Antenna system

Abstract

This antenna system (10) comprises: a plurality of beamformers (31-39) that emit incident electromagnetic waves in mutually different beam shapes; and an antenna device (20) that can individually emit electromagnetic waves to each of the plurality of beamformers (31-39). The antenna device (20) includes: a first antenna that emits electromagnetic waves to a first beamformer among the beamformers (31-39); and a second antenna that emits electromagnetic waves to a second beamformer that is different from the first beamformer among the beamformers (31-39). To emit electromagnetic waves from the antenna device (20) to the first beamformer, a controller (40) supplies, to the first antenna, an electric signal serving as the source of the electromagnetic waves to be emitted. To emit electromagnetic waves from the antenna device (20) to the second beamformer, the controller (40) supplies, to the second antenna, an electric signal serving as the source of the electromagnetic waves to be emitted.

Description

Antenna System

[0001] The present invention relates to an antenna system.

[0002] As a technology for changing the beam shape, such as the emission direction of an electromagnetic wave, a technology is known that uses a dynamic metasurface, which can dynamically change the emission direction of an electromagnetic wave, as a beamformer (Non-Patent Document 1).

[0003] Jun Yang, et al., “Electrically tunable liquid crystal terahertz device based on double-layer plasmonic metamaterial”, Optics Express, vol.27, No.19, pp.27039-27045, 2019

[0004] As in Non-Patent Document 1, when changing the beam shape by changing the characteristics (such as scattering characteristics) of the beamformer, there are inconveniences such as it taking time to change the characteristics of the beamformer and the control to change the characteristics becoming complicated.

[0005] An object of the present invention is to change the beam shape without changing the characteristics of the beamformer.

[0006] In order to solve the above problem, the antenna system of the present invention comprises a plurality of beamformers that emit incident electromagnetic waves in beam shapes that are different from each other, and an antenna device that can emit electromagnetic waves individually to each of the plurality of beamformers.

[0007] According to the present invention, the beam shape can be changed without changing the characteristics of the beamformer.

[0008] FIG. 1 is a schematic configuration diagram of an antenna system according to a first embodiment of the present invention. FIG. 2 is a schematic configuration diagram of a beamformer according to the first embodiment of the present invention. FIG. 3 is a conceptual diagram for explaining a phase difference of electromagnetic waves transmitted by the beamformer according to the first embodiment of the present invention. FIG. 4 is a diagram showing an example configuration of a table stored in a memory according to the first embodiment of the present invention. FIG. 5 is a diagram showing a correspondence relationship between beam IDs and beam shapes in the first embodiment of the present invention. FIG. 6 is a diagram showing an example configuration of a table stored in a memory according to a second embodiment of the present invention. FIG. 7 is a timing chart showing the timing at which each beamformer emits (shapes) electromagnetic waves. FIG. 8 is a schematic configuration diagram of an antenna system according to a modified example. FIG. 9 is a schematic configuration diagram of an antenna system according to another modified example. FIG. 10 is a schematic configuration diagram of an antenna system according to another modified example.

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

[0010] (First Embodiment) The antenna system 10 according to this embodiment shown in FIG. 1 is a system including an antenna, and is configured to shape electromagnetic waves emitted from the antenna into a desired beam shape and output the waves. Examples of the electromagnetic waves include millimeter wave / terahertz wave band radio waves that 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 into a beam shape and output, i.e., electromagnetic waves in a specific frequency band used for communications, etc. The beam shape may include at least one of the direction in which the electromagnetic waves are emitted or the width of the emission area of ​​the electromagnetic waves (beam width).

[0011] The antenna system 10 comprises an antenna device 20, a plurality of beamformers 31 to 39, and a controller 40.

[0012] The antenna device 20 converts modulated waves (electrical signals) from the controller 40 into electromagnetic waves and outputs them. The antenna device 20 can individually emit these electromagnetic waves to each of the beamformers 31 to 39. In other words, the antenna device 20 can output the electromagnetic waves to any of the beamformers 31 to 39.

[0013] The antenna device 20 has multiple antennas 21 to 29. The antennas 21 to 29 are arranged in a matrix along the X-axis and Y-axis directions, which are orthogonal to each other, and correspond one-to-one to the beamformers 31 to 39, which are also arranged in a matrix along the X-axis and Y-axis directions. The antennas 21 to 29 face the beamformers 31 to 39, respectively, along the Z-axis direction, which is orthogonal to the X-axis and Y-axis directions. For example, when an electromagnetic wave is to be emitted to the beamformer 31, the electromagnetic wave is emitted from the antenna 21 corresponding to the beamformer 31. When an electromagnetic wave is to be emitted to the beamformer 32, the electromagnetic wave is emitted from the antenna 22 corresponding to the beamformer 32. This also applies to the other antennas and beamformers. By selecting an antenna to emit an electromagnetic wave, the electromagnetic wave can be emitted individually to each beamformer. It may be acceptable for part of the electromagnetic waves emitted from a certain antenna (e.g., antenna 21) to be incident on a beamformer (e.g., beamformer 32) adjacent to the corresponding beamformer (e.g., beamformer 31). Such a mode may also be included in the mode of individual emission of electromagnetic waves to each beamformer.

[0014] Each of the antennas 21 to 29 may be any antenna, such as a horn antenna, a linear antenna, or a patch antenna. The antennas 21 to 29 are of the same type and have the same characteristics. The antennas 21 to 29 may also be a combination of two or more types of antennas.

[0015] Each of the beamformers 31 to 39 transmits electromagnetic waves emitted and incident from the antenna corresponding to the antenna device 20, more specifically, from the antennas 21 to 29, and emits the waves in a desired beam shape. This desired beam shape differs for each of the beamformers 31 to 39. In other words, by selecting a beamformer to which an electromagnetic wave is incident, the beam shape of the electromagnetic wave can be controlled. In this embodiment, the beamformers 31 to 39 correspond one-to-one to the antennas 21 to 29, so selecting an antenna to emit an electromagnetic wave selects a beamformer, and as a result, a beam shape is selected.

[0016] As described above, the beam formers 31 to 39 are arranged in a matrix along the X-axis and Y-axis directions. The beam formers 31 to 39 are arranged with the in-plane directions of their surfaces set as the X- and Y-axis directions, and their thickness direction set as the Z-axis direction.

[0017] The beamformers 31 to 39 are transmissive metasurfaces. As shown in FIG. 2, the beamformer 31 as a metasurface includes a periodic structure S in which structures S1 (schematically depicted as circles in FIG. 2) having dimensions shorter than the wavelength of the incident electromagnetic wave (electromagnetic wave from the antenna) are periodically arranged. The dimensions of the structure S1 are, for example, the lengths in the X-axis and Y-axis directions. The structure S1 is also called a unit cell or a metamolecule. An example of the structure S1 is a conductive resonator. An example of a resonator is a split-ring resonator. A transmissive metasurface is also called a transmit array. Note that a reflective metasurface, described later, is also called a reflect array. The beamformers 32 to 39 as metasurfaces also have a periodic structure S including the structure S1. However, the shape of the structure S1 may differ between beamformers.

[0018] There are two types of metasurfaces: static metasurfaces that cannot dynamically change the beam shape of the emitted electromagnetic waves, and dynamic metasurfaces that can dynamically change the beam shape. Here, static metasurfaces are used for each of the beamformers 31 to 39. In other words, by adjusting the shape and arrangement (period) of each of the structures S1 that make up the periodic structure S during beamformer design, the distribution of the electromagnetic wave scattering characteristics of each of the beamformers 31 to 39 is adjusted, and the beam shape formed by each of the beamformers 31 to 39 is determined in advance. Each of the beamformers 31 to 39 may be configured to include multiple regions (e.g., multiple types of periodic structures S) that emit electromagnetic waves with mutually different beam shapes.

[0019] Here, an example of the design concept of a beamformer will be described with reference to FIG. 3 . While FIG. 3 depicts a beamformer 31 as a metasurface, the following description also applies to other beamformers. In the following description, the number of structures S1 (see FIG. 2 ; not shown in FIG. 3 ) constituting the beamformer 31 is defined as N, the phase center of the antenna 21 (FIG. 1 ) from which the electromagnetic waves are emitted is defined as P1, and the point at which the electromagnetic waves are to be guided via the beamformer 31 (a point in the direction of the electromagnetic waves included in the beam shape) is defined as P2. Furthermore, the position of the nth structure S1 is defined as pn (n is an integer from 1 to N), the distance from P1 to an arbitrary reference point of the beamformer 31 (which is the substrate center of the beamformer 31 in FIG. 2 ) is defined as D1, the distance from P2 to the reference point is defined as D2, the distance from P1 to pn is defined as d1n, and the distance from P2 to pn is defined as d2n. The phase difference Gn associated with the difference in the optical path length of the electromagnetic waves for each structure S1 is expressed by the following equation (1): Gn=2π((d1n-D1)+(d2n-D2)) / λ...(1)

[0020] The electromagnetic wave can be guided to P2 by adjusting the transmittance and / or transmission phase of the structure S1 according to the range of the phase difference Gn. The transmittance and / or transmission phase are adjusted by the shape, period, etc. of the structure S1. For example, the structure S1 at a position where the remainder when Gn is divided by 2π is in the range of 0 or more and less than π is made to have a shape that transmits the electromagnetic wave to be guided. Note that the transparent shape also includes the case where the structure S1 is not provided at all. The structure S1 at a position where the remainder is in the range of π or more and less than 2π is made to have a low transmittance of the electromagnetic wave. This allows the electromagnetic wave to be guided to P2. Note that the electromagnetic wave can be similarly guided to P2 even if the transmission state and the low transmittance state are reversed. Alternatively, the electromagnetic wave can be guided to P2 by adjusting the transmission phase distribution so as to cancel the phase difference Gn rather than the transmission intensity of the electromagnetic wave. Furthermore, if the distance D2 is calculated to be sufficiently far compared to the size of the beamformer 31, the function of deflecting the electromagnetic wave in the direction of P2 is realized.

[0021] This concept is also used when dynamically changing the beam shape in the dynamic metasurface described below. In such cases, by applying a control signal to the metasurface and changing the permittivity, etc. of each structure S1, the transmittance, etc. can be changed, thereby dynamically controlling the destination of the electromagnetic wave, i.e., the emission direction of the electromagnetic wave.

[0022] The controller 40 shown in FIG. 1 includes a processor 41 , a memory 42 , and a modulation circuit 43 .

[0023] The processor 41 includes at least one of a central processing unit (CPU), an application specific integrated circuit (ASIC), and a field-programmable gate array (FPGA). The processor 41 is configured, for example, from one or more integrated circuit (IC) chips.

[0024] The memory 42 stores a table (see FIG. 4) showing the correspondence between beam IDs, beamformer IDs, and antenna IDs. Beam IDs "B1" to "B9" each identify the beam shape of the electromagnetic waves emitted from the antenna system 10. Antenna IDs "21" to "29" each identify the antennas 21 to 29. The antenna IDs are represented by the symbols assigned to the antennas. Beamformer IDs "31" to "39" each identify the beamformers 31 to 39. The beamformer IDs are represented by the symbols assigned to the beamformers. According to FIG. 4, the beam shapes of beam IDs "B1" to "B9" are assigned to the beamformers 31 to 39 (and their corresponding antennas 21 to 29), respectively.

[0025] The modulation circuit 43 operates under the control of the processor 41, converts the communication data supplied from the processor 41 into an analog electrical signal (that is, a modulated wave), and outputs it to one of the antennas 21 to 29.

[0026] The processor 41 receives, for example, a set of communication data to be transmitted currently, supplied from an external device, and a beam ID specifying the beam shape when the communication data is emitted as electromagnetic waves, via a network card (not shown). The processor 41 references a table in the memory 42 based on the received beam ID and acquires an antenna ID corresponding to the beam ID. The processor 41 outputs the received communication data and the acquired antenna ID to the modulation circuit 43.

[0027] The modulation circuit 43 converts the communication data from the processor 41 into an analog electrical signal (modulated wave) and outputs the analog electrical signal obtained by the conversion to one of the antennas 21 to 29 identified by the antenna ID from the processor 41.

[0028] Of the antennas 21 to 29, an antenna that receives an analog electrical signal converts the analog electrical signal into an electromagnetic wave and outputs it. The electromagnetic wave is incident on one of the beamformers 31 to 39 that corresponds to that antenna. The beamformer that receives the electromagnetic wave shapes the electromagnetic wave into a beam shape based on the distribution of its own scattering characteristics and emits the beam. As a result, the electromagnetic wave of communication data supplied from an external device is emitted in the beam shape specified by the external device via the beam ID. As a result, the communication data is wirelessly transmitted, for example, in the emission direction specified by the external device.

[0029] For example, assuming that the relationship between the beam IDs "B1" to "B9" and the beam shapes specified by each of them is as shown in FIG. 5, if the beam ID supplied from an external device is "B1", electromagnetic waves are emitted from the antenna 21 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. Note that the beam shape of the electromagnetic waves may be specified by an external device, and the processor 41 may acquire the beam ID by referring to the relationship table shown in FIG. 5, for example. Furthermore, data specifying the beam shape may be registered in the table in FIG. 4 instead of the beam ID, and the antenna ID may be acquired using the beam shape as a key.

[0030] The sets of communication data and beam IDs may be input continuously from an external device. For example, when an external device wants to continuously transmit transmission data to a moving object moving at high speed, the external device acquires the position of the moving object by any method, specifies a beam shape (emission direction) corresponding to the position, and sequentially transmits the communication data and a beam ID corresponding to the specified beam shape.

[0031] The controller 40 (processor 41) may control the modulation circuit 43 to sequentially supply analog electrical signals representing the same communication data to the antennas 21 to 29. In such a case, electromagnetic waves representing the communication data are sequentially emitted from the beamformers 31 to 39 in the beam shapes (emission directions) of the beamformers, and scanned over a certain range.

[0032] As described above, the antenna system 10 includes multiple beamformers 31-39 that emit incident electromagnetic waves with different beam shapes, and the antenna device 20 that can individually emit electromagnetic waves to each of the multiple beamformers 31-39. Thus, simply switching the beamformer to which the electromagnetic waves from the antenna device 20 are emitted changes the beam shape of the electromagnetic waves emitted from the antenna system 10 to its exterior, thereby changing the beam shape without changing the beamformer characteristics. Here, if the characteristics of the beamformer are changed when changing the beam shape as in Non-Patent Document 1, a liquid crystal is used to change the characteristics, and the slow response speed of the liquid crystal when the state of the liquid crystal changes delays the completion of the characteristic change. This can cause, for example, an inconvenience when the antenna system 10 is forced to change the direction of the electromagnetic waves to follow a moving object moving at high speed, in that the tracking cannot keep up. Furthermore, when changing the characteristics, the dielectric constant (state of the liquid crystal, etc.) of each structure S1 must be individually controlled, and since there are generally a large number of structures S1, this control becomes complicated. In this embodiment, the beam shape is changed without changing the characteristics of the beamformer, so that such inconveniences are prevented from occurring.

[0033] Furthermore, the controller 40 can cause the antenna device 20 to emit electromagnetic waves to, for example, the beam former 31 of the beam formers 31 to 39 at a first timing, and can cause the antenna device 20 to emit electromagnetic waves to, for example, the beam former 32 of the beam formers 31 to 39 at a second timing. This allows the beam shape to be changed without changing the characteristics of the beam former.

[0034] The antenna device 20 also includes a first antenna that emits electromagnetic waves to a first beamformer among the beamformers 31-39, and a second antenna that emits electromagnetic waves to a second beamformer among the beamformers 31-39 that is different from the first beamformer. This allows the beam shape to be changed simply by switching the antenna that emits the electromagnetic waves, i.e., by switching the antenna to which the electrical signal that is the source of the electromagnetic waves is output. Therefore, the time required to change the beam shape of the electromagnetic waves is the same as the time required to switch the antennas. Since this time is generally short, this embodiment reduces the time required to change the beam shape compared to conventional methods (especially when changing the characteristics of a beamformer that includes liquid crystal). Furthermore, the control for changing the beam shape is simplified because it only requires switching the antennas.

[0035] Furthermore, when the antenna device 20 emits electromagnetic waves to the first beam former, the controller 40 supplies the first antenna with an electrical signal that is the source of the emitted electromagnetic waves, and when the antenna device 20 emits electromagnetic waves to the second beam former, the controller 40 supplies the second antenna with an electrical signal that is the source of the emitted electromagnetic waves. This shortens the time required to change the beam shape. Also, the control for changing the beam shape is simplified.

[0036] Furthermore, by using static metasurfaces for the beamformers 31 to 39, the beam shape can be changed with a simple configuration.

[0037] Second Embodiment Dynamic metasurfaces may be used as the beamformers 31 to 39. In this case, the processor 41 of the controller 40 sends control signals to each of the beamformers 31 to 39, and changes the scattering characteristics by changing the dielectric constant of each structure S1 of the beamformers 31 to 39. This allows one beamformer to form two or more beam shapes, and the number of beam shapes that can be formed by the entire antenna system 10 is greater than in the first embodiment.

[0038] The processor 41 may refer to the table shown in FIG. 6. This table is stored, for example, in the memory 42 of FIG. 1. This table shows the correspondence between beam IDs, antenna IDs, beamformer IDs, and control signal patterns. The control signal pattern indicates the pattern of control signals to be supplied to the beamformer of the corresponding beamformer ID. When a control signal of this pattern is supplied to the beamformer, which is a dynamic metasurface, the beamformer can emit electromagnetic waves in the beam shape of the beam ID corresponding to the beamformer ID in the table.

[0039] Now, consider a case where the antenna system 10 according to this embodiment sequentially emits electromagnetic waves of predetermined communication data in each beam shape specified by the beam IDs "B1" to "B18." A timing chart for this emission is shown in FIG. 7. "ID: 31" in FIG. 7 is the beamformer ID, and the timing chart next to it indicates the emission timing of the electromagnetic waves from the beamformer 31. "B1" at the time of emission indicates the emission of electromagnetic waves in the beam shape of beam ID "B1," and "B10" indicates the emission of electromagnetic waves in the beam shape of beam ID "B10." This is also true for the other timing charts.

[0040] In such a case, the processor 41 acquires in advance each piece of data corresponding to the beam IDs "B1" to "B9" from the table of FIG. 6, and supplies control signals of the first to ninth patterns to the beam formers 31 to 39, respectively, based on the acquired data. As a result, each of the beam formers 31 to 39 shapes an electromagnetic wave in a beam shape specified by the beam IDs "B1" to "B9". In this state, the processor 41 sequentially supplies communication data to the modulation circuit 43 along with the antenna ID corresponding to the beam ID. As a result, electromagnetic waves are sequentially emitted from each of the beam formers 31 to 39. In other words, electromagnetic waves of each beam shape specified by the beam IDs "B1" to "B9" are sequentially emitted. Note that the beam shape is changed by switching the beam former that emits the electromagnetic wave, and is not dependent on a change in the characteristics of the beam former.

[0041] After the beamformer 31 emits electromagnetic waves with a beam shape of beam ID "B1," the processor 41 outputs a control signal of a tenth pattern corresponding to beam ID "B10" to the beamformer 31 corresponding to "B10." This updates the distribution of scattering characteristics of the beamformer 31, and the beam shape formed by the beamformer 31 is updated to the beam shape specified by beam ID "B10." This update may be performed during the period T (see the top row of FIG. 7 ) from the emission of electromagnetic waves from the first beamformer 31 to the emission of electromagnetic waves from the next beamformer 31. During the period T, electromagnetic waves are emitted by the other beamformers. Note that if the emission of electromagnetic waves from each of the beamformers 31 to 39 is t seconds, then T = "8, which is the number of times electromagnetic waves are emitted in the period T" × t, which is sufficient time for updating the scattering characteristics. The same applies to the other beam IDs. As a result, the processor 41 sequentially supplies communication data to the modulation circuit 43 along with the antenna IDs corresponding to the beam IDs "B9" to "B18." This causes electromagnetic waves to be emitted sequentially from each of the beam formers 31 to 39. In other words, electromagnetic waves of the beam shapes specified by the beam IDs "B9" to "B18" are emitted sequentially. Here too, the beam shape is changed by switching the beam former that emits the electromagnetic waves, and is not dependent on a change in the characteristics of the beam former.

[0042] In this way, the beamformers 31 to 39 include a beamformer made of a dynamic metasurface that is a metasurface including a periodic structure S in which structures S1 having dimensions shorter than the wavelength of the incident electromagnetic wave are periodically arranged, and that dynamically changes the beam shape of the emitted electromagnetic wave by updating the characteristics (scattering characteristics) of the periodic structure S. This makes it possible to set a large number (types) of beam shapes for the emitted electromagnetic wave. In particular, it is possible to set more beam shapes than the number of antennas.

[0043] The controller 40 can update the characteristics of the periodic structure S of this beamformer to characteristics that emit electromagnetic waves in the second beam shape during a period T after the beamformer, which is a dynamic surface, emits electromagnetic waves in the first beam shape and before this beamformer emits electromagnetic waves in the second beam shape, and during a period T when one or more other beamformers are emitting electromagnetic waves. With this configuration, the operation of the entire antenna system 10 is prevented from entering a standby state until the updating of the characteristics of the periodic structure S is completed, and the time required to change the beam shape is prevented from becoming long.

[0044] 8, in an antenna system 110 according to a modified example, an antenna device 120 includes an antenna 121 and a direction control device 122 that changes the orientation of a reflector 122A that reflects electromagnetic waves emitted by the antenna 121. The direction control device 122 is formed of a galvanometer mirror mechanism or the like, and reflects the electromagnetic waves to one of the beamformers 31 to 39. A controller 40 (processor 41) controls the direction control device 122 to cause the antenna device 120 to emit electromagnetic waves to any one of the beamformers 31 to 39. Even with this configuration, the beam shape of the emitted electromagnetic waves can be changed without changing the characteristics of the beamformer.

[0045] 9, in an antenna system 210 according to another modification, an antenna device 220 includes an antenna 221 and a direction control device 222 that changes the direction of the antenna 221. A controller 40 (processor 41) controls the direction control device 222 to cause the antenna device 220 to emit electromagnetic waves to any one of the beamformers 31 to 39. Even in this configuration, the beam shape of the emitted electromagnetic waves is changed without changing the characteristics of the beamformer.

[0046] 10 , in an antenna system 310 according to another modification, an antenna device 320 includes a plurality of antennas 321 and 322 that form, for example, a phased array. A controller 40 controls the characteristics (phase, frequency, intensity) of each electromagnetic wave emitted from each of the plurality of antennas 321 and 322, thereby controlling the direction of combining these electromagnetic waves and causing the combined wave to be incident on any one of the beamformers 31 to 39. Even with this configuration, the beam shape of the emitted electromagnetic waves can be changed without changing the characteristics of the beamformer.

[0047] The number of beamformers and the number of antennas included in the antenna device are arbitrary and may be any number other than nine. Furthermore, the beamformer may be a reflective type rather than a transmissive type. The beamformer may be configured to include an optical system such as a lens rather than a metasurface. The multiple beamformers may be a combination of different types of beamformers. Examples of such types include static metasurfaces, dynamic metasurfaces, and optical systems. As an example, the multiple beamformers may include a combination of one or more static metasurfaces and one or more dynamic metasurfaces.

[0048] 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 cause contradictions. In addition, any of the above-described configurations can be deleted.

[0049] (Supplementary Notes) Configurations that are examples of the above-mentioned embodiments and modified examples disclosed in this specification are exemplified below. (Supplementary Note 1) An antenna system comprising: a plurality of beamformers that emit incident electromagnetic waves in beam shapes that are different from one another; and an antenna device that can individually emit electromagnetic waves to each of the plurality of beamformers. (Supplementary Note 2) The antenna system according to Supplementary Note 1, further comprising a controller that causes the antenna device to emit electromagnetic waves to a first beamformer among the plurality of beamformers at a first timing, and causes the antenna device to emit electromagnetic waves to a second beamformer among the plurality of beamformers at a second timing. (Supplementary Note 3) The antenna system according to Supplementary Note 1 or 2, wherein the antenna device includes: a first antenna that emits electromagnetic waves to a first beamformer among the plurality of beamformers (which may be the same as or different from the first beamformer in Supplementary Note 2), and a second antenna that emits electromagnetic waves to a second beamformer (which may be the same as or different from the second beamformer in Supplementary Note 2) that is different from the first beamformer among the plurality of beamformers. (Supplementary Note 4) The antenna system according to Supplementary Note 3, further comprising a controller that, when emitting electromagnetic waves from the antenna device to the first beamformer, supplies the first antenna with an electrical signal that is a source of the emitted electromagnetic waves, and when emitting electromagnetic waves from the antenna device to the second beamformer, supplies the second antenna with an electrical signal that is a source of the emitted electromagnetic waves. (Supplementary Note 5) The antenna system according to Supplementary Note 1 or 2, wherein the antenna device includes: an antenna; and a direction control device that changes the direction of a reflector that reflects the electromagnetic waves emitted from the antenna, or changes the direction of the antenna. (Supplementary Note 6) The antenna system according to Supplementary Note 5, further comprising a controller that controls the direction control device to emit electromagnetic waves from the antenna device to any one of the multiple beamformers. (Supplementary Note 7) The antenna system according to Supplementary Note 1 or 2, wherein the antenna device comprises a plurality of antennas.(Supplementary Note 8) The antenna system according to Supplementary Note 7, further comprising a controller that controls the characteristics of each electromagnetic wave emitted from each of the plurality of antennas to control the direction of combining of the electromagnetic waves and cause the combined wave to be incident on any one of the plurality of beamformers. (Supplementary Note 9) The antenna system according to any one of Supplements 1 to 8, wherein the plurality of beamformers include a beamformer made of a static metasurface that is a metasurface including a periodic structure in which structures having dimensions shorter than the wavelength of the incident electromagnetic waves are periodically arranged, and the beam shape of the emitted electromagnetic waves cannot be dynamically changed. (Supplementary Note 10) The antenna system according to any one of Supplements 1 to 9, wherein the plurality of beamformers include a beamformer made of a dynamic metasurface that is a metasurface including a periodic structure in which structures having dimensions shorter than the wavelength of the incident electromagnetic waves are periodically arranged, and the beam shape of the emitted electromagnetic waves is dynamically changed by updating the characteristics of the periodic structure. (Supplementary Note 11) The antenna system described in Supplementary Note 10 further comprises a controller that controls the antenna device and the beamformer, wherein the controller updates the characteristics of the periodic structure of the dynamic metasurface to characteristics that emit electromagnetic waves in the second beam shape during a period after the dynamic metasurface emits electromagnetic waves in a first beam shape and before the dynamic metasurface emits electromagnetic waves in a second beam shape, during a period when one or more other beamformers among the plurality of beamformers are emitting electromagnetic waves.

[0050] 10...antenna system, 20...antenna device, 21-29...antennas, 31-39...beamformer, 40...controller, 41...processor, 42...memory, 43...modulation circuit, 110...antenna system, 120...antenna device, 121...antenna, 122...direction control device, 122A...reflector, 210...antenna system, 220...antenna device, 221...antenna, 222...direction control device, 310...antenna system, 320...antenna device, 321, 322...antennas, S...periodic structure, S1...structure.

Claims

1. An antenna system comprising: a plurality of beamformers that emit incident electromagnetic waves in mutually different beam shapes; and an antenna device that can individually emit electromagnetic waves to each of the plurality of beamformers.

2. The antenna system of claim 1, wherein the antenna device includes: a first antenna that emits electromagnetic waves to a first beamformer among the plurality of beamformers; and a second antenna that emits electromagnetic waves to a second beamformer among the plurality of beamformers that is different from the first beamformer.

3. The antenna system according to claim 1, wherein the plurality of beamformers include a beamformer made of a dynamic metasurface that dynamically changes the beam shape of the emitted electromagnetic waves.

4. The antenna system of claim 3, further comprising a controller for controlling the antenna device and the beamformer, wherein the controller updates the characteristics of the periodic structure of the dynamic metasurface to characteristics that emit electromagnetic waves in the second beam shape during a period after the dynamic metasurface emits electromagnetic waves in a first beam shape and before the dynamic metasurface emits electromagnetic waves in a second beam shape, during which one or more other beamformers among the plurality of beamformers are emitting electromagnetic waves.

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