Broadband multi-beam hemispherical luneberg lens antenna

Abstract

The invention discloses a broadband multi-beam hemispherical Luneberg lens antenna, and belongs to the technical field of Luneberg lenses, the broadband multi-beam hemispherical Luneberg lens antenna comprises a hemispherical Luneberg lens, the Luneberg lens is fixedly installed on an emission bottom plate, and the end, away from the Luneberg lens, of a reflection bottom plate is coaxially and fixedly connected with a supporting shaft; a plurality of supporting frames are arranged on the supporting shaft in the circumferential direction with the axis of the supporting shaft as the center, the supporting frames are arranged in a staggered mode in the axial direction of the supporting shaft, a main shaft penetrating through the Luneberg lens in the axis direction of the Luneberg lens is fixedly arranged on the reflection bottom plate, and a feed source track arranged along the cambered surface of the Luneberg lens is fixedly connected between the main shaft and the supporting frames. And a feed source capable of moving along the feed source track is arranged on the feed source track. The Luneberg lens antenna composed of the Luneberg lens and the feed sources has the characteristic of high gain, due to the spherical symmetry of the Luneberg lens, any point on the spherical surface is the focus of the Luneberg lens, and the multiple feed sources are placed on the surface of the Luneberg lens to form multiple wave beams capable of covering the whole space range.

Description

Technical Field

[0001] The invention belongs to the technical field of Luneburg lenses, and in particular relates to a broadband multi-beam hemispherical Luneburg lens antenna. Background Art

[0002] As a key link in the communication system, the antenna is not only directly related to the performance of the communication, but also affects the resource consumption, electromagnetic compatibility and stealth of the platform on which it is carried.

[0003] Existing directional communication antennas mainly include parabolic antennas that are spherical after being equipped with antenna covers, and flat phased array antennas. With the gradual increase in the demand for wireless communications in modern systems, both types of antennas have certain limitations: parabolic antennas have relatively single functions and frequency bands. One antenna works in a specific frequency band and has only a single beam. It can only support mutual communication with a single object at the same time. One antenna is difficult to meet the multi-node communication and networking requirements of offshore terminals, and the scattering characteristics are large, which is not conducive to the stealth design of the platform; phased array antennas achieve multi-beams to meet the needs of multi-node networking, but in order to cover the omnidirectional field of view, multiple antennas are also required. In addition, the system is complex, the reliability is relatively low, the price is expensive, and the maintenance cost is high. Liquid cooling and other guarantees are often required, and the overall resource requirements are also high. Innovative antenna design ideas are needed to achieve multi-beam and multi-band integration at low cost using a single antenna.

[0004] Based on the traditional Luneburg lens, the present invention innovatively proposes a wide-band, multi-beam, full-space coverage Luneburg lens antenna system to achieve high-gain communication support for different frequency bands and different objects. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a broadband multi-beam hemispherical Luneburg lens antenna. Based on the traditional Luneburg lens, an innovative Luneburg lens antenna system with wide-band, multi-beam and full-space coverage is proposed to achieve high-gain communication support for different frequency bands and different objects.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention provides a broadband multi-beam hemispherical Luneburg lens antenna, comprising a Luneburg lens arranged in a hemispherical shape, wherein the Luneburg lens is fixedly mounted on a transmitting base plate, and a reflecting base plate is coaxially fixedly connected with a supporting shaft at an end away from the Luneburg lens, and a plurality of supporting frames are circumferentially arranged on the supporting shaft with the axis of the supporting shaft as the center, and the plurality of supporting frames are axially staggered along the supporting shaft, and a main shaft penetrating the Luneburg lens along the axis direction of the Luneburg lens is fixedly arranged on the reflecting base plate, and a feed track arranged along the curved surface of the Luneburg lens is fixedly connected between the main shaft and the supporting frame, and a feed source that can move along the feed track is arranged on the feed track.

[0008] Furthermore, an azimuth motor for controlling the rotational movement of the support frame along the circumferential direction of the support axis and a pitch motor for controlling the movement of the feed source along the feed source track are fixedly mounted on the support frame.

[0009] Furthermore, it also includes a base, on which a lifting motor is fixedly installed, on which a lifting pump is fixedly installed, and the output end of the lifting pump is fixedly connected to a supporting platform, and the supporting platform is fixedly connected to the end of the supporting shaft away from the reflective bottom plate.

[0010] Furthermore, the upper array of Luneburg lenses is provided with through holes which axially penetrate the Luneburg lenses.

[0011] Furthermore, the Luneburg lenses are arranged in multiple layers, each layer of Luneburg lenses is arranged in a hemispherical shape, and each layer of Luneburg lenses is provided with a groove for covering the previous layer of Luneburg lenses, so that each layer of Luneburg lenses is nested in sequence.

[0012] Furthermore, the Luneburg lens is prepared by 3D printing, and its preparation process includes the following steps: using micron-sized spherical granular polystyrene powder as the printing material, adopting selective laser sintering technology, and using a computer to accurately control the laser beam to scan the powder surface, so that the plastic powder is sintered or melted and then re-solidified to form a solid sheet in the shape of the model's cross-section, and the solid sheets are accumulated layer by layer to form a molded workpiece, and then the molded workpiece is immersed in paraffin liquid for a preset time and then taken out.

[0013] The beneficial effects of the present invention are:

[0014] 1. The Luneburg lens antenna composed of a Luneburg lens and a feed source has the characteristics of high gain;

[0015] 2. The dielectric constant distribution of the Luneburg lens has nothing to do with the frequency, so the Luneburg lens has a broadband characteristic;

[0016] 3. Due to the spherical symmetry of the Luneburg lens, any point on the spherical surface is its focus. Multiple feed sources are placed on its surface to form multiple beams that can cover the entire space range.

[0017] 4. Moving the feed on the spherical surface can achieve full-space scanning of the beam, so its servo system is much simpler and lighter than the traditional parabolic antenna.

[0018] Other advantages, objectives and features of the present invention will be described in the following description and will be apparent to those skilled in the art to some extent, or those skilled in the art may be taught from the practice of the present invention. The objectives and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the present invention provides the following drawings for illustration:

[0020] Figure 1 A schematic diagram of the overall structure of a Luneburg lens antenna according to an embodiment of the present invention;

[0021] Figure 2 A schematic diagram of through hole arrangement according to an embodiment of the present invention;

[0022] Figure 3 The simulated radiation pattern of the 552mm diameter non-uniform 7-layer Luneburg lens antenna according to an embodiment of the present invention;

[0023] Figure 4 This is a test result diagram of the Luneburg lens antenna pattern of an embodiment of the present invention.

[0024] The markings in the attached drawings are as follows: Luneburg lens 1, reflecting base plate 2, supporting shaft 3, supporting frame 4, main shaft 5, feed track 6, feed 7, azimuth motor 8, pitch motor 9, base 10, lifting motor 11, lifting pump 12, supporting platform 13. DETAILED DESCRIPTION

[0025] like Figures 1 to 4 As shown, the present invention provides a broadband multi-beam hemispherical Luneburg lens antenna, comprising: a Luneburg lens 1 arranged in a hemispherical shape, the Luneburg lens 1 is fixedly mounted on a reflecting base plate 2, the reflecting base plate 2 is coaxially fixedly connected with a support shaft 3 at the end away from the Luneburg lens 1, three support frames 4 are circumferentially arranged on the support shaft 3 with the axis of the support shaft 3 as the center, the three support frames 4 are staggered along the axial direction of the support shaft 3, a main shaft 5 that passes through the Luneburg lens 1 along the axial direction of the Luneburg lens 1 is fixedly arranged on the reflecting base plate 2, a feed track 6 arranged along the arc surface of the Luneburg lens 1 is fixedly connected between the main shaft 5 and the support frame 4, and a feed 7 is slidably arranged on the feed track 6.

[0026] The working principle of the above technology is: the Luneburg lens 1 uses spherical symmetry to achieve that any point on the spherical surface is its focus; multiple feed sources 7 are placed on its surface to form multiple beams that can cover the entire spatial range, and the feed sources 7 are moved on the spherical surface at the same time to achieve full-space scanning of high-gain beams. The signals emitted by each of the multiple feed sources 7 do not interfere with each other, so that the performance of the full-space beam can be stable and the system circuit design is simple.

[0027] The technical effect of the above technology is: compared with traditional high-gain antennas, the single-width multi-feed Luneburg lens antenna can greatly reduce the resource requirements for space, weight, etc. while achieving multi-beam full-space scanning, and reduce the installation and manufacturing maintenance costs. The hemispherical Luneburg lens 1 antenna gain reaches 28.5dBi and 31.8dBi respectively, which is much higher than the antenna gain indicators of the L-band and C-band shipborne communication equipment currently in service and under development. It can significantly improve the information transmission capabilities between sea, air, and space terminals in terms of transmission signal strength, receiving sensitivity, communication bandwidth, and bit error rate.

[0028] In one embodiment of the present invention, an azimuth motor 8 and a pitch motor 9 are fixedly mounted on the support frame 4 .

[0029] The working principle of the above technology is: the azimuth motor 8 is used to control the rotation movement of the support frame 4 in the horizontal azimuth, and the pitch motor 9 is used to control the pitch movement of the feed source 7 on the feed source track 6. The two together realize the movement control of the feed source on the surface of the hemispherical Luneburg lens 1.

[0030] In one embodiment of the present invention, it also includes a base 10, on which a lifting motor 11 is fixedly installed, on which a lifting pump 12 is fixedly installed, and the output end of the lifting pump 12 is fixedly connected to a supporting platform 13, and the supporting platform 13 is fixedly connected to the end of the supporting shaft 3 away from the reflective bottom plate 2.

[0031] In this solution, the height of the support platform 13 can be adjusted through the lifting motor 11 and the lifting pump 12, thereby adjusting the height of the Luneburg lens 1.

[0032] In one embodiment of the present invention, the Luneburg lens 1 is provided with an array of through holes 101 axially penetrating the Luneburg lens 1. The Luneburg lens 1 is provided with seven layers, and each layer of Luneburg lenses 1 is sequentially connected. The dielectric constant and thickness of each layer are shown in the following figure:

[0033] Table 1 Dielectric constants and thickness of each layer of the non-uniform 7-layer Luneburg lens

[0034]

[0035]

[0036] Where ε is the dielectric constant, r i is the thickness of the i-th layer, and R is the radius of the Luneburg lens 1.

[0037] This scheme adopts a columnar vertically open metamaterial crystal unit structure to achieve multi-layer non-uniform equivalent dielectric constants, and designs seven-layer hemispherical Luneburg lenses with diameters of 240 mm and 552 mm (the dielectric constants and thicknesses of each layer are detailed in Table 1), achieving simulation gains of 28.5 dBi and 33.8 dBi, respectively.

[0038] In one embodiment of the present invention, the Luneburg lens 1 is prepared by 3D printing, and its preparation process includes the following steps: using micron-sized spherical granular polystyrene powder as the printing material, adopting selective laser sintering technology, and using a computer to accurately control the laser beam to scan the powder surface, so that the plastic powder is sintered or melted and then re-solidified to form a solid sheet in the shape of the model cross-section, and by continuously repeating the cycle of "lowering the workbench → roller re-spreading powder → laser scanning and sintering", the solid sheets are accumulated layer by layer into a three-dimensional workpiece, and then the molded workpiece is immersed in paraffin liquid to increase the structural strength.

[0039] The above process breaks through the difficulty of 3D printing of large-size Luneburg lenses, ensuring their electrical performance and mechanical strength. This method was used to process a hemispherical Luneburg lens with a diameter of 552mm. The test results showed that the gain reached 31.8dBi at 12.5GHz. This process uses polystyrene as the material, adopts a multi-layer stacking structure, laser sintering 3D printing and paraffin infiltration technology, so that the processed lens antenna has good heat and impact resistance, extremely high mechanical strength, excellent corrosion resistance, easy maintenance, pollution resistance and other characteristics. It greatly improves the stability of the antenna and reduces the maintenance and replacement costs.

[0040] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A broadband multi-beam hemispherical Luneburg lens antenna, comprising a Luneburg lens arranged in a hemispherical shape, characterized in that: The Luneburg lens is fixedly mounted on the emitting base plate, the reflecting base plate is coaxially fixedly connected with a support shaft away from the Luneburg lens end, a plurality of support frames are circumferentially arranged on the support shaft with the axis of the support shaft as the center, the plurality of support frames are axially staggered along the support shaft, a main shaft that passes through the Luneburg lens along the axis of the Luneburg lens is fixedly arranged on the reflecting base plate, a feed track arranged along the curved surface of the Luneburg lens is fixedly connected between the main shaft and the support frame, and a feed source that can move along the feed track is arranged on the feed track.

2. The broadband multi-beam hemispherical Luneburg lens antenna according to claim 1, characterized in that: The support frame is fixedly mounted with an azimuth motor for controlling the support frame to rotate and move along the circumference of the support axis, and a pitch motor for controlling the feed source to move along the feed source track.

3. The broadband multi-beam hemispherical Luneburg lens antenna according to claim 2, characterized in that: It also includes a base, on which a lifting motor is fixedly installed, on which a lifting pump is fixedly installed, and an output end of the lifting pump is fixedly connected to a supporting platform, and the supporting platform is fixedly connected to the end of the supporting shaft away from the reflective bottom plate.

4. The broadband multi-beam hemispherical Luneburg lens antenna according to claim 3, characterized in that: The upper array of the Luneburg lenses is provided with through holes which axially penetrate the Luneburg lenses.

5. The broadband multi-beam hemispherical Luneburg lens antenna according to claim 4, characterized in that: The Luneburg lenses are arranged in multiple layers, each layer of Luneburg lenses is arranged in a hemispherical shape, and each layer of Luneburg lenses is provided with a groove for covering the previous layer of Luneburg lenses, so that each layer of Luneburg lenses is nested in sequence.

6. The broadband multi-beam hemispherical Luneburg lens antenna according to claim 5, characterized in that: The Luneburg lens is prepared by 3D printing, and its preparation process includes the following steps: using micron-sized spherical granular polystyrene powder as the printing material, adopting selective laser sintering technology, and using a computer to accurately control the laser beam to scan the powder surface, so that the plastic powder is sintered or melted and then re-solidified to form a solid layer in the shape of the model cross-section, and the solid layers are accumulated layer by layer to form a molded workpiece, and then the molded workpiece is immersed in paraffin liquid for a preset time and then taken out.

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