3D printing circularly polarized lens antenna

Abstract

The invention provides a 3D printed circularly polarized lens antenna, which relates to the technical field of communication, and comprises a plurality of inclined fan-shaped flat plates and a central circular connection structure, the plurality of inclined fan-shaped flat plates are rotationally arranged around the central axis of the lens; the inclination angle of the fan-shaped flat plate is 60 degrees, and a corner cutting structure is arranged on the edge of the fan-shaped flat plate. A novel lens structure is used, and the multi-beam coverage problem of directional circular polarization radiation in a millimeter wave communication system is solved.

Description

Technical Field

[0001] The present invention belongs to the field of communication technologies, and particularly relates to a 3D printed circularly polarized lens antenna. Background Art

[0002] Millimeter wave (mmWave), as an important frequency band of the new generation of wireless communication technologies, has become one of the core technologies of the fifth-generation (5G) and future sixth-generation (6G) communication systems due to its characteristics of high bandwidth, low latency, and high rate. Millimeter wave communication uses a high-frequency band of 30 to 300 GHz, with rich spectrum resources. However, in the high-frequency transmission process, it is easily restricted by path loss, scattering, and multipath effects, which poses higher requirements for antenna design. Circularly polarized antennas have become one of the key components in millimeter wave communication systems due to their excellent anti-interference ability and good transmission stability. At the same time, with the rapid development of 3D printing technology, its application in antenna design and manufacturing has brought important changes to traditional processes.

[0003] Currently, the design of circularly polarized antennas generally adopts two main technical solutions: one is based on traditional microstrip antenna technology, and circular polarization is achieved through mode perturbation or by using a special feeding network; the other is to use lens antenna technology, and the beam is focused and polarization is adjusted by introducing an electromagnetic lens structure. The implementation of these two solutions faces different technical challenges in the millimeter wave band. Microstrip antennas usually have high design flexibility, but their efficiency is limited by the substrate material loss and metallization process, and it is difficult to achieve both high gain and low loss in the millimeter wave band. The lens antenna, on the other hand, realizes beam forming and polarization conversion through the optimized design of high dielectric constant materials or geometric shapes. Although it has higher gain and scanning performance, traditional manufacturing processes are difficult to meet the precise machining requirements of complex three-dimensional structures.

[0004] The introduction of 3D printing technology provides a new solution for the design of millimeter-wave circularly polarized antennas. Compared with traditional manufacturing methods, 3D printing technology can quickly and precisely process complex three-dimensional structures and support low-cost, small-batch personalized customization. This technology is particularly suitable for the research and development and manufacturing of millimeter-wave lens antennas. On the one hand, 3D printing technology can achieve efficient regulation of electromagnetic waves by precisely controlling the distribution of the dielectric constant of materials; on the other hand, its highly flexible forming process can manufacture lenses with complex curved surface structures, significantly improving the radiation performance of antennas. Specifically, for the design of circularly polarized lens antennas based on 3D printing, the following technical path is usually adopted: First, optimize the geometric shape and material distribution of the lens through numerical simulation to achieve efficient radiation of circularly polarized beams; second, use 3D printing technology to manufacture the main body of the lens, and common materials include photosensitive resin, nylon, and high-performance dielectric materials; finally, verify the key performance such as the gain, axial ratio, and radiation pattern of the antenna through experiments. Compared with traditional processes, this technology shows excellent performance in the millimeter-wave band and significantly reduces the design and manufacturing costs. Therefore, the application of 3D printing technology in the field of millimeter-wave circularly polarized lens antennas not only provides new ideas for antenna performance optimization but also provides a technical foundation for the development of future millimeter-wave communication systems.

[0005] The 3D-printed circularly polarized lens antenna in the millimeter-wave band combines millimeter-wave communication, circularly polarized antennas, and 3D printing technology, providing an innovative solution for efficient antenna design. However, the existing technologies still face many deficiencies and challenges in practical applications, mainly reflected in aspects such as circular polarization bandwidth, feeding method, and lens volume. First of all, the circular polarization bandwidth in the millimeter-wave band needs to be further broadened. The design of existing circularly polarized lens antennas mostly achieves polarization conversion through geometric shape optimization or material property adjustment, but their circular polarization performance is usually limited to a relatively narrow frequency band range. This limitation is particularly prominent under the requirements of high data rate and multi-band communication. Especially in millimeter-wave communication, broadband circularly polarized antennas can better adapt to complex channel environments and improve the reliability of the system, while the existing designs cannot maintain excellent axial ratio performance and high gain simultaneously in a wide frequency range. Secondly, the feeding method of the lens antenna is relatively complex and urgently needs to be further simplified. Millimeter-wave lens antennas usually need to be paired with high-performance feed antennas to form a complete system, but the existing feed designs are complex, with bulky structures, and their polarization performance will affect the overall radiation effect of the lens antenna. An overly complex feeding network not only increases the difficulty of system design and manufacturing cost but also places higher requirements on assembly accuracy, easily leading to feed deviation and thus affecting the overall antenna performance. How to simplify the feeding structure while maintaining high efficiency is an urgent problem for the current technology. Thirdly, the volume of the lens antenna needs to be further reduced. An important development trend of millimeter-wave communication systems is the miniaturization and lightweight of devices. However, existing lens antennas mostly use large-sized geometric structures to achieve beam focusing and polarization conversion, which not only increases the volume and weight of the antenna but also limits its application in portable devices and compact systems. At the same time, large-sized lenses may face installation difficulties and reliability issues in complex environments. Therefore, how to achieve miniaturization and low-profile design of the lens through structural optimization and material improvement is an important direction to improve its practicality.

[0006] In summary, the 3D-printed circularly polarized lens antenna in the millimeter-wave band still faces important technical challenges in aspects such as broadening the circular polarization bandwidth, simplifying the feeding method, and reducing the lens volume. Future research needs to focus on broadband design methods, efficient feeding structures, and optimization of miniaturized lenses, as well as the improvement of 3D printing processes and material properties, to promote the wide application and development of this technology in the field of millimeter-wave communication. Summary of the Invention

[0007] Aiming at the above deficiencies in the existing technology, a 3D-printed circularly polarized lens antenna provided by the present invention solves the problem of multi-beam coverage of directional circular polarization radiation in a millimeter-wave communication system.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A 3D printed circularly polarized lens antenna includes a plurality of inclined fan-shaped flat plates and a circular connection structure at the center; the plurality of inclined fan-shaped flat plates are arranged in a rotational pattern around the central axis of the lens;

[0009] The inclination angle of the fan-shaped flat plate is 60 degrees, and a chamfer structure is provided at the edge of the fan-shaped flat plate.

[0010] Further, the material of the 3D printed circularly polarized lens antenna is polylactic acid, which is made by 3D printing technology.

[0011] Furthermore, when the linearly polarized wave is incident along any inclined fan-shaped flat plate, it will simultaneously excite the surface wave mode of the dielectric flat plate, providing two orthogonal polarization components for circular polarization radiation;

[0012] The volume of the air gap between the plurality of inclined fan-shaped flat plates increases outward along the radial direction of the lens.

[0013] Furthermore, the 3D printed circularly polarized lens antenna has rotational symmetry.

[0014] Furthermore, the fan-shaped flat plate with a chamfer structure serves as a circular polarizer.

[0015] Advantages of the present invention:

[0016] (1) The present invention provides a novel 3D printed circularly polarized lens antenna, which can achieve excellent radiation performance in the millimeter wave band, including high gain beam, multi-beam radiation and circular polarization radiation. The lens is composed of a plurality of inclined fan-shaped structures, which are arranged in a rotational pattern around the central axis of the lens, enabling the lens to have the ability to convert linearly polarized waves into left-handed circularly polarized waves. Due to the rotational symmetry of the lens structure around its center, high-consistency circularly polarized multi-beam radiation can be achieved. The lens achieves a peak gain of 16.3 dBi and an axial ratio better than 3 dB in the frequency range of 30.4 GHz to 40.3 GHz.

[0017] (2) The present invention proposes a novel 3D printed dielectric lens structure, which realizes high-gain radiation of circular polarization based on the surface wave mode of the dielectric flat waveguide and the principle of gradually changing equivalent dielectric constant. Due to the central symmetry of the lens, excellent multi-beam radiation is also achieved.

[0018] (3) In terms of the working bandwidth, due to the use of a low dielectric constant material, the S11 parameter of the lens antenna is lower than -15 dB in the range of 26 GHz to 44 GHz, having excellent impedance bandwidth performance; due to the use of a chamfered inclined fan-shaped flat plate as a circular polarizer, the axial ratio of the lens antenna is lower than 3 dB in the range of 30.4 GHz to 40.3 GHz, realizing broadband circular polarization radiation.

[0019] (4) In terms of the multi-beam radiation performance, due to the rotationally symmetric characteristic of the lens antenna, beams corresponding to corresponding angles can be obtained when excited from any sector-shaped flat plate, and the consistency between different beams is good, with a scanning loss of only 0.33 dB.

[0020] (5) In terms of the antenna gain, due to the gradually changing equivalent refractive index of this lens antenna, the electromagnetic wave energy can be effectively radiated in a directional manner. The peak gain of the antenna within the circular polarization operating frequency band is greater than 15 dB, and it has a maximum peak gain of 16.3 dB. Description of the Drawings

[0021] Figure 1 Schematic diagram of the main structure of the 3D printed circularly polarized lens antenna of the present invention.

[0022] Figure 2 Schematic diagram of the support structure of the 3D printed circularly polarized lens antenna of the present invention.

[0023] Figure 3 S11 parameter of the 3D printed circularly polarized lens antenna of the present invention.

[0024] Figure 4 Axial ratio parameter of the 3D printed circularly polarized lens antenna of the present invention.

[0025] Figure 5 Multi-beam pattern of the 3D printed circularly polarized lens antenna of the present invention.

[0026] Figure 6 Schematic diagram of the peak gain curve of the 3D printed circularly polarized lens antenna of the present invention.

[0027] Figure 7 Schematic diagram of the influence of the inclination angle and length of the sector-shaped flat plate on the circular polarization axial ratio.

[0028] Figure 8 Another schematic diagram of the influence of the inclination angle and length of the sector-shaped flat plate on the circular polarization axial ratio.

[0029] Among them, 1 - sector-shaped flat plate, 2 - circular connection structure, 3 - chamfer structure, 4 - rectangular waveguide, 5 - support structure. Detailed Embodiments

[0030] The following describes the detailed embodiments of the present invention to facilitate those skilled in the art of the present technology to understand the present invention. However, it should be clear that the present invention is not limited to the scope of the detailed embodiments. For those of ordinary skill in the art of the present technology, as long as various changes are within the spirit and scope of the present invention defined and determined by the appended claims, these changes are obvious, and all inventions and creations using the concept of the present invention are within the scope of protection.

[0031] Embodiment

[0032] As Figure 1 shown, the present invention provides a 3D printed circularly polarized lens antenna, which includes a plurality of inclined sector flat plates 1 and a central circular connection structure 2; the plurality of inclined sector flat plates 1 are arranged in a rotational arrangement around the central axis of the lens; the inclination angle of the sector flat plate 1 is 60 degrees, and a chamfer structure 3 is provided at the edge of the sector flat plate 1. The material of the 3D printed circularly polarized lens antenna is polylactic acid, which is made by 3D printing technology. When a linearly polarized wave is incident along any inclined sector flat plate 1, the surface wave mode of the dielectric flat plate will be excited simultaneously, providing two orthogonal polarization components for circular polarization radiation; the volume of the air gap between the plurality of inclined sector flat plates 1 increases outward along the radial direction of the lens. The 3D printed circularly polarized lens antenna has rotational symmetry. The sector flat plate 1 with the chamfer structure 3 serves as a circular polarizer.

[0033] In this embodiment, the present invention proposes a novel 3D printed dielectric lens structure. First, in terms of structural design, the lens antenna is composed of 24 inclined sector flat plates 1 and a central circular connection structure 2. Among them, the inclination angle of the sector flat plate 1 is 60 degrees, and there is a chamfer structure 3 at the edge of the sector flat plate 1. The material of this dielectric lens antenna is polylactic acid (PLA), which is made by 3D printing technology. Secondly, in terms of working principle, the present invention uses the surface wave mode of the dielectric flat plate waveguide and the principle of gradual change of the equivalent dielectric constant. On the one hand, when a linearly polarized wave is incident along any inclined sector flat plate 1, the TE and TM surface wave modes of the dielectric flat plate will be excited simultaneously, providing two orthogonal polarization components for circular polarization radiation; on the other hand, the volume of the air gap between the plurality of sector flat plates 1 gradually increases outward along the radial direction of the lens, so the equivalent dielectric constant on this lens antenna also gradually decreases outward along the radial direction, changing the propagation speed of the electromagnetic wave at different positions on the lens antenna, and finally converging the diffused electromagnetic wave energy into a directional radiation. To illustrate the influence of the structure of the sector flat plate 1 on the circular polarization radiation performance of the antenna, Figure 7 And Figure 8 respectively show the influence of the inclination angle and length of the sector flat plate 1 on the circular polarization axial ratio. In Figure 7 , when the inclination angle of the sector flat plate 1 increases, the circular polarization operating frequency band of the antenna gradually shifts to higher frequencies, because the energy obtained by the two polarization components changes with the inclination angle. In Figure 8 , as the height of the sector flat plate 1 increases, the axial ratio of the antenna first decreases and then increases, and there is an optimal state, because the electromagnetic mode of the polarization component parallel to the flat plate changes with the increase of the flat plate length, thereby affecting the synthesis of circularly polarized waves. By combining these two variables of the inclination angle and length, the best circular polarization performance can be optimized within the millimeter wave band.

[0034] In a specific embodiment, as Figure 2 shown, by using a plurality of rectangular waveguides 4 with a cross-sectional size of 7.112 mm × 7.112 mm to excite the lens antenna from different angles, circularly polarized high-gain multi-beam radiation can be obtained. The rectangular waveguides 4 are installed on the lens which is installed on the support structure 5.

[0035] In this embodiment, in terms of the working bandwidth, due to the use of a low-dielectric constant material, the S11 parameter of the lens antenna is lower than -15 dB within the range of 26 GHz to 44 GHz, having excellent impedance bandwidth performance, as Figure 3 shown; due to the use of a beveled inclined sector flat plate as a circular polarizer, the axial ratio of the lens antenna is lower than 3 dB within the range of 30.4 GHz to 40.3 GHz, achieving broadband circularly polarized radiation, as Figure 4 shown.

[0036] In this embodiment, in terms of the multi-beam radiation performance, due to the rotationally symmetric characteristic of the lens antenna, a beam corresponding to a corresponding angle can be obtained when excited from any sector flat plate, and the consistency between different beams is good, and the scanning loss is only 0.33 dB, as Figure 5 shown.

[0037] In this embodiment, in terms of the antenna gain, due to the gradually changing equivalent refractive index of the lens antenna, the electromagnetic wave energy can be effectively radiated in a directed manner. The peak gain of the antenna within the circularly polarized working frequency band is greater than 15 dB, and it has a maximum peak gain of 16.3 dB, as Figure 6 shown.

Claims

1. A 3D printed circularly polarized lens antenna, characterized in that, It includes a plurality of inclined fan-shaped flat plates (1) and a central circular connection structure (2); the plurality of inclined fan-shaped flat plates (1) are arranged around the central axis of the lens in a rotational manner; The inclination angle of the fan-shaped flat plate (1) is 60 degrees, and a chamfer structure (3) is provided at the edge of the fan-shaped flat plate (1).

2. The 3D printed circularly polarized lens antenna according to claim 1, wherein The material of the 3D printed circularly polarized lens antenna is polylactic acid, which is made by 3D printing technology.

3. The 3D printed circularly polarized lens antenna according to claim 1, wherein When a linearly polarized wave is incident along any inclined fan-shaped flat plate (1), it will simultaneously excite the surface wave mode of the dielectric flat plate to provide two orthogonal polarization components for circular polarization radiation; The volume of the air gap between the plurality of inclined fan-shaped flat plates (1) gradually increases outward along the radial direction of the lens.

4. The 3D printed circularly polarized lens antenna according to claim 1, characterized in that, The 3D printed circularly polarized lens antenna has rotational symmetry.

5. The 3D printed circularly polarized lens antenna according to claim 1, characterized in that The fan-shaped flat plate (1) with a chamfer structure (3) serves as a circular polarizer.

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