An orbital angular momentum microstrip array antenna using graphene

Abstract

The application discloses a kind of track angular momentum microstrip array antennas using graphene, including dielectric substrate, the upper and lower surface of the dielectric substrate is equipped with regular dodecagon graphene and metal patch, wherein metal patch is located in the midpoint of each side of regular dodecagon dielectric substrate, and a total of twelve metal patch units are circular array arrangement, with dielectric substrate center as symmetry center, it is rotationally symmetric distribution, and the rotation angle is 30 °, and a feed port is arranged in the center of the bottom side of metal patch.The antenna uses graphene material to achieve better impedance matching, and the structure is simple and convenient to process, and only needs to adjust the phase difference of feed to produce stable mode number l=0, 1, 2, 3, 4 track angular momentum vortex wave.

Description

Technical Field

[0001] This invention belongs to the field of orbital angular momentum antenna technology, and mainly relates to an orbital angular momentum microstrip array antenna using graphene. Background Technology

[0002] In the field of wireless communication, the spectrum available for allocation to wireless communication systems is becoming increasingly scarce. To cope with the explosive growth of mobile data services, we urgently need a new generation of wireless mobile communication technologies that are faster, more efficient, and smarter. For example, the core code division multiple access (CDMA) technology of the 3G era, the core frequency division multiple access (FDMA) technology of the 4G era, and the massive MIMO (Multiple Input Multiple Output) antenna technology of 5G—each generation of mobile communication systems has been accompanied by the emergence of these revolutionary technologies. Currently, the capacity of mobile communication systems is approaching the Shannon limit; therefore, how to improve the utilization rate of limited spectrum resources, ensure the accurate transmission of congestion information, and increase information transmission speed are all challenges that need to be addressed in the 5G era.

[0003] Orbital angular momentum (OAM) is a property present in electromagnetic waves that orthogonals multiple beams carrying different OAMs without interference. Utilizing this property, different channels can be distinguished by using different modes, providing new insights into multiplexing techniques in wireless communication. Theoretically, OAM electromagnetic vortex multiplexing can achieve unlimited transmission capacity on the same carrier frequency. This offers a possibility for solving the problems of spectrum scarcity and channel congestion.

[0004] Graphene is a two-dimensional material composed of carbon atoms, possessing unique electrical, optical, and mechanical properties. Its crystal structure is hexagonal, resembling a honeycomb. Furthermore, graphene exhibits excellent electrical and thermal conductivity, enabling rapid conduction of electrons and heat even under extremely small electric fields or temperature differences. Simultaneously, due to its unique electronic structure, graphene also displays some unusual electrical and optical effects, such as the quantum Hall effect and photovoltaic effect, which hold broad application prospects in novel electronic and optoelectronic devices. Summary of the Invention

[0005] The purpose of this invention is to provide a graphene microstrip array antenna capable of generating OAM. This antenna structure is easy to implement and easy to process and operate. Compared with traditional microstrip antennas, by increasing the number and arrangement of individual antennas, the array formed has a better bandwidth. The addition of graphene material also makes the antenna have better performance. Stable OAM vortex waves with mode numbers l=0, 1, 2, 3, 4 can be generated by changing the feed phase difference.

[0006] To achieve the above objectives, the solution of the present invention is:

[0007] An OAM microstrip array antenna using graphene, comprising a dielectric substrate;

[0008] The upper and lower surfaces of the dielectric substrate are respectively provided with a regular dodecagonal graphene layer that is rotationally symmetrical about the center of the dielectric substrate, and the two graphene layers are symmetrical about the dielectric substrate.

[0009] The upper and lower surfaces of the dielectric substrate are respectively provided with twelve metal patches arranged in a circular array and rotate symmetrical about the center of the dielectric substrate; the twelve metal patches on the upper / lower surfaces of the dielectric substrate correspond one-to-one with the twelve edges of the graphene layer, and the projection of any metal patch on the corresponding edge of the graphene layer is located at the center of that edge.

[0010] Each of the metal patches has a power supply port at the center of the edge furthest from the graphene layer, and the power supply port penetrates the dielectric substrate and the metal patches on its upper and lower surfaces.

[0011] Furthermore, the dielectric substrate is a regular dodecagonal Rogers RT5880 with an inscribed circle radius a = 120 mm and a thickness of 1.35 mm.

[0012] Furthermore, the metal patch on the upper surface of the dielectric substrate includes a rectangular patch and an L-shaped patch. The power supply port is located at the center of one side of the rectangular patch. One arm of the L-shaped patch is connected to the rectangular patch from the center of the opposite side of the rectangular patch. The L-shaped patch has a chamfer at the bend.

[0013] Furthermore, the other arm of the L-shaped patch is parallel to the edge of the corresponding graphene layer.

[0014] Furthermore, a groove extending into the rectangular patch is provided at the connection between the rectangular patch and the L-shaped patch.

[0015] Furthermore, the metal patch on the lower surface of the dielectric substrate is an L-shaped patch with a chamfered corner at the bend. One arm of the L-shaped patch is parallel to the edge of the corresponding graphene layer, and the other arm is perpendicular to the edge of the corresponding graphene layer.

[0016] Furthermore, the inscribed circle radius of the graphene layer is b = 78 mm.

[0017] Furthermore, the graphene has a chemical potential of 0.9 eV and a relaxation time of 1 ps.

[0018] Furthermore, the antenna employs lumped feeding. When a 0° phase difference is used to feed any one of the feed ports, a vortex wave with mode number l = 0 is generated. When continuous phase differences of 30°, 60°, 90° and 120° are used to feed, vortex waves with mode numbers l = 1, 2, 3 and 4 are generated, respectively.

[0019] Furthermore, the rotation angle of the rotational symmetry is 30°.

[0020] Compared with existing technologies, the significant advantages of this invention are: Compared with traditional OAM microstrip antennas that do not use graphene, this invention, by using graphene material, achieves better impedance matching, reduces port reflection loss, and more efficiently converts input power into radiated power, thus improving antenna performance. The antenna structure designed in this invention is simple, and mode changes are easy. Only the feed phase difference needs to be adjusted to generate OAM vortex waves with mode numbers l = 0, 1, 2, 3, and 4. It offers high operational controllability, and the generated vortex waves are stable, exhibiting distinct vortex wave characteristics. Attached Figure Description

[0021] Figure 1 This is a structural diagram of the upper surface of the antenna of the present invention;

[0022] Figure 2 This is a structural diagram of the lower surface of the antenna of the present invention;

[0023] Figure 3 This is a dimension diagram of the metal patch on the upper surface of the antenna of the present invention;

[0024] Figure 4 This is a dimension diagram of the metal patch on the lower surface of the antenna of the present invention;

[0025] Figure 5 The return loss S of an antenna using graphene material versus a metal antenna without graphene material is... 11 Parameter comparison chart;

[0026] Figure 6 The diagram shows the vortex wave phase diagrams at 5.9 GHz with different mode numbers, where (a) mode number l = 0; (b) mode number l = 1; (c) mode number l = 2; (d) mode number l = 3; and (e) mode number l = 4. Detailed Implementation

[0027] To demonstrate the advantages, technical solutions, and applications of this invention, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0028] like Figure 1 and Figure 2As shown, an embodiment of the present invention is an OAM microstrip array antenna using graphene. This structure consists of a graphene layer, metal patches, and a dielectric substrate. The dielectric substrate is a Rogers RT5880 with a regular dodecagonal shape, an inscribed circle radius a = 120 mm, and a thickness h = 1.35 mm. The graphene has a temperature of 300 K, a chemical potential of 0.9 eV, a relaxation time of 1 ps, and is also a regular dodecagonal shape, sharing a center with the dielectric substrate. It is located on the upper and lower surfaces of the dielectric substrate, with an inscribed circle radius b = 78 mm. The metal patches are located at the midpoint of each side of the dielectric substrate, on the upper and lower surfaces. Twelve metal patch units are arranged in a circular array, with the center of the regular dodecagonal dielectric substrate as the center of symmetry, exhibiting rotational symmetry with a rotation angle of 30°. A feed port is located at the center of the bottom edge of each metal patch. With an input impedance of 50 Ω, the impedance matching is good, effectively reducing the return loss of each coaxial feed port. The power of each feed port is set to 1 W. Metal patches located on the upper surface of the dielectric substrate, such as Figure 3 As shown, it consists of a rectangular patch and an L-shaped patch with a chamfered corner at the bend. The power supply port is located at the center of one side of the rectangular patch. One arm of the L-shaped patch connects to the rectangular patch from the center of the opposite side. A groove extending into the rectangular patch is formed at the connection between the rectangular and L-shaped patches. The specific dimensions are: W1 = 4mm, W2 = 4mm, W3 = 4mm, W4 = 0.9mm, L1 = 20mm, L2 = 12.02mm, L3 = 13.9mm, L4 = 9.5mm. A metal patch located on the lower surface of the dielectric substrate is shown below. Figure 4 As shown, this is an L-shaped patch with a chamfered corner at the bend. The specific dimensions are: W5 = 4mm, W6 = 4mm, L5 = 20mm, L6 = 12.02mm.

[0029] A feed port is located at the center of the bottom edge of each metal patch unit. After the structural design is completed, the feed port is fed with continuous phase difference to excite vortex waves. When the feed port is fed with a phase difference of 0°, a vortex wave with mode number l=0 is generated; when the phase difference is 30°, a vortex wave with mode number l=1 is generated; when the phase difference is 60°, a vortex wave with mode number l=2 is generated; when the phase difference is 90°, a vortex wave with mode number l=3 is generated; and when the phase difference is 120°, a vortex wave with mode number l=4 is generated.

[0030] A comparison was made between a metal antenna and an antenna using graphene. The reflection loss at feed port 1 was simulated, and the simulation yielded the reflection loss, S. 11 The parameters are Figure 5 As shown. At the center frequency, the SA of the graphene OAM antenna and the metal OAM antenna are different. 11 The value is -32dB, while the S of the graphene OAM antenna is... 11The reflection loss of the graphene OAM antenna at the center frequency is lower, reaching -44dB, a reduction of 12dB, resulting in superior performance.

[0031] Furthermore, wavefront phase distribution and mode number are the two most important indicators for generating OAM vortex waves. Figure 6 (a) is the phase diagram obtained by continuously feeding the feed port with an orthogonal phase difference of 0°. It can be observed that the spiral phase forms a ring with a central singularity. At this time, the corresponding mode number l = 0. It does not carry OAM and only has the same planar phase structure as the conventional plane electromagnetic wave, without the rotating spiral phase. Figure 6 (b) is the phase diagram obtained by continuously feeding the feed port with an orthogonal phase difference of 30°. Two clockwise spiral phase curves can be clearly observed in the figure. It can also be observed that the phase of the two curves has changed by 2π, with a central phase singularity, which corresponds to a vortex wave with mode number l=2. Figure 6 Figure (c) shows the phase diagram obtained by continuously orthogonally feeding the feed port with a phase difference of 60°. Three clockwise spiral phase curves can be observed in this diagram, corresponding to vortex waves with mode number l = 3, and the phase of these three spiral curves changes by 4π. Then, from... Figure 6 In diagrams (d) and (e), when continuous phase differences of 90° and 120° are applied to the feed port, three and four clockwise spiral phase curves are observed, respectively, with a central singularity. These correspond to vortex waves with mode numbers l = 3 and 4, respectively. At this point, the OAM beam phase changes by 6π and 8π, respectively. Therefore, the phase change of the OAM vortex wave differs by 2πl each time, indicating a stable state. In summary, the graphene-based OAM patch array antenna designed in this invention can generate OAM vortex waves with stable mode numbers l = 0, 1, 2, 3, and 4.

[0032] The above embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Any modifications and alterations made to the invention within the spirit and scope of the claims should be included within the protection scope of the invention.

Claims

1. A microstrip array antenna using graphene orbital angular momentum, characterized in that, Including dielectric substrate; The upper and lower surfaces of the dielectric substrate are respectively provided with a regular dodecagonal graphene layer that is rotationally symmetrical about the center of the dielectric substrate, and the two graphene layers are symmetrical about the dielectric substrate. The upper and lower surfaces of the dielectric substrate are respectively provided with twelve metal patches arranged in a circular array and rotate symmetrical about the center of the dielectric substrate; the twelve metal patches on the upper / lower surfaces of the dielectric substrate correspond one-to-one with the twelve edges of the graphene layer, and the projection of any metal patch on the corresponding edge of the graphene layer is located at the center of that edge. Each of the metal patches has a power supply port at the center of the edge furthest from the graphene layer, and the power supply port penetrates the dielectric substrate and the metal patches on its upper and lower surfaces.

2. The orbital angular momentum microstrip array antenna using graphene according to claim 1, characterized in that, The dielectric substrate is a regular dodecagonal Rogers RT5880 with an inscribed circle radius of a = 120 mm and a thickness of 1.35 mm.

3. The orbital angular momentum microstrip array antenna using graphene according to claim 1, characterized in that, The metal patch on the upper surface of the dielectric substrate includes a rectangular patch and an L-shaped patch. The power supply port is located at the center of one side of the rectangular patch. One arm of the L-shaped patch is connected to the rectangular patch from the center of the opposite side of the rectangular patch. The L-shaped patch has a chamfer at the bend.

4. The orbital angular momentum microstrip array antenna using graphene according to claim 3, characterized in that, The other arm of the L-shaped patch is parallel to the edge of the corresponding graphene layer.

5. The orbital angular momentum microstrip array antenna using graphene according to claim 3, characterized in that, The rectangular patch and the L-shaped patch are connected by a groove that extends into the rectangular patch.

6. The orbital angular momentum microstrip array antenna using graphene according to claim 1, characterized in that, The metal patch on the lower surface of the dielectric substrate is an L-shaped patch with a chamfered corner at the bend. One arm of the L-shaped patch is parallel to the edge of the corresponding graphene layer, and the other arm is perpendicular to the edge of the corresponding graphene layer.

7. The orbital angular momentum microstrip array antenna using graphene according to claim 1, characterized in that, The inscribed circle radius of the graphene layer is b = 78 mm.

8. The orbital angular momentum microstrip array antenna using graphene according to claim 1, characterized in that, The graphene has a chemical potential of 0.9 eV and a relaxation time of 1 ps.

9. A microstrip array antenna using graphene for orbital angular momentum according to claim 1, characterized in that, The antenna uses lumped feeding. When a 0° phase difference is used to feed any one of the feed ports, a vortex wave with mode number l = 0 is generated. When continuous phase differences of 30°, 60°, 90° and 120° are used to feed, vortex waves with mode numbers l = 1, 2, 3 and 4 are generated, respectively.

10. A microstrip array antenna using graphene for orbital angular momentum according to claim 1, characterized in that, The rotation angle of each rotational symmetry is 30°.

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