Wireless power supply device

Abstract

To provide a wireless power supply device configured to achieve various radiation patterns.SOLUTION: A wireless power supply device includes a metasurface having a plurality of waveguide patches and a plurality of switches arranged in association with the plurality of waveguide patches, a control device that controls a power supply state to the plurality of switches, and an antenna that radiates an electromagnetic wave for transmitting power, and is capable of changing a connection relationship of the plurality of waveguide patches by switching the plurality of switches and changing a radiation pattern of the electromagnetic wave radiated from the antenna.SELECTED DRAWING: Figure 18

Description

[Technical Field]

[0001] The present invention relates to a wireless power supply device. [Background technology]

[0002] Controlling the antenna's directivity is often an issue for wireless power supplies. There are various ways to control this, and depending on the application, there are various antennas available, such as omnidirectional antennas that transmit signals in various directions, and directional antennas that transmit signals most strongly in one direction.

[0003] For example, International Publication No. 2020 / 084841 (Patent Document 1) discloses "an antenna module to be installed in a vehicle, the antenna module comprising an array antenna that forms a beam directed toward the outside of the vehicle from an opening provided in the outer wall of the vehicle, and a housing that holds the array antenna inside the vehicle (see abstract)." [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2020 / 084841 Summary of the Invention [Problem to be solved by the invention]

[0005] The most important feature of the present invention is to provide a wireless power supply that is configured to achieve a variety of radiation patterns. [Means for solving the problem]

[0006] In order to solve the above problems, for example, the configurations described in the claims are adopted. The present application includes a plurality of means for solving the above problems. One example of such means is a wireless power supply device, which comprises: a metasurface having a plurality of waveguide patches and a plurality of switches disposed relative to the plurality of waveguide patches; a control device that controls a power supply state to the plurality of switches; an antenna that emits electromagnetic waves to transmit power; and By switching the plurality of switches, a connection relationship between the plurality of waveguide patches is changed, thereby changing a radiation pattern of electromagnetic waves radiated from the antenna. A wireless power supply device is provided. [Effects of the Invention]

[0007] According to the present invention, it is possible to construct a wireless power supply that is configured to achieve a variety of radiation patterns. [Brief explanation of the drawings]

[0008] [Figure 1] Figure 1 shows schematic diagrams (A) and (B) of an example of a wireless power supply device including a metasurface (Example 1). [Figure 2] Figure 2 shows schematic diagrams (A) and (B) of an example of a wireless power supply device including a 3x3 array of metasurfaces (Example 1). [Figure 3] Figure 3 shows an example of the power supply state of a 3 × 3 array metasurface in (A) and (B) (Example 1). [Figure 4] Figure 4 shows examples of switching of a 3x3 array metasurface as (A) to (D) (Example 1). [Figure 5] FIG. 5 is a diagram showing an example of a radiation pattern corresponding to the switching of the switch in FIG. 4 (Example 1). [Figure 6] Figure 6 is a graph showing an example of the reflection loss of a metasurface with a 3x3 array (Example 1). [Figure 7] FIG. 7 is a graph showing an example of the radiation efficiency of a metasurface with a 3×3 array (Example 1). [Figure 8] Figure 8 shows an example of a 3x3 metasurface with adjustable height (Example 1). [Figure 9] FIG. 9 shows an example of a radiation pattern corresponding to the adjustment of the height of the metasurface in FIG. 8 (Example 1). [Figure 10] FIG. 10 shows an example of a hexagonal metasurface (Example 1). [Figure 11] FIG. 11 is a diagram showing an example of the radiation pattern of the hexagonal metasurface of FIG. 10 (Example 1). [Figure 12] FIG. 12 is a perspective view showing an example of a wireless power supply device having a three-layer structure (Example 2). [Figure 13] FIG. 13 is a diagram illustrating the state of the intermediate layer when the top layer of the three-layer structure shown in FIG. 12 is removed, with (A) and (B) being separate views (Example 2). [Figure 14] FIG. 14 is a diagram illustrating the state of the bottom layer when the top layer and the middle layer of the three-layer structure shown in FIG. 12 are removed (Example 2). [Figure 15] FIG. 15 is a diagram illustrating the wiring of the wireless power supply device having a three-layer structure shown in FIG. 12 (Example 2). [Figure 16] FIG. 16 is a diagram illustrating the intermediate layer of the three-layer structure shown in FIG. 12 (Example 2). [Figure 17] FIG. 17 is a diagram illustrating the bottom layer of the three-layer structure shown in FIG. 12 (Example 2). [Figure 18] FIG. 18 is a diagram showing an example of a radiation pattern of the wireless power supply device with a three-layer structure shown in FIG. 12 (Example 2). [Figure 19] FIG. 19 is a diagram showing an example of a radiation pattern of the wireless power supply device having a three-layer structure shown in FIG. 12 (Example 2). [Figure 20] FIG. 20 is a perspective view showing an example of a wireless power supply device having a metasurface with a 3×5 array (Example 3). [Figure 21]FIG. 21 is a diagram illustrating the state of the bottom layer when the top layer and the middle layer of the three-layer structure shown in FIG. 20 are removed (Example 3). [Figure 22] FIG. 22 is a perspective view illustrating the state of two antennas inside the three-layer structure shown in FIG. 20 (Example 3). [Figure 23] FIG. 23 is a diagram showing the connection state of the two antennas illustrated in FIG. 22 in (A) to (D) (Example 3). [Figure 24] FIG. 24 is a diagram illustrating an example in which four antennas are connected in a swastika shape (Example 3). [Figure 25] 25A and 25B are diagrams showing an example in which the connection paths of the two antennas illustrated in FIG. 22 can be selected in stages using switches and branches (third embodiment). [Figure 26] 26A and 26B are diagrams showing an example in which the connection paths of the two antennas illustrated in FIG. 22 can be selected in stages using switches and branches (third embodiment). [Figure 27] FIG. 27 is a diagram showing an example of a radiation pattern of the wireless power supply device illustrated in FIG. 26 (Example 3). [Figure 28] FIG. 28 is a diagram showing an example of a radiation pattern of the wireless power supply device illustrated in FIG. 26 (Example 3). [Figure 29] Figure 29 shows an example in which a 3x5 array metasurface is combined with the wireless power supply device illustrated in Figure 25 (A) and (B) (Example 3). [Figure 30] Figure 30 shows examples (A), (B), and (C) of the antenna orientation relative to the operating robot hand, a graph of the periodically changing position of the robot hand, and the power receiving state of the power receiving terminal installed on the robot hand (Example 4). [Figure 31] Figure 31 shows examples (A), (B), and (C) of the antenna orientation relative to the operating robot hand, a graph of the periodically changing position of the robot hand, and the power receiving state of the power receiving terminal installed on the robot hand (Example 4). [Figure 32] Figure 32 shows examples (A), (B), and (C) of the antenna orientation relative to the operating robot hand, a graph of the periodically changing position of the robot hand, and the power receiving state of the power receiving terminal installed on the robot hand (Example 4). [Figure 33] Figure 33 shows examples (A), (B), and (C) of the antenna orientation relative to the operating robot hand, a graph of the periodically changing position of the robot hand, and the power receiving state of the power receiving terminal installed on the robot hand (Example 4). [Figure 34] FIG. 34 is a diagram showing an example of the process of position learning and inference of the power receiving terminal in examples (A) and (B) (Example 3). [Figure 35] FIG. 35 is a diagram illustrating an example of an environment in which a measurement experiment was conducted when power was supplied wirelessly from a power transmitting device to a power receiving device. [Figure 36] FIG. 36 shows examples of (A) and (B) of the measurement results obtained under the measurement environment illustrated in FIG. [Figure 37] FIG. 37 shows examples of (A), (B), and (C) of the measurement results obtained under the measurement environment illustrated in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] Various devices such as sensors and actuators are used in fields such as factory automation (FA), the Internet of Things (IoT), and home appliances. In recent years, wireless power wiring for these devices has been considered. This is because wired power wiring can cause problems such as wiring strain, disconnection, and maintenance.

[0010] Further improvements are needed in beamforming (beam adjustment), which controls the directivity of antennas, to achieve more diverse radiation patterns. In recent years, the use of metamaterials for this control has been investigated.

[0011] "Metamaterials" are artificial materials that behave in a way that is not found in natural materials when it comes to electromagnetic waves, including light. Generally, metamaterials are constructed by artificially arranging minute unit elements at equal intervals at distances sufficiently smaller than the wavelength of the electromagnetic waves, so that they behave as a homogeneous medium when it comes to electromagnetic waves.

[0012] For example, International Publication No. 2020 / 084841 (Patent Document 1) proposes adjusting a beam using a metamaterial. However, in this disclosure, the metamaterial is only used as a substitute for a reflecting element, and its application is limited, and a variety of radiation patterns is not realized.

[0013] This embodiment provides a wireless power supply device configured to realize a variety of radiation patterns using a metamaterial. In particular, this embodiment provides a wireless power supply device capable of supplying power to various devices such as sensors and actuators in the fields of FA, IoT, home appliances, etc. In this regard, this embodiment is configured in consideration of the problems of conventional wireless power supplies described below.

[0014] "Physical constraints" In conventional wireless power supply devices, when transmitting electromagnetic waves (such as microwaves) to supply power wirelessly in free space, power loss can occur. In particular, the efficiency of power reception depends on the orientation of the transmitting antenna of the power supply device and the location of the power receiving device, and if these settings are not appropriate, good power reception can be difficult.

[0015] "Legal constraints" In conventional wireless power supply devices, there are regulations regarding antenna power and antenna gain, and therefore there are cases where upper limits on power supply are legally regulated.

[0016] "Electrical constraints" With previous wireless power supply devices, multiple devices were sometimes used simultaneously in the same space. In this case, two waves traveling in free space could overlap, causing a standing wave. This phenomenon was particularly likely to occur when multiple waves with the same wavelength, period, amplitude, and speed existed in the same space. In this case, there was a risk of power consumption for power detection.

[0017] "Environmental constraints" In conventional wireless power supply devices, when the power receiving device frequently changes position and power is supplied wirelessly from the power transmitting device, it can be difficult to set an optimal beamforming. For example, when a power receiving terminal is installed on the tip of a robot hand operating in a factory, the position changes depending on the application, so the beamforming direction cannot be uniquely determined.

[0018] Hereinafter, a first embodiment of a wireless power supply device configured to realize a variety of radiation patterns will be described with reference to FIGS. 1 to 11. FIG. [Example]

[0019] Referring to Figures 1(A) and (B), a wireless power supply device 1 using a metasurface 10 according to this embodiment is illustrated in schematic form. In particular, FIG. 1A illustrates a schematic side view of a metasurface 10. In particular, FIG. 1B illustrates a schematic front view of the metasurface 10.

[0020] 1A, the symbol Tx generally denotes a transmitter (power transmitting device). This transmitter Tx is configured to transmit electromagnetic waves (hereinafter referred to as electromagnetic waves) (E1 to E3) for power supply to the outside using any suitable antenna (not shown). These electromagnetic waves (E1 to E3) are configured to be transmitted wirelessly in free space (three-dimensional space) and received by a receiver (not shown).

[0021] The wireless power supply device 1 according to this embodiment can use various types of antennas in the transmitter Tx to transmit the electromagnetic waves (E1 to E3) to the outside. For example, the wireless power supply device 1 can use a single patch antenna (planar antenna) or multiple patch antennas (including a patch array antenna) as the antenna. The transmitter Tx has any appropriate means for generating electromagnetic waves (including microwaves) to be radiated from the antenna. For example, the transmitting device Tx includes a microwave oscillator 170 and an amplifier 190 therein, which enables the generation of electromagnetic waves (E1 to E3), and also enables the control device 200 to control the radiation pattern (beam direction).

[0022] In this embodiment, the wireless power supply device 1 adds a reconfigurable metasurface (hereinafter simply referred to as metasurface) 10, which can freely control the radiation pattern, to the transmitter Tx of the antenna. Because the beam is steered by this metasurface 10, no phase shifter is required on the transmitter Tx side. That is, as will be described later, the current pattern on the metasurface 10 can be adaptively changed by turning on / off a high-frequency signal using the control device 200, making it possible to control the radiation pattern.

[0023] The control device 200 can control not only the radiation of electromagnetic waves that is normally performed within the transmitter device Tx, but also the radiation of electromagnetic waves via the added metasurface 10. In this embodiment, the control device 200 of the transmitter device Tx is configured to control the metasurface 10, but it is also possible to provide a control device that controls the metasurface 10 separately from the control device 200 of the transmitter device Tx. The following description of the control of the radiation pattern of electromagnetic waves by the control device 200 mainly relates to the control of the radiation pattern of electromagnetic waves via the metasurface 10.

[0024] A metasurface 10 is a type of metamaterial (artificial medium) and is a waveguide element with arbitrary permittivity and permeability, consisting of a periodic arrangement of small structures relative to the wavelength. Metasurface 10 has the advantage of being able to control the reflection and transmission phase of electromagnetic waves incident on its surface. Therefore, metasurface 10 can be used to control incident light. In this example, a similar concept is applied to microwaves to design an antenna using metasurface 10. A planar antenna that combines a metamaterial and an antenna is sometimes called a metasurface 10.

[0025] 1A and 1B, the metasurface 10 is composed of multiple waveguide or radiating patches (hereinafter simply referred to as patches) 12a, 12b, 12c, etc. Each patch 12a, 12b, 12c has small structures periodically arranged relative to the wavelength, and is configured to achieve the desired permittivity and permeability. Each patch is configured so that electromagnetic waves incident on one surface side can pass through the interior and be emitted from the opposite surface side.

[0026] Each of the patches 12a, 12b, and 12c has a predetermined shape and is regularly arranged. For example, each of the patches 12a, 12b, and 12c is configured to have a quadrilateral (e.g., square) shape in the XY plane shown in FIG. 1B and an extremely thin thickness in the Z-axis direction shown in FIG. 1A. Each of the patches 12a, 12b, and 12c is regularly arranged on the same plane. In this way, the multiple patches 12a, 12b, and 12c are preferably configured to be small, extremely thin, and extremely lightweight.

[0027] 1B shows an example of an m×n array (m horizontal, n vertical) of patches periodically arranged in the vertical and horizontal directions on the same plane. For example, adjacent patches are arranged so that the length of one side of each quadrangle (e.g., the positions of both ends of each side) is aligned in the vertical direction, and the intervals (gaps) between each quadrangle are kept uniform in the horizontal direction.

[0028] The multiple patches 12a, 12b, and 12c that make up the metasurface 10 can each be made of any material. For example, each patch 12a, 12b, and 12c can be made of a precious metal such as gold, silver, or copper. Furthermore, each patch 12a, 12b, and 12c can be disposed on any substrate (e.g., a silicon substrate, etc.) not shown.

[0029] Each patch 12a, 12b, and 12c can be manufactured using any process. For example, multiple patches 12a, 12b, and 12c can be arranged in a predetermined pattern on the surface of a substrate. For example, the surface of the substrate can be controlled to a uniform film thickness, and then a nanopattern can be drawn, created, and coated on the film to form a metasurface 10 consisting of multiple patches 12a, 12b, and 12c. In this case, any process, such as spin coating, can be used. Although the number of patches 12a, 12b, and 12c used is not limited, it is preferable to configure a metasurface 10 that is relatively inexpensive and small in size.

[0030] 1B, the wireless power supply device 1 according to this embodiment has high-frequency switches 20a and 20b arranged in the gaps between adjacent patches 12a, 12b, and 12c, respectively. Therefore, the wireless power supply device 1 is configured to freely change the current pattern on the surface of the metasurface 10 by selectively controlling these high-frequency switches 20a and 20b.

[0031] The high-frequency switches 20a and 20b are switches that switch the path of high-frequency signals and are also called RF switches. The high-frequency switches 20a and 20b are classified into mechanical and electronic types. The high-frequency switches 20a and 20b (hereinafter simply referred to as switches) can match characteristic impedances to allow high-frequency signals to pass through.

[0032] Referring to FIG. 1B, switches 20a and 20b are provided between adjacent patches 12a, 12b, and 12c in the vertical and / or horizontal directions. Therefore, by switching the energization state of one switch, the power supply state of portions of two patches arranged on either side of the switch is controlled. Each switch 20a and 20b is centrally managed and individually controlled by a control device (not shown). As a result, rather than supplying power to all of the multiple patches 12a, 12b, and 12c uniformly, power can be supplied to each portion of the patch, each patch, or each small group of patches.

[0033] For example, in the configuration illustrated in FIG. 1B, patches 12a, 12b, and 12c, each formed as a square of the same size, are aligned at equal intervals in the vertical and horizontal directions with their relative positions aligned. Adjacent patches 12a, 12b, and 12c are arranged on the outer periphery with switches 20a and 20b sandwiched between them. In this way, when there are m horizontal and n vertical patches 12a, 12b, 12c, etc., a total of "m*(n-1)+n*(m-1)" switches 20a, 20b, etc. can be used.

[0034] The current pattern flowing through each patch 12a, 12b, 12c can be controlled by the ON / OFF combination of the corresponding switches 20a, 20b. For example, by using electronic high-frequency switches 20a, 20b, the path through which the high-frequency signal passes can be switched on and off depending on the state of the control signal. In this way, if there are X switches in total, there are 2 to the power of X possible combinations of the switches. As a result, versatility can be significantly improved compared to general phase-controlled beamforming.

[0035] Therefore, in this embodiment, by arranging the multiple patches 12a, 12b, and 12c and the switches 20a and 20b as described above, it is possible to configure a wireless power supply 1 that performs beamforming in a variety of ways. Referring to (A) of Fig. 1, it is illustrated that by individually controlling each switch 20a and 20b, beamforming can be performed in a variety of different ways, as exemplified by the symbols E1, E2, and E3. Note that (A) of Fig. 1 shows the symbols E1, E2, and E3 overlapping, but in practice, any one of these symbols E1, E2, and E3 is selectively used.

[0036] For example, as shown by symbol E1, the wireless power supply device 1 may adjust the direction and spread of the transmitted wave or beam so that it spreads along the plane of the metasurface 10. For example, as indicated by the symbol E2, the wireless power supply device 1 may adjust the direction and spread of the beam so that it spreads in a direction perpendicular to the plane of the metasurface 10 (approximately at a right angle). For example, as indicated by reference symbol E3, the wireless power supply device 1 may adjust the direction and spread of the beam so that it spreads at an oblique angle (approximately an acute angle) relative to the plane of the metasurface 10. Furthermore, the wireless power supply device 1 can perform beamforming to more precisely adjust the angle, direction, spread, etc. of the emitted beam relative to the plane of the metasurface 10.

[0037] Referring to FIGS. 2A and 2B, the wireless power supply device 1 illustrated in FIGS. 1A and 1B is illustrated more specifically. In particular, FIG. 2A is a perspective view of the wireless power supply device 1. As shown in FIG. In particular, FIG. 2B shows a schematic side view of the wireless power supply device 1. As shown in FIG.

[0038] As can be seen from (A) and (B) of Figures 2, the wireless power supply device 1 can be configured as a three-layer structure. A metasurface 10 consisting of multiple patches 12, as illustrated in Figure 1, is arranged on the front side of this layer structure. An antenna radiation side (radiating element) 30 is arranged on the center side of the three-layer structure. An antenna GND (ground plane) 40 is arranged on the back side of the three-layer structure. For example, the antenna 30 is a single patch antenna. This antenna 30 is fed by a power supply line (not shown) via the GND 40, and is configured to radiate electromagnetic waves from the opposite side (i.e., the metasurface 10 side).

[0039] A control device 200 for controlling the transmission of electromagnetic waves is provided inside or outside the three-layer structure. Preferably, the control device 200 controls the operation of the wireless power supply device 1, particularly the antenna 30 and the metasurface 10.

[0040] 2A and 2B, the plane of the metasurface 10 is arranged parallel to and close to the plane of the radiating element of the patch antenna 30. This distance is selected so that the electromagnetic waves radiated from the patch antenna 30 can be effectively transmitted to the outside through the metasurface 10.

[0041] In this example, the metasurface 10 is configured using nine patches 12 arranged in a 3x3 array (m horizontal and n vertical). Each patch 12 has the same size and square shape. Therefore, in this example, a total of 12 switches 20 are used based on the above formula "m*(n-1)+n*(m-1)", that is, "2n*mmn". The possible combinations of the switches 20 are 4096 in total (2 to the power of X, or 2 to the power of 12).

[0042] When nine patches 12 are arranged in a 3x3 array, they can be divided into one centrally located patch 12 and eight outer patches 12 surrounding the centrally located patch 12. The former differs from the latter in that it does not contact the outer periphery of the metasurface 10. Based on this difference, the position of the switch 20 applied to each patch 12 can be changed.

[0043] For example, as shown by the reference numeral 20c, a switch 20 can be provided on the center side of one side of a square between a patch 12 arranged in the center and the patch 12 adjacent thereto. For example, as illustrated by the reference numeral 20d, between the eight patches 12 arranged on the outside, a switch 20 can be provided on the outer periphery of one side of the square between adjacent patches 12. In this way, by arranging the switches 20 arranged in the outer patches as close to the outer periphery of the outer patches as possible, the distance between the switches 20c, etc. arranged in the central patch and the outer periphery switches 20d, etc. can be made as wide as possible, thereby reducing noise caused by the current flowing between each switch.

[0044] 2, the patch 12 located in the center can be powered by four switches. The eight patches 12 located on the outside can each be powered by three switches. By changing the position of the switches according to the position of the patch, the current on the surface of the metasurface 10 can be distributed relatively evenly across the entire surface.

[0045] The metasurface 10 can be configured to be small overall. For example, in this example, a 900 MHz band antenna can be configured with a square shape with a side length of approximately 20 cm. However, this is just an example, and the present embodiment is not limited to this.

[0046] Referring to Figures 3(A) and (B), an example of the current pattern when power is selectively supplied to each patch 12 of the metasurface 10 illustrated in Figure 2(A) by controlling each switch 20 is shown. Figure 3(A) illustrates an example of the current pattern on the surface of the metasurface 10 when all 12 switches 20 are turned on and power is supplied to all 9 patches 12. Figure 3B illustrates the current pattern on the surface of the metasurface 10 when only the four switches 20 at the top left of the nine patches 12 are selectively turned OFF and only the remaining eight switches 20 are turned ON. This pattern will be shown in more detail in Figure 4B, which will be described later.

[0047] 3A and 3B, the current pattern during power supply is shown in grayscale. In this case, the state in which switch 20 is turned on and current is applied is shown in a relatively light color (white). Also, the state in which switch 20 is turned off and no current is applied is shown in a relatively dark color (black). Figures 3A and 3B were obtained by computer simulation using a mathematical model. This simulation was conducted under ideal conditions without disturbances, but it can be assumed that the actual situation is similar.

[0048] Referring to FIG. 3A, it can be seen that when all the switches 20 are turned on, it is possible to energize all of the nine patches 12. As can be seen from the corners indicated by the reference numeral 210, the four corners of the metasurface 10 are shown in black because there are no switches 20 nearby, which means that the four corners of the metasurface 10 can be ignored from the perspective of beamforming optimization. It is possible to increase the number of switches to more fully distribute the current across the entire surface of the metasurface 10. Ultimately, this may be determined comprehensively from various perspectives, such as the efficiency and cost of controlling the metasurface 10.

[0049] Referring to FIG. 3B, it can be seen that by selectively turning off some of the switches 20, it is possible to energize only some of the nine patches 12. As can be seen from the display of the upper left region, denoted by reference numeral 220, the region where the switch 20 is selectively turned off is displayed in a darker color. Comparing (A) and (B) of Figure 3 reveals that the current state of a portion of the metasurface 10 is effectively switched. Therefore, by using a combination of nine patches and twelve switches, it is possible to selectively configure various current states.

[0050] 4A to 4D show examples in which the energization state of switch 20 is further divided into more detailed categories than those shown in FIGS. 3A and 3B. In FIGS. 4B to 4D, the switches shown in dark colors are OFF switches. FIG. 4A, like FIG. 3A, illustrates the state when all 12 switches 20 are turned on. In FIG. 4B, similar to FIG. 3B, an example is shown in which only the four switches 20 in the upper left corner are selectively turned OFF and only the remaining eight switches 20 are turned ON. FIG. 4C illustrates an example in which only the two outermost switches on the upper left are selectively turned OFF, and only the remaining 10 switches are turned ON. FIG. 4D illustrates an example of what happens when only the three switches on the upper left side are selectively turned OFF and only the remaining nine switches are turned ON. In this way, when changing the current state of the upper left region, the change can be made stepwise and in various ways, and the same can be done for the upper right region, lower right region, lower left region, and central region.

[0051] Referring to Figure 5, changes in the radiation pattern of electromagnetic waves emitted from antenna 30 are shown for each of the cases illustrated in Figures 4A to 4D. Figure 5 illustrates the radiation direction of the antenna. In this figure, the four radiation patterns are shown overlapping each other to clearly show the comparison. It can be seen that the radiation direction and spread are different for each case. For example, in the upper part of Figure 5(A), electromagnetic waves are sent symmetrically, spreading equally to the left and right with the 0° direction as the center. For example, in the upper part of FIG. 5(B), electromagnetic waves are sent asymmetrically, shifting to the left from the 0° direction. 5, it can be seen that the direction, range, etc. of the electromagnetic waves change minutely in each of the cases (A) to (D) of FIG. 4. In this embodiment, by utilizing this characteristic, it becomes possible to variously control the direction, spread, range, etc. of the electromagnetic waves emitted from the antenna 30.

[0052] From Figure 5, it can be seen that in each of the cases (A) to (D), the main lobe (the lobe in the strongest radiation direction) and side lobes (lobes other than the main lobe) change. As a result, the antenna's directivity changes. The same is true for the front-to-back ratio and beam width. Therefore, even if the relative relationship between the wireless power supply device 1 of this embodiment and the power receiving device that acts as a pair changes in various ways, by finely controlling the direction, range, etc. of sending the electromagnetic waves, it is possible to follow the changes and always transmit electromagnetic waves in a good manner. Note that Figure 5 was obtained by simulation using a mathematical model on a computer. In this case, the power supply state was obtained under ideal conditions without disturbances. The same applies to Figures 6 and 7 shown below.

[0053] Referring to FIG. 6, a graph is shown illustrating the return loss of the wireless power supply device 1 illustrated in FIGS. 6a in the same figure is a graph corresponding to the state shown in FIG. 3(A) and FIG. 4(A). 6b in the same figure is a graph corresponding to the state shown in FIG. 3B and FIG. 4B.

[0054] As is well known to those skilled in the art, when a change in impedance occurs on the wireless power supply device 1 side, it may cause a reflected wave and result in a reflection loss. In this embodiment, by switching the multiple switches 20 ON and OFF in various ways, a change in impedance may occur on the wireless power supply device 1 side. This change can be inferred from FIG. 6.

[0055] In the application example shown in Fig. 6, it is assumed that the wireless power supply device 1 operates at 0.9 GHz. As can be seen from 6a in the figure, when all switches are turned on, the return loss is about -8 dB at 0.9 GHz. On the other hand, as can be seen from 6b in the figure, when some switches are turned off, the return loss is about -10 dB at 0.9 GHz.

[0056] As can be seen from FIG. 6, by operating the wireless power supply device 1 at 0.9 GHz, it is possible to avoid the region where the return loss increases sharply. As can be seen from Fig. 6, the spatial radiation power changes depending on the combination of the switches 20. Therefore, in this embodiment, when the power from the antenna is expressed as effective isotropic radiated power (EIRP), a system design is adopted in which the output is always 36 dBm in EIRP. Therefore, in this embodiment, the output of the amplifier (see amplifier 190 in Fig. 1) used in the wireless power supply device 1 can be controlled using the control device 200.

[0057] Referring to FIG. 7, the radiation efficiency of the wireless power supply 1 illustrated in FIGS. 2 to 4 is illustrated in a graph. 7a in the same figure is a graph corresponding to the state shown in FIG. 3(A) and FIG. 4(A). 7b in the same figure is a graph corresponding to the state shown in FIG. 3B and FIG. 4B.

[0058] In the application example shown in Fig. 7, the operation of the wireless power supply device 1 is assumed to be at 0.9 GHz. As can be seen from Fig. 7a, when all switches are turned on, the radiation efficiency is approximately 0.98. On the other hand, as can be seen from Fig. 7b, when some switches are turned off, the radiation efficiency is approximately 0.95. In this way, the radiation efficiency changes depending on the combination of switches. As can be seen from Fig. 7, by operating the wireless power supply 1 at 0.9 GHz, good radiation efficiency can generally be maintained. Therefore, the wireless power supply device 1 according to this embodiment is expected to operate well when actually used.

[0059] In the cases illustrated in Figures 1 to 7 above, the radiation pattern of the electromagnetic waves (beams) emitted through the metasurface 10 was changed by switching the switches 20 associated with multiple patches 12 on and off. In this case, it is possible to energize only a part of one patch 12 . Alternatively, the current can be applied to almost the entire area of ​​one patch 12 . Alternatively, only a small group of patches 12 may be energized. Alternatively, the entire group of patches 12 can be energized. However, in this embodiment, the method of controlling beamforming is not limited to this mode.

[0060] Referring to Figure 8, an example is shown in which the radiation pattern of the electromagnetic waves emitted through the metasurface 10 can be changed by changing the separation distance (height h of the metasurface) between the plane of the radiating element of the antenna 30 and the plane of the metasurface 10 directly opposite it. Referring to FIG. 9, an example is shown of how the radiation pattern of the electromagnetic waves radiated from the antenna 30 changes when the height h of the metasurface 10 is changed, as illustrated in FIG.

[0061] 8, the plane of the radiating element of the antenna 30 and the plane of the metasurface 10 facing it are arranged close to each other, and the separation distance between them can be varied. For example, the height h of the metasurface can be varied within a range from several millimeters to several tens of millimeters. For example, the height h of the metasurface 10 can be varied within a range from 5 mm to 20 mm.

[0062] The height h of the metasurface can be controlled in various mechanical and electrical ways. For example, in this embodiment, the position of the antenna 30 may be fixed and the position of the metasurface 10 directly opposite it may be changed relatively. Alternatively, in this embodiment, the position of the metasurface 10 may be fixed and the position of the antenna 30 directly opposite it may be changed relatively. Or, both may be used. Referring to FIG. 9, an example is shown of how the radiation pattern of the electromagnetic waves emitted from the antenna 30 changes when the height h of the metasurface is changed within a range from 5 mm to 20 mm.

[0063] As can be seen from Figure 9, the radiation pattern (direction, spread, etc.) of the electromagnetic waves emitted from the antenna 30 changes as the height h of the metasurface changes stepwise from 5 mm to 7.5 mm, 9 mm, 10 mm, 11 mm, and 20 mm. Therefore, in this embodiment, beamforming can also be controlled by controlling the change in the height h of the metasurface in this way. For example, because the operating frequency of the metasurface is very narrow, simply changing the height by a few mm can effectively change the frequency, and as a result, the radiation pattern of the metasurface can be changed.

[0064] 8, the height h of the metasurface 10 is changed over the entire plane so that the distance between the metasurface 10 and the antenna 30 facing it is uniform. However, this embodiment is not limited to this. For example, in this embodiment, it is possible to change the height of only some of the multiple patches 12 that make up the metasurface 10. For example, in this embodiment, the height of the patch 12 located in the center of the multiple patches 12 that make up the metasurface 10 may be changed relatively to the height of the other patches 12 located on the outside.

[0065] 8, the metasurface 10 is configured as a flat plane, but this embodiment is not limited to this. For example, metasurface 10 may be configured as a concave curved surface, or metasurface 10 may be configured as a convex curved surface, or metasurface 10 may be configured as a more complex curved surface that repeats convex and concave patterns in three-dimensional space.

[0066] Furthermore, the beamforming by controlling the change in the height h of the metasurface illustrated in Fig. 8 and the beamforming by controlling the ON / OFF switching of the switch 20 illustrated in Fig. 1 to Fig. 7 can be used in combination. This allows the present embodiment to perform more ideal beamforming control.

[0067] 1 to 9, the multiple patches 12 constituting the metasurface 10 each have a square shape and have a regular tessellation shape. However, this embodiment is not limited to this form. For example, the shape of the patch 12 may be any other shape that has a regular tessellation, such as an equilateral triangle or a regular hexagon. However, the shape of the patch 12 is not limited to a regular tessellation. For example, the patch 12 may have any quadrilateral shape, including a rectangle, a rhombus, a trapezoid, or a parallelogram. For example, the patch 12 may have any polygonal shape, including a triangle, a pentagon, or a hexagon.

[0068] Alternatively, the patch 12 may have a more complex shape. For example, the patch 12 may have a circular or oval shape. For example, the patch 12 may have a semicircular or semi-elliptical shape. For example, the patch 12 may have a substantially L-shaped or V-shaped configuration. For example, the patch 12 may have a substantially C-shaped or U-shaped configuration. For example, the patch 12 may have a generally cross-shaped or generally X-shaped configuration. For example, the patch 12 may have a substantially T-shaped or Y-shaped configuration.

[0069] Depending on the shape of each patch 12, the size of the gap between adjacent patches can vary. For example, if one side of adjacent patches extends directly toward one another, the gap size may be constant along the length of that side. For example, if one side of adjacent patches curves towards one another, the size of the gap may vary along the length of that side. However, in order to obtain a good electrical conduction state on the surface of the metasurface 10, it is preferable that the gap between adjacent patches is small.

[0070] 1 to 9, the multiple patches 12 constituting the metasurface 10 each have the same size, shape, and / or material. However, this embodiment is not limited to this. For example, the patches 12 do not necessarily have to have the same size, shape and / or material. For example, among the multiple patches 12 that make up the metasurface 10, the patch 12 located in the center may have a relatively different size, shape, and / or material compared to the other patches 12 located on the outside.

[0071] Referring to FIG. 10, a modified example of the wireless power supply device 1 having a metasurface 10 consisting of multiple patches 12 illustrated in FIGS. 1 to 9 is illustrated. Referring to FIG. 10, the hexagonal (honeycomb) metasurface 14 similarly includes a plurality of patches 16c, 16d, and 16e. In this example, the central patch 16c has a hexagonal (honeycomb) shape. Each side of this hexagon has the same length, and the angles between two adjacent sides are equal. In this example, the central patch 16c and the peripheral patches 16d and 16e arranged outside of it are arranged so that the lengths, positions, and angles of adjacent sides are the same. Preferably, these multiple patches 16c, 16d, and 16e are spaced apart by uniform gaps.

[0072] As illustrated in FIG. 10, the multiple patches 16c, 16d, and 16e that make up the metasurface 14 do not need to have the same size and / or shape. For example, the shapes of the patches 16d and 16e arranged on the outer side of the central patch 16c are different from those of the central patch 16c. Six of these outer peripheral patches 16d and 16e are arranged along the six sides of the hexagon of the central patch 16c, but none of them need to be the size of a perfect hexagon. For example, the patch 16d arranged above and below the central patch 16c and the patch 16e arranged to the left and right may have different shapes.

[0073] For each of the multiple patches 16c, 16d, and 16e that make up the hexagonal metasurface 14, the switches 26c and 26d can be placed at the center of each hexagonal edge. For example, for the central patch 16c, the switch 26c can be placed at the center of the six edges of the hexagon. Also, for the outer peripheral patches 16d and 16e that are placed outside of the central patch 16c, the switch 26d can be placed at the center of the edges of the hexagon. These outer peripheral patches 16d and 16e each have a shape in which a portion of the outer periphery of the hexagon is cut out, eliminating the need to position the switch 26d closer to the outer periphery than the center of the edge.

[0074] That is, in the example illustrated in FIG. 2A, the position of the switch 20 was changed depending on the position of the patch in order to pass current across the entire surface of the metasurface 10. On the other hand, in the example illustrated in Figure 10, the shapes of the patches 16c, 16d, and 16e are changed to pass electricity across the entire surface of the metasurface 14, but the positions of the switches 26c and 26d are not changed.

[0075] That is, the configuration in which the switches are placed in the center of each hexagon is the structure in which the distance between the switches is the greatest, and can suppress the generation of noise due to the current flowing through the switch parts. Furthermore, compared to the configuration of Figure 2, the switches are evenly distributed on the metasurface 10, eliminating bias due to each switch and resulting in a uniform radiation pattern.

[0076] Referring to Figure 11, an example of the radiation pattern of electromagnetic waves emitted from the antenna 30 to the outside when the power supply state of each switch 26c, 26d is switched for the hexagonal metasurface 14 illustrated in Figure 10 is shown. Reference numeral 11a illustrates a state when all switches 26c and 26d are powered. In this case, electromagnetic waves are radiated to the outside equally to the left and right with 0° as the center.

[0077] Reference numeral 11b illustrates a state when some of the switches 26c and 26d are powered. In this case, the electromagnetic waves are biased to the left of 0° and radiated to the outside unequally to the left and right. Therefore, it can be seen that the main lobe and side lobe change when changing from 11a to 11b. As a result, the directivity of the antenna changes. The same can be said for the front-to-back ratio and beam width. In this way, even in the case of the hexagonal metasurface 14 illustrated in Figure 10, the radiation pattern of the electromagnetic waves emitted to the outside from the antenna 30 can be changed, as in the case of the metasurface 10 illustrated in Figures 1 to 9.

[0078] In the embodiments described above with reference to Figures 1 to 11, beamforming that realizes a variety of radiation patterns is made possible by combining a metasurface 10 (or 14) consisting of multiple patches 12 (or 16c, 16d, 16e) with multiple switches 20 (or 26c, 26d) for the antenna 30. For example, in this embodiment, when beamforming control is performed using 12 switches, there are 4096 (2 to the power of 12) possible combinations of switches. In general phase-controlled beamforming, a phase shifter is added to the microwave oscillator 170 and amplifier 190 shown in Fig. 1 to generate electromagnetic waves, and the beam direction is controlled by the control device 200, but the control content is limited. In contrast, in this embodiment, the control device 200 controls the radiation pattern of the electromagnetic waves radiated through the metasurface 10, thereby significantly increasing the versatility of the control.

[0079] There are various beamforming methods, but in this embodiment, the radiation pattern can be swung at least to about ±30°. In this case, multiple options are available for the direction, spread (range), shape, size, branching method, etc. of the electromagnetic waves. Therefore, in this embodiment, fine beam adjustment is possible. Furthermore, in this embodiment, the antenna can be made smaller and lighter, making it possible to apply it to a relatively compact installation area.

[0080] For example, in the above-mentioned Patent Document 1, the purpose is to "effectively radiate the transmission wave emitted in the direction of the inner end of the opening outside the vehicle (see paragraph 0015, Figure 11)" and "merely uses a metamaterial as a substitute for a reflecting element that directs the incident transmission wave outside the vehicle (see paragraph 0015 and claim 5)." Although the radiation path of the transmitted wave is adjusted, the application of metamaterials is extremely limited.

[0081] In Patent Document 1, the adjustment of the radiation path of the transmission wave simply involves providing a metamaterial at the position of a predetermined induction section 55 (see paragraph 0075), and does not disclose controlling the power supply state for a portion of the metamaterial. In the adjustment of the radiation path of the transmission wave in Patent Document 1, the adjustment of the beam is limited, and for example, the reflected wave is merely guided to the outside of the vehicle so as to avoid the edge portion 21d (see paragraph 0073). In particular, this control is performed in the same way as in a general reflecting element, and the configuration is different from that of this embodiment.

[0082] In Patent Document 1, the adjustment of the radiation path of the transmission wave is achieved by simply providing a metamaterial on the protrusion 56 for holding the guide portion 55 (see paragraph 0072). Therefore, the distance between the antenna base 25 and the metamaterial is relatively large, and they are not disposed close to each other. In addition, the relative positional relationship between the antenna base 25 and the metamaterial cannot be changed. In contrast to this, the present embodiment illustrated in FIGS. 1 to 11 enables beamforming with significantly improved versatility compared to the prior art such as Patent Document 1. [Example]

[0083] Next, a second embodiment of the wireless power supply device will be described with reference to FIGS. In addition, in order to avoid duplication of description, the same or similar devices, components, parts, functions, etc. as those described in Example 1 with reference to Figures 1 to 11 will be referred to using the same reference symbols, and detailed description will be omitted.

[0084] FIG. 12 illustrates a perspective view of a wireless power supply 1 that comprises a three-layer reconfigurable metasurface. As can be seen from the figure, the wireless power supply 1 includes three stacked substrates 52, 54, and 56. Each substrate 52, 54, and 56 is provided with the metasurface 10 illustrated in FIG. 2B and wiring for energizing it. Each substrate 52, 54, and 56 is supported by supports 58 at its four corners. The supports 58 are, for example, Teflon (registered trademark) posts.

[0085] 2B illustrates an example in which the radiation side (radiation element) 30 of the antenna and the GND (ground plane) 40 of the antenna are arranged in three layers. The three-layer structure for wiring illustrated in FIG. 12 does not need to strictly correspond one-to-one to the three layers in FIG. 2B.

[0086] The metasurface 10 described with reference to FIGS. 1 to 11 is provided on the top layer substrate 52 of the three-layer structure. A plurality of switches 20 are associated with the metasurface 10 to control the energization state of a plurality of patches 12. The voltage (V1) that controls each switch 20 is controlled by a control device 200. Therefore, the ON / OFF combination of each switch can be freely controlled centrally by the control device 200. The control device 200 may be, for example, a single-board computer equipped with a processor. The control device 200 may be, for example, a Raspberry Pi (registered trademark) or the like. The control device 200 may be built into the three-layer structure illustrated in FIG. 12 or may be provided outside the three-layer structure.

[0087] In the center of board 54, the middle layer of the three-layer structure, is provided a wiring connector 60 that brings together the wires that control each switch 20. In Fig. 12, wiring connector 60 is shown visible through the top layer so that the relative position and size of the wiring connector can be understood. Wires extend from wiring connector 60 to each of the multiple switches 20.

[0088] 13, (A) and (B) show an example of the state of the intermediate layer board 54 when the top layer board 52 is removed from the wireless power supply device 1 shown in FIG. Referring to FIG. 13A, the metasurface 10 is shown superimposed to allow understanding of relative position and size. Referring to (B) of Figure 13, the metasurface 10 is removed so that the wiring state of the wiring connector 60 can be understood.

[0089] As illustrated with reference to Fig. 2A, the position of the switch 20 can be changed depending on the position of the patch 12. This is to efficiently energize the surface of the metasurface 10 using the minimum number of switches 20 required. For example, a centrally located patch 12 has switches 20 located in the center of each side of a square. For example, the patch 12 arranged on the outer periphery has the switches 20 arranged on the outer periphery of each side of the square. Therefore, there are roughly two types of wires that extend from the wiring connector 60 to each switch.

[0090] For example, as illustrated by the symbol 72 in Figure 13 (B), four wires extend from the centrally located wiring connector 60 at a relatively short distance to the center of each side of the square of the centrally located patch 12. For example, as illustrated by the symbol 74 in Figure 13 (B), eight wires 74 extend from the wiring connector 60 located in the center to the outer periphery of each side of the square of the patch 12 located on the outer periphery, over a relatively long distance. These wirings 72, 74 are arranged regularly according to the arrangement of the multiple patches 12 that make up the metasurface 10.

[0091] As can be seen from Figure 13 (B), the wires 72, 74 extending from the centrally located wiring connector 60 toward its periphery each extend linearly in the same direction or at the same angle so as not to overlap each other. Furthermore, the wires 72, 74 extending from the centrally located wiring connector 60 to the periphery extend with a relatively large space or interval between adjacent wires, thereby reducing interference between adjacent wires 72, 74. As can be seen from the figure, the high frequency switch 20 is connected to the end of each of the wires 72 and 74 extending from the wiring connector 60 .

[0092] FIG. 14 illustrates the state of the bottom layer board 56 when the top and middle layer boards 52, 54 are removed from the wireless power supply device 1 illustrated in FIG. In this case, the metasurface 10 and the wiring connector 60, etc. are shown overlapping each other so that their relative positions and sizes can be understood. As described above, the wiring connector 60 extends the wires 72, 74 to the twelve switches 20, thereby enabling the electrical conduction state of each switch 20 to be individually controlled. Accordingly, as shown by the reference numeral 76, twelve wires extend collectively from below the wiring connector 60 toward the bottom board 56. The supply of voltage via these wires 76 is controlled by a control device, shown in FIG. 12, which is disposed below the board 56. The wiring of each switch 20 will be described in more detail below.

[0093] 15A and 15B, the wires 72, 74 extending from the wire connector 60 are illustrated in more detail. FIG. 15A illustrates the configuration illustrated in FIG. 12 as a front view. FIG. 15B shows an enlarged view of part of the wiring illustrated in FIG. 15A.

[0094] In Fig. 15(B), the portion referred to as an RF switch corresponds to one of the high-frequency switches exemplified by reference numeral 20 in Fig. 12. One high-frequency switch 20 is arranged so as to straddle two adjacent patches 12, 12. Because one high-frequency switch 20 can supply power to the corresponding locations of two adjacent patches 12, 12 at once, it is also possible to refer to it as a set consisting of two high-frequency switches (RF1 and RF2). In the illustrated example, one high-frequency switch 20 feeds power to two adjacent patches 12, 12, but this embodiment is not limited to this. For example, one high-frequency switch 20 can feed power to one patch 12.

[0095] 15A and 15B, twelve wires 72, 74 extend from the wiring connector 60 toward each high-frequency switch 20. Each wire (72 or 74) can be made up of three wires. These three wires can be wrapped in any material, such as resin, and combined into one wire (72 or 74).

[0096] 15(B), three wires are combined and extended from the wiring connector 60 for one high-frequency switch 20. One of the three wires (for example, the one located in the center of FIG. 15(B)) corresponds to GND (ground) and represents the part where the difference with the reference potential in the circuit is "0V (volts)." The remaining two of the three wires correspond to a wire that supplies a voltage (V1) that controls the ON / OFF of the switch, and a wire that supplies a power supply voltage (Vdd), respectively.

[0097] In this way, the wiring (72 or 74) consisting of three wires can arbitrarily switch the power supply state for each of the high-frequency switches 20. As described above, one high-frequency switch 20 simultaneously switches the power supply state of the corresponding locations of two adjacent patches 12, and therefore can also be referred to as a set of two switches (RF1 and RF2).

[0098] Referring to FIG. 16, the substrate 54 of the middle layer (mid-layer) of the three-layer structure shown in FIG. 12 is taken out and illustrated. Referring to FIG. 17, the substrate 56, which is the bottom layer of the three-layer structure shown in FIG. 12, is taken out and illustrated. The three-layer structure houses the antenna 30, as shown in Fig. 2. The antenna 30 can be positioned at a height offset from the bases 54, 56 to avoid interference with the wiring 72, 74 of the wiring connector 60. The configuration example of the wireless power supply device 1 has been outlined above with reference to FIGS.

[0099] Referring to FIG. 18, four examples (A) to (D) of the radiation patterns formed by the combinations of the switches 20 for the wireless power supply device 1 illustrated in FIGS. 12 to 17 are shown. For example, in (A) of Figure 18, some of the switches are turned on, and the electromagnetic waves emitted from the antenna are not emitted straight up in three-dimensional space, but are emitted biased to the left. For example, in (B) of Figure 18, some of the switches are turned on, and the electromagnetic waves emitted from the antenna are not emitted straight up in three-dimensional space, but are emitted biased to the right. For example, in (C) of Figure 18, some of the switches are turned on, and the electromagnetic waves emitted from the antenna are not emitted straight up in three-dimensional space, but are radiated in two branches to the left and right. For example, in FIG. 18(D), all switches are turned on, and the electromagnetic waves emitted from the antenna are radiated straight up in three-dimensional space.

[0100] Therefore, when the radiation pattern of the electromagnetic waves emitted from the antenna travels upward (Z axis) from the surface of the metasurface 10 (X axis, Y axis) in three-dimensional space, it can be directed not only vertically straight on the surface, but also diagonally upward. The directions may be distinguished as upper, right, lower, or left on the surface (X-axis, Y-axis) of the metasurface 10. Alternatively, the directions may be distinguished as upper right, lower right, upper left, or lower left on the surface (X-axis, Y-axis) of the metasurface 10. Alternatively, the directions may be distinguished every 45°, 30°, or at finer intervals on the surface (X-axis, Y-axis) of the metasurface 10.

[0101] The radiation pattern of the electromagnetic waves emitted from the antenna can be directed vertically in a straight line on the surface of the metasurface 10 in three-dimensional space as it travels upward (Z axis) from the surface (X axis, Y axis) (see Figure 18 (D)). Alternatively, the radiation pattern of the electromagnetic waves emitted from the antenna can be directed vertically in a straight line as it branches into two on the surface of the metasurface 10 when it travels upward (Z axis) from the surface (X axis, Y axis) in three-dimensional space (see (C) of Figure 18).

[0102] It is possible to split the radiation pattern into two or more. When splitting the radiation pattern into two or more, the respective directional directions may be opposite to each other (the angle between the two is obtuse), or the respective directional directions may be close to each other (the angle between the two is acute). In addition, the radiation pattern of the electromagnetic waves emitted from the antenna can be varied in size and spread.

[0103] Referring to FIG. 19, three examples of radiation patterns are shown overlapping one another for the wireless power supply device 1 illustrated in FIGS. For example, in the state illustrated by reference numeral 19a, all switches are turned on, and the electromagnetic waves emitted from the antenna are emitted without any bias to the left or right, centered at 0° (see (D) of Figure 18). For example, in the state illustrated by reference numeral 19b, some of the switches are turned on, and the electromagnetic waves emitted from the antenna are biased to the left of 0° (see FIG. 18(A)). For example, in the state illustrated by reference numeral 19c, some of the switches are turned ON, and the electromagnetic waves emitted from the antenna are radiated so as to branch into two waves, one to the left and one to the right, from 0° (see (C) of Figure 18).

[0104] As can be seen from the results of FIGS. 18 and 19, the spread of the radiation pattern can be controlled relatively precisely in terms of its direction, size, etc. Therefore, in Example 2 illustrated in Figures 12 to 19, similar to Example 1 illustrated in Figures 1 to 11, beamforming with significantly improved versatility is possible compared to conventional technologies such as Patent Document 1. The results in Figures 18 and 19 were obtained by computer simulation using a mathematical model. In this case, the power supply state was obtained under ideal conditions without disturbances, but it can be assumed that the actual state will be similar. [Example]

[0105] Next, a third embodiment of the wireless power supply device 2 will be described with reference to FIGS. In addition, in order to avoid duplication of description, the same or similar devices, components, parts, functions, etc. as those described in Example 1 with reference to Figures 1 to 11 will be referred to using the same reference symbols, and detailed description will be omitted. Furthermore, in order to avoid duplication of description, the same or similar devices, components, parts, functions, etc. as those described in Example 2 with reference to Figures 12 to 19 will be referred to using the same reference symbols, and detailed description will be omitted.

[0106] In the third embodiment, the control device 200 is specially devised for the radiation of electromagnetic waves generated on the transmitting device Tx side (see FIG. 1). The transmitting device Tx has any configuration for generating electromagnetic waves, and can have, for example, a microwave oscillator 170, an amplifier 190, and the control device 200 (see FIG. 1). 20, the wireless power supply 2 may include three substrates 52, 54, and 56, similar to the three-layer structure illustrated in FIG. 12. The top substrate 52 of the wireless power supply 2 similarly includes multiple patches 12 that constitute the metasurface 10, but in this case, the m×n array of patches 12 is vertically or horizontally oriented. For example, in Example 3 illustrated in Figure 20, the metasurface 10 has a total of 15 patches 12 arranged in a 3 row x 5 column array.

[0107] Referring to Figure 21, the top layer substrate 52 and the middle layer substrate 54 of the three-layer structure of the wireless power supply device 2 illustrated in Figure 20 are removed, and the illustration is shown to clearly show the relative relationship between the multiple antennas 32, 34 housed therein and the metasurface 10. In the configuration shown in the figure, two patch antennas 32, 34 are arranged side by side to match the m × n arrangement of horizontally or vertically elongated patches 12. Each patch antenna 32, 34 is connected by a single wiring, as shown by the reference numeral 80, and has a connection point 86 in the center.

[0108] Referring to FIG. 22, the two patch antennas 32, 34 illustrated in FIG. 21 are more clearly illustrated. The connecting portion 80 includes portions 82, 84 that extend relatively long in parallel with the juxtaposition direction of the two antennas 32, 34 to connect them, and portions 81, 83 that are bent at approximately right angles to connect to the corresponding antennas 32, 34. The connecting portion 80 can be divided into two parts at a central connection point 86, and each part is a mirror image of the other. Therefore, the connecting portion 80 has an approximately U-shape as a whole.

[0109] Referring to FIG. 22, the connecting portion 80 having a generally U-shape that connects the two patch antennas 32, 34 is provided together, biased to one side (the upper side in FIG. 22). When a current flows through a conductor, a magnetic field is generated around the conductor as a result of magnetic action. When a current flows through the connection 80 connecting the two patch antennas 32 and 34, the magnetic field is biased toward the upper side of the two patch antennas 32 and 34 as shown in Figure 22. This phenomenon may be undesirable in some cases. This embodiment provides a means for avoiding or reducing this phenomenon.

[0110] Referring to Figures 23A to 23D, the two patch antennas and their connections are illustrated in more detail. 23A shows patch antennas 31 and 33, each having a typical rectangular shape, arranged side by side. These patch antennas 31 and 33 can be configured to perform the same function. 23B, patch antennas 32 and 34 are arranged side by side, each capable of performing different functions so as to be compatible with right-handed and left-handed polarized waves, respectively. In this case, one pair of patch antennas 32 and 34 can accommodate both clockwise and counterclockwise radio waves. For example, when it is required to prevent radio wave interference, the embodiment shown in FIG. 23(B) is more preferable than the embodiment shown in FIG. 23(A).

[0111] As shown in (A) and (B) of Figures 23A and 23B, the patch antennas 31 and 33 and the patch antennas 32 and 34 can be connected to each other by the connecting portion 80 shown in Figure 22. In this case, two adjacent patches can be connected over the shortest distance. However, when a current flows through the connecting portion 80, a magnetic field may be generated that is biased toward the lower side of Figure 23 with respect to the two patch antennas 32 and 34.

[0112] Referring to Figures 23C and 23D, a connection 90 is illustrated that improves on the routing of connection 80 illustrated in Figure 22 so as to avoid or reduce the above problems that arise as a result of magnetic interaction.

[0113] 23C and 23D, in order to connect two juxtaposed patch antennas, the connection portion 90 has portions 92, 94 that extend in a broken line (bend at a right angle). In other words, instead of the portions 82, 84 that extend straight in the connection portion 80, the connection portion 90 has a portion 94 that extends parallel to the juxtaposition direction of the two antennas 32, 34, and a portion 92 that extends in a direction perpendicular to that. The two portions 92, 94 are connected in a broken line at a connection point 96 in the center of the connection portion 90. By rotating the direction of each patch antenna 31 and 33 by 90 degrees in this way, it is possible to radiate horizontally polarized waves from 31 and vertically polarized waves from 33.

[0114] The connecting portion 90 includes portions 91 and 93 that are bent at approximately right angles to connect to the corresponding antennas 32 and 34 (or 31 and 33) on the end sides of the two portions 92 and 94. The extending directions of these two portions 91 and 93 are also orthogonal to each other. The connection portion 90 can be divided into two parts at the central connection point 96, but the two parts are not mirror images of each other. Instead of having a generally U-shaped overall shape, the connection portion 90 has a shape that is roughly half of a swastika. Therefore, the path direction of the connection portion 90 changes at a right angle along at least a portion of the roughly swastika shape.

[0115] In this way, the connection part 90 changes the direction of the transmission line connecting two adjacent antennas 32, 34 (or 31, 33), thereby preventing the magnetic field from being biased due to the current flowing along this path. Preferably, the connection part 90 extends along approximately half of a swastika shape, so that the magnetic fields generated at parts 91 and 94 cancel each other out, or the magnetic fields generated at parts 92 and 93 cancel each other out, thereby reducing the influence of the current flowing through the connection line. By making it shaped like a swastika, rotational symmetry is ensured. In this case, by rotating it into a swastika, it is possible to radiate vertically polarized waves and horizontally polarized waves.

[0116] Referring to FIG. 24, a further improvement to the combination of the two patch antennas and the connection portion 90 illustrated in FIGS. 23(C) and 23(D) is shown to prevent the magnetic field from being biased. In the configuration shown in Fig. 24, two sets of combinations of two patch antennas and connection parts 90, as shown in Fig. 23(C), are prepared and placed side by side one above the other. In this case, the lower set is rotated 180 degrees relative to the upper set (the configuration shown in Fig. 23(C)). As a result, the two connection parts 90 are concentrated near the center of the four patch antennas, and the two connection parts 90 as a whole form a roughly swastika shape.

[0117] 24, in particular, the two portions 92, 92 extending straight in the up-down direction and the two portions 94, 94 extending straight in the left-right direction intersect at right angles to each other. Also, the two portions 93, 93 extending straight in the up-down direction and the two portions 91, 91 extending straight in the left-right direction intersect at right angles to each other over a shorter distance. In this way, by arranging the two connection parts 90 in a roughly interdigital shape, when current flows through the conductor, a magnetic field is generated around the conductor as a result of magnetic action, but overall, these magnetic fields cancel each other out in a roughly interdigital shape, preventing or reducing uneven generation. 24, the two connection portions 90 may be positioned adjacent to or overlapping each other so as to share a single central connection point 96.

[0118] Referring to (A) and (B) of Figure 25, this embodiment is illustrated as including a means (branch section) 110 for adjusting the phase advance or delay of the AC when current is applied to the two antennas 32, 34 via the connection section 80. FIG. 25A shows a modified embodiment of the embodiment shown in FIG. FIG. 25(B) shows an enlarged view of the main part of FIG. 25(A).

[0119] As described above, the two antennas 32, 34 are connected by the connection part 80 having a predetermined path length. In this case, when the two antennas 32, 34 are fed with power along the path of the connection part 80, the phases of the beams radiated from the two antennas 32, 34 can be changed by shifting the timing of feeding power. Referring to FIGS. 25A and 25B, this embodiment makes it possible to address this problem by adding a branch portion 110 to the connecting portion 80.

[0120] 25A and 25B, in this embodiment, in order to make it possible to change the path length of the connection part 80 connecting two adjacent antennas 32 and 34, the branch part 110 has four switches 111, 113, 115, and 117 arranged in four stages in parallel with the extension direction of the connection part 80. Therefore, two paths 112 and 114 branch off from the center of the connection part 80 and extend in a direction perpendicular to the extension direction of the connection part 80.

[0121] For example, when only switch 111 is turned on via a control device (control device 200, etc.), the flow through connection part 80 is transmitted straight without branching into two paths 112 and 114. Similarly, when only switch 113 is turned on, the flow through connection 80 branches into two paths 112 and 114, and flows through switch 113, thereby increasing the path length and path time.

[0122] Similarly, when only switch 115 is turned on, the flow through connection 80 branches into two paths 112 and 114, and flows through switch 115, further increasing the path length and path time. Similarly, when only switch 117 is turned on, the flow through connection 80 branches into two paths 112 and 114, and flows through switch 117, further increasing the path length and path time.

[0123] In this way, by selectively turning on any of the four switches 111, 113, 115 and 117, the path length and path time of the flow through the connection part 80 are increased in stages. As a result, when the two antennas 32, 34 are fed along the path of the connection part 80, the phase of the electromagnetic waves radiated from the two antennas 32, 34 can be adjusted over time. In other words, the longer the path length, the greater the phase difference between the electromagnetic waves radiated from the two patch antennas.

[0124] Referring to (A) and (B) of FIG. 26, a modified example 120 of the path length adjusting means (branching section 110) of the connection section 80 is illustrated, which includes the four-stage switches 111, 113, 115, and 117 illustrated in (A) and (B) of FIG. 25. Referring to (A) and (B) of Figures 26, the branching section 120 has three paths 122, 124, and 126 that branch off and extend in a direction perpendicular to the extension direction of the connection section 80 at the center of the connection section 80, and four switches 121, 123, 125, and 127 arranged between these three branching paths 122, 124, and 126.

[0125] For example, when only switches 121 and 123 are turned on via a control device (such as control device 200), the flow through connection part 80 is transmitted straight without branching into three paths 122, 124, and 126. Similarly, when only switches 121 and 127 are turned on, the flow through connection 80 branches into two paths 124 and 126, increasing the path length and path time. Similarly, when only switches 125 and 127 are turned on, the flow through connection 80 branches into two paths 122 and 126, further increasing the path length and path time.

[0126] In this way, by selectively turning on the four switches 121, 123, 125, and 127, the path length and path time of the flow through the connection part 80 are increased in stages. As a result, when power is fed to the two antennas 32, 34 along the path of the connecting portion 80, the phase difference between the electromagnetic waves radiated from the two antennas 32, 34 can be adjusted to increase in stages in accordance with changes in the path length. By superimposing the electromagnetic waves with a phase difference emitted from the two patch antennas 32 and 34, it is possible to swing the radiation pattern left and right.

[0127] Referring to Figure 27, an example radiation pattern in three-dimensional space is shown for the example case of Figure 26. In this example, the flow through connection 80 is adjusted to provide the longest path length by turning on switches 125 and 127. Referring to FIG. 27, it is illustrated that when two antennas 32, 34 are fed, different left and right radiation patterns can be achieved.

[0128] Referring to FIG. 28, it is illustrated that different radiation patterns can be configured for the case illustrated in FIG. For example, in the case illustrated by the symbol 28a, it can be seen that by switching the switch provided at the connection part 80, the electromagnetic waves radiated from the antenna are emitted equally to the left and right with 0° as the center. In contrast, in the cases illustrated by symbols 28b to 28d, it can be seen that by switching the switch provided in connection portion 80, the electromagnetic waves radiated from the antenna are biased to the left or right of 0°.

[0129] As described above, in Figures 25 to 28, by providing a branch section 110 or 120 consisting of multiple switches to a connection section 80 that connects two antennas in a straight line, it is possible to control the phase difference flowing through the two antennas via any control device (for example, control device 200). In addition, by providing a branch section 110 or 120 consisting of multiple switches to the connection section 90 that connects two antennas in a broken line, as illustrated in Figures 23 and 24, it is possible to control the phase difference flowing through the two antennas via any control device (e.g., control device 200). Furthermore, control by the branching section 110 or 120 consisting of multiple switches can also be combined with control of the metasurface 10 consisting of multiple patches, as exemplified in Examples 1 and 2.

[0130] 29A and 29B illustrate an example in which a metasurface 10 consisting of 15 patches 12 arranged in 3 rows and 5 columns is provided with switches that control the current state of each patch. By controlling these switches, the current state of the multiple patches 12 that make up the metasurface 10 can be changed in various ways. As a result, the radiation direction of the electromagnetic waves passing through the metasurface 10 can be changed.

[0131] 29(A) and 29(B), two antennas 31 and 33 arranged on the back side of a metasurface 10 consisting of 15 patches 12 arranged in 3 rows and 5 columns are connected by a connection part 80 and have a branch part 110 consisting of multiple switches. By controlling the above switches, the phase difference flowing through the two antennas 31 and 33 via the connection part 80 can be changed in various ways. As a result, the radiation direction of the electromagnetic waves radiated from the patch antennas 31 and 33 can be changed. By combining these two types of control, it is possible to more complexly control the radiation pattern of the electromagnetic waves emitted from the antenna and transmitted through the metasurface 10.

[0132] In the above, in Example 1 described with reference to Figures 1 to 11, Example 2 described with reference to Figures 12 to 19, and Example 3 described with reference to Figures 20 to 29, beamforming of electromagnetic waves emitted from the antenna is possible in each case. Each of Example 1, Example 2, and Example 3 can be implemented independently. Also, each of Example 1, Example 2, and Example 3 can be used in combination with each other. Therefore, the wireless power supply devices 1 and 2 can be configured to be able to supply power to various devices such as sensors and actuators in the fields of FA, IoT, home appliances, etc. [Example]

[0133] Next, with reference to FIGS. 30 to 35, an example of beamforming performed using the wireless power supply devices 1 and 2 in the field of actual factory automation will be described. 30 to 34, a schematic example is shown of a case where wireless power is supplied from a power transmitting device to a power receiving device when the power receiving device is attached to the tip of a robot hand (tip of an arm). Referring to (A) of Figure 30, an example is shown in the field of factory automation, where the main body of a robot hand is installed on a substrate, and the movable part frequently moves back and forth in three-dimensional space.

[0134] In this example, at time t1, the tip of the robot hand is facing left, so the antenna of the power transmitting device is set to face left in order to wirelessly supply power to a power receiving device such as a sensor placed at the tip. At time t1, the orientation of the antenna of the power transmitting device corresponds to the position of the power receiving device, so that the electromagnetic waves transmitted in free space from the power transmitting device can be received relatively well by the power receiving device.

[0135] 30(A) illustrates that the robot hand operates more frequently as time progresses from t1 to t2, t3, and t4. In this case, since the orientation of the antenna of the power transmitting device is fixed, for example, at times t2 and t4, the tip of the robot hand faces right, which does not correspond to the power transmitting direction of the antenna, which is set to face left. In this case, it becomes difficult for the power receiving device to properly receive the electromagnetic waves transmitted from the power transmitting device in free space.

[0136] Referring to FIG. 30(B), it can be seen that as time progresses from t1 to t2 to t3 to t4, the tip of the robot hand periodically moves left and right. 30(C), it can be seen that the received energy of the power receiving device attached to the tip of the robot hand fluctuates greatly as time progresses from t1 to t2 to t3 to t4. In particular, at times t2 and t4, the position of the electromagnetic waves transmitted from the power transmitting device and the position of the tip of the robot hand to which the power receiving device is attached are different, and it can be seen that power is not being received by the power receiving device.

[0137] Referring to (A) to (C) of FIG. 31, a case similar to the example illustrated in (A) to (C) of FIG. 30 is illustrated. The only difference between the examples in (A) to (C) of FIG. 31 is that the antenna of the power transmitting device is fixed to face right. In this case, too, it can be seen that the frequent operation of the tip of the robot hand causes large fluctuations in the received energy of the power receiving device attached to the tip of the robot hand. In particular, it can be seen that the electromagnetic waves transmitted from the power transmitting device are not received by the power receiving device at times t1 and t3.

[0138] Referring to (A) to (C) of FIG. 32, a case similar to the example illustrated in (A) to (C) of FIG. 30 is illustrated. The only difference between the examples in FIGS. 32(A) to 32(C) is that the antenna of the power transmitting device is fixed to face forward. In this case too, it can be seen that frequent operation of the tip of the robot hand causes large fluctuations in the received energy of the power receiving device provided at the tip of the robot hand.

[0139] Referring to (A) to (C) of Figure 33, an example is shown in which beamforming of electromagnetic waves emitted from an antenna is possible using the wireless power supply devices 1 and 2 according to the present embodiment 1, embodiment 2, and embodiment 3. As can be seen from Figure 33 (A), when the tip of the robot hand moves frequently, the power transmission direction of the antenna of the power transmission device is adjusted (i.e., beamforming is performed) in response to these changes. Therefore, as can be seen from (B) of Figure 33, even if the tip of the robot hand periodically moves back and forth as time progresses from t1 to t2, t3, and t4, as can be seen from (C) of Figure 33, the power transmitting device can continuously send electromagnetic waves in the optimal direction, as exemplified by the symbols Z1, Z2, Z3, Z4, Z5, Z6, and Z7, and the power receiving device can receive them.

[0140] Referring to (A) to (C) of Figure 33, when beamforming of electromagnetic waves emitted from an antenna is performed using the wireless power supply devices 1 and 2 according to the present embodiment 1, embodiment 2, and embodiment 3, the "learning" and "inference" models can be utilized.

[0141] Referring to FIG. 34(A), a process of learning the position of a power receiving terminal placed at the tip of a robot hand that is frequently in operation is illustrated. The position of the tip of a robot hand changes in various ways, but is usually not changed randomly. Therefore, some kind of calculation means (such as a control device) can be used to learn the changes in the position of the tip of the robot hand. For example, as shown in Fig. 34(A), information on the transmission direction of the antenna of the power transmitting device at a certain time and the received power of the power receiving terminal placed at the tip of the robot hand are input. By continuously tracking both values, it becomes possible to construct a mathematical model of the power receiving situation.

[0142] For example, when the antenna's transmission direction is aligned with the position of the tip of the robot hand, the power receiving terminal may show a good value of received power. On the other hand, when the antenna's transmission direction is aligned with the position of the tip of the robot hand, the power receiving terminal may show a poor value of received power. By comprehensively tracking and accumulating these values, it becomes possible to construct a mathematical model for determining at what time (sampling timer) and in what direction the antenna should be pointed to achieve a good power receiving effect.

[0143] For example, a mathematical model F(t, d)=V may be constructed using the time (t: sampling time) obtained from a sampling timer, the transmitting direction of the antenna at that time (d: direction), and the received power (V) of the power receiving device at that time. In this case, F is an arbitrary function, and may be obtained by computer simulation using an appropriate algorithm. In this case, for example, the Euler method, the finite element method, the Monte Carlo method, etc. may be used.

[0144] Next, referring to FIG. 34(B), an example of a process for inferring the position of a power receiving terminal placed at the tip of a robot hand that is frequently in operation is shown. 34(A), after the mathematical model is obtained, by inputting information at a certain time (sampling timer) into the mathematical model (for example, F(t, d)=V), it is possible to find the optimal transmission direction to obtain a good power receiving effect. Therefore, by performing beamforming of the electromagnetic waves emitted from the antenna using the wireless power supply devices 1 and 2 according to the first, second, and third embodiments based on this output, it becomes possible to continuously transmit power energy in the optimal direction.

[0145] In addition, the above learning and inference process can automatically adjust the "sampling timer" used in optimization. Since a system is constructed that automatically corrects the mathematical model regardless of the starting time, there is no need to specify the start of the "sampling timer." Furthermore, the "direction" does not need to be determined from the actual factory system, but can be determined independently by the power transmitter. This embodiment is intended to evaluate the effectiveness of the independently determined "direction" and build a mathematical model. Ultimately, it is expected that either method will produce similarly optimal results. Therefore, this embodiment is suitable for utilizing the correction that is unique to FA, which involves repeating a certain operation.

[0146] Therefore, this embodiment constitutes a method for transmitting energy to a power receiving terminal whose position in a three-dimensional space is changed using a wireless power supply apparatus and a control apparatus. The control device comprises the following steps: Tracking time, the direction of transmission of electromagnetic waves E1 to E3 (see FIG. 1) from the wireless power supply device 1 (see FIG. 1), and the received power of the power receiving device with respect to changes in the position of the power receiving device; calculating the power transmission directions of the electromagnetic waves E1 to E3 of the wireless power supply device 1 based on the tracking; A step of controlling the transmission direction of the electromagnetic waves E1 to E3 from the wireless power supply device 1 based on the calculation result.

[0147] The control device may be, for example, a single-board computer equipped with a processor. The control device may be, for example, a Raspberry Pi. It may also be realized by edge computing using Python (registered trademark) on a Raspberry Pi. The control device is not limited to the above examples and may be, for example, a mobile terminal such as a smartphone, tablet, mobile phone, or personal digital assistant (PDA), a wearable terminal such as glasses, a wristwatch, or clothing, a stationary computer or a portable notebook personal computer, a server located in the cloud or on a network, or a combination of multiple such terminals. For example, a combination of one smartphone and one wearable terminal can logically function as one terminal. Other information processing terminals may also be used.

[0148] A main memory device can be associated with the control device. This main memory device stores various programs, applications, etc. (modules), and the processor executes these programs and applications to realize each functional element of the overall system. Each of these modules may be implemented in hardware, for example by integration. Each module may be an independent program or application, or may be implemented as a subprogram or function within a single integrated program or application.

[0149] The wireless power supply devices according to the first to fourth embodiments and the methods for transmitting power to a power receiving terminal using the devices have been described above with reference to the drawings. By using Examples 1 to 4 alone or in combination, it is possible to configure a wireless power supply device suitable for automatically learning the optimal method (XYZ plane direction and frequency) without a teacher and for beamforming, and a method for transmitting power to a receiving terminal using the device. In particular, by using the first to fourth embodiments alone or in combination, it is possible to improve the efficiency of power reception. At this time, it is possible to reduce dependency on the environment. Furthermore, even when multiple power transmission devices are used simultaneously in the same space, it is possible to automatically prevent standing waves from occurring.

[0150] It should be understood that the present embodiment is not limited to the illustrated configuration. For example, in the above description, a wireless power supply device is described as being preferably configured using a patch antenna (planar antenna) in combination with a metasurface, but it should be understood that this embodiment is not limited to this configuration. The wireless power supply device can be configured using a linear antenna in combination with a metasurface in addition to the patch antenna (planar antenna), or in place of a part or multiple of the patch antenna. Any linear antenna, such as a dipole antenna, a monopole antenna, or an inverted-F antenna, can be used as the linear antenna.

[0151] It should be understood that any device or the like can be added to the antenna according to this embodiment to improve the flow of current. Furthermore, although the antenna according to this embodiment has been described as an antenna on the power transmitting side, some or all of the antennas can be applied as antennas on the power receiving side.

[0152] As described above, the applicant performed a simulation of the power transmission device using a mathematical model on a computer. Furthermore, the applicant actually conducted a measurement experiment when power was supplied wirelessly from a power transmitting device to a power receiving device. From this measurement experiment, the effectiveness of the power transmission device according to the present invention was confirmed, as will be described in detail below.

[0153] Referring to FIG. 35, an example of the environment used to perform the above measurement experiments is shown. As can be seen from the figure, the above measurement experiment used an anechoic chamber on six sides in a three-dimensional space. Therefore, we devised a highly reliable and efficient way to conduct wireless power transmission measurement experiments while minimizing the influence of external electromagnetic waves or electromagnetic noise. The power transmitting device and power receiving device according to the present invention were positioned in the anechoic chamber so that a 3-meter distance between them could be obtained. Furthermore, each device was positioned at a predetermined height. Furthermore, the relative orientation of the power transmitting device and power receiving device was made changeable, so that experimental results could be obtained for changes in this orientation. Therefore, the measurement experiment was conducted under ideal conditions, approximating as closely as possible the actual wireless power transmission state.

[0154] Furthermore, various measurement experiments were carried out assuming general wireless transmission waves in the environment shown in Figure 35. Specifically, a standard signal generator (SSG or SG) was used on the transmitting side, and a spectrum analyzer was used on the receiving side. Furthermore, in this measurement experiment, assuming general wireless transmission and reception, the EIRP (Effective Isotropic Radiated Power) was measured by determining how much output was obtained compared to the EIRP of a reference dipole. Note that EIRP refers to the strength of the power of radio waves radiated in a certain direction. A horn antenna capable of switching between horizontal and vertical polarization (HV plane) was used as the receiving antenna.

[0155] Figures 36(A) and (B) show the measurement results under the measurement environment shown in Figure 35. These measurement results correspond to the EIRP measurement results of the two-patch antenna shown in Figure 23(C). In this case, the patch has a thin, approximately rectangular shape. 36A1 is the radiation surface, and 36A2 is the ground. Fig. 23(C) shows a thin plate-shaped antenna, and Fig. 36(A) shows the antenna installed so that the longitudinal direction (longer side) of Fig. 23(C) is on the left-right side of the page. Fig. 36(B) shows the antenna in (A) rotated 90 degrees and installed so that the lateral direction (shorter side) of Fig. 23(C) is on the left-right side of the page.

[0156] As explained in Figure 23(C), two patch antennas are arranged rotated by 90 degrees, one of which radiates horizontally polarized waves and the other radiates vertically polarized waves. In other words, this two-patch antenna can radiate both horizontally and vertically polarized waves. Figures 36(A) and (B) show the radiation patterns measured when this two-patch antenna is rotated by 90 degrees, and it was found that a beam output was obtained in both cases. The EIRP was 3.394dB in the vertical plane and 4.27dB in the horizontal plane (at 1W input).

[0157] Referring to (A), (B) and (C) of FIG. 37, other measurement results under the measurement environment illustrated in FIG. 35 are shown. Figure 37 corresponds to the EIRP measurement results of the switch antenna in Figure 26(A), and is a diagram showing the measured radiation pattern when each switch (123 / 127 / 125 / 121) in Figure 26(B) is switched ON and OFF. Referring to Figure 37(A), when the four switches of the two-patch antenna are set to the (ON / OFF / OFF / ON) combination, the EIRP is confirmed to be 3.218 dB in the horizontal plane when the center 0 degrees is used as the reference. For example, referring to (B) in Figure 37, when the four switches of the two-patch antenna are set to the (ON / OFF / OFF / OFF) combination, the EIRP is confirmed to be 4.073 dB, 9 degrees to the right of the reference. For example, referring to (C) in Figure 37, when the four switches of the two-patch antenna are set to the (OFF / OFF / OFF / ON) combination, the EIRP is confirmed to be 3.675 dB, 7 degrees to the left of the reference.

[0158] In the case of Figure 37(A), the direction of the main lobe (the lobe with the strongest radiation direction) is directed in the standard 0-degree direction, but by appropriately switching the four switches, it was confirmed that the direction of the main lobe can be shifted to the right (see Figure 37(B)) or to the left (see Figure 37(C)). It was also confirmed that in each case, the side lobes (lobes other than the main lobe) also change. Furthermore, it was confirmed that the direction of the main lobe can be switched in increments of about 10 degrees either left or right. Therefore, in practice, it was expected that the beamforming direction could be adjusted relatively precisely. These measurement results not only confirmed through computer simulation that beamforming is possible according to the present invention, but also proved through actual measurements.

[0159] The present invention is not limited to the above-described embodiments and includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, or to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of each embodiment with other configurations.

[0160] In addition, the control lines and information lines shown are those that are considered necessary for the explanation, and do not necessarily show all the control lines and information lines in the product. In reality, it can be assumed that almost all components are interconnected. The above-described embodiments disclose at least the configurations described in the claims. [Explanation of symbols]

[0161] 1...wireless power supply device, 10...metasurface, 12a, 12b, 12c...patches (waveguide patches or radiating patches), 20a, 20b...switches (high frequency switches or RF switches), 30...antenna (patch antenna or planar antenna), 200...control device

Claims

1. A wireless power supply device, a metasurface having a plurality of waveguide patches and a plurality of switches disposed relative to the plurality of waveguide patches; a control device that controls a power supply state to the plurality of switches; an antenna that emits electromagnetic waves to transmit power; and a radiation pattern of the electromagnetic waves radiated from the antenna is changed by changing the connection relationship of the plurality of waveguide patches by switching the plurality of switches; Wireless power supply device.

2. a radiation pattern of the electromagnetic wave can be adjusted by changing a current-carrying state for each of the plurality of waveguide patches; The wireless power supply device according to claim 1 .

3. The radiation pattern of the electromagnetic wave can be adjusted by changing the distance between the waveguide patch and the antenna.

3. The wireless power supply device according to claim 1 or 2.

4. the switches are associated with the plurality of waveguide patches so as to straddle two adjacent waveguide patches; The wireless power supply device according to claim 1 .

5. the plurality of waveguide patches as a whole constitute one metasurface; The waveguide patch arranged on the outside in contact with the periphery of the metasurface has the switches assigned to the periphery sides of adjacent sides, and The waveguide patch arranged inside and not in contact with the outer periphery of the metasurface has the switch assigned to the center side of adjacent sides, The wireless power supply device according to claim 1 .

6. the plurality of waveguide patches as a whole constitute one metasurface; The waveguide patch arranged on the outside in contact with the outer periphery of the metasurface is assigned three of the switches, and The waveguide patch arranged inside and not in contact with the outer periphery of the metasurface is assigned four of the switches, The wireless power supply device according to any one of claims 1 to 5.

7. the plurality of waveguide patches are periodically arranged on a substrate in an array of n patches vertically and m patches horizontally; The switches associated with the plurality of waveguide patches are arranged in a total of m*(n-1)+n*(m-1) pieces. The wireless power supply device according to any one of claims 1 to 6.

8. The antenna comprises at least two antennas; The connecting line connecting the at least two antennas is provided with a plurality of switches and a plurality of branching sections that enable the path length to be changed. The wireless power supply device according to any one of claims 1 to 7.

9. The antenna comprises at least two antennas; The connecting line connecting the at least two antennas changes its path direction at a right angle along at least a part of the substantially swastika-shaped configuration.

9. The wireless power supply device according to claim 1.

10. The antenna is a patch antenna.

10. The wireless power supply device according to claim 1.

11. the antenna includes at least two patch antennas; The at least two patch antennas are configured to be capable of supporting right-handed and left-handed polarization.

11. The wireless power supply device according to claim 1.

12. The radiation pattern of the electromagnetic waves radiated from the antenna includes at least A pattern that radiates electromagnetic waves straight along a 0° direction in three-dimensional space; a pattern that radiates electromagnetic waves biased to the left of the 0° direction; a pattern that radiates electromagnetic waves biased to the right from the 0° direction; 12. The wireless power supply of claim 1, optionally comprising:

13. The radiation pattern of the electromagnetic waves radiated from the antenna includes at least A pattern that radiates electromagnetic waves in one direction in a three-dimensional space in a convex shape, A pattern that radiates electromagnetic waves in two convex shapes in one direction in three-dimensional space, 13. The wireless power supply of claim 1, optionally comprising:

14. By changing the radiation pattern of the electromagnetic waves radiated from the antenna, the radiation pattern can be swung at least within ±30°.

14. The wireless power supply device according to any one of claims 1 to 13.

15. A method for radiating electromagnetic waves to a power receiving device using the wireless power supply device according to any one of claims 1 to 14 and a control device, comprising: The control device Tracking time, a direction of electromagnetic wave transmission of the wireless power supply device, and received power of the power receiving device with respect to a change in the position of the power receiving device; calculating a transmission direction of electromagnetic waves of the wireless power supply device based on the tracking; controlling a transmission direction of electromagnetic waves of the wireless power supply device based on the calculation result; having method.

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