Electromagnetic wave control system

Abstract

In an electromagnetic wave control system (10), beamformers (31 to 36) of a beamformer unit (30) form electromagnetic waves incident from an antenna (20) into different beam shapes. Also, a drive device (40) rotationally drives the beamformer unit (30) to move the beamformers (31 to 36) relative to the antenna (20), and switches the beamformer among the beamformers (31 to 36) on which electromagnetic waves emitted by the antenna (20) are incident. For example, the drive device (40) switches the beamformer on which electromagnetic waves emitted by the antenna (20) are incident from the beamformer (31) to the beamformer (36) among the plurality of beamformers (31 to 36). Such a configuration allows for easy switching of the beam shape because the switching of the beam shape of the electromagnetic waves is performed automatically.

Description

Electromagnetic Wave Control System

[0001] The present invention relates to an electromagnetic wave control system.

[0002] Patent Document 1 discloses a beam former that shapes electromagnetic waves into a desired beam shape.

[0003] JP 2019-41138 A

[0004] In shaping the beam shape of an electromagnetic wave, it is desirable to appropriately switch the beam shape (e.g., emission direction) depending on the transmission of the electromagnetic wave. To achieve this, it is conceivable to manually replace the beamformer (metasurface) with another specific beamformer, but this is time-consuming.

[0005] An object of the present invention is to facilitate switching of the beam shape of an electromagnetic wave.

[0006] In order to solve the above problems, the electromagnetic wave control system of the present invention comprises a first beam former unit having a plurality of first beam formers that shape electromagnetic waves incident from an emission source into beam shapes that are different from each other, and a drive device that drives at least one of the first beam former unit and the emission source to move the plurality of first beam formers relative to the emission source, thereby switching the first beam former onto which the electromagnetic waves emitted from the emission source are incident.

[0007] According to the present invention, the beam shape of the electromagnetic wave can be easily switched.

[0008] FIG. 1 is a schematic diagram of an electromagnetic wave control system according to a first embodiment of the present invention. FIG. 2 is a schematic diagram of an electromagnetic wave control system according to the first embodiment of the present invention. FIG. 3 is a schematic diagram of a beam former according to the first embodiment of the present invention. FIG. 4 is a diagram showing an example of the configuration of a table stored in a memory according to the first embodiment of the present invention. FIG. 5 is a diagram showing the correspondence relationship between a beam ID and a beam shape according to the first embodiment of the present invention. FIG. 6 is a schematic diagram of a beam former unit according to a modified example of the first embodiment of the present invention. FIG. 7 is a schematic diagram of a beam former unit according to a modified example of the first embodiment of the present invention. FIG. 8 is a schematic diagram of a beam former unit according to a modified example of the first embodiment of the present invention. FIG. 9 is a schematic diagram of a beam former unit according to a modified example of the first embodiment of the present invention. FIG. 10 is a schematic diagram of a beam former unit according to a modified example of the first embodiment of the present invention. FIG. 11 is a schematic diagram of an electromagnetic wave control system according to a second embodiment of the present invention. FIG. 12 is a schematic diagram of a beam former unit according to a modified example of the second embodiment of the present invention. FIG. 13 is a schematic diagram of an electromagnetic wave control system according to a third embodiment of the present invention. FIG. 14 is a schematic exploded perspective view of a beam former unit according to a modified example of the third embodiment of the present invention. Fig. 15 is a schematic configuration diagram of a beamformer unit according to a fourth embodiment of the present invention. Fig. 16 is a schematic configuration diagram of a beamformer unit according to the fourth embodiment of the present invention. Fig. 17 is a schematic exploded perspective view of a beamformer unit according to a modification of the fourth embodiment of the present invention and a mask as an emission source of electromagnetic waves. Fig. 18 is a schematic perspective view of a beamformer unit according to the modification.

[0009] Hereinafter, an embodiment of the present invention and its modifications will be described with reference to the drawings.

[0010] (First Embodiment) The electromagnetic wave control system 10 according to this embodiment, shown in Figures 1 and 2, is configured to emit electromagnetic waves and control the beam shape of the electromagnetic waves (see arrows A2 and A3). Examples of electromagnetic waves include millimeter wave / terahertz wave bands, which are expected to be used in sixth-generation mobile communication systems (6G) and beyond. Unless otherwise specified, the electromagnetic waves in the following description refer to electromagnetic waves in a specific frequency band that are to be shaped and emitted as a beam, i.e., electromagnetic waves in a specific frequency band used for data transmission in wireless communication. The beam-shaped beam may be any electromagnetic wave that is emitted, and the beam shape refers to the emission mode of the electromagnetic waves, and includes, for example, at least one of the emission direction of the electromagnetic waves, the focus of the electromagnetic waves, and the width of the emission area of ​​the electromagnetic waves (beam width).

[0011] The electromagnetic wave control system 10 includes an antenna 20, a beam former unit 30, a driving device 40, and a controller 50.

[0012] The antenna 20 is a directional antenna that emits electromagnetic waves in the +Z direction. In this embodiment, a horn antenna is used as the antenna 20, but the antenna 20 may be another directional antenna. The antenna 20 converts a modulated wave (described later) supplied as an electrical signal from the controller 50 into an electromagnetic wave. The modulated wave converted into an electromagnetic wave is emitted in the +Z direction (arrow A1 in FIG. 1 ). The antenna 20 is disposed inside a cylindrical beamformer unit 30. The antenna 20 emits electromagnetic waves to an area of ​​the inner surface of the beamformer unit 30 located in the +Z direction, i.e., an area facing the antenna 20 (the inner surface of one of the beamformers 31 to 36 described later).

[0013] The beam former unit 30 is configured to transmit electromagnetic waves emitted by the antenna 20 and to shape the transmitted electromagnetic waves into a beam. The beam former unit 30 includes a plurality of beam formers 31 to 36, which are formed into a cylindrical shape arranged along the circumferential direction. Each of the plurality of beam formers 31 to 36 is formed into a curved sheet shape with a cross section of an arc obtained by dividing the cylinder into six equal parts along the circumferential direction. The central axis of the cylindrical beam former unit 30 extends in the X-axis direction. The beam former unit 30 can rotate around its own central axis extending in the X-axis direction.

[0014] Each of the beamformers 31 to 36 transmits incident electromagnetic waves and emits them in a desired beam shape, which differs from one beamformer to another.

[0015] The beamformers 31 to 36 are transmission-type static metasurfaces. As shown in FIG. 3 , each of the beamformers 31 to 36 includes a periodic structure S in which structures S1 (schematically depicted as circles in FIG. 3 ) are periodically arranged. The structure S1 is a two-dimensional or three-dimensional structure having dimensions shorter than the wavelength of the electromagnetic wave incident from the antenna 20. The structure S1 is also called a unit cell or a metamolecule. An example of the structure S1 is a conductive or dielectric resonator. An example of a resonator is a split-ring resonator. Transmission-type metasurfaces are also called transmit arrays, etc. Note that reflection-type metasurfaces, which will be described later, are also called reflect arrays, etc. The configuration of the periodic structure S (including the shape, pitch, etc. of the structure S1) differs for each of the beamformers 31 to 36. By adjusting the configuration of the periodic structure S during beamformer design, the resonant frequency of the structure S1 and the distribution of the electromagnetic wave scattering characteristics are adjusted. This determines in advance the beam shape formed by each of the beamformers 31 to 36. The periodic structure S of the beamformers 31 to 36 may be a single layer or multiple layers.

[0016] The beamformer unit 30 can be formed by any method. For example, a periodic structure S including the structural element S1 is formed using metal or titanium oxide on a deformable flexible film such as SU-8 or polyimide. The beamformers 31 to 36 are formed by dividing a single flexible film into six regions and forming different periodic structures S in each region. This results in a single metasurface on which the beamformers 31 to 36 are arranged. The single metasurface is then rolled into a cylindrical shape to form the beamformer unit 30. Alternatively, the beamformers 31 to 36 may be individually fabricated. In this case, for example, six support rods 41B extending in the X-axis direction of the support member 41 (described below) are extended in the +X direction, and the beamformers 31 to 36 are fixed to these six support rods 41B. The substrates of the beamformers 31 to 36 may be curved substrates made of a rigid dielectric. Examples of materials for the curved substrate include glass, silicon, calcium fluoride, and multilayer substrate materials (eg, Megtron®).

[0017] The driving device 40 is configured to drive the beam former unit 30 and rotate it about its central axis as a rotation axis. The driving device 40 includes a support member 41 that supports the beam former unit 30 and a motor 42 that rotates the support member 41.

[0018] The support member 41 includes a wheel 41A connected to the rotation shaft of the motor 42, and a support rod 41B extending from the wheel 41A in the +X direction and connected to the beamformer unit 30. The motor 42 rotates the support member 41, thereby rotating the beamformer unit 30.

[0019] When the driving device 40 rotates the beamformer unit 30, the multiple beamformers 31 to 36 arranged in the circumferential direction of the beamformer unit 30 move relative to the antenna 20 arranged within the beamformer unit 30. This relative movement switches the beamformer facing the antenna 20, i.e., the beamformer that transmits the electromagnetic waves from the antenna 20, in the order of, for example, beamformer 31 → beamformer 32 → ... beamformer 36 → beamformer 31 ... or in the reverse order. The beamformers 31 to 36 form the incident electromagnetic waves into beam shapes that are different from one another, and therefore, switching the beamformer due to the rotation of the beamformer unit 30 switches the beam shape of the electromagnetic waves that have transmitted through the beamformer unit 30. For example, when the beamformer facing antenna 20 is in the state of beamformer 31 (Figure 1), and beamformer unit 30 rotates so that beamformer 36 faces antenna 20 (Figure 2), the beam shape of the passing electromagnetic wave also switches from the beam shape by beamformer 31 (see arrow A2 in Figure 1) to the beam shape by beamformer 36 (see arrow A3 in Figure 2).

[0020] The controller 50 includes a processing unit 51 , a memory 52 , and a modulation circuit 53 .

[0021] The processing unit 51 is a circuit that includes at least one of a processor that executes a program stored in the memory 52, such as a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), and an FPGA (Field-Programmable Gate Array).

[0022] The memory 52 stores a table (see FIG. 4) showing the correspondence between beam IDs, beamformer IDs, and rotational positions. Beam IDs "B1" to "B6" identify the beam shapes of electromagnetic waves formed by the beamformers 31 to 36, respectively. Beamformer IDs "31" to "36" identify the beamformers 31 to 36, respectively. The beamformer IDs are represented by the symbols assigned to the beamformers. The rotational position is the rotational position of the beamformer unit 30 when the beamformer identified by the corresponding beamformer ID faces the antenna 20. In the table of FIG. 4, the rotational position is the rotational angle of the beamformer unit 30, and is indicated by a rotational angle where the rotational angle when the antenna 20 faces the beamformer 31 is set to 0 degrees.

[0023] The modulation circuit 53 operates under the control of the processing unit 51 , and is configured to convert the communication data supplied from the processing unit 51 into an analog electrical signal (i.e., a modulated wave) and output it to the antenna 20 .

[0024] The processing unit 51 receives, for example, a set of communication data to be transmitted currently, supplied from the external device 90, and a beam ID that specifies the beam shape when the communication data is emitted as electromagnetic waves, via a network card (not shown) or the like. The processing unit 51 refers to the table in the memory 52 based on the received beam ID, and acquires the rotation position corresponding to the beam ID.

[0025] The processing unit 51 controls the driving device 40 to rotate the beamformer unit 30 to the rotation position obtained above. As a result, the beamformer identified by the beamformer ID corresponding to the beam ID faces the antenna 20. Thereafter, the processing unit 51 outputs the communication data to the modulation circuit 43.

[0026] The modulation circuit 53 converts the communication data from the processing unit 51 into a modulated analog electrical signal, and supplies the modulated analog electrical signal obtained by the conversion to the antenna 20. The antenna 20 converts the analog electrical signal from the modulation circuit 53 into an electromagnetic wave and outputs it. The electromagnetic wave is incident on one of the beamformers 31 to 36 that is facing the antenna 20 at that time.

[0027] For example, assuming that the relationship between the beam IDs "B1" to "B6" and the beam shapes they respectively specify is as shown in FIG. 5, if the beam ID supplied from the external device 90 is "B1," the antenna 20 emits electromagnetic waves to the beam former 31 (see the table in FIG. 4), and the beam former 31 emits the electromagnetic waves in a beam shape with an azimuth angle of a degrees and an elevation angle of X degrees, for example. The beam shape of the electromagnetic waves may be specified by the external device 90, and the processing unit 51 may acquire the beam ID by referring to the table showing the relationship in FIG. 5. Alternatively, data specifying the beam shape may be registered in the table in FIG. 4 instead of the beam ID, and the rotational position may be directly acquired using the beam shape as a key. The beam former ID is not required for the table in FIG. 4.

[0028] As described above, the controller 50 controls the driving device 40 and drives the beamformer unit 30 so that the electromagnetic waves emitted by the antenna 20 are incident on one of the beamformers 31 to 36 that forms electromagnetic waves of a specified beam shape (for example, the beamformer corresponding to the beam ID).

[0029] As described above, in the electromagnetic wave control system 10, the beamformers 31 to 36 of the beamformer unit 30 shape the electromagnetic waves incident from the antenna 20 into beam shapes that are different from one another. Furthermore, the driver 40 rotates the beamformer unit 30, thereby moving the beamformers 31 to 36 relative to the antenna 20 and switching the beamformer among the beamformers 31 to 36 onto which the electromagnetic waves emitted from the antenna 20 are incident. For example, the driver 40 switches the beamformer onto which the electromagnetic waves emitted from the antenna 20 are incident from one beamformer 31 ( FIG. 1 ) among the multiple beamformers 31 to 36 to another beamformer 36 ( FIG. 2 ). This configuration automatically switches the beam shape of the electromagnetic waves, making beam shape switching easy. Furthermore, the beam shape can be switched simply by moving the multiple beamformers 31 to 36 with the driver 40, enabling beam shape switching with a simple configuration. Depending on the beam shape, the electromagnetic waves emitted from the antenna 20 may be incident on not only one beamformer facing the antenna 20, but also on an adjacent beamformer. Switching the beamformer on which the electromagnetic waves emitted from the antenna 20 are incident includes changing one beamformer or a combination of multiple beamformers on which the electromagnetic waves are mainly incident.

[0030] In addition to the above configuration, the beamformer unit 30 is formed in a cylindrical shape with transmissive beamformers 31-36 arranged in the circumferential direction. The beamformers 31-36 may be arranged in the circumferential direction with a gap between them. The antenna 20 is configured as a directional antenna and emits electromagnetic waves to the inner surface of the beamformer unit 30. Furthermore, the driver 40 rotates the beamformer unit 30 to move the beamformers 31-36 in the circumferential direction of the beamformer unit 30 and switch the beamformer to which the electromagnetic waves from the antenna 20 are incident. This configuration allows the beamformers 31-36 to be arranged three-dimensionally, making the beamformer unit 30 more compact than when the beamformers 31-36 are formed in a planar shape. Furthermore, the drive amount of the beamformer unit 30 is reduced compared to when the beamformers 31-36 are formed in a planar shape.

[0031] As shown in FIGS. 1 and 2 , the antenna 20 is preferably positioned so that the longitudinal direction of the electromagnetic wave emission portion of the antenna 20, in other words, the longitudinal direction of the electromagnetic waves, is parallel to the central axis of the beamformer unit 30 (the X-axis direction). This narrows the radiation angle of the electromagnetic waves as viewed from the Z-axis direction compared to when the longitudinal direction of the electromagnetic waves is perpendicular to the central axis of the beamformer unit 30 (the Y-axis direction). This allows the circumferential width of the beamformers arranged around the beamformer unit 30 to be narrowed accordingly. As a result, the number of beamformers that can be arranged can be increased. Furthermore, depending on the position of the antenna 20, it is possible to reduce the diameter of the beamformer unit 30 and thereby achieve miniaturization. For example, by positioning the electromagnetic wave emission portion of the antenna 20 closer to the beamformer facing the antenna 20, for example, closer than the axis of rotation, the beamformers 31 to 36 can be made smaller, thereby enabling the beamformer unit 30 to be reduced in size. The orientation of the longitudinal direction can also be applied to other embodiments. For example, in the second embodiment described below, the longitudinal direction is set to the X-axis direction, which is orthogonal to the arrangement and movement direction (Y-axis direction) of the beamformers, thereby shortening the length of the beamformers in the Y-axis direction, which makes it possible to increase the number of beamformers that can be arranged or to reduce the size of the entire beamformer unit without increasing the number of beamformers.

[0032] (First Modification of the First Embodiment) The beamformer unit 30 may have another cylindrical shape, such as a polygonal cylindrical shape. The above-described effects can be obtained as appropriate with other cylindrical shapes. Examples of other cylindrical beamformer units are shown in FIGS. 6 to 8.

[0033] As shown in FIG. 6 , a beamformer unit 130 having a cross section shaped like an athletics track (two semicircles connected by a straight line) may be used instead of the beamformer unit 30. The beamformer unit 130 is formed in the shape of a flexible belt. The beamformer unit 130 includes beamformers 131 to 138, each of which is formed from a deformable static metasurface. Although not shown, the beamformer unit 130 is rotated by a drive device (not shown) including pulleys, driven rollers, and motors for driving the pulleys, thereby moving the beamformers 131 to 138 relative to the antenna 20.

[0034] 7 includes four flat beamformers 231 to 234 each made of a static metasurface with a periodic structure S formed on a rigid dielectric substrate, and is formed in a rectangular cylindrical shape. Examples of materials for the substrate include glass, silicon, calcium fluoride, and multilayer substrate materials (e.g., Megtron (registered trademark)).

[0035] 8 is formed as a crawler, consisting of a number of planar beamformers 331, 332, ... 338 ... made of static metasurfaces having the same configuration as the beamformers 231 to 234. In such a case, the drive device that rotates the beamformer unit 330 includes a sprocket, a guide roller, a motor that rotates the sprocket, etc. (not shown).

[0036] (Second Modification of First Embodiment) As shown in Fig. 9 , an omnidirectional antenna 420 may be adopted instead of the directional antenna 20. In such a case, for example, a beamformer unit 430 may be provided instead of the beamformer unit 130. Although the beamformer unit 430 is formed in a cylindrical shape in Fig. 9 , it may also be formed in another cylindrical shape. The antenna 420 is formed inside the beamformer unit 430 and emits electromagnetic waves to the entire inner surface of the beamformer unit 430.

[0037] The beamformer unit 430 includes a plurality of beamformers 431 to 434 arranged in the circumferential direction. For example, the beamformer 431 is a transmissive beamformer similar to that in the first embodiment. The beam shape after shaping is arbitrary. The beamformers 432 to 434 are electromagnetic wave opaque beamformers. Note that the beamformers 432 to 434 may be configured as a single beamformer with the same structure. The opaque beamformer is configured from a metasurface or the like that reflects or absorbs electromagnetic waves from the antenna 420. The opaque beamformer may also be a reflector or the like. Even with such a beamformer, a beam-shaped electromagnetic wave called a reflected wave is formed by reflection.

[0038] In the electromagnetic wave control system according to Modification 2, beamformers 431 to 434 of beamformer unit 430 also shape the electromagnetic waves incident from antenna 420 into mutually different beam shapes. Furthermore, drive device 40 rotates beamformer unit 430, thereby moving beamformers 431 to 434 relative to antenna 420 and switching between beamformers 431 to 434 on which the electromagnetic waves emitted by antenna 420 (here, a portion of the total electromagnetic waves emitted by antenna 420, the electromagnetic waves emitted in the +Y direction) are incident. As a result, the +Y direction electromagnetic waves emitted by antenna 420 are either transmitted through beamformer 431 or blocked by beamformer 432, etc., thereby switching between a transmitted beam shape and a non-transmitted beam shape. This configuration automatically switches the beam shape of the electromagnetic waves (electromagnetic waves in the +Y direction), making beam shape switching easy. Furthermore, in this modification 2, only electromagnetic waves that reach the transmission-type beamformer 431 out of the electromagnetic waves from the antenna 420 can pass through the beamformer unit 430, and therefore the emission direction of the electromagnetic waves from the beamformer unit 430 can be controlled by rotating the beamformer unit 430. This also makes it easy to control the emission direction (beam shape) of the electromagnetic waves.

[0039] (Third Modification of the First Embodiment) As shown in FIG. 10 , the electromagnetic waves arriving at the beamformer unit 30 may come from outside the beamformer unit 30 or the electromagnetic wave control system 10. In such a case, the antenna 20 may be unnecessary. Even if the electromagnetic waves arrive from outside, there is always a source from which the electromagnetic waves are emitted. This source P includes devices that transmit or reflect the arriving electromagnetic waves, such as an antenna external to the electromagnetic wave control system 10, a beamformer external to the electromagnetic wave control system 10, and a reflecting portion of the electromagnetic wave control system 10 (including structures such as buildings). The electromagnetic wave source P may be located far away from the electromagnetic wave control system 10.

[0040] In the third modification, a beamformer unit 530 is provided. The beamformer unit 530 includes a plurality of beamformers 531 to 534 arranged in the circumferential direction thereof. Note that the beamformer unit 530 has a rectangular tubular shape here, but may have another tubular shape such as a cylindrical shape. The beamformers 531 to 534 are reflective beamformers such as reflective metasurfaces. The beamformers 531 to 534 cause the beam shapes of the reflected electromagnetic waves to differ from one another.

[0041] Even in such a modified example, the driving device drives the beamformer unit 530 to move the multiple beamformers 531 to 534 relative to the emission source P, so that it is possible to switch the beamformer onto which the electromagnetic waves emitted by the emission source P are incident and reflected, making it easy to switch the beam shape.

[0042] Second Embodiment An electromagnetic wave control device 610 according to a second embodiment includes a beam former unit 630 and a driver 640 instead of the beam former unit 130 and the driver 140, as shown in FIG.

[0043] The beamformer unit 630 is configured as a flexible sheet member in which beamformers 631 to 633 are arranged in the Y-axis direction. The beamformers 631 to 633 may be any flexible, deformable static metasurfaces as described above.

[0044] The driving device 640 is configured to move the beamformers 631 to 633 in the Y-axis direction relative to the antenna 20 by winding up the beamformer unit 630. Here, the driving device 640 includes winding members 641 and 642 that extend along the X-axis direction perpendicular to the Y-axis direction, are spaced apart along the Y-axis direction, and are each provided to be able to wind up the beamformer unit 630. The driving device 640 further includes motors 643 and 644 that rotate the winding members 641 and 642, respectively. The motors 643 and 644 are controlled to rotate in the same direction. When one of the winding members 641 and 642 winds up the beamformer unit 630, the other rotates to unwind the beamformer unit 630. The winding members 641 and 642 may be rotated by a combination of a single motor and gears, for example.

[0045] 4 is changed to, for example, the rotational position of the winding members 641 and / or 642, and the rotational position is expressed by the rotational angle of the winding members 641 and / or 642. The processing unit 51 drives the motors 643 and 644 based on the rotational position to rotate the winding members 641 and 642.

[0046] Here, each of the beamformers 631 to 633 is a transmission type beamformer, and the antenna 20, which is a directional antenna, is arranged to face the flat portion of the beamformer unit 630 that is not wound up by the drive device 640 (winding members 641 and 642). As a result, when looking in the +X direction (the direction in which the radio waves are emitted) from the antenna 20, the beamformers 631 to 633, which move in the Y-axis direction, cross. This switches the beamformer into which the electromagnetic waves are incident.

[0047] In the second embodiment, too, it is easy to switch the beam shape of the emitted electromagnetic waves. Moreover, since the beam shape can be switched simply by moving the multiple beam formers 631 to 633 with the drive device 640, the beam shape can be switched with a simple configuration. Moreover, since the beam formers that are not used to form the beam shape are wound up, less space is required to accommodate the beam former unit 630. The antenna 20 may be located far outside the system.

[0048] (Modification of the Second Embodiment) A beamformer unit 730 shown in FIG. 12 may be employed instead of the beamformer unit 630. The structure of the beamformer unit 730 is similar to that of the beamformer unit 630, but differs from the beamformer unit 630 in that the beamformer is a reflective type. The beamformer unit 730 is formed as a flexible sheet member in which reflective beamformers 731 to 733 are arranged in the Y-axis direction. In such a case, the electromagnetic wave emission source P may be located nearby or far away outside the system.

[0049] Third Embodiment An electromagnetic wave control system 810 according to a third embodiment shown in FIG. 13 has a plurality of beam former units 831 and 832 superimposed on the path of an electromagnetic wave.

[0050] The electromagnetic wave control system 810 includes beamformer units 831 and 832. The beamformer unit 831 is formed in a cylindrical shape with a plurality of transmission-type beamformers 831A to 831D, which form electromagnetic waves with different beam shapes, arranged in the circumferential direction. The beamformer unit 832 is formed in a cylindrical shape with a plurality of transmission-type beamformers 832A to 832D, which form electromagnetic waves with different beam shapes, arranged in the circumferential direction. Each beamformer is made of a static metasurface, as described above. The beamformer unit 832 surrounds the outer periphery of the beamformer unit 831.

[0051] The driving device 840 of this embodiment includes two motors that rotate the beam former units 831 and 832, respectively. The driving device 840 rotates the beam former units 831 and 832 individually, and moves the beam formers 831A to 831D and the beam formers 832A to 832D relative to the antenna 20. This switches the combination of beam formers facing the antenna 20. Electromagnetic waves from the antenna 20 pass through each of the beam formers in the beam former units 831 and 832 that face the antenna 20. The beam shape of the electromagnetic waves is formed by each beam former through which the electromagnetic waves pass. For example, the inner beam former performs deflection in the X direction, and the outer beam former performs deflection in the Y direction.

[0052] The controller 50 (processing unit 51) controls the driving device 840 to drive the beam former unit 831 and the beam former unit 832 so that the electromagnetic waves emitted by the antenna 20 are incident on a pair of two beam formers, among the beam formers 831A to 831D and the beam formers 832A to 832D, that form electromagnetic waves with a specified beam shape. To achieve this, for example, in the table of Fig. 4, the rotational positions of the beam former units 831 and 832 are defined in advance in association with the beam ID.

[0053] This embodiment makes it possible to form various beam shapes by combining two beamformers, an inner beamformer and an outer beamformer.

[0054] (Variation of the Third Embodiment) Instead of the beamformer units 831 and 832, multiple beamformer units 630 of FIG. 12 may be stacked. For example, as shown in FIG. 14, a beamformer unit 930 having a similar configuration may be added to the beamformer unit 630. The beamformer unit 930 includes beamformers 931 to 934, and the beamformer unit 630 and the beamformer unit 930 are wound separately. Although the beamformer unit 930 is shown distant from the beamformer unit 630 in FIG. 14, in practice, it is preferable to position the beamformer unit 930 closer to the beamformer unit 630 (see the two-dot chain arrow). This is to ensure that the electromagnetic waves emitted by the beamformer unit 630 are incident on the beamformer unit 930. The beamformer unit 930 has a longer length in the Y direction than the beamformer unit 630 so as not to interfere with the beamformer unit 630. The beamformer unit 930 may be arranged perpendicular to the beamformer unit 630.

[0055] (Fourth Embodiment) The beamformer unit may be formed in a flat plate shape as shown in FIGS. 15 and 16 . The beamformer unit 1030 shown in FIG. 15 includes flat beamformers 1031 to 1039 arranged in a matrix. The beamformer unit 1130 shown in FIG. 16 includes flat beamformers 1131 to 1134 for each sector-shaped area obtained by dividing a disk. A driving device controlled by a controller moves the beamformer unit 1030 in the X and Y directions and rotates the beamformer unit 1130 around a rotation axis extending in the Z direction through its center. This allows, for example, switching between the beamformer facing the antenna 20, i.e., the beamformer into which the electromagnetic waves are incident. The electromagnetic wave emission source may be an emission source external to the electromagnetic wave control system. The beamformers 1031 to 1039 and 1131 to 1134 may be either transmissive or reflective. The beamformers are described in accordance with the above embodiments. As described below, the antenna 20 side may also be moved in addition to or instead of the beamformer unit.

[0056] (Variation of the Fourth Embodiment) As shown in FIG. 17 , a mask M that transmits only a portion of electromagnetic waves from a distance may be provided for beamformers 1031 to 1039 of a beamformer unit 1030. Note that although FIG. 17 shows the mask M separated from the beamformer unit 1030, in reality, the distance between the two is close. The mask M includes an opaque portion M1 that does not transmit electromagnetic waves and a transparent portion M2 that transmits electromagnetic waves. The transparent portion M2 may be, for example, an opening or made of a material that transmits electromagnetic waves. The controller controls the drive device to move the beamformer unit 1030 so that the transparent portion M2 of the mask M faces the beamformer onto which the electromagnetic waves are to be incident. As a result, for example, if the transparent portion M2 faces the beamformer 1031, the electromagnetic waves will be incident on the beamformer 1031 via the transparent portion M2, while the electromagnetic waves will not be incident on the beamformers 1032 to 1039 due to the opaque portion M1. The transmission portion M2 has the function of transmitting and emitting the electromagnetic wave, and can also be considered as an electromagnetic wave emission source. The mask M may be applied to the disk-shaped beamformer unit 1130 shown in FIG. 16. In such a case, a fan-shaped transmission portion M2 is provided, and the beamformer onto which the electromagnetic wave is incident is selected by rotating the beamformer unit 1130. As described below, the mask M may also be moved in addition to or instead of the beamformer unit. If it is considered that the electromagnetic wave may reach the beamformer unit from both the +Z direction and the -Z direction, two masks M may be arranged on both sides of the beamformer unit in the Z direction.

[0057] (Variations of the First to Fourth Embodiments) The number of beamformers constituting a beamformer unit is arbitrary. A beamformer unit including multiple transmissive beamformers may further include other non-transmissive (including reflective) beamformers. Conversely, a beamformer unit including multiple non-transmissive (including reflective) beamformers may further include other transmissive beamformers. Although a static metasurface is used as the beamformer in the above, a dynamic metasurface may also be used as at least a part of the beamformer. In a dynamic metasurface, the dielectric constant and other parameters change in response to a control signal from the controller 50, thereby changing the resonant frequency and other parameters of the structure S1, thereby dynamically changing the beam shape of the electromagnetic wave. The beamformer may also be composed of optical elements such as lenses. The antenna 20 may be a phased array controlled by the controller 50. A phased array is also considered a type of directional antenna. The directional antenna 20 may be a passive antenna different from a phased array. A driving device may drive and move the antenna 20 in addition to or instead of the beamformer unit. The beamformer unit and the beamformer only need to move relative to an electromagnetic wave emission source such as an antenna, and this relative movement includes movement of only the beamformer unit and the beamformer, movement of only the emission source, and movement of both. The antenna may be a combination of multiple antennas, and relative movement between the antenna and the beamformer unit may align one of the multiple antennas with the beamformer of the beamformer unit. Each of the above structures can also be applied to the electromagnetic wave receiver side. As in the third embodiment, the number of beamformer units stacked in the direction of propagation of the electromagnetic waves is arbitrary.

[0058] As described above, an example of a configuration in which a driving device moves a beamformer unit and a beamformer relative to an electromagnetic wave emission source such as an antenna is shown in FIG. 17 . As shown in FIG. 17 , a cylindrical beamformer unit 1230 includes multiple rows of beamformers at different positions along its rotation axis (X-axis direction), and the antenna 20 and / or the beamformer unit 1230 may be movable along the X-axis direction. In the example of FIG. 17 , the beamformer unit 1230 includes, in addition to the beamformers 31 to 36 (first row) described in the first embodiment, beamformers 1231 to 1236 (second row) that are arranged in a circumferential direction similar to the beamformers 31 to 36 but are offset from the beamformers 31 to 36 in the rotation axis direction. The description of the beamformers 1231 to 1236 follows the description of the beamformers 31 to 36. The driving device rotates the beamformer unit 1230 in the same direction as in the first embodiment, and also moves the antenna 20 and / or the beamformer unit 1230 in the direction of the rotation axis (X-axis) of the beamformer unit 1230 using a linear motor or the like.With this configuration, it is possible to ensure the number of beamformers while preventing the diameter of the beamformer unit from becoming larger.

[0059] (Scope of the present invention) The present invention is not limited to the above-described embodiments and modifications. For example, the present invention includes various modifications to the above-described embodiments and modifications that can be understood by a person skilled in the art within the scope of the technical concept of the present invention. The configurations listed in the above-described embodiments and modifications can be combined as appropriate within a range that does not contradict. In addition, any of the above-described configurations can be deleted.

[0060] (Supplementary Note) The following is an example of a configuration that is one example of the above-described embodiment and modified examples disclosed in this specification. (Supplementary Note 1) An electromagnetic wave control system comprising: a first beamformer unit including a plurality of first beamformers that shape electromagnetic waves incident from an emission source into beam shapes that are different from one another; and a drive device that drives at least one of the first beamformer unit and the emission source to move the plurality of first beamformers relative to the emission source, thereby switching the first beamformer onto which the electromagnetic waves emitted from the emission source are incident. (Supplementary Note 2) The electromagnetic wave control system described in Supplementary Note 1, wherein the first beamformer unit has a cylindrical shape with the plurality of first beamformers arranged in a circumferential direction, and the drive device moves the plurality of first beamformers in the circumferential direction by rotating the first beamformer unit. Note that the first beamformer unit may further include a plurality of other beamformers that shape the electromagnetic waves incident from the emission source into beam shapes that are different from one another. The other multiple beamformers may be arranged in the circumferential direction at different positions in the rotation axis direction of the first beamformer unit from the multiple first beamformers (i.e., different rows along the rotation axis direction from the first beamformer), and the drive device may move the first beamformer unit in the rotation axis direction relative to the emission source. (Supplementary Note 3) The electromagnetic wave control system according to Supplementary Note 2, further comprising: a directional antenna arranged inside the first beamformer unit, which is the emission source; and each of the multiple first beamformers is a transmission type beamformer. (Supplementary Note 4) The electromagnetic wave control system according to Supplementary Note 2, further comprising: an omnidirectional antenna arranged inside the first beamformer unit, which is the emission source; and the multiple first beamformers include a transmission type first beamformer and a non-transmission type first beamformer. (Supplementary Note 5) The electromagnetic wave control system according to Supplementary Note 2, further comprising: an omnidirectional antenna arranged inside the first beamformer unit, which is the emission source; and the multiple first beamformers include a transmission type first beamformer and a non-transmission type first beamformer.(Supplementary Note 6) The electromagnetic wave control system according to Supplementary Note 1, wherein the first beam former unit is a flexible sheet member on which the plurality of first beam formers are arranged in a predetermined direction, and the drive device moves the plurality of first beam formers in the predetermined direction relative to the emission source by winding up the first beam former unit. (Supplementary Note 7) The electromagnetic wave control system according to Supplementary Note 6, wherein the drive device comprises a first winding member and a second winding member extending in a direction perpendicular to the predetermined direction and arranged at an interval along the predetermined direction, each of which is provided so as to be able to wind up the first beam former unit. (Supplementary Note 8) The electromagnetic wave control system according to Supplementary Note 6 or 7, further comprising a directional antenna which is the emission source, each of the plurality of first beam formers being a transmission type beam former, and the directional antenna being arranged at a position beyond the direction in which the electromagnetic waves are emitted and which is crossed by the plurality of first beam formers moving in the predetermined direction. (Supplementary Note 9) The electromagnetic wave control system according to Supplementary Note 6 or 7, wherein each of the plurality of first beamformers is a reflective beamformer. (Supplementary Note 10) The electromagnetic wave control system according to any of Supplements 1 to 9, further comprising a second beamformer unit having a plurality of second beamformers that shape the electromagnetic waves incident from the emission source into beam shapes different from each other, wherein the driver drives at least one of the first beamformer unit, the second beamformer unit, and the emission source to move the plurality of first beamformers and the plurality of second beamformers relative to the emission source, thereby switching the set of first beamformers and second beamformers onto which the electromagnetic waves emitted from the emission source are incident. Note that the second beamformer unit can have a configuration similar to that of each of the above-mentioned first beamformer units.(Supplementary Note 11) The electromagnetic wave control system according to any of Supplements 1 to 10, further comprising a controller that controls the driving device, wherein the controller controls the driving device to drive at least one of the first beamformer unit and the emission source so that electromagnetic waves emitted by the emission source are incident on a first beamformer of the plurality of first beamformers that shapes electromagnetic waves having a specified beam shape. (Supplementary Note 12) The electromagnetic wave control system according to any of Supplements 1 to 11, further comprising a controller that controls the driving device, wherein the controller controls the driving device to drive at least one of the first beamformer unit, the second beamformer unit, and the emission source so that electromagnetic waves emitted by the emission source are incident on a set of a first beamformer and a second beamformer that shape electromagnetic waves having a specified beam shape, among the plurality of first beamformers and the plurality of second beamformers. (Supplementary Note 13) The electromagnetic wave control system according to any one of Supplements 1 to 12, wherein the drive device includes one or more motors that drive the first beamformer unit and / or the second beamformer unit. (Supplementary Note 14) The electromagnetic wave control system according to any one of Supplements 1 to 13, wherein each of the plurality of first beamformers and / or each of the plurality of second beamformers is a metasurface. (Supplementary Note 15) The electromagnetic wave control system according to Supplementary Note 1, wherein the first beamformer unit is flat. (Supplementary Note 16) The electromagnetic wave control system according to Supplementary Note 15, wherein the emission source is the transmissive portion of a member having a non-transmissive portion that does not transmit electromagnetic waves and a transmissive portion that transmits electromagnetic waves, and the drive device moves the first beamformer unit relative to the emission source, thereby causing the transmissive portion to face any one of the first beamformers of the plurality of first beamformers.

[0061] 10...electromagnetic wave control system, 20...antenna, 30...beam former unit, 31 to 36...beam former, 40...drive device, 41...support member, 41A...wheel, 41B...support rod, 42...motor, 43...modulation circuit, 50...controller, 51...processing unit, 52...memory, 53...modulation circuit, 90...external device, 130...beam former unit, 131 to 138...beam former, 140...drive device, 230...beam former unit, 231 to 234...beam former, 330...beam former unit, 331 to 338...beam former, 420...antenna, 430...beam former unit, 431 to 434...beam former, 530...beam former unit, 531 to 534...beam former, 610...electromagnetic wave control device, 630...beam former unit, 631 to 633... Beam former, 640...drive device, 641-642...winding members, 643-644...motors, 730...beam former unit, 731-733...beam formers, 810...electromagnetic wave control system, 831...beam former unit, 831A-831D...beam formers, 832...beam former units, 832A-832D...beam formers, 840...drive device, 930...beam former beamformer unit, 931-934...beamformer, 1030...beamformer unit, 1031-1039...beamformer, 1130...beamformer unit, 1131-1134...beamformer, 1230...beamformer unit, 1231-1236...beamformer, A1-A3...arrows, M...mask, M1...non-transparent part, M2...transparent part, P...emission source, S...periodic structure, S1...structure.

Claims

1. An electromagnetic wave control system comprising: a first beam former unit having a plurality of first beam formers that shape electromagnetic waves incident from an emission source into beam shapes that are different from one another; and a drive device that drives at least one of the first beam former unit and the emission source to move the plurality of first beam formers relative to the emission source, thereby switching the first beam former onto which the electromagnetic waves emitted from the emission source are incident.

2. The electromagnetic wave control system described in claim 1, wherein the first beamformer unit is cylindrical with the plurality of first beamformers arranged in a circumferential direction, and the driving device moves the plurality of first beamformers in the circumferential direction by rotating the first beamformer unit.

3. The electromagnetic wave control system according to claim 2, further comprising a directional antenna arranged inside the first beamformer unit, which is the emission source, and each of the plurality of first beamformers is a transmission type beamformer.

4. The electromagnetic wave control system according to claim 2, further comprising an omnidirectional antenna arranged inside the first beamformer unit, which is the emission source, and wherein the plurality of first beamformers include a transparent first beamformer and an opaque first beamformer.

5. The electromagnetic wave control system described in claim 1, wherein the first beam former unit is a flexible sheet member on which the plurality of first beam formers are arranged in a predetermined direction, and the driving device moves the plurality of first beam formers in the predetermined direction relative to the emission source by winding up the first beam former unit.

6. An electromagnetic wave control system as described in claim 5, further comprising a directional antenna which is the emission source, each of the plurality of first beamformers being a transmission type beamformer, and the directional antenna being arranged at a position beyond the direction in which the electromagnetic waves are emitted, where it is crossed by the plurality of first beamformers moving in the specified direction.

7. The electromagnetic wave control system according to claim 2 or 6, wherein each of the plurality of first beamformers is a reflective beamformer.

8. The electromagnetic wave control system of claim 1, further comprising a second beam former unit having a plurality of second beam formers that shape the electromagnetic waves incident from the emission source into beam shapes different from each other, wherein the driving device drives at least one of the first beam former unit, the second beam former unit, and the emission source to move the plurality of first beam formers and the plurality of second beam formers relative to the emission source, thereby switching the set of first beam formers and second beam formers onto which the electromagnetic waves emitted from the emission source are incident.

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