Power transmission device, method, and program

Abstract

To improve radio wave radiation in a direction other than a front direction of an antenna comprising a plurality of antenna elements.SOLUTION: A power transmission device comprises an antenna comprising: a first antenna element 111 for transmitting radio waves, that is provided on a circuit board 110; a second antenna element 112 for transmitting the radio waves, that is provided on the circuit board 110; and a third antenna element 113 for transmitting the radio waves, that is provided on the circuit board 110. A gain of element directivity of the first antenna element 111 in a front direction of the antenna is higher than a gain of element directivity of each of the second antenna element 112 and the third antenna element 113.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present application relates to a power transmission device, a method, and a program. [Background technology]

[0002] In wireless power transmission, a power transmitting device uses an array antenna to form a beam in the direction of a power receiving device, thereby wirelessly supplying power. Patent Document 1 discloses an array antenna in which the element width of the inner two radiating elements out of four radiating elements is narrower than the element width of the outer two radiating elements. Patent Document 2 discloses an array antenna device formed by combining only multiple equal power distributors with multiple antenna elements arranged in a straight line. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2000-269735 A [Patent Document 2] JP 2003-283244 A Summary of the Invention [Problem to be solved by the invention]

[0004] In wireless power transmission, an array antenna with a high antenna gain, in other words, a narrow beam width, is effective for efficient power reception by a power receiving device. In a power transmitting device for wireless power transmission, one method for improving the power transmission efficiency is to increase the antenna gain of each antenna element of the array antenna to increase the antenna gain of the entire array antenna. However, narrowing the directivity of the antenna elements causes a problem that while the beam power in the front direction of the array antenna increases, the beam power in directions other than the front direction decreases according to the element directivity. In a power transmitting device for wireless power transmission, there is room for improvement in the radiation of radio waves in directions other than the front direction of an antenna having multiple antenna elements. [Means for solving the problem]

[0005] A power transmission device in one aspect includes an antenna having a first antenna element mounted on a substrate and transmitting radio waves, a second antenna element mounted on the substrate and transmitting the radio waves, and a third antenna element mounted on the substrate and transmitting the radio waves, wherein the element directivity gain of the first antenna element in a front direction of the antenna is higher than the element directivity gains of the second antenna element and the third antenna element.

[0006] A method according to one aspect is a method performed by a power transmission device equipped with an antenna mounted on a substrate and having a first antenna element for transmitting radio waves, a second antenna element for transmitting the radio waves, and a third antenna element for transmitting the radio waves, in which a second power is supplied to the second antenna element and the third antenna element, and the second power is adjusted based on the angle so that the second power becomes larger as the angle from the front direction of the antenna to the power supply target becomes larger.

[0007] A program according to one aspect causes a power transmission device having an antenna mounted on a substrate and having a first antenna element for transmitting radio waves, a second antenna element for transmitting the radio waves, and a third antenna element for transmitting the radio waves to execute a process of setting the power supplied to the second antenna element and the third antenna element as a second power, and adjusting the second power based on the angle so that the second power becomes larger as the angle from the front direction of the antenna to a power supply target becomes larger. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram for explaining an overview of a wireless power transmission system according to an embodiment. [Diagram 2] FIG. 2 is a diagram for explaining an example of the arrangement of the array antenna shown in FIG. [Diagram 3] FIG. 3 is a diagram showing an example of an antenna radiation pattern of a one-dimensional eight-element array antenna composed of omnidirectional elements. [Figure 4] FIG. 4 is a diagram showing an example of an antenna radiation pattern when configured with low-gain antenna elements. [Diagram 5] FIG. 5 is a diagram showing an example of an antenna radiation pattern when configured with high-gain antenna elements. [Figure 6] FIG. 6 is a diagram showing an example of an antenna radiation pattern of an antenna configured by single low-gain and high-gain antenna elements. [Figure 7] FIG. 7 is a schematic diagram for explaining a first array antenna for reference that is constituted by high gain elements. [Figure 8] FIG. 8 is a schematic diagram for explaining a second array antenna for reference that is configured with low gain elements. [Figure 9] FIG. 9 is a diagram illustrating an example of the configuration of a power transmitting device according to an embodiment. [Figure 10] FIG. 10 is a schematic diagram for explaining an example of the arrangement of the array antenna shown in FIG. [Figure 11] FIG. 11 is a diagram for explaining the results of the angle dependency of the maximum beam of the array antenna. [Figure 12] FIG. 12 is a diagram showing the dependence of the maximum beam of the array antenna according to the embodiment. [Figure 13] FIG. 13 is a schematic diagram for explaining an example of power supply to the array antenna shown in FIG. [Figure 14] FIG. 14 is a diagram for explaining optimization of power allocation in an array antenna. [Figure 15] FIG. 15 is a diagram for explaining a model of an array antenna used for optimizing power distribution. [Figure 16] FIG. 16 is a flowchart showing an example of a processing procedure for allocating power to an array antenna. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A number of embodiments according to the present application will be described in detail with reference to the drawings. Note that the present invention is not limited to the following description. Furthermore, the components in the following description include those that a person skilled in the art can easily imagine, those that are substantially the same, and those that are within the so-called equivalent range. In the following description, similar components may be given the same reference numerals. Furthermore, duplicated descriptions may be omitted.

[0010] FIG. 1 is a diagram for explaining an outline of a wireless power transmission system according to an embodiment. The system 1 shown in FIG. 1 includes, for example, a wireless power transmission system capable of microwave transmission type (space transmission type) wireless power transmission. Wireless power transmission is a mechanism that allows power to be transmitted without using, for example, a cable or a plug. The system 1 can be applied to, for example, space solar power generation. The microwave transmission type system 1 uses radio waves (microwaves) as energy transmission. A plurality of frequency bands are available for the radio waves used in the microwave transmission type system 1, and in Japan, for example, the 920 MHz band, the 2.4 GHz band, the 5.7 GHz band, and the like are included. The microwave transmission type system 1 can use a retrodirective method. In this embodiment, the system 1 can achieve both improvement of power supply efficiency appropriate to the situation and ensuring safety. Note that, in the wireless power transmission system of the present disclosure, the frequency band of the radio waves used is not limited to microwaves, and radio waves of other appropriate frequency bands can be used.

[0011] In the example shown in FIG. 1, the system 1 uses a multipath retrodirective method. The system 1 includes a power transmitting device 10 and a power receiving device 20. The system 1 transmits power from the power transmitting device 10 to the power receiving device 20 using multiple paths (propagation channels). The power transmitting device 10 is a transmission device in the system 1 that transmits power wirelessly and is a device capable of transmitting radio waves for power supply. The power transmitting device 10 includes a sensor unit 15 that can detect an object such as a human body in the vicinity of the array antenna 11. In the following description, the power transmitting device 10 may be referred to as "own device".

[0012] The power receiving device 20 is a power-supplied device that receives radio waves for power supply and obtains power in the system 1. The power receiving device 20 includes, for example, a smartphone, a tablet terminal, an IoT (Internet of Things) sensor, a notebook personal computer, a drone, an electric car, an electric bicycle, a game machine, etc. In this manner, the power receiving device 20 of the present disclosure is an example of a power supply target, and may be a mobile device.

[0013] In scene C1, the power receiving device 20 can transmit a prescribed signal 1000 determined between the power receiving device 20 and the power transmitting device 10. The prescribed signal 1000 includes, for example, a beacon, a pilot signal, and the like. The power receiving device 20 can transmit the prescribed signal 1000, for example, at a transmission period. The power receiving device 20 can transmit the prescribed signal 1000 by emitting radio waves including the prescribed signal 1000. On the other hand, when the power transmitting device 10 receives the prescribed signal 1000, it estimates characteristic values ​​(array response vectors) of multiple paths from the power receiving device 20 to the power transmitting device 10 based on the prescribed signal 1000. The power transmitting device 10 calculates a weighting coefficient for transmission using the estimated array response vector for the power receiving device 20.

[0014] In scene C2, the power transmitting device 10 performs directivity control by multiplying each antenna by a weighting coefficient, and radiates radio waves including a transmission signal 2000 for power supply. Directivity control means, for example, controlling the relationship between the radiation direction and radiation intensity of radio waves. If the frequencies of the prescribed signal 1000 and the transmission signal 2000 are the same and time fluctuations in the propagation path are ignored, the characteristics of the multiple paths from the power transmitting device 10 to the power receiving device 20 match the characteristics from the power receiving device 20 to the power transmitting device 10. As a result, the radio waves 2000W radiated from the power transmitting device 10 have a radiation pattern that makes use of not only paths toward the power receiving device 20, but also paths toward a direction different from the power receiving device 20.

[0015] Methods for increasing the gain of the power transmission antenna of the power transmission device 10 include a first method of increasing the number of antenna elements (hereinafter referred to as the number of elements) of the array antenna 11 to increase the antenna aperture area, and a second method of narrowing the element directivity of each element, i.e., increasing the gain of each element to increase the gain of the entire array antenna 11.

[0016] The first method is effective, but has practical limitations because it requires an increase in the size of the antenna and an increase in the scale of the transmission signal processing and transmission circuit. The second method also has limitations, but is often used because, in addition to the first method, it can improve the overall antenna gain and reduce the coupling between antenna elements, making it possible to bring the performance of the array antenna 11 closer to the ideal.

[0017] Hereinafter, a description will be given of a case where the second method of narrowing the element directivity (increasing the element antenna gain) is applied to the wireless power transmission system 1. Fig. 2 is a diagram for explaining an example of the arrangement of the array antenna 11 shown in Fig. 1.

[0018] As shown in Fig. 1, the array antenna 11 of the power transmitting device 10 has a plurality of antenna elements 11A arranged in a matrix. In the example shown in Fig. 2, in order to simplify the explanation, one of the plurality of arrangements along the arrangement direction 11X is shown. In Fig. 2, the direction in which the plurality of antenna elements 11A are arranged is the arrangement direction 11X, the direction perpendicular to the arrangement direction 11X is the front direction 11Y, the direction of the power supply target including the power receiving device 20 is the direction R, and the angle at which the front direction 11Y and the direction R intersect is the angle θ. The case where the angle θ=0° may be defined as the front of the antenna or antenna element.

[0019] Array antenna 11 has N antenna elements 11A arranged at intervals d in arrangement direction 11X. N is an integer. The N antenna elements 11A are assigned i=1, 2, 3,...N. The radiation directivity E(θ) of array antenna 11, in which N antenna elements 11A having element directivity g(θ) are arranged one-dimensionally at intervals d, is given by the following (Equation 1). Radiation directivity E(θ) is an antenna pattern. It is known that the radiation directivity of array antenna 11 is expressed by adding only the phase difference due to the arrangement position of antenna elements 11A in consideration. In (Equation 1), the excitation amplitude of Nth antenna element 11A is expressed as a n , the excitation phase is ψ n Here, k=2π / λ is the wave number in free space, and λ is the free space wavelength.

number

[0020] Here, k=2π / λ is the wave number in free space, and λ is the wavelength. Also, D(θ) is called the array factor, and is the excitation amplitude a of the signal input to each antenna element 11A. n and the excitation phase ψ n The antenna radiation pattern is determined by the element directivity g(θ) ≡ 1, i.e., the element is omnidirectional and the excitation amplitude a n is constant regardless of n, that is, in the case of a phased array, the maximum beam size is constant regardless of the direction. Note that "≡" is a congruence symbol.

[0021] Fig. 3 is a diagram showing an example of an antenna radiation pattern of a one-dimensional eight-element array antenna composed of non-directional elements. In Fig. 3, the vertical axis shows the magnitude [dB] of the maximum beam, and the horizontal axis shows the angle ψ [°] at which the maximum beam is directed. Fig. 3 shows pattern P1 with angle ψ = 0° at which the maximum beam is directed, pattern P2 with angle ψ = 10°, and pattern P3 with angle ψ = 20°, all of which have the same magnitude (power) of the maximum beam.

[0022] On the other hand, when element directivity g(θ) ≡ 1, the angular dependency of radiation directivity is determined by element directivity g(θ). For example, the calculation results of the radiation patterns when the same one-dimensional 8-element (N = 8) array antenna is configured with low gain elements and when configured with high gain elements are shown below. High gain and low gain indicate the difference in the reach of an antenna that efficiently concentrates power in an antenna with directivity that spreads power in various directions. High gain elements are antenna elements that can reach farther than low gain elements.

[0023] Fig. 4 is a diagram showing an example of an antenna radiation pattern when configured with low-gain antenna elements. Fig. 5 is a diagram showing an example of an antenna radiation pattern when configured with high-gain antenna elements. Figs. 4 and 5 show patterns P11 and P21 with an angle ψ=0° at which the maximum beam is directed, patterns P12 and P22 with an angle ψ=10°, and patterns P13 and P23 with an angle ψ=20°.

[0024] As shown in Figure 4, the maximum beam size when configured with low-gain antenna elements attenuates along the element directivity g(θ), and the gain at angle ψ=0° in the front direction 11Y of the antenna is low (about 25 dB), but the decrease in gain is small when the angle ψ changes. Also, as shown in Figure 5, the maximum beam size when configured with high-gain antenna elements attenuates along the element directivity g(θ), and the gain at angle ψ=0° in the front direction 11Y of the antenna is high (about 30 dB), but the decrease in gain is large when the angle ψ changes.

[0025] FIG. 6 is a diagram showing an example of an antenna radiation pattern of an antenna composed of single low-gain and high-gain antenna elements. As shown in FIG. 6, the low-gain pattern P31 and the high-gain pattern P32 are consistent with the shape (ratio) of the angle dependency of the maximum beam power of the array antenna shown in FIG. 4 and FIG. 5. That is, the element directivity can determine the angle dependency of the maximum beam power of the array antenna. In FIG. 6, the pattern P31 shows the wide directivity of a low-gain element, and has an absolute gain of 7.1 dBi. The absolute gain is the power in the maximum radiation direction, and can be expressed as a ratio [dBi] to an isotropic antenna. The pattern P32 shows the narrow directivity of a high-gain element, and has an absolute gain of 12.2 dBi.

[0026] FIG. 7 is a schematic diagram for explaining a reference first array antenna composed of high gain elements. As shown in FIG. 7, the first array antenna 610 is arranged with eight high gain elements 612 having element directivity g(θ) shown in the pattern P32 of FIG. 6 aligned along the arrangement direction 600D of the substrate 611. The high gain elements 612 are high gain antenna elements. The size of the maximum beam has angle dependency determined by the element directivity g(θ). Since this angle dependency is equivalent to the element directivity, in the following description, the beam angle to the power supply target is represented as ψ, and the angle dependency of the size of the maximum beam is represented as g(ψ). Since the angle dependency is strong when composed of the high gain elements 612, the gain in the front direction 11Y is high, and efficient power transmission to the power supply target 20A can be realized, but conversely, the power transmission efficiency to the power supply target 20B in the direction of angle ψ=30° is greatly deteriorated.

[0027] Fig. 8 is a schematic diagram for explaining a reference second array antenna composed of low-gain elements. As shown in Fig. 8, the second array antenna 620 has eight low-gain elements 622 having element directivity g(θ) shown in the pattern P31 in Fig. 6 arranged along the arrangement direction 600D of the substrate 621. As described above, the low-gain elements 622 have the maximum beam size with angle dependency g(ψ), so that power transmission with little degradation due to angle dependency (for example, about -3 dB) can be realized in the direction of about ±40°, but conversely, high power transmission efficiency to the power supply target 20A in the front direction 11Y cannot be realized (for example, about 6 dB worse).

[0028] In this embodiment, an array antenna is configured with antenna elements having different element directivities, and a power transmitting device 10 is provided in which the beam power reduction is small even in directions other than the front direction 11Y of the array antenna.

[0029] (Embodiment) [Configuration of power transmitting device according to embodiment] Fig. 9 is a diagram showing an example of the configuration of the power transmitting device 10 according to the embodiment. Fig. 10 is a schematic diagram for explaining an example of the arrangement of the array antenna shown in Fig. 9.

[0030] As shown in FIG. 9, the power transmitting device 10 includes an array antenna 11, a transmission signal generating unit 12, a transmitting / receiving unit 13, an estimating unit 14, a sensor unit 15, a detecting unit 16, a control unit 17, and a multiplying unit 18.

[0031] The array antenna 11 is configured to enable directivity control (beam forming). The array antenna 11 has a plurality of antenna elements 11A arranged in a matrix. The array antenna 11 is configured such that, for example, each of the plurality of antenna elements 11A radiates a radio wave, and by adjusting the phase and power intensity of each, the array antenna 11 can strengthen the radio wave in a specific direction and weaken it by canceling each other out in another direction. The array antenna 11 is an example of an antenna.

[0032] The array antenna 11 emits radio waves including a transmission signal 2000, and receives radio waves including a specified signal 1000 from the power receiving device 20. The array antenna 11 supplies the received signal to the transmitting / receiving unit 13. In the example shown in Fig. 10, for the sake of simplicity, a case will be described in which the array antenna 11 has eight antenna elements 11A arranged side by side along an arrangement direction 11X, but the number of antenna elements 11A is not limited to this.

[0033] FIG. 10 shows an example of the arrangement of a plurality of antenna elements 11A in a predetermined row or column of the array antenna 11 arranged in a matrix as shown in FIG. 1. As shown in FIG. 10, the array antenna 11 has a substrate 110 and a plurality of antenna elements 11A. The substrate 110 is, for example, a circuit substrate having a substantially rectangular, circular, or elliptical shape on which the plurality of antenna elements 11A are mounted, and is configured to be capable of supplying power to each of the plurality of antenna elements 11A. The plurality of antenna elements 11A have two first antenna elements 111, three second antenna elements 112, and three third antenna elements 113 in an arrangement direction 11X. The arrangement direction 11X is set at a predetermined interval along a side, edge, or the like in a first direction of the substrate 110. Furthermore, the arrangement direction 11X is set at a predetermined interval along a side, edge, or the like in a second direction intersecting with the first direction of the substrate 110. That is, a plurality of arrangement directions 11X along the first direction and a plurality of arrangement directions 11X along the second direction intersect on the substrate 110.

[0034] The two first antenna elements 111 are provided on the substrate 110 and are high-gain antenna elements capable of transmitting radio waves. The two first antenna elements 111 are arranged in an arrangement direction 11X of the substrate 110 near a point where the arrangement direction 11X intersects with or is perpendicular to a front direction 11Y of the array antenna 11. In this embodiment, the array antenna 11 is configured such that the two first antenna elements 111 are arranged in an arrangement direction 11X near a point where the arrangement direction 11X intersects with the front direction, thereby improving the efficiency of power transmission in the front direction.

[0035] The three second antenna elements 112 are arranged on the substrate 110 so as to be aligned in a straight line with the first antenna element 111 along the arrangement direction 11X of the first antenna element 111, and are antenna elements capable of transmitting radio waves. The three third antenna elements 113 are arranged on the substrate 110 so as to be aligned in a straight line with the first antenna element 111 and the three second antenna elements 112 along the arrangement direction 11X of the first antenna element 111, and are antenna elements capable of transmitting radio waves. That is, the array antenna 11 arranges the three third antenna elements 113 at a predetermined interval in the arrangement direction 11X toward a direction away from one side 110E1 of the region 110E of the substrate 110 in which the first antenna element 111 is arranged. The array antenna 11 arranges the three second antenna elements 112 at a predetermined interval in the arrangement direction 11X toward a direction away from the other side 110E2 of the region 110E of the substrate 110 in which the first antenna element 111 is arranged. In the array antenna 11, three elements are arranged on each side of the two first antenna elements 111 in the arrangement direction 11X, thereby improving the efficiency of power transmission in directions other than the forward direction.

[0036] In an example shown in FIG. 10, the two first antenna elements 111 are high-gain antenna elements having element directivity g(θ) in which the maximum beam is large when the angle ψ is near 0° and the maximum beam is small when the angle ψ is near ±30°, as shown in pattern P32 in FIG. 6. The three second antenna elements 112 and the three third antenna elements 113 are low-gain antenna elements having element directivity g(θ) in which the maximum beam is large when the angle ψ is near ±30°, as shown in pattern P31 in FIG. 6. In this embodiment, the second antenna element 112 and the third antenna element 113 are the same low-gain element, but are not limited to this. For example, the second antenna element 112 and the third antenna element 113 may be configured as antenna elements having a lower gain than the gain of the first antenna element 111 and different gains.

[0037] 10, in the arrangement direction 11X, the array antenna 11 has two high-gain first antenna elements 111 arranged near a central portion 11C corresponding to the front direction, and has low-gain second antenna elements 112 and third antenna elements 113 arranged on both sides of an area 110E. In the array antenna 11, a strong beam reaches a power supply target 20A near the front direction from the high-gain first antenna element 111 in the central portion 11C, and a medium-intensity beam reaches the power supply target 20B from the left and right of the area 110E. In addition, in the array antenna 11, the beam from the high-gain first antenna element 111 in the central portion 11C is weaker at a power supply target 20B that is angled with respect to the front direction, but the sum of the beams from the low-gain second antenna element 112 and third antenna element 113 on the left and right of the area 110E increases. As a result, in the array antenna 11, in the arrangement direction 11X, a high-gain first antenna element 111 is arranged in the central portion 11C, and a low-gain second antenna element 112 and a low-gain third antenna element 113 are arranged on either side of it, thereby improving the power transmission efficiency to the power supply target 20B in the direction of angle ψ=30°, and therefore the power transmission efficiency can be improved more than that of the first array antenna 610 for reference shown in Figure 7, which is made up entirely of high-gain elements.

[0038] Returning to FIG. 9, the transmission signal generating unit 12 generates a transmission signal 2000 for power supply to be transmitted to the power receiving device 20. The transmission signal 2000 is a signal for emitting radio waves 2000W capable of supplying power. For example, the transmission signal 2000 may be a baseband signal. The transmission signal 2000 may be, for example, an unmodulated signal or a modulated signal. In the case of an unmodulated signal, there is no time variation in the transmission signal 2000 during the transmission period. In the case of a modulated signal, the transmission signal generating unit 12 time-varies the transmission signal 2000 during the transmission period. For example, the transmission signal generating unit 12 includes stopping the transmission signal 2000 at the timing of receiving the regulation signal 1000. The transmission signal generating unit 12 is electrically connected to the multiplier unit 18 and supplies the generated transmission signal 2000 to the multiplier unit 18.

[0039] The transmitting / receiving unit 13 has a plurality of transmitting / receiving circuits 13A electrically connected to each of the plurality of antenna elements 11A of the array antenna 11. The transmitting / receiving circuit 13A is electrically connected to the estimation unit 14, the multiplication unit 18, and the like. The transmitting / receiving circuit 13A extracts a reception signal received by the antenna element 11A and supplies it to the estimation unit 14. The transmitting / receiving circuit 13A causes the antenna element 11A to radiate a transmission signal 2000 multiplied by a transmission weight in the multiplication unit 18. The transmission weight includes, for example, a weighting coefficient capable of adjusting the amplitude and phase. The transmitting / receiving unit 13 causes the plurality of antenna elements 11A to simultaneously radiate radio waves 2000W including the transmission signal 2000 multiplied by the transmission weight (complex amplitude), so that the power transmitting device 10 radiates radio waves 2000W with controlled directivity.

[0040] The estimation unit 14 estimates a propagation channel characteristic (impulse response) from a reference signal 1000 included in a received signal received by the multiple antenna elements 11A. The propagation channel characteristic (impulse response) includes, for example, an amplitude characteristic and a phase characteristic. The array response vector indicates, for example, channel characteristics for the number of antennas. The array response vector includes, for example, a vector in which the propagation channel characteristic (impulse response) for each of the multiple antenna elements 11A is arranged. The array response vector in the receiving process is also called a receiving response vector. The estimation unit 14 estimates the receiving response vector using a known algorithm, for example, as disclosed in Japanese Patent Application Laid-Open No. 2002-43995. The estimation unit 14 supplies vector data of the array response vector to the control unit 17.

[0041] The sensor unit 15 can obtain information capable of detecting the presence or absence, direction, etc. of a power supply target in the radio wave propagation environment of the power transmitting device 10. The radio wave propagation environment includes, for example, a space in which radio waves of 2000 W are propagated between the power transmitting device 10 and the power receiving device 20. The sensor unit 15 obtains information on the power supply target present in the radio wave propagation environment using, for example, a camera, a LIDAR (Laser Imaging Detection and Ranging), a radar such as a millimeter wave radar, a ToF (Time of Flight) sensor, an infrared sensor, a human presence sensor, etc. The sensor unit 15 may be provided outside the power transmitting device 10. The sensor unit 15 is electrically connected to the detection unit 16, and supplies the detection unit 16 with sensor information capable of detecting the direction of the power supply target in the radio wave propagation environment. The sensor information includes, for example, information on the presence or absence, distance, position, image, etc. of the power supply target.

[0042] The detection unit 16 detects information on the position of the power supply target in the radio wave propagation environment based on the sensor information from the sensor unit 15. The detection unit 16 detects the direction of the power supply target from the array antenna 11. For example, the detection unit 16 detects the direction of the power supply target from the array antenna 11 based on the direction, position, etc. of the power supply target indicated by the sensor information and the relative positional relationship between the sensor unit 15 and the array antenna 11. When there are multiple power supply targets, the detection unit 16 detects the positions of the multiple power supply targets. The detection unit 16 is electrically connected to the control unit 17 and supplies the control unit 17 with directional information indicating the direction of the power supply target from the array antenna 11. The directional information includes, for example, information indicating the direction of the power supply target from the array antenna 11. In this way, the detection unit 16 of the present disclosure detects information on the position of the power supply target in the radio wave propagation environment based on sensor information including position information, directional information, distance information, etc. of the power supply target such as GPS information from the sensor unit 15.

[0043] The control unit 17 can control power supply to the first antenna element 111, the second antenna element 112, and the third antenna element 113 based on the direction of the power supply target from the array antenna 11. The control unit 17 generates weights for power transmission based on the array response vector for the power supply target, which is the estimation result of the estimation unit 14, and directional information of the power supply target from the detection unit 16. For example, a ZF (Zero-Forcing) algorithm or an MMSE (Minimum Mean Square Error) algorithm used in MIMO can be used as a method for generating the weights. The control unit 17 is electrically connected to the multiplication unit 18, and supplies weight information indicating the power transmission weights to the multiplication unit 18.

[0044] The control unit 17 has a storage unit 17D. The storage unit 17D may include any non-transient storage medium such as a semiconductor storage medium and a magnetic storage medium. The storage unit 17D may include a combination of a storage medium such as a memory card, an optical disk, or a magneto-optical disk, and a storage medium reader. The storage unit 17D may include a storage device used as a temporary storage area such as a RAM. The storage unit 17D can store a control program that causes the control unit 17 (computer) to execute a control method related to power transmission of the power transmitting device 10. The storage unit 17D may be provided outside the control unit 17.

[0045] The storage unit 17D may store various programs that cause the entire power transmission device 10 or the control unit 17 to function, and various information used by the entire power transmission device 10 or the control unit 17. In addition, the implementation form of the program is not limited to application programs such as object code compiled by a compiler and program code executed by an interpreter, and may be in the form of a program module incorporated into an operating system. Furthermore, the program may or may not be configured so that all processing is performed only by the CPU on the control board. The program used in the present disclosure may be configured so that a part or all of it is executed by another processing unit implemented on an expansion board or expansion unit added to the board as necessary.

[0046] The multiplier 18 multiplies the transmission signal 2000 from the transmission signal generator 12 by a weight for each of the antenna elements 11A based on the weight information of the controller 17. The multiplier 18 has, for example, a multiplier. The multiplier 18 supplies the transmission signal 2000 multiplied by the weight corresponding to the antenna element 11A to the transmission / reception circuit 13A of the antenna element 11A.

[0047] At least one of the transmission signal generating unit 12, the transceiver unit 13, the estimation unit 14, the sensor unit 15, the detection unit 16, the control unit 17, the multiplication unit 18, and the like that constitute the power transmitting device 10 may be realized by one or more processors and memories. The processor may include a general-purpose processor that executes a specific function by loading a specific program, and a dedicated processor specialized for a specific process. The dedicated processor may include an application-specific IC such as an ASIC (Application Specific Integrated Circuit). The processor may include a programmable logic device (PLD), for example. The PLD may include a field-programmable gate array (FPGA). At least one of the transmission signal generating unit 12, the transceiver unit 13, the estimation unit 14, the sensor unit 15, the detection unit 16, the control unit 17, the multiplication unit 18, and the like that constitute the power transmitting device 10 may be realized by either a system-on-a-chip (SoC) in which one or more processors work together, or a system in a package (SiP). At least one of the components constituting the power transmission device 10, such as the transmission signal generating unit 12, the transceiver unit 13, the estimation unit 14, the sensor unit 15, the detection unit 16, the control unit 17, and the multiplication unit 18, may control the operation of each component of the power transmission device 10.

[0048] An example of the functional configuration of the power transmitting device 10 according to the present embodiment has been described above. Note that the above configuration described with reference to Fig. 9 is merely an example, and the functional configuration of the power transmitting device 10 according to the present embodiment is not limited to this example. The functional configuration of the power transmitting device 10 according to the present embodiment can be flexibly modified according to the specifications and operation.

[0049] [Operation example of array antenna according to embodiment] FIG. 11 is a diagram for explaining the result of the angle dependency of the maximum beam of the array antenna 11. In FIG. 11, the reference direction of the array antenna 11 perpendicular to the arrangement direction 11X from the center 11C of the substrate 110 is the front direction 11Y. In the case of the 2.4 GHz band, the array antenna 11 has a plurality of antenna elements 11A arranged within a range of the length 110L (4λ=25 cm) of the substrate 110 in the arrangement direction 11X passing through the center 11C, and the element spacing is λ / 2. The power supply target 20C is located in the direction of angle ψ from the center 11C of the array antenna 11, and the distance L is 2 m in the front direction 11Y of the array antenna 11. The angle ψ indicates the angle to the power supply target 20C, which is the target to which the array antenna 11 directs the beam. The distance from the position of the power supply target 20C to the front direction 11Y is set to be 20d. In the array antenna 11, in the arrangement direction 11X, a high-gain first antenna element 111 is arranged near a central portion 11C of a substrate 110, and a low-gain third antenna element 113 and a second antenna element 112 are arranged on either side of the first antenna element 111.

[0050] FIG. 12 is a diagram showing the dependence of the maximum beam of the array antenna 11 according to the embodiment. In FIG. 12, the vertical axis shows the magnitude [dB] of the maximum beam, and the horizontal axis shows the angle ψ [°] at which the maximum beam is directed. Pattern P1 shown in FIG. 12 shows the result of the angle dependence of the maximum beam when the array antenna 11 transmits power to the power supply target 20C located in the direction of angle ψ. Pattern P2 shows the result of the angle dependence of the maximum beam when a reference array antenna composed of only high-gain elements transmits power to the power supply target 20C located in the direction of angle ψ. Pattern P3 shows the result of the angle dependence of the maximum beam when a reference array antenna composed of only low-gain elements transmits power to the power supply target 20C located in the direction of angle ψ.

[0051] As shown in pattern P1 of Fig. 12, the array antenna 11 can obtain a maximum beam improvement of about 2 dB in the front direction 11Y (angle ψ = 0°) compared to the case of only low-gain elements shown in pattern P3, and can obtain power transmission efficiency at least as high as that of only low-gain elements in almost all directions, although there is some deterioration at some angles. Also, the array antenna 11 can obtain a maximum beam improvement of about 2 dB in the front direction 11Y (angle ψ = 0°) compared to the case of only high-gain elements shown in pattern P2, but can obtain an improvement at around angle ψ = 30°. Thus, by arranging the high-gain first antenna element 111 and the low-gain second antenna element 112 and third antenna element 113, which have different antenna gains (directivities), the array antenna 11 can ensure high power transmission efficiency in the front direction 11Y and suppress a decrease in beam power in the angular direction from the front direction 11Y to the second antenna element 112 side and the angular direction from the front direction 11Y to the third antenna element 113 side.

[0052] In the embodiment, the array antenna 11 is described as arranging a plurality of high-gain first antenna elements 111 in the central portion 11C of the arrangement direction 11X, and arranging a plurality of low-gain second antenna elements 112 and third antenna elements 113 on both sides thereof, but the present invention is not limited thereto. The array antenna 11 can determine the arrangement of the high-gain elements and the low-gain elements based on the arrangement relationship between the central portion 11C and the power supply target. For example, when the power transmission device 10 is installed in the center of the ceiling of a room and the power supply target is present at an unspecified position in the room, it is preferable that the array antenna 11 arranges the high-gain first antenna element 111 in the central portion 11C of the arrangement direction 11X. For example, when the power transmission device 10 is installed near a wall, not in the center of the room, the array antenna 11 arranges the high-gain first antenna element 111 on the end side close to the center of the room, and arranges the low-gain second antenna element 112, the third antenna element 113, etc. on the side close to the wall, thereby enabling efficient power transmission.

[0053] In this disclosure, for the sake of simplicity, the configuration of the array antenna 11 of the power transmission device 10 has been described as a one-dimensional configuration. However, even if the high-gain first antenna element 111 and the low-gain second antenna element 112 and third antenna element 113 are arranged in a matrix as shown in FIG. 1, it is possible to ensure high power transmission efficiency in the forward direction 11Y and to realize appropriate radiation of radio waves in directions other than the forward direction 11Y.

[0054] [Example of power supply to each element of an array antenna] Fig. 13 is a schematic diagram for explaining an example of power supply to the array antenna shown in Fig. 9. As shown in Fig. 13, the array antenna 11 has a power circuit 120 capable of supplying power to each of the multiple antenna elements 11A. The power circuit 120 supplies power P N is input, and power P W The power circuit 120 is electrically connected to the control unit 17, and inputs (supplies) the power instructed by the control unit 17 to each element.

[0055] The control unit 17 has a function of controlling the power supply to the first antenna element 111, the second antenna element 112, and the third antenna element 113 based on the direction from the array antenna 11 to which power is to be supplied. The control unit 17 controls the power P N and the power P input to the low-gain second antenna element 112 and the low-gain third antenna element 113 arranged on both sides of the antenna. W By optimizing the angle ψ of the power supply target, the power transmission efficiency to the power supply target in all directions is improved.

[0056] FIG. 14 is a diagram for explaining optimization of power allocation of array antenna 11. In FIG. 14, the vertical axis indicates the magnitude [dB] of the maximum beam, and the horizontal axis indicates the angle ψ [°] at which the maximum beam is directed. Pattern P4 in FIG. 14 shows the angle dependency of array antenna 11 shown in FIG. 13. Pattern P5 shows the angle dependency when configured with only high-gain elements. Pattern P6 shows the angle dependency when configured with only low-gain elements. In FIG. 14, array antenna 11 distributes power P N is input, and power P W As a result, the array antenna 11, as shown in pattern P4, achieves about 5 dB improvement in the front direction 11Y compared to the case where only low-gain elements are used as shown in pattern P6, and obtains power almost equivalent to that obtained by only high-gain elements as shown in pattern P5, thereby enabling power transmission efficiency in all directions to be equal to or greater than that of low-gain elements.

[0057] [Example of optimized power distribution in array antenna] FIG. 15 is a diagram for explaining a model of the array antenna 11 used for power distribution optimization. In FIG. 15, as in FIG. 11, the reference direction of the array antenna 11 perpendicular to the arrangement direction 11X from the center 11C of the substrate 110 is the front direction 11Y. In the case of the 2.4 GHz band, the array antenna 11 has a plurality of antenna elements 11A arranged within a range of the length 110L (4λ=25 cm) of the substrate 110 in the arrangement direction 11X passing through the center 11C, and the element spacing is λ / 2. The power supply target 20C is located in the direction of angle ψ from the center 11C of the array antenna 11, and the distance L is 2 m in the front direction 11Y of the array antenna 11. The distance from the position of the power supply target 20C to the front direction 11Y is set to be 20d. In the array antenna 11, in the arrangement direction 11X, a high-gain first antenna element 111 is arranged near a central portion 11C of a substrate 110, and a low-gain third antenna element 113 and a second antenna element 112 are arranged on either side of the first antenna element 111.

[0058] The array antenna 11 receives the power W t In the array antenna 11, from one side (left side in the figure) to the other side (right side in the figure) of the arrangement direction 11X, j=1, 2 is assigned to the two first antenna elements 111, i=1, 2, 3 is assigned to the three third antenna elements 113, and i=4, 5, 6 is assigned to the three second antenna elements 112. Angle θ Nj is the angle from each of the high-gain first antenna elements 111 to the target 20C. Wi is the angle from each of the low-gain second antenna element 112 and the third antenna element 113 to the target, that is, the power supply destination 20C.

[0059] In the example shown in FIG. 15, the power supplied to the first antenna element 111 with high gain before the power adjustment is P N , the power supplied to the low-gain second antenna element 112 and the third antenna element 113 is P W , the number of high gain elements is k N , the number of low gain elements is k W When the amount of power supply adjustment is ΔP, the total power supply after power adjustment Ptotal can be expressed by the following formula (2). However, the condition of formula (2) is -P N ·k N <ΔP <P W ·k W In this embodiment, "·" in the formula means multiplication. P total =(P W ·k W -ΔP)+(P N ·k N +ΔP) …(Formula 2)

[0060] At this time, the received power W t (ΔP) is given by the following (Equation 3).

number

[0061] In (Equation 3), Γ represents the spatial loss to the power supply target. G W (θ Wi ) is the θ of the second antenna element 112 and the third antenna element 113 with low gain. Wi The antenna gain in the direction of G N (θ Nj ) is the θ of the first antenna element 111 with high gain Nj The symbol i indicates the position of the second antenna element 112 and the third antenna element 113. The symbol j indicates the position of the first antenna element 111. The control unit 17 calculates the received power W t The control unit 17 determines the power supply adjustment amount ΔP that maximizes the optimal power supply P' after the adjustment. W ,P' N is calculated using the following (Equation 4) and (Equation 5). P' W =(P W -ΔP / k W ) …(Formula 4) P' N =(P N +ΔP / k N ) …(Formula 5)

[0062] The control unit 17 varies the power supply adjustment amount ΔP according to the condition of (Equation 2) to obtain the received power W t The control unit 17 applies the determined power supply adjustment amount ΔP to (Equation 5) to obtain the power supply P′ to the first antenna element 111 with high gain. N The control unit 17 applies the determined power supply adjustment amount ΔP to (Equation 4) to calculate the power supply P′ to the second antenna element 112 and the third antenna element 113 having low gain. W Calculate.

[0063] FIG. 16 is a flowchart showing an example of a processing procedure for power allocation of an array antenna. The processing procedure shown in FIG. 16 is executed by the control unit 17. As shown in FIG. 16, the control unit 17 acquires directional information of the power supply target 20C (step S101). For example, the control unit 17 acquires directional information capable of identifying the direction, angle, position, etc. from the center part 11C of the power supply target from the detection unit 16, or acquires directional information stored in the storage unit 17D, an external storage device, etc. Based on the directional information, the control unit 17 determines the angle θ of the high-gain first antenna element 111 toward the power supply target 20C. N1 , angle θ N2 , and the angle θ of the low-gain third antenna element 113 W1 , angle θ W2 , angle θ W3 , the angle θ of the second antenna element 112 with low gain W4 , angle θ W5 , angle θ W6 are calculated and stored in the storage unit 17D.

[0064] Next, the control unit 17 calculates the received power W t For example, the control unit 17 varies the power supply adjustment amount ΔP according to the condition of (Equation 2) to maximize the received power W in (Equation 3) (step S102). t Determine the power supply adjustment amount ΔP that maximizes (ΔP).

[0065] Next, the control unit 17 calculates the feed power for the multiple antenna elements based on the determined feed power adjustment amount ΔP (step S103). For example, the control unit 17 calculates the feed power for all of the two first antenna elements 111, the three second antenna elements 112, and the three third antenna elements 113. The control unit 17 calculates the optimal feed power P' after adjustment for each of the high-gain first antenna elements 111 using (Equation 5). N Then, using (Equation 4), the optimal power supply power P′ after adjustment for each of the low-gain second antenna element 112 and the third antenna element 113 is calculated. W Calculate.

[0066] In the example shown in FIG. 15, the control unit 17 calculates the optimal feed power P′ W ,P' N By supplying the received power W to each of the plurality of antenna elements 11A, it is possible to cause each of the plurality of antenna elements 11A to radiate an appropriate radio wave to the power supply target 20C. t Since wireless power feeding can be performed as described above, it is possible to radiate an appropriate power feeding radio wave of 2000 W in a direction other than the front direction 11Y of the array antenna 11.

[0067] 13, in the arrangement direction 11X, the array antenna 11 has a plurality of high-gain first antenna elements 111 arranged in the center 11C, and a plurality of low-gain second antenna elements 112 and third antenna elements 113 arranged on both sides. In the array antenna 11, a high-intensity beam reaches the power supply target 20A near the front direction 11Y from the high-gain first antenna element 111 in the center 11C, and a medium-intensity beam reaches the power supply target 20A from the second antenna element 112 and third antenna element 113 on both sides, so that it is possible to obtain a power transmission efficiency close to that of a reference antenna in which all elements are high-gain elements.

[0068] In the array antenna 11, the beam from the high-gain first antenna element 111 in the central portion 11C is weak toward the power supply target 20B located at an angle ψ with respect to the front direction 11Y, but the sum of the beams from the low-gain second antenna element 112 and third antenna element 113 on either side of it can achieve a higher power transmission efficiency than a reference antenna which has all high-gain elements.

[0069] Furthermore, in the power transmitting device 10, the power P N and the power P input to the low-gain second antenna element 112 and the low-gain third antenna element 113 on both sides of the antenna. W By optimizing in accordance with the angle φ to the power supply target 20B, high power transmission efficiency can be obtained for power supply targets in all directions of the array antenna 11.

[0070] (Modification of the embodiment) In the above-described embodiment, it is assumed that the array antenna 11 is installed at the center of the arrangement range of multiple power supply targets by arranging multiple high-gain first antenna elements 111 near the central portion 11C in the arrangement direction 11X of the substrate 110 and arranging multiple low-gain second antenna elements 112 and third antenna elements 113 on both sides of the first antenna elements 111. The power transmitting device 10 according to the embodiment is assumed to be installed at the center of the ceiling of a room and the power supply targets are present at unspecified positions in the room.

[0071] For example, when the array antenna 11 is installed near one wall rather than at the center of a room, the power transmitting device 10 may be configured to arrange the high-gain first antenna element 111 at an end close to the center of the room and arrange the low-gain second antenna element 112 or third antenna element 113 on the side close to the wall, or to arrange a combination of the second antenna element 112 and the third antenna element 113 with different low gains. This allows the power transmitting device 10 to arrange the first antenna element 111 near the center of the room even when the power transmitting device 10 is arranged near the wall of the room, thereby improving the efficiency of power transmission compared to arranging the first antenna element 111 near the central portion 11C in the arrangement direction 11X.

[0072] In the above embodiment, the array antenna 11 is described as being arranged such that the third antenna element 113 is arranged from one side 110E1 of the area 110E of the first antenna element 111 in the arrangement direction 11X, and the second antenna element 112 is arranged from the other side 110E2 of the area 110E, but is not limited thereto. For example, the array antenna 11 may be arranged such that the second antenna element 112 and the third antenna element 113 are arranged in sequence from either one side 110E1 or the other side 110E2 of the area 110E in the arrangement direction 11X. For example, the array antenna 11 may be arranged such that either the second antenna element 112 or the third antenna element 113 is arranged from either one side 110E1 or the other side 110E2 of the area 110E in the arrangement direction 11X.

[0073] In the above-described embodiment, the array antenna 11 uses low-gain elements having the same gain as the second antenna element 112 and the third antenna element 113, but is not limited thereto. For example, the array antenna 11 may use antenna elements having different gains as the second antenna element 112 and the third antenna element 113. The array antenna 11 can use the second antenna element 112 and the third antenna element 113 having gains suitable for the environment in which the power transmitting device 10 is installed, the surrounding environment of the array antenna 11, the positional relationship with the power supply target, and the like.

[0074] In the above embodiment, the power transmitting device 10 has been described as having a linear array of antenna elements 11A arranged at equal intervals in the array antenna 11. However, the present invention is not limited to this. As long as the power transmitting device 10 can calculate the array response vector, the arrangement of the antenna elements 11A does not have to be an equal-interval linear array.

[0075] Characteristic embodiments have been described in order to fully and clearly disclose the technology according to the attached claims. However, the attached claims should not be limited to the above-mentioned embodiments, but should be configured to embody all modifications and alternative configurations that a person skilled in the art can create within the scope of the basic matters shown in this specification. The contents of this disclosure can be modified and amended by a person skilled in the art based on this disclosure. Therefore, these modifications and amendments are included in the scope of this disclosure. For example, in each embodiment, each functional unit, each means, each step, etc. can be added to other embodiments so as not to be logically contradictory, or can be replaced with each functional unit, each means, each step, etc. of other embodiments. In each embodiment, multiple functional units, each means, each step, etc. can be combined into one or divided. In addition, each embodiment of the present disclosure described above is not limited to being faithfully implemented to each of the embodiments described respectively, and can be implemented by combining each feature or omitting a part as appropriate.

[0076] For example, the appended claims may be realized by implementing the array antenna 11 of the power transmitting device 10 as a separate antenna. The separate antenna may be configured to be provided, for example, outside the power transmitting device 10 of the above embodiment.

[0077] [Appendix 1] A first antenna element provided on the substrate and capable of transmitting radio waves; a second antenna element that is provided on the substrate so as to be aligned with the first antenna element along an arrangement direction of the first antenna element and is capable of transmitting the radio wave; a third antenna element that is provided on the substrate so as to be aligned with the first antenna element and the second antenna element along the arrangement direction and is capable of transmitting the radio wave; Equipped with An antenna, wherein in the arrangement direction of the substrate, the gain of element directivity of the first antenna element is higher than the gains of element directivity of the second antenna element and the third antenna element. [Explanation of symbols]

[0078] 1 System 10 Power transmission equipment 11 Array Antenna 11A Antenna element 11C Central part 11X orientation 11Y Front direction 12 Transmission signal generator 13 Transmitter / receiver 14 Estimation part 15 Sensor section 16 Detection section 17 Control Unit 17D Storage section 18 Multiplication section 20 Power receiving device 20A, 20B, 20C power supply target 110 Substrate 110E area 110E1 One side 110E2 Other side 111 First antenna element 112 Second antenna element 113 3rd antenna element 120 Power circuit 1000 regulation signal 2000 Transmitted signal 2000W radio wave

Claims

1. A first antenna element provided on the substrate and configured to transmit radio waves; a second antenna element provided on the substrate and configured to transmit the radio wave; a third antenna element provided on the substrate and configured to transmit the radio wave; an antenna having A power transmitting device, wherein a gain of element directivity of the first antenna element in a front direction of the antenna is higher than a gain of element directivity of the second antenna element and the third antenna element.

2. The power transmitting device according to claim 1 , wherein the antenna includes the first antenna element, the second antenna element, and the third antenna element that are linearly arranged on the substrate.

3. The power transmitting device according to claim 1 , wherein the antennas are arranged on the board in the following order in an arrangement direction on the board: the third antenna element, the first antenna element, and the second antenna element.

4. The power transmitting device according to claim 1 , wherein the antenna includes at least two of the first antenna elements.

5. The power transmitting device according to claim 1 , wherein the antenna includes a plurality of the second antenna elements or the third antenna elements.

6. 2. The power transmitting device according to claim 1, further comprising a control unit that adjusts the second power based on an angle so that the power supplied to the second antenna element and the third antenna element is a second power and the second power increases as the angle from a front direction of the antenna to a power supply target increases.

7. The power supplied to the first antenna element is defined as a first power, The control unit controls the supply power to P ｔｏｔａｌ , the first power to the first antenna element is P Ｎ , the second power to the second antenna element and the third antenna element is P Ｗ , the number of the first antenna elements is k Ｎ , the total number of the second antenna elements is k Ｗ The power transmitting device according to claim 6 , wherein when a supply power adjustment amount conditioned by the following (Equation 101) is ΔP, the first power and the second power are adjusted using the following (Equation 101). [0030]

8. The control unit sets a spatial loss to the power supply target as Γ and a gain of the second antenna element and the third antenna element as θ Ｗｉ The antenna gain in the direction is G Ｗ (θ Ｗｉ ), θ of the first antenna element with high gain Ｎｊ The antenna gain in the direction is G Ｎ (θ Ｎｊ ), a number indicating the positions of the second antenna element and the third antenna element is i, and a number indicating the position of the first antenna element is j, and the received power W ｔ The power transmitting device according to claim 7 , further comprising: determining a supply power adjustment amount ΔP that maximizes (ΔP), and adjusting the first power and the second power based on the supply power adjustment amount ΔP. [0045]

9. A method executed by a power transmitting device including an antenna provided on a substrate, the antenna including a first antenna element for transmitting radio waves, a second antenna element for transmitting the radio waves, and a third antenna element for transmitting the radio waves, the method comprising: A method for adjusting the power supplied to the second antenna element and the third antenna element as a second power, and adjusting the second power based on the angle such that the second power increases as the angle from the front direction of the antenna to a power supply target increases.

10. A power transmitting device including an antenna provided on a substrate, the antenna including a first antenna element for transmitting radio waves, a second antenna element for transmitting the radio waves, and a third antenna element for transmitting the radio waves, a program for executing a process of adjusting the second power based on an angle such that the power supplied to the second antenna element and the third antenna element is a second power and the second power becomes larger as the angle from a front direction of the antenna to a power supply target becomes larger.

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