Antenna and beamforming method

Abstract

The objective of the present invention is to provide an antenna with which the speed of beam forming can be increased. This antenna comprises: a metasurface having an opening portion for accepting electromagnetic waves; and a MEMS mechanism for changing the shape of the opening portion of the metasurface by operating a movable member with respect to the opening portion.

Description

[Technical field]

[0001] The present invention relates to an antenna and a beamforming method. [Background technology]

[0002] Antennas that perform beam forming using liquid crystal are known (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2014-531843 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above antenna, there is a risk that the beamforming speed will be slowed down due to the slow operation speed of the liquid crystal. An object of the present disclosure is to provide an antenna and a beamforming method that solves the above-mentioned problems. [Means for solving the problem]

[0005] One aspect of the present invention for achieving the above object is to a metasurface having an opening for receiving an electromagnetic wave; a MEMS mechanism that changes the shape of an opening in the metasurface by moving a movable member relative to the opening; An antenna comprising: It is. One aspect of the present invention for achieving the above object is to a MEMS mechanism operates a movable member relative to an opening in the metasurface to change the shape of the opening, thereby changing a resonance condition of the opening and the movable member, and changing an electromagnetic radiation pattern radiated from the opening; Beamforming Method may be also possible. Effect of the Invention

[0006] According to the present disclosure, it is possible to provide an antenna and a beamforming method that solves the above-mentioned problems. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of an antenna according to an embodiment of the present invention. [Diagram 2] 11A to 11C are diagrams illustrating the operation of a movable member. [Diagram 3] FIG. 13 is a diagram showing an example of a movable member that is combined with a plurality of members. [Figure 4] 13A and 13B are diagrams showing a configuration for moving a movable member in a direction perpendicular to an opening portion. [Diagram 5] 1A and 1B are schematic diagrams showing a side view of a configuration for three-dimensionally displacing a movable member. [Figure 6] 1 is a schematic diagram showing the top surface of a configuration for three-dimensionally displacing a movable member. FIG. [Figure 7] 13 is a diagram showing a configuration in which the opening shape of an opening is changed by a cantilever. FIG. [Figure 8] FIG. 1 is a diagram showing a schematic configuration of an antenna according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] EMBODIMENT 1 Hereinafter, the present embodiment will be described with reference to the drawings. Fig. 1 is a diagram showing a schematic configuration of an antenna according to the present embodiment. Antenna 1 according to the present embodiment includes traveling-wave tube 2 through which electromagnetic waves travel, metasurface 3 provided on traveling-wave tube 2, movable member 4 provided on metasurface 3, and MEMS mechanism 5 for operating movable member 4.

[0009] The metasurface 3 is formed in a multi-layer structure, and at the top thereof, at least one opening 31 for receiving electromagnetic waves is formed. A plurality of openings are formed in the metasurface 3, for example, in an array shape. Note that, for ease of understanding, only the opening 31 is shown in FIG. 1, but in reality, the multi-layer structure of the metasurface 3 exists below it.

[0010] At least one movable member 4 that moves relative to the opening 31 is provided in the opening 31 of the metasurface 3. The movable member 4 is made of a metal or the like that affects electromagnetic waves. The movable member 4 is provided with a MEMS mechanism 5 that operates the movable member 4.

[0011] Here, a beamforming method according to this embodiment will be described. The MEMS mechanism 5 changes the shape of the opening 31 by operating the movable member 4 relative to the opening 31 of the metasurface 3. This changes the resonance conditions of the opening 31 and the movable member 4, and changes the radiation pattern of the electromagnetic waves radiated from the opening 31, thereby enabling beamforming.

[0012] More specifically, the MEMS mechanism 5 of each opening 31 changes the opening shape of each opening 31 and changes the resonance conditions of each opening 31 and each movable member 4, thereby controlling the intensity of the electromagnetic waves emitted from each opening 31 and performing beamforming.

[0013] For example, the shape of the opening 31, the number of openings 31, the shape of the movable members 4, the number of the movable members 4, the operation method of the movable members 4, and the like are determined by design in accordance with the desired electromagnetic radiation pattern.

[0014] MEMS (Micro Electro Mechanical Systems) mechanisms are devices with micron-level structures that integrate mechanical components such as sensors, actuators, and electronic circuits on semiconductor silicon substrates, glass substrates, organic materials, etc. As frequencies increase, finer wires are required, so it is advantageous to use such fine MEMS mechanisms 5.

[0015] The MEMS mechanism 5 is driven by a TFT (thin-film-transistor) or the like. The MEMS mechanism 5 has a feature that it can move the movable member 4 minutely and at high speed. According to the antenna of this embodiment, the high-speed operation feature of the MEMS mechanism 5 is utilized to operate the movable member 4 at high speed to change the shape of the opening 31.

[0016] This makes it possible to increase the speed of beamforming by quickly changing the resonance conditions of the aperture 31 and the movable member 4 and quickly changing the electromagnetic radiation pattern radiated from the aperture 31. This enables a wide range of applications not only to satellite communications but also to fronthauls and the like that perform high-speed beamforming.

[0017] 2 is a diagram showing the operation of the movable member 4. The movable member 4 is provided in the opening 31 of the metasurface 3. The movable member 4 is provided so as to be movable in a direction parallel to the opening 31. The movable member 4 covers at least a part of the opening 31.

[0018] The MEMS mechanism 5 changes the shape of the opening 31 by moving the movable member 4 in a direction parallel to the opening 31, thereby changing the resonance condition of the movable member 4 and the opening 31. The MEMS mechanism 5 moves the movable member 4 in a direction parallel to the opening 31 by using, for example, electrostatic force.

[0019] 2, each opening 31 is provided with a pair of movable members 4, but may be provided with only one movable member 4. Each MEMS mechanism 5 may move both of the pair of movable members 4, or may move only one of the movable members 4.

[0020] 3 is a diagram showing an example of a movable member 4 that is combined with a plurality of members. Each movable member 4 may be configured by combining a plurality of members. For example, as shown in FIG. 3, each movable member 4 may have a first movable part 41 and a second movable part 42 that moves relatively in a parallel direction to the first movable part 41. The MEMS mechanism 5 moves the first and second movable parts 41, 42 in a parallel direction to the opening 31. This allows the opening shape of the opening 31 to be changed in a more diverse manner.

[0021] Here, the MEMS mechanism 5 displaces the movable member 4 only by about several μm, but the metasurface 3 is sensitive to changes in shape. Therefore, the resonance conditions of the movable member 4 and the opening 31 can be effectively changed by only a small displacement of the movable member 4.

[0022] As described above, MEMS mechanism 5 slightly displaces movable member 4 in a direction parallel to opening 31, thereby switching between a radiation state in which electromagnetic waves are radiated outward from within traveling-wave tube 2 through opening 31 in metasurface 3, and a non-radiation state in which electromagnetic waves are not radiated outward from within traveling-wave tube 2 through opening 31 in metasurface 3.

[0023] 4 is a diagram showing a configuration in which the movable member 4 is moved in a direction perpendicular to the opening. As shown in FIG. 4, the MEMS mechanism 5 may change the shape of the opening 31 by moving the movable member 4 in a direction perpendicular to the opening 31, thereby changing the resonance conditions of the movable member 4 and the opening 31.

[0024] MEMS mechanism 5, for example, by slightly displacing movable member 4 of opening 31 in metasurface 3 vertically upward, switches from a non-radiation state (1), in which electromagnetic waves are not radiated from within traveling-wave tube 2 through opening 31 in metasurface 3, to a radiation state (2), in which electromagnetic waves are radiated from within traveling-wave tube 2 through opening 31 in metasurface 3.

[0025] Fig. 5 is a schematic diagram showing a side view of the configuration for three-dimensionally displacing the movable member. Fig. 6 is a schematic diagram showing a top view of the configuration for three-dimensionally displacing the movable member. The MEMS mechanism 5 may change the shape of the opening 31 by three-dimensionally displacing the movable member 4, thereby changing the resonance conditions of the movable member 4 and the opening 31.

[0026] The movable member 4 has a first movable member 43 provided below the opening 31 of the metasurface 3 and covering at least a portion of the opening 31 from below, and a second movable member 44 provided above the opening 31 and covering at least a portion of the opening 31 from above.

[0027] The MEMS mechanism 5 changes the opening shape of the opening 31 in three dimensions by moving the first and second movable members 43, 44 in a direction parallel to the opening 31, thereby changing the resonance conditions of the first and second movable members 43, 44 and the opening 31.

[0028] The MEMS mechanism 5 may change the opening shape of the opening 31 by moving the first and second movable members 43, 44 in a direction perpendicular to the opening 31, thereby changing the resonance conditions of the first and second movable members 43, 44 and the opening 31. Furthermore, the MEMS mechanism 5 may change the opening shape of the opening 31 by moving the first and second movable members 43, 44 in a direction parallel to and perpendicular to the opening 31, thereby changing the resonance conditions of the first and second movable members 43, 44 and the opening 31.

[0029] 7 is a diagram showing a configuration in which a cantilever is used to change the shape of the opening 31. The movable member 4 is provided in the opening 31 of the metasurface 3 and may have a cantilever 45 that covers at least a part of the opening 31. The MEMS mechanism 5 swings the cantilever 45 to change the shape of the opening 31 and change the resonance conditions of the cantilever 45 and the opening 31. The MEMS mechanism 5 uses the principle of leverage of the cantilever 45 to increase the travel distance of the movable part, thereby more effectively changing the shape of the opening 31.

[0030] EMBODIMENT 2 8 is a diagram showing a schematic configuration of an antenna according to this embodiment. Antenna 20 according to this embodiment may further include a liquid crystal layer 6 provided on traveling-wave tube 2 in addition to the configuration of the above embodiment. Metasurface 3 may be provided on liquid crystal layer 6. For example, impedance matching may be performed by controlling the polarization of the liquid crystal in liquid crystal layer 6.

[0031] In this embodiment, rough phase modulation can be performed by controlling the liquid crystal layer 6. Furthermore, minute phase modulation can be performed by operating the movable member 4 with the MEMS mechanism 5 to change the opening shape of the opening 31. By performing such two-stage phase modulation, high-speed and high-precision beam forming can be performed.

[0032] The metasurface 3 according to the above embodiment is provided on the traveling wave tube 2, but is not limited thereto. For example, the metasurface 3 may be provided on a highly directional antenna. More specifically, a plurality of highly directional small antennas may be arranged, and the metasurface 3 may be provided on the antennas. As described above, the shape of the opening 31 of the metasurface 3 may be controlled to perform high-speed beamforming on the electromagnetic waves from the highly directional antennas.

[0033] Although the antenna 1 according to the above embodiment is applied to a case where electromagnetic waves are transmitted, the present invention is not limited thereto, and the antenna 1 according to the present embodiment can also be applied to a case where electromagnetic waves are received.

[0034] In the above embodiment, an impedance matching layer for impedance matching may be provided between traveling-wave tube 2 and metasurface 3. The impedance matching layer is composed of, for example, a conductor whose resistance can be changed. This impedance matching layer makes it possible to easily achieve impedance matching. Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. This application claims priority based on Japanese Patent Application No. 2021-056223, filed on March 29, 2021, the disclosure of which is incorporated herein in its entirety. [Explanation of symbols]

[0035] 1 Antenna 2 traveling wave tube 3 Metasurface 4 Movable parts 5 MEMS mechanism 6 Liquid crystal layer 31 Opening 41 1st moving part 42 Second moving part 43 First movable member 44 Second movable member 45 Cantilever

Claims

1. a metasurface having an opening for receiving an electromagnetic wave; a MEMS mechanism that changes the shape of an opening in the metasurface by moving a movable member relative to the opening; a traveling wave tube in which the electromagnetic wave travels; Equipped with the metasurface is provided on the traveling wave tube; an impedance matching layer for performing impedance matching is provided between the traveling wave tube and the metasurface; antenna.

2. 2. The antenna of claim 1, the movable member is provided in an opening of the metasurface and covers at least a portion of the opening; The MEMS mechanism changes an opening shape of the opening by moving the movable member in a direction parallel to the opening, thereby changing a resonance condition of the movable member and the opening.

3. A metasurface having an opening for receiving an electromagnetic wave; a MEMS mechanism that changes the shape of an opening in the metasurface by moving a movable member relative to the opening; Equipped with the movable member is provided in an opening of the metasurface and covers at least a portion of the opening; The MEMS mechanism changes an opening shape of the opening by moving the movable member in a direction perpendicular to the opening, thereby changing a resonance condition of the movable member and the opening.

4. 2. The antenna of claim 1, The movable member is a first movable member provided below the opening and covering at least a portion of the opening from below; a second movable member provided above the opening and covering at least a portion of the opening from above, The MEMS mechanism changes the opening shape of the opening by moving the first and second movable members in at least one of a direction parallel to and a direction perpendicular to the opening, thereby changing the resonance conditions of the movable members and the opening.

5. A metasurface having an opening for receiving an electromagnetic wave; a MEMS mechanism that changes the shape of an opening in the metasurface by moving a movable member relative to the opening; Equipped with the movable member has a cantilever provided in an opening of the metasurface and covering at least a portion of the opening; The MEMS mechanism changes the shape of the opening by swinging the cantilever, thereby changing the resonance condition of the movable member and the opening.

6. A metasurface having an opening for receiving an electromagnetic wave; a MEMS mechanism that changes the shape of an opening in the metasurface by moving a movable member relative to the opening; Equipped with The metasurface is disposed on a liquid crystal layer.

7. a MEMS mechanism that operates a movable member relative to an opening of a metasurface provided on a traveling wave tube through which an electromagnetic wave travels, thereby changing a shape of the opening, changing a resonance condition of the opening and the movable member, and changing an electromagnetic radiation pattern radiated from the opening; an impedance matching layer for performing impedance matching is provided between the traveling wave tube and the metasurface; Beamforming method.

8. A beamforming method in which a MEMS mechanism changes the shape of an opening in a metasurface having an opening that receives electromagnetic waves by operating a movable member relative to the opening, the movable member is provided in an opening of the metasurface and covers at least a portion of the opening; the MEMS mechanism changes an opening shape of the opening by moving the movable member in a direction perpendicular to the opening, thereby changing a resonance condition of the movable member and the opening. Beamforming method.

9. A beamforming method in which a MEMS mechanism changes the shape of an opening in a metasurface having an opening that receives electromagnetic waves by operating a movable member relative to the opening, the movable member has a cantilever provided in an opening of the metasurface and covering at least a portion of the opening; The MEMS mechanism changes the shape of the opening by swinging the cantilever, thereby changing the resonance condition of the movable member and the opening. Beamforming method.

10. A beamforming method in which a MEMS mechanism changes the shape of an opening in a metasurface having an opening that receives electromagnetic waves by operating a movable member relative to the opening, The metasurface is provided on a liquid crystal layer. Beamforming method.

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