layer of the ring increases gradually from the center (center of the circle) thereof. Specifically, the number of cubic structural units in each layer of the ring is num=(8+(i-2)×8), where the number of ring layers is obtained by counting from the center outward.

[0072] In this embodiment, the side length of the cubic structure unit is p=2.5 mm, and the second plane Luneburg lens is formed by stacking 4 layers of cubic structure units, so the thickness (height) of the second plane Luneburg lens is 10 mm.

[0073] In this embodiment, refer to Figure 4 , cylindrical air holes can be processed on part or all of the cubic structural units.

[0074] In this embodiment, refer to Figure 5 , after assembling the first plane Luneburg lens, the second plane Luneburg lens and the third plane Luneburg lens together and aligning their centers, their centers are located on the same straight line, which is the central axis of the sandwich Luneburg lens antenna as a cylinder. Starting from the central axis, along the radial extension of the first plane Luneburg lens, the second plane Luneburg lens and the third plane Luneburg lens for a certain distance (this distance can be half of the bottom radius of the first plane Luneburg lens, the second plane Luneburg lens and the third plane Luneburg lens or other proportional values, for example, refer to Figure 5 The bottom radius of the first plane Luneburg lens is R1=75mm, so the extended distance is R2=37.5mm), and a certain space area is extended. This extended space area is also a cylinder, which is called the inner cylindrical area in this embodiment. The bottom radius of the inner cylindrical area is R2=37.5mm.

[0075] Reference Figure 5 The sandwich Luneburg lens antenna is a cylinder as a whole, and the space it occupies except for the inner cylindrical area is the outer circular area.

[0076] In this embodiment, the components located in the inner cylindrical region and the components located in the outer annular region may have different specific structures.

[0077] For example, each dielectric rod in the inner cylindrical region has a first size parameter, and each dielectric rod in the outer ring region has a second size parameter. For example, the first size parameter and the second size parameter both represent the cross-sectional width of the dielectric rod, wherein the value of the first size parameter is specifically 4.5 mm, and the value of the second size parameter is specifically 2.7 mm, that is, each dielectric rod in the inner cylindrical region is thicker than each dielectric rod in the outer ring region.

[0078] For example, each cubic structure unit located in the inner cylindrical area is solid, that is, it is not provided with a cylindrical air hole, while each cubic structure unit located in the outer annular area is provided with a cylindrical air hole, which is perpendicular to the plane where the second plane Luneburg lens is located, and the aperture of the cylindrical air hole is d=0.64mm.

[0079] In this embodiment, a second plane Luneburg lens composed of a plurality of cubic structural units is used, so that the structure of the second plane Luneburg lens is different from that of the first plane Luneburg lens and the third plane Luneburg lens, and the dual-frequency radiation characteristics can be independently adjusted. Moreover, the metamaterial unit period (e.g., horizontal period) constituting the first plane Luneburg lens and the third plane Luneburg lens can be greater than the metamaterial unit period (e.g., the side length of the cubic structural unit) constituting the second layer plane Luneburg lens, so that high-frequency electromagnetic waves propagate only in the second plane Luneburg lens, while low-frequency electromagnetic waves propagate in the first plane Luneburg lens and the third plane Luneburg lens.

[0080] In this embodiment, dielectric protrusion fixing structures (not shown in the figure) can be respectively set on the edges of the first plane Luneburg lens, the second plane Luneburg lens and the third plane Luneburg lens. The dielectric protrusion fixing structures are provided with through holes. Nylon screws are passed through the through holes of each dielectric protrusion fixing structure, and finally the nylon screws are tightened with nylon nuts, so as to mechanically connect the first plane Luneburg lens, the second plane Luneburg lens and the third plane Luneburg lens.

[0081] In this embodiment, nylon gaskets can be arranged between the dielectric protrusion fixing structure of the first plane Luneburg lens and the dielectric protrusion fixing structure of the second plane Luneburg lens, and between the dielectric protrusion fixing structure of the third plane Luneburg lens and the dielectric protrusion fixing structure of the second plane Luneburg lens. Nylon screws pass through the nylon gaskets, so that air gap layers are formed between the first plane Luneburg lens and the second plane Luneburg lens, and between the third plane Luneburg lens and the second plane Luneburg lens, respectively.

[0082] In this embodiment, Figure 6 As shown, the sandwich Luneburg lens antenna also includes multiple dual-frequency feed antennas. Figure 6 These dual-frequency feed antennas are distributed on the edge of the second plane Luneburg lens and are mechanically connected to the second plane Luneburg lens.

[0083] In this embodiment, refer to Figure 6 , each dual-frequency feed antenna is located on the same plane, and the main radiation direction of each dual-frequency feed antenna points to the center of the second plane Luneburg lens. Each dual-frequency feed antenna can be evenly arranged on the second plane Luneburg lens, for example, the main radiation direction angle Δφ of any two adjacent dual-frequency feed antennas is equal, and in this embodiment, Δφ=40°, so that the radiation beam generated by stimulating each feed source can evenly cover a certain area.

[0084] In this embodiment, each dual-frequency feed antenna is provided with a high-frequency port and a low-frequency port. In this embodiment, the number of dual-frequency feed antennas is 5, so there are a total of 10 ports. Figure 6, the high-frequency ports are named ports 1 to 5 from left to right, and the low-frequency ports are named ports 6 to 10 from left to right.

[0085] In this embodiment, the dual-frequency feed antenna is used as a feed antenna to feed the sandwich Luneburg lens antenna. Specifically, by exciting one of the dual-frequency feed antennas, the excited dual-frequency feed antenna can generate a spherical wave, which is converted into a plane wave by the second plane Luneburg lens to output a corresponding beam; by switching the number of dual-frequency feed antennas to be excited, a wide-angle beam can be achieved; by switching the position of the dual-frequency feed antenna to be excited, a multi-beam scanning effect can be achieved, for example Figure 6 When the sandwich Luneburg lens antenna shown is scanning, multi-beam scanning within the range of ±80° can be achieved by switching the working dual-frequency feed antenna; if the dual-frequency feed antennas are evenly arranged on the second plane Luneburg lens, a wide-angle uniform multi-beam scanning effect can be achieved.

[0086] In this embodiment, the structure of the dual-frequency feed antenna is as follows: Figure 7 See Figure 7 The dual-frequency feed antenna is composed of a patch antenna and a metal open waveguide antenna. Figure 7 The patch antenna is provided with an opening, and the metal open waveguide antenna passes through the opening of the patch antenna, thereby being nested in the patch antenna to form a whole to become a dual-frequency feed antenna.

[0087] In this embodiment, the operating frequency of the metal open waveguide antenna is in a higher first frequency band (for example, above 20 GHz, specifically 24 GHz), and the operating frequency of the patch antenna is in a lower second frequency band (for example, below 10 GHz, specifically 5.8 GHz).

[0088] In this embodiment, the structures of the patch antenna and the metal open waveguide antenna are as follows: Figure 8 See Figure 8 The patch antenna includes a substrate, a metal patch, a metal ground and a second SMA connector, wherein the metal patch is arranged on one side of the substrate (the side facing the second planar Luneburg lens), and the metal ground is arranged on the other side of the substrate. The second SMA connector is mounted on the substrate, the outer conductor of the second SMA connector is in electrical contact with the metal ground, and the inner conductor of the second SMA connector passes through the substrate and is in electrical contact with the metal patch (the inner conductor of the second SMA connector is not in electrical contact with the metal ground).

[0089] The substrate and the metal patch may both be rectangular, and the model of the substrate is RO4003C.

[0090] In this embodiment, refer to Figure 8, one end of the metal open waveguide antenna is an opening, and the other end is a metal short-circuit wall. The open end of the metal open waveguide antenna protrudes a certain length relative to the substrate of the patch antenna, and the edge of the second plane Luneburg lens is provided with a groove (not shown in the figure) whose shape and size match the protruding part of the metal open waveguide antenna, so that the protruding part of the metal open waveguide antenna can be embedded in the groove of the second plane Luneburg lens, thereby forming a mechanical connection with the second plane Luneburg lens, so that the dual-frequency feed antenna is installed as a whole on the edge of the second plane Luneburg lens. In this embodiment, the number of slots of the second plane Luneburg lens is the same as the number of dual-frequency feed antennas, that is, one dual-frequency feed antenna is installed in each slot.

[0091] In this embodiment, refer to Figure 7 and Figure 8 , the dual-frequency feed antenna is also equipped with a first SMA connector. Figure 7 The first SMA connector is installed at one end of the metal short-circuit wall outside the metal open waveguide antenna.

[0092] In this embodiment, refer to Figure 8 A pair of trapezoidal metal ridges are arranged inside the metal open waveguide antenna, and each trapezoidal metal ridge includes four sides: a longer bottom side, a shorter bottom side, an oblique waist and a right-angle waist.

[0093] Reference Figure 8 The longer bottom side of the trapezoidal metal ridge faces the outside of the metal open waveguide antenna, the oblique waist of the trapezoidal metal ridge extends from the opening of the metal open waveguide antenna to the inside of the metal open waveguide antenna, the right-angle waist of the trapezoidal metal ridge is connected to the metal short-circuit wall of the metal open waveguide antenna, and the shorter bottom sides of the two trapezoidal metal ridges are opposite.

[0094] Reference Figure 8 Two-level stepped notches are arranged at the shorter bottom side of the trapezoidal metal ridge, and the width of the stepped notches is b1.

[0095] Reference Figure 8 The trapezoidal metal ridge located on the top is provided with a through hole perpendicular to the bottom edge, the inner conductor of the first SMA connector passes through the through hole of the trapezoidal metal ridge and forms an electrical contact with the other trapezoidal metal ridge (there is no electrical contact between the trapezoidal metal ridge located on the top and the inner conductor of the first SMA connector), and the inner conductor of the first SMA connector is also in electrical contact with the metal patch in the patch antenna, and the outer conductor of the first SMA connector can be fixed to the outside of the metal open waveguide antenna by screws and other components.

[0096] In this embodiment, Figure 7 and Figure 8The first SMA connector in the dual-frequency feed antenna shown is used as a high-frequency port, and the second SMA connector is used as a low-frequency port, wherein the high-frequency port is used to receive power feeding from an external device at a higher first frequency band, and the low-frequency port is used to receive power feeding from an external device at a lower second frequency band. For example, Figure 6 In the figure, port 3 used as a high frequency port and port 8 used as a low frequency port are two ports in the same dual-frequency feed antenna, wherein port 3 is the first SMA connector and port 8 is the second SMA connector.

[0097] In this embodiment, Figure 7 and Figure 8 The dual-frequency feed antenna shown can receive feeds of two frequency bands at the same time and generate spherical waves to feed three plane Luneburg lenses respectively. Among them, the electromagnetic waves generated by the higher first frequency band feed will be transmitted in the second plane Luneburg lens, and the electromagnetic waves generated by the lower second frequency band feed will also be transmitted in the first plane Luneburg lens and the third plane Luneburg lens.

[0098] In this embodiment, the technical effect of the dual-frequency feed antenna is mainly brought about by its structure. Figure 7 and Figure 8 The specific values ​​of the parameters are shown in Table 1.

[0099] Table 1

[0100] <![CDATA[l0]]> <![CDATA[w0]]> <![CDATA[l1]]> <![CDATA[w1]]> <![CDATA[l2]]> <![CDATA[w2]]> 40mm 23mm 25.6mm 15.9mm 12.67mm 6.32mm th <![CDATA[d0]]> <![CDATA[d1]]> <![CDATA[d2]]> <![CDATA[d3]]> <![CDATA[d4]]> 1.52mm 14mm 9.45mm 2.65mm 0.45mm 4.25mm dr <![CDATA[b1]]> <![CDATA[b2]]> <![CDATA[b3]]> 2.6mm 1.13mm 0.85mm 0.51mm

[0101] The comparison of the propagation of electromagnetic waves of different frequencies inside the sandwich Luneburg lens antenna in this embodiment and the existing broadband metamaterial planar Luneburg lens is shown in FIG. Fig. 9 As shown. Fig. 9 The upper part shows the propagation of electromagnetic waves of different frequencies inside the existing broadband metamaterial planar Luneburg lens, and the lower part shows the propagation of electromagnetic waves of different frequencies inside the sandwich Luneburg lens antenna in this embodiment.

[0102] pass Figure 1 , Figure 2 , Figure 5 and Figure 6 The structure shown in the figure, the sandwich Luneburg lens antenna in this embodiment has the following technical effects:

[0103] (1) High gain, narrow beam, and low sidelobe: Through the refraction of the Luneburg lens, the incident spherical wave can be converted into an outgoing plane wave by refraction at both high and low frequencies, thereby increasing the gain, narrowing the beam, and reducing the sidelobe level.

[0104] (2) Wide scanning angle: By switching the direction as well as The dual-frequency feed antenna can realize multi-beam scanning.

[0105] (3) Simple structure, easy to process and manufacture: The antenna proposed in this embodiment can be easily processed and manufactured through mature 3D printing, CNC machine tool processing, and circuit board processing. In addition, due to the sandwich design of the lens, a heterogeneous metamaterial structure can be used to build the lens. The metamaterial used in the first and third layer planar Luneburg lenses can be composed of structural units with a larger period compared to the metamaterial used in the second layer planar Luneburg lenses. It avoids the use of broadband metamaterials for the two frequency bands of coverage and low frequency to construct the entire lens, greatly simplifying the lens structure.

[0106] (4) Can generate a large frequency ratio dual-frequency radiation beam: Existing dual-frequency Luneburg lenses all use a single type of broadband metamaterial structure that covers both low and high frequencies to construct the lens. The period of the structural unit must be smaller than the high-frequency wavelength, and the lens size must be several times the low-frequency wavelength. When the two frequencies have a large frequency ratio, the complexity of the lens structure will increase significantly. Limited by structural complexity and other issues, the existing dual-frequency Luneburg lens antennas have a small frequency ratio, generally less than 2:1. Through the use of sandwich design and heterogeneous metamaterial solutions, the proposed Luneburg lens antenna has a larger frequency ratio. In this embodiment, the frequency ratio of the center frequencies of the two bands is approximately 25.5:5.8, which is approximately 4.4:1.

[0107] (5) Independent adjustment capability of dual-frequency radiation characteristics: In this embodiment, the dual-frequency feed antenna radiates high-frequency and low-frequency electromagnetic waves simultaneously relative to the proposed sandwich Luneburg lens. Under ideal conditions, its electromagnetic field propagation area is as follows: Figure 6 As shown. In the low frequency band, the woodpile structure applied to the first and third layers of planar Luneburg lenses can be equivalent to a uniform medium in the low frequency band through the equivalent medium theory, and the broadband metamaterial structure with cylindrical through holes applied to the second layer of planar Luneburg lenses can also be equivalent to a uniform medium in the low frequency band. The air gap layer can be ignored because it is much smaller than the wavelength of the electromagnetic wave in the low frequency band. Therefore, the propagation area of ​​the low-frequency electromagnetic wave inside the lens includes the entire lens. In the high frequency band, the woodpile structure applied to the first and third layers of planar Luneburg lenses can show a certain band-stop effect in the high frequency band. The band-stop effect of this structure, combined with the certain isolation effect of the air gap layer on the high frequency band electromagnetic waves, can effectively suppress the propagation of high-frequency electromagnetic waves. The existence of the first and third field layer planar Luneburg lenses and the air gap layer can limit the propagation range of high-frequency electromagnetic waves to the second layer of planar Luneburg lenses. By adjusting the overall thickness of the sandwich Luneburg lens while maintaining the thickness of the second-layer plane Luneburg lens unchanged, independent adjustment of the low-frequency band radiation characteristics can be achieved; and by adjusting the thickness of the second-layer plane Luneburg lens while maintaining the overall thickness of the sandwich Luneburg lens unchanged, independent adjustment of the high-frequency band radiation characteristics can be achieved.

[0108] The designed sandwich Luneburg lens antenna with large frequency ratio and independent adjustment capability of dual-frequency radiation characteristics was simulated, processed and measured. The simulation software was CST studio suite. The simulation and measurement results are shown in the figure. Figure 10-Figure 18 shown.

[0109] Fig.10 The figure shows the simulation and measured results of the return loss-operating frequency of the sandwich Luneburg lens antenna in this embodiment. Fig.10 It can be clearly seen that the measured results are highly consistent with the simulation results. In the frequency range of 5.7GHz to 5.9GHz and 18.7GHz to 27.3GHz, the measured reflection coefficients of all ports are lower than -10dB. The relative impedance bandwidths at low and high frequencies are 3.4% and 37.4%, respectively. The operating bandwidth is the intersection of the impedance bandwidth and the 3dB gain bandwidth, which is located at 5.7GHz to 5.9GHz and 23.1GHz to 27.3GHz. The relative operating bandwidths are 3.4% and about 16.8%, respectively. Fig.10 The operating bandwidth is highlighted in purple. The 3dB gain bandwidth is described later.

[0110] Fig.11 The isolation coefficients between the ports are shown. In the higher frequency band, the coupling between the two ports of the rectangular patch antenna and the rectangular metal open waveguide antenna, which belong to the same dual-frequency feed antenna, is the strongest, with the maximum simulation and measured values ​​of -16.53dB and -23.58dB, respectively. In the high frequency band, the isolation between port 1 and port 5 is the worst. In the working frequency band, the highest simulation |S 15 The value is -13.62dB, and the measured value is -18.42dB. The isolation coefficients between other ports are all lower than -25dB.

[0111] Fig.12 The radiation patterns of ports 6-10 in the XoY plane at 5.8 GHz are shown. The five ports produce beams with directions of 0°, ±40°, and ±80°, with a scanning loss of 1.54 dB. The 3 dB beamwidth of these beams is approximately 20°, with sidelobe levels close to -15 dB.

[0112] Fig.13 and Fig.14The sandwich Luneburg lens antenna in this embodiment produces stable high-gain multi-beam radiation at 24 GHz and 27 GHz, and the measured results are highly consistent with the simulation data. The 3dB beamwidth of the central beam at 24 GHz and 27 GHz is 7.33° and 6°, respectively. The sidelobe level of the central beam is about -15 dB, however, the sidelobe level of the beam pointing to ±80° is higher, about -7 dB, due to the influence of the opposite dual-frequency feed antenna. This influence also leads to an effective aperture loss at the maximum scanning angle, resulting in a scanning loss of 3.71 dB.

[0113] Fig.15 and Fig.16 The sandwich Luneburg lens antenna in this embodiment is capable of independently adjusting the dual-frequency radiation characteristics. This characteristic can be attributed to the sandwich structure used in the design of the Luneburg lens antenna and the separation of the propagation areas of the two-band radiation electromagnetic waves. Fig.15 It is shown that by adjusting the thickness H1 of the Luneburg lens antenna while keeping the thickness H2 of the second layer of planar Luneburg lens unchanged, independent adjustment of the low-frequency radiation characteristics can be achieved. Fig.16 It shows that the radiation characteristics of the high frequency band can be adjusted independently by adjusting H2 while keeping H1 unchanged.

[0114] Fig.17 The electric field distribution diagrams on the XoZ plane at different frequencies obtained by simulation are shown. Fig.17 (a) shows the electric field distribution when the operating frequency is 5.8 GHz. Fig.17 (a) It can be seen that at this frequency, the electromagnetic wave propagation range is the entire lens. Fig.17 (b) shows the electric field distribution when the operating frequency is 24 GHz. Fig.17 (b) It can be seen that at this frequency, the electromagnetic wave propagation range is only the second layer of the planar Luneburg lens. This shows that through the sandwich design with a woodpile structure, the proposed Luneburg lens can better realize the concept proposed in the previous article, that is, to separate the propagation areas of the two frequency bands of electromagnetic waves to independently control them.

[0115] The gain-frequency relationship of all ports is as follows Fig.18 As shown. Overall, the simulation and measured results are in good agreement. All ports 6-10 reach peak gain at 5.8GHz, and the maximum gain variation in the low frequency band is 1.1dB. In the high frequency band, the highest gain measured is 18.8dBi, and the gain variation is less than 3dB in the frequency range of 23.1GHz to 27.3GHz. Port 1 shows the most significant gain fluctuation, with a measured fluctuation of 2.8dB.

[0116] It should be noted that, unless otherwise specified, when a feature is referred to as being "fixed" or "connected" to another feature, it may be directly fixed or connected to the other feature, or it may be indirectly fixed or connected to the other feature. In addition, the descriptions of up, down, left, right, etc. used in the present disclosure are only relative to the relative positional relationship of the components of the present disclosure in the accompanying drawings. The singular forms of "a", "" and "the" used in the present disclosure are also intended to include the plural forms, unless the context clearly indicates other meanings. In addition, unless otherwise defined, all technical and scientific terms used in this embodiment have the same meaning as those generally understood by those skilled in the art. The terms used in the specification of this embodiment are only for describing specific embodiments and are not intended to limit the present invention. The term "and / or" used in this embodiment includes any combination of one or more related listed items.

[0117] It should be understood that, although the term first, second, third etc. may be adopted to describe various elements in the present disclosure, these elements should not be limited to these terms. These terms are only used to distinguish the same type of elements from each other. For example, without departing from the scope of the present disclosure, the first element may also be referred to as the second element, and similarly, the second element may also be referred to as the first element. The use of any and all examples or exemplary language ("for example", "such as" etc.) provided by the present embodiment is only intended to better illustrate embodiments of the present invention, and unless otherwise required, the scope of the present invention will not be limited.

[0118] It should be appreciated that embodiments of the present invention may be implemented or enforced by computer hardware, a combination of hardware and software, or by computer instructions stored in a non-transitory computer-readable memory. The method may be implemented in a computer program using standard programming techniques - including a non-transitory computer-readable storage medium configured with a computer program, wherein the storage medium so configured causes the computer to operate in a specific and predefined manner - according to the methods and drawings described in the specific embodiments. Each program may be implemented in a high-level procedural or object-oriented programming language to communicate with a computer system. However, if desired, the program may be implemented in assembly or machine language. In any case, the language may be a compiled or interpreted language. In addition, the program may be run on a programmed dedicated integrated circuit for this purpose.

[0119] In addition, the operations of the process described in this embodiment may be performed in any suitable order, unless otherwise indicated in this embodiment or otherwise clearly contradicted by the context. The process described in this embodiment (or variations and / or combinations thereof) may be performed under the control of one or more computer systems configured with executable instructions, and may be implemented as a code (e.g., executable instructions, one or more computer programs, or one or more applications) executed on one or more processors in common, by hardware or a combination thereof. A computer program includes a plurality of instructions that may be executed by one or more processors.

[0120] Further, the method can be implemented in any type of computing platform that is operably connected to a suitable computer, including but not limited to a personal computer, a minicomputer, a mainframe, a workstation, a network or distributed computing environment, a separate or integrated computer platform, or in communication with a charged particle tool or other imaging device, etc. Various aspects of the present invention can be implemented in machine-readable code stored on a non-transitory storage medium or device, whether removable or integrated into a computing platform, such as a hard disk, an optical read and / or write storage medium, a RAM, a ROM, etc., so that it can be read by a programmable computer, and when the storage medium or device is read by the computer, it can be used to configure and operate the computer to perform the process described herein. In addition, the machine-readable code, or part thereof, can be transmitted via a wired or wireless network. When such media includes instructions or programs that implement the above steps in conjunction with a microprocessor or other data processor, the invention of this embodiment includes these and other different types of non-transitory computer-readable storage media. When programmed according to the methods and techniques of the present invention, the present invention also includes the computer itself.

[0121] The computer program can be applied to input data to perform the functions of the present embodiment, thereby converting the input data to generate output data stored in a non-volatile memory. The output information can also be applied to one or more output devices such as a display. In a preferred embodiment of the present invention, the converted data represents a physical and tangible object, including a specific visual depiction of the physical and tangible object produced on the display.

[0122] The above are only preferred embodiments of the present invention. The present invention is not limited to the above embodiments. As long as the technical effects of the present invention are achieved by the same means, any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention. Within the scope of protection of the present invention, its technical solutions and / or implementation methods may have various modifications and changes.

Claims

1. A sandwich Luneburg lens antenna with independent adjustment capability of dual-frequency radiation characteristics, characterized in that: The sandwich Luneburg lens antenna with the ability to independently adjust dual-frequency radiation characteristics includes: A first plane Luneburg lens, a second plane Luneburg lens and a third plane Luneburg lens; the first plane Luneburg lens is located on the upper side of the second plane Luneburg lens, the third plane Luneburg lens is located on the lower side of the second plane Luneburg lens, the structure of the first plane Luneburg lens is the same as that of the third plane Luneburg lens, and different from the structure of the second plane Luneburg lens.

2. The sandwich Luneburg lens antenna with independent adjustment capability of dual-frequency radiation characteristics according to claim 1, characterized in that: The first plane Luneburg lens and the third plane Luneburg lens are both woodpile structures; The second plane Luneburg lens comprises a plurality of cubic structural units; The edges of the first plane Luneburg lens, the second plane Luneburg lens and the third plane Luneburg lens are respectively provided with a dielectric protrusion fixing structure, and the dielectric protrusion fixing structure is provided with a through hole; The sandwich Luneburg lens antenna with the ability to independently adjust dual-frequency radiation characteristics also includes a nylon screw, a nylon nut and a nylon gasket; the nylon gasket is placed between two corresponding dielectric protrusion fixing structures, the nylon screw passes through the through hole of the dielectric protrusion fixing structure and the nylon gasket, and the nylon nut fixes the nylon screw.

3. The sandwich Luneburg lens antenna with independent adjustment capability of dual-frequency radiation characteristics according to claim 2, characterized in that: The first planar Luneburg lens and the third planar Luneburg lens respectively include a plurality of dielectric rods with rectangular cross-sections, each of the dielectric rods is located in a corresponding layer, and the dielectric rods in each layer are stacked; The dielectric rods in the same layer are parallel to each other and are periodically arranged according to a horizontal period; The dielectric rods in any layer are vertical to the dielectric rods in an adjacent layer; The dielectric rods in any layer are relatively offset from the dielectric rods in an alternate layer by half a horizontal period.

4. The sandwich Luneburg lens antenna with independent adjustment capability of dual-frequency radiation characteristics according to claim 2, characterized in that: The first plane Luneburg lens, the second plane Luneburg lens and the third plane Luneburg lens are all in the shape of a disk; The first plane Luneburg lens, the second plane Luneburg lens and the third plane Luneburg lens have the same radius and their centers are aligned; The cubic structural units in the second plane Luneburg lens are arranged around a multi-layer circular ring formed by the center of the circular disk.

5. The sandwich Luneburg lens antenna with independent adjustment capability of dual-frequency radiation characteristics according to claim 4, characterized in that: Each of the dielectric rods located in the inner cylindrical region has a first size parameter, and each of the dielectric rods located in the outer annular region has a second size parameter; Each of the cubic structural units located in the inner cylindrical region is solid, and each of the cubic structural units located in the outer annular region is provided with a cylindrical air hole, and the cylindrical air hole is perpendicular to the plane where the second plane Luneburg lens is located; Among them, the inner cylindrical area is the spatial area extending from the central axis of the cylinder to the edge of the cylinder in the cylinder formed by the superposition of the first plane Luneburg lens, the second plane Luneburg lens and the third plane Luneburg lens, and the outer annular area is the spatial area in the cylinder except the inner cylindrical area.

6. The sandwich Luneburg lens antenna with independent adjustment capability of dual-frequency radiation characteristics according to any one of claims 1 to 5, characterized in that: The sandwich Luneburg lens antenna having the ability to independently adjust dual-frequency radiation characteristics also includes: Multiple dual-frequency feed antennas; each of the dual-frequency feed antennas is distributed on the edge of the second planar Luneburg lens and is mechanically connected to the second planar Luneburg lens.

7. The sandwich Luneburg lens antenna with independent adjustment capability of dual-frequency radiation characteristics according to claim 6, characterized in that: The dual-frequency feed antenna comprises a patch antenna and a metal open waveguide antenna; the operating frequency of the metal open waveguide antenna is in a first frequency band, and the operating frequency of the patch antenna is in a second frequency band, and the first frequency band is higher than the second frequency band; The patch antenna is provided with an opening; The metal open waveguide antenna passes through the opening of the patch antenna, thereby being nested in the patch antenna.

8. The sandwich Luneburg lens antenna with independent adjustment capability of dual-frequency radiation characteristics according to claim 7, characterized in that: The edge of the second plane Luneburg lens is provided with a plurality of slots; the shape and size of the slots match one end of the metal open waveguide antenna; One end of the metal open waveguide antenna is an opening, and the other end is a metal short-circuit wall; The end of the metal open waveguide antenna where the opening is located is embedded in the slot, thereby forming a mechanical connection with the second planar Luneburg lens; A first SMA connector is installed at the other end of the metal open waveguide antenna.

9. The sandwich Luneburg lens antenna with independent adjustment capability of dual-frequency radiation characteristics according to claim 8, characterized in that: A pair of trapezoidal metal ridges are provided inside the metal open waveguide antenna; The longer bottom side of the trapezoidal metal ridge faces the outside of the metal open waveguide antenna, and the oblique waist of the trapezoidal metal ridge extends from the opening of the metal open waveguide antenna to the inside of the metal open waveguide antenna; the right-angle waist of the trapezoidal metal ridge is connected to the metal short-circuit wall of the metal open waveguide antenna; and the upper part of the right-angle waist of the trapezoidal metal ridge has two-level stepped grooves; The shorter bottom sides of the two trapezoidal metal ridges are opposite to each other; One of the trapezoidal metal ridges is provided with a through hole perpendicular to the bottom edge, the inner conductor of the first SMA connector passes through the through hole of the trapezoidal metal ridge and forms electrical contact with the other trapezoidal metal ridge, and the outer conductor of the first SMA connector is connected to the outside of the metal open waveguide antenna.

10. The sandwich Luneburg lens antenna with independent adjustment capability of dual-frequency radiation characteristics according to claim 8, characterized in that: The patch antenna comprises a substrate, a metal patch, a metal ground and a second SMA connector; The metal patch is arranged on one side of the substrate, and the metal ground is arranged on the other side of the substrate; The inner conductor of the second SMA connector is in electrical contact with the metal patch, and the outer conductor of the second SMA connector is in electrical contact with the metal ground.

Images