阅读说明：本技术 一种产生具有梳状模态谱的涡旋波的双臂立体螺旋天线 (Double-arm three-dimensional spiral antenna for generating vortex wave with comb-shaped modal spectrum ) 是由 孙胜 刘童 阳棂均 于 2020-12-07 设计创作，主要内容包括：本发明公开了一种产生具有梳状模态谱的涡旋波的双臂立体螺旋天线,属于天线技术移动无线通信技术领域。该天线包括介质基板、覆盖于介质基板下表面的金属接地板、位于介质基板上表面的馈电结构、以及立体对称设置且半径逐渐增大的双臂立体螺旋金属线。本发明的螺旋金属线的半径线性增大,当螺旋周长是波长的整数倍时,该螺旋区域能产生对应的单一模态的涡旋波,而当螺旋周长不断变化时,会有相邻模式的存在,从而在单个频点上同时产生多个模态叠加的涡旋波,并且这些叠加的模态成等间隔分布,形成一个梳状的模态谱图,从而可以进一步地提升所产生波的自由度与复杂度。(The invention discloses a double-arm three-dimensional spiral antenna for generating vortex waves with comb-shaped modal spectrums, and belongs to the technical field of antenna technology mobile wireless communication. The antenna comprises a dielectric substrate, a metal grounding plate covering the lower surface of the dielectric substrate, a feed structure positioned on the upper surface of the dielectric substrate, and double-arm three-dimensional spiral metal wires which are arranged in a three-dimensional symmetrical mode and the radius of each double-arm three-dimensional spiral metal wire is gradually increased. The radius of the spiral metal wire is linearly increased, when the spiral perimeter is integral multiple of the wavelength, the spiral area can generate corresponding single-mode vortex waves, and when the spiral perimeter is continuously changed, adjacent modes exist, so that vortex waves overlapped by a plurality of modes are simultaneously generated on a single frequency point, and the overlapped modes are distributed at equal intervals to form a comb-shaped mode spectrogram, so that the degree of freedom and the complexity of the generated waves can be further improved.)

1. A double-arm three-dimensional spiral antenna for generating vortex waves with comb-shaped modal spectrums comprises a dielectric substrate (1), a metal grounding plate (2) covering the lower surface of the dielectric substrate, feed structures (5-8) located on the upper surface of the dielectric substrate, and double-arm three-dimensional spiral metal wires (3, 4);

the double-arm three-dimensional spiral metal wires (3 and 4) comprise two spiral metal wires which are arranged in a three-dimensional symmetrical mode and the radius of the two spiral metal wires is gradually increased;

the feed structures (5-8) comprise lumped ports (8) located in the centers of the dielectric substrates and two sections of microstrip lines symmetrically arranged on two sides of each lumped port (8); the phase difference of the output ports of the two sections of microstrip lines is 180 degrees, and the output ports are respectively connected with the starting ends of the two spiral metal lines.

2. The dual-arm three-dimensional helical antenna for generating vortex waves with comb-shaped modal spectrums according to claim 1, wherein the two sections of microstrip lines each comprise a straight microstrip line and a 90-degree arc microstrip line, wherein the starting end of the straight microstrip line is connected with the lumped port (8), and the other end of the straight microstrip line is connected with the 90-degree arc microstrip line.

3. A two-arm helical volumetric antenna for generating vortex waves having a comb mode spectrum according to claim 1, wherein the lumped port (8) is fed using a coaxial probe.

4. A bifilar solid helical antenna for generation of vortex waves having a comb mode spectrum as claimed in claim 1, wherein the radius of the helical wire is in the range 0.3mm to 2.5 mm.

Technical Field

The invention belongs to the technical field of antenna technology mobile wireless communication, and particularly relates to a single-port-fed double-arm three-dimensional helical antenna for generating vortex waves with comb-shaped modal spectrums, which can be used for simultaneously generating vortex electromagnetic waves overlapped by a plurality of modes under a single frequency point, and the overlapped modes are distributed at equal intervals to form a comb-shaped modal spectrum.

Background

In recent years, Orbital Angular Momentum (OAM) has been widely focused and studied by a great number of researchers due to the infinite modes and orthogonality between the modes. The angular momentum is composed of two components, the spin angular momentum and the orbital angular momentum, wherein the orbital angular momentum is related to the beam space phase distribution, and in 1992, Holland physicist Allen et al found that the wave front structure exp has a spiral typeThe optical beam of (a) analyzes the Orbital angular momentum characteristic of the vortex optical beam for the first time, and indicates that the OAM has infinite states in the term of "Orbital angular momentum of light and transformation of Laguerre Gaussian Laser modes" and different OAM states are orthogonal to each other, so that researchers believe that it can play a role in expanding the channel capacity in the radio frequency band wireless communication system. Electromagnetic waves carrying orbital angular momentum are called vortex waves. The corresponding vortex electromagnetic wave technology is used as a new multiplexing technology, so that the multi-channel signals can be coaxially transmitted at the same frequency, and the vortex electromagnetic wave technology is applied to the field of radio frequency and shows a wide prospect. In addition, it has considerable potential in radar target imaging.

In 2017, a single-arm Archimedes planar spiral antenna was used to generate eddy electromagnetic waves in the "Broadband Generation of Orbital Angular displacements Beams in RF registers" but the antenna volume was large. In 2019, the guo faithful group of subjects generated Vortex Electromagnetic Waves of Three modes at Three frequency points by using a single-arm Three-Dimensional Helical Antenna in "Generation of continuouslly Variable-Mode Vortex Electromagnetic Waves With Three-Dimensional reliable-Dimensional Antenna", but the Vortex Electromagnetic Waves excited at a single frequency point were of a single Mode. In 2018, the guo faithful topic group generated four modes of Vortex Electromagnetic Waves at a single frequency point by using four coaxially arranged Helical antennas in the Generation of Multi-mode Vortex Electromagnetic Waves Based on magnetic Antenna, but four feeding ports were required, and the feeding structure was complicated. The team then used bifilar helical antennas with a symmetrical structure to improve the mode purity of the generated vortex waves, but the modes generated were still single.

Disclosure of Invention

The invention aims to provide a double-arm three-dimensional spiral antenna for generating vortex waves with comb-shaped modal spectrums, which can simultaneously generate vortex electromagnetic waves with a plurality of superposed modes under a single frequency point to form a comb-shaped modal spectrum, thereby further improving the freedom degree and the complexity of the generated waves and being beneficial to further expanding the application prospect of the vortex waves.

The invention is realized by the following technical scheme:

a double-arm three-dimensional spiral antenna for generating vortex waves with comb-shaped modal spectrums comprises a dielectric substrate (1), a metal grounding plate (2) covering the lower surface of the dielectric substrate, feed structures (5-8) located on the upper surface of the dielectric substrate, and double-arm three-dimensional spiral metal wires (3, 4).

The double-arm three-dimensional spiral metal wires (3, 4) comprise two spiral metal wires which are arranged in a three-dimensional symmetrical mode and the radius of the two spiral metal wires is gradually increased.

The feed structures (5-8) comprise lumped ports (8) located in the centers of the dielectric substrates and two sections of microstrip lines symmetrically arranged on two sides of each lumped port (8); the phase difference of the output ports of the two sections of microstrip lines is 180 degrees, and the output ports are respectively connected with the starting ends of the two spiral metal lines.

Furthermore, the two sections of microstrip lines comprise a section of straight microstrip line and a section of 90-degree arc microstrip line, wherein the starting end of the straight microstrip line is connected with the lumped port (8), and the other end of the straight microstrip line is connected with the 90-degree arc microstrip line.

Further, the lumped port (8) may be fed using a coaxial probe.

Further, the radius range of the spiral metal wire is 0.3 mm-2.5 mm.

The innovation of the invention is that: two symmetrical spiral metal wires with unchanged pitch and gradually increased radius are adopted. The radius of the spiral metal wire is linearly increased, when the spiral perimeter is integral multiple of the wavelength, the spiral area can generate corresponding vortex waves in a single mode, and when the spiral perimeter is continuously changed, adjacent modes exist, so that vortex waves overlapped by multiple modes are simultaneously generated on a single frequency point, and the overlapped modes are distributed at equal intervals to form a comb-shaped mode spectrogram, so that the degree of freedom and the complexity of the generated waves can be further improved.

Drawings

Fig. 1 is a schematic structural diagram of the antenna of this embodiment.

In the figure: 1. the antenna comprises a dielectric substrate, 2 a metal grounding plate, 3 and 4 spiral metal wires, 5 and 6.90-degree arc microstrip lines, 7 linear microstrip lines and 8 lumped ports.

FIG. 2 is a graph showing the results of the electric field amplitude of the antenna according to the embodiment of the present invention.

Fig. 3 is a three-dimensional field strength pattern of an antenna according to an embodiment of the present invention.

FIG. 4 is a diagram showing the results of the vortex phase of the antenna according to the embodiment of the present invention.

FIG. 5 is a graph showing the results of the eddy wave electric field intensity of the antenna according to the embodiment of the present invention.

Fig. 6 is a normalized modal spectrum of an antenna according to an embodiment of the present invention.

Detailed Description

In order to further understand the present invention and make the objects, technical solutions and advantages of the present invention more apparent, a two-arm three-dimensional helical antenna for generating a vortex wave having a comb-shaped mode spectrum according to the present invention will be further fully described with reference to the accompanying drawings and embodiments. It should be noted that the embodiments described herein are only used for clearly explaining the present application and are not intended to limit the present application.

Referring to fig. 1, the two-arm three-dimensional helical antenna for generating a vortex wave with a comb-shaped modal spectrum comprises a dielectric substrate (1), a metal grounding plate (2) positioned on the lower surface of the dielectric substrate, feed structures (5-8) positioned on the upper surface of the dielectric substrate, and two-arm three-dimensional helical metal wires (3-4). The double-arm three-dimensional spiral metal wires (3-4) comprise two spiral metal wires which are arranged in a three-dimensional symmetrical mode and the radius of each spiral metal wire is gradually increased. The feed structures (5-8) comprise lumped ports (8) located in the centers of the dielectric substrates and two sections of microstrip lines arranged on two sides of the lumped ports (8) in a centrosymmetric mode; the output ports of the two microstrip lines are respectively connected with the initial parts of the two spiral metal wires, and the phase difference of the two output ports is 180 degrees.

The metal grounding plate (2) is a copper plate, and the thickness is 0.018 mm.

The used planar dielectric substrate (1) is made of Rogers RO4350, the relative dielectric constant is 3.66, the dielectric loss is 0.004, the radius is 50mm, and the thickness is 0.508 mm.

The thickness of two sections of microstrip lines is 0.018mm, and each section of microstrip line includes a section of straight line microstrip line and a section of 90-degree circular arc microstrip line. The line width of the linear microstrip line is 2mm, the outer radius of the arc microstrip line is 13.6mm, and the line width is 1 mm;

the spiral metal wires are concentrically and symmetrically arranged, the spiral radius is R, and the initial spiral radius is R₀The pitch is S, the average circumference of one turn is L, the number of turns is N, the radius of the spiral wire is a, and the radius of each turn is r. Wherein the radius a of the spiral metal wire is 0.5mm, and the initial spiral radius R₀13.1mm, the pitch S12 mm, the number N of turns 2, and the change r 6mm per radius of rotation, it is clear that L²＝(2πR)²+S²(ii) a The rotation direction of the double-arm spiral is the left-hand direction, and left-hand circular polarization vortex waves are generated.

In this embodiment, referring to fig. 2, as can be seen from the electric field amplitude of the near-field observation plane, the vortex beam generated by the present invention in fig. 2 has ideal circularly polarized electric field amplitude distribution and electric field phase distribution, and meets the design requirements of the orbital angular momentum reflective array antenna. And in the appointed area, the vortex waves of a plurality of modes are generated simultaneously on a single frequency point within the range of the divergence angle of the vortex wave beams.

Referring to fig. 3, in the present embodiment, the hollow pattern confirms that the generated electromagnetic wave has a vortex electromagnetic wave characteristic.

Referring to fig. 4, in this embodiment, the size of the observation plane is 200mm by 200mm, the observation position is 80mm away from the reflective array, and the obtained phase distribution diagram is shown in fig. 4, and a modal spectrogram can be obtained by normalization after sampling phase data.

Referring to fig. 5, in the present embodiment, the size of the observation plane is 200mm by 200mm, the observation position is 80mm away from the reflective array, and the obtained electric field intensity distribution graph is shown in fig. 5, and a modal spectrogram can be obtained by normalization after sampling electric field intensity data.

Referring to fig. 6, in the present embodiment, as can be seen from a normalized modal spectrum obtained after sampling amplitude phase data, vortex waves with the mode numbers of-2, 0, 2, and 4 are generated at the same time, the minimum spiral circumference of the two-arm three-dimensional helical antenna used in the embodiment is 2 times the wavelength, and the maximum spiral circumference is 4 times the wavelength, which is consistent with the result, a comb pattern of the modes is formed.

The above-mentioned embodiment is only one embodiment of the present invention, and the description is specific, but it should not be taken as limiting the scope of the invention. It should be noted that, for those skilled in the art, it is possible to make various changes and modifications to the present invention without departing from the gist of the present invention, and these changes and modifications are still within the scope of the present invention. Therefore, the specific protection scope of the present application shall be subject to the appended claims.