Multi-antenna and power receiving device

Abstract

To provide a multi-antenna that avoids or inhibits electromagnetic coupling problems while increasing spatial efficiency.SOLUTION: A multi-antenna comprises: a substrate; a first antenna element comprising two linear antennas extending from a first feeding point in two different directions, and a second antenna element comprising two linear antennas extending from a second feeding point in two different directions, the first and second antenna elements being arranged to surround one area of the substrate 1; and a connecting line connecting the first feeding point of the first antenna element and the second feeding point of the second antenna element. The connecting line is connected to the first feeding point of the first antenna element without extending along the bisector of the interior angle formed by the two linear antennas whose the apex is the first feeding point of the first antenna element. The connecting line is connected to the second feeding point of the second antenna element without extending along the bisector of the interior angle formed by the two linear antennas whose apex is the second feeding point of the second antenna element.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a multi-antenna and a power receiving device. [Background technology]

[0002] In recent years, wireless power transfer (WPT) has been used in various fields. By utilizing WPT, problems such as wiring strain, breakage, and maintenance can be avoided compared to wired power transfer.

[0003] Generally, a linear antenna such as a dipole antenna is used on the power receiving device side of a WPT to receive the transmitted energy. Normally, when using a single linear antenna, it is difficult to ensure sufficient power receiving capacity and directivity, so multiple linear antennas or multi-antennas are used.

[0004] When using multiple antennas, it is necessary to optimize the number of antennas, the distance between the antennas, the direction, and the connection, etc. Otherwise, electromagnetic coupling may occur, which may reduce the efficiency of receiving power. The optimal combination depends greatly on the environment.

[0005] As a background art of this technical field, there is Japanese Patent Application Laid-Open No. 2010-41566 (Patent Document 1). Patent Document 1 shows an example in which two dipole antennas are crossed in a cross shape. Background art of this technical field includes International Publication No. 2018 / 096740 (Patent Document 2). Patent Document 2 shows an example in which two dipole antennas are crossed in a cross shape, with each end being shaped like an arrow, and the shape is repeated in the vertical and horizontal directions. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2010-41566 A [Patent Document 2] International Publication No. 2018 / 096740 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention provides a multi-antenna that is inexpensive to manufacture and has excellent receiving performance. [Means for solving the problem]

[0008] A multi-antenna comprising: a substrate; a first antenna element arranged to surround one area of ​​the substrate and consisting of two linear antennas extending in two different directions from a first feed point; a second antenna element consisting of two linear antennas extending in two different directions from a second feed point; and a connecting line connecting the first feed point of the first antenna element and the second feed point of the second antenna element, wherein the connecting line is connected to the first feed point of the first antenna element without following the bisector of an interior angle formed by the two linear antennas with the first feed point of the first antenna element as an apex, and the connecting line is connected to the second feed point of the second antenna element without following the bisector of an interior angle formed by the two linear antennas with the second feed point of the second antenna element as an apex. Effect of the Invention

[0009] The present invention provides a multi-antenna that is inexpensive to manufacture and has excellent receiving performance. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing the overall configuration of a WPT system. [Diagram 2] 1 is a block diagram illustrating an example of the configuration of a power transmitting device and a power receiving device. [Diagram 3] 2A and 2B are a top view and a side view of the main bodies of power receiving devices 1 and 2. FIG. [Figure 4] 2 is a top view of a substrate 10 built into the main body of a power receiving device 1. FIG. [Diagram 5] This is an oblique view of a single multi-antenna mounted on an FPC. [Figure 6] FIG. 1 is a diagram showing a configuration according to a first embodiment of a multi-antenna (first embodiment). [Figure 7] FIG. 13 is a diagram showing a configuration according to a second embodiment of the multi-antenna (first embodiment). [Figure 8] FIG. 13 is a diagram showing a configuration according to a third embodiment of the multi-antenna (first embodiment). [Figure 9] FIG. 13 is a diagram showing a configuration according to a fourth embodiment of the multi-antenna (first embodiment). [Figure 10] FIG. 13 is a diagram showing a configuration according to a fifth embodiment of the multi-antenna (first embodiment). [Figure 11] FIG. 13 is a diagram showing a configuration according to a sixth embodiment of the multi-antenna (first embodiment). [Figure 12] FIG. 13 is a diagram showing a configuration according to a seventh embodiment of the multi-antenna (first embodiment). [Figure 13] FIG. 13 is a diagram showing a configuration according to an eighth embodiment of the multi-antenna (first embodiment). [Figure 14] FIG. 2 is a plan view showing multiple combinations of multi-antennas (first embodiment). [Figure 15] FIG. 13 is a diagram showing a configuration according to a modified example of the multi-antenna (first embodiment). [Figure 16] FIG. 2 is a diagram showing a configuration according to a first embodiment of a multi-antenna (second embodiment). [Figure 17] FIG. 13 is a diagram showing a configuration according to a second embodiment of the multi-antenna (second embodiment). [Figure 18] FIG. 13 is a diagram showing a configuration according to a third embodiment of the multi-antenna (second embodiment). [Figure 19] FIG. 11 is a plan view showing multiple combinations of multi-antennas (second embodiment). [Figure 20] FIG. 13 is a diagram showing a configuration according to a modified example of the multi-antenna (second embodiment). [Figure 21]FIG. 13 is a diagram showing a configuration according to a first embodiment of a multi-antenna (third embodiment). [Figure 22] FIG. 13 is a diagram showing a configuration according to a second embodiment of the multi-antenna (third embodiment). [Diagram 23] FIG. 13 is a diagram showing a configuration according to a second embodiment of the multi-antenna (third embodiment). [Figure 24] FIG. 13 is a diagram showing a configuration according to a second embodiment of the multi-antenna (third embodiment). [Diagram 25] 1 is a side view of the main body of power receiving devices 1 and 2 including a multi-antenna (third embodiment). [Figure 26] 1A to 1C are a top view, a side view and a perspective view of the main body of power receiving devices 1 and 2 (fourth embodiment); [Figure 27] 11A to 11C are a top view, a side view and a perspective view of the main body of power receiving devices 1 and 2 (a fifth embodiment). [Figure 28] FIG. 13 is a diagram showing a configuration according to a first embodiment of a multi-antenna (sixth embodiment). [Figure 29] The diagram illustrates the connection relationship between the antenna elements, connecting wires, and a rectifier. [Diagram 30] 13A to 13C are diagrams showing a configuration of an interface board (seventh embodiment) and a diagram showing an example of application of the interface board to a multi-antenna consisting of multiple linear antennas. [Diagram 31] This is an example of a table showing substrates to which a multi-antenna can be applied. [Diagram 32] (1) to (3) are examples showing the radiation efficiency of various multi-antennas. [Diagram 33] 1A and 1B are diagrams illustrating an example of application of a power receiving device in a building management field, and a usage pattern of the power receiving device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, the embodiment of the present invention will be described with reference to the drawings. Note that the embodiment shown below is merely an example of an embodiment used to explain the present invention. It should be understood that the contents of the present invention should not be interpreted as being limited based on the following description.

[0012] 2. Description of the Related Art In recent years, WPT (Wireless Power Transmission or Wireless Power Transfer) has been used in various fields to transmit energy to PCs, sensors, actuators, robots, devices, and the like. For example, in WPT, energy is transmitted between a power transmitting device and a power receiving device using microwaves. Generally, a linear antenna such as a dipole antenna is used in a power receiving device to receive energy transmitted from a power transmitting device.

[0013] In order to transmit and receive energy efficiently based on WPT, various issues must be considered. For example, the power transmitting device must consider physical constraints such as attenuation of radio waves during power transmission in free space. In addition, legal constraints must be considered, such as the upper limit of transmitted power being regulated to 1W. On the other hand, such legal restrictions have been relaxed on the power receiving device side, but the power receiving device side has its own problems as described below.

[0014] "Electrical Issues" When receiving energy using one antenna, it can be difficult to obtain sufficient power and directivity to operate a sensor, etc. On the other hand, when using multiple antennas, it is necessary to optimize the number of antennas, the distance between the antennas, the direction, and the connection, etc. Otherwise, the power receiving efficiency of the multiple antennas will decrease.

[0015] "Physical Issues" In order to arrange and hold multiple antennas inside a power receiving device, the arrangement may be optimized using a case. However, when a flexible substrate is used as the material for the case, there is a physical issue that it is vulnerable to heat and strong stress. Therefore, it is necessary to ensure that the arrangement of the multiple antennas is not damaged by such heat and strong stress.

[0016] "Environmental issues" If a multi-antenna is exposed or protruding in the surrounding environment, it may spoil the aesthetics. In general, there is a trade-off between the amount of power received by a multi-antenna (optimally arranging multiple antennas in a large area) and aesthetics (not being aware of the antennas). Therefore, it is preferable to blend the multi-antenna into the surrounding environment so that it does not look unnatural.

[0017] "Manufacturing issues" Generally, a multi-antenna with a small component mounting area and a large board area tends to increase its manufacturing cost. In addition, if the linear antennas used in the multi-antenna cannot be uniformly applied, there is a risk that the efficiency of mass production will be impaired. Therefore, it is preferable to configure the multi-antenna so as to reduce the burden on the manufacturing side.

[0018] “Legal issues” As described above, upper limits may be set for the transmission power and the transmission antenna gain. However, strict regulations are not imposed on the power receiving device side, and there may be no upper limit on the number of receiving antennas. However, it is preferable to increase the efficiency of power reception between the power transmitting device and the power receiving device after understanding the problems on the transmission side.

[0019] "Challenges in the Building Management Field" When power receiving devices are used in the field of building management (comprehensive management of buildings such as office buildings and commercial facilities), the size of the receiving antenna is considered to be relatively unrestricted. However, since the distance between the power transmitting device and the power receiving device tends to be relatively long, there is a demand for improving the efficiency of power reception. There is also an increasing demand for the power receiving antenna to blend into the surrounding environment.

[0020] In consideration of these various points of view, the applicant has devised a method for obtaining suitable performance for a multi-antenna used in a WPT power receiving device (first to sixth embodiments). Furthermore, the applicant has provided an interface board for assisting the arrangement and connection of each linear antenna (seventh embodiment).

[0021] Generally, an antenna with multiple elements arranged is called an array antenna. Usually, elements of the same shape and size are arranged in an array antenna. Depending on the number of elements and how they are installed, it is possible to design the desired characteristics such as the amount of power received and directivity. Generally, an array antenna radiates strong radio waves in a specific direction. The strength of the received radio waves decreases almost inversely proportional to the distance. In general, in an array antenna, the length of the elements is adjusted to minimize phase difference in the current and to flow a uniform, strong current.

[0022] The element is configured as a linear antenna, such as a dipole antenna, made of copper wire or the like. In general, a dipole antenna can be simplified to a single wire. A dipole antenna is a balanced circuit with the left and right sides of the antenna being the same length and the currents flowing through them being equal. Generally, when the length of a dipole antenna is approximately half the wavelength, resonance occurs and the strongest current flows.

[0023] In general, a dipole antenna is also called a 1 / 2λ (half wavelength) dipole antenna, and its length d can be calculated based on the operating frequency f (Hz) as follows: d=3×108 / 2f(m)

[0024] However, the formula for calculating d is not limited to the above. For example, to eliminate inductive reactance, the length of the element may be limited to within the range of 96% to 97%. d = {3 × 108 / 2f} × (0.96 ~ 0.97) (m)

[0025] In this way, dipole antennas are designed as resonant antennas and as electric field detection antennas based on the wavelength of the operating frequency. However, when they are installed on the board of an electric circuit, the wavelength shortening rate may differ depending on the thickness and dielectric constant of the dielectric layer of the board. Furthermore, depending on the arrangement of the dipole antenna, it is possible to make corrections to the formula for calculating d above.

[0026] The multi-antenna according to this embodiment basically follows the design concept of an array antenna, but special considerations are given to the arrangement and connection of the elements. By applying the multi-antenna according to this embodiment, it is possible to secure sufficient power reception and directivity to operate sensors, etc. In this case, each linear antenna is efficiently connected, and problems such as electromagnetic coupling caused by the distance, direction, connection, etc. between each linear antenna are suppressed.

[0027] By arranging multiple antennas in this basic configuration, we were able to ensure sufficient power reception and directivity, and improve radiation efficiency. Furthermore, when connecting the multi-antenna with a DC output connector or DC connection line (hereinafter simply referred to as the connection line), we have devised a way to avoid any adverse effects on the antennas by arranging the connection line along the bisector of the interior angle formed by two adjacent linear antennas.

[0028] Note that it is not always necessary to arrange the DC connection line along the angle bisector of the inner angle formed by two adjacent linear antennas. The DC connection line may be connected to and arranged on the two linear antennas without following the angle bisector of the inner angle formed by the two linear antennas.

[0029] Furthermore, by using the interface board, the arrangement and connection of each linear antenna and the connection line constituting the multi-antenna are devised so as to be performed efficiently.

[0030] <Basic Configuration of WPT System> FIG. 1 is a diagram showing the overall configuration of the WPT system according to the present embodiment.

[0031] The WPT system shown in FIG. 1 includes, for example, a power transmission device 4, power reception devices 1 and 2, a first information processing device 61, and a second information processing device 62. The WPT system shown in FIG. 1 is used, for example, in a building or a factory. Note that the connection between the power transmission device 4 and the first information processing device 61 and the connection between the first information processing device 61 and the second information processing device 62 may be wired or wireless.

[0032] In FIG. 1, an example in which the WPT system includes three power transmission devices 4 is shown, but the number of power transmission devices 4 included in the WPT system is not limited to three. The number of power transmission devices 4 included in the WPT system may be two or less, or may be four or more.

[0033] In FIG. 1, an example in which the WPT system includes seven power reception devices 1 and 2 is shown, but the number of power reception devices 1 and 2 included in the WPT system is not limited to seven. The number of power reception devices 1 and 2 included in the WPT system may be six or less, or may be eight or more.

[0034] In FIG. 1, an example in which the WPT system includes two first information processing devices 61 is shown, but the number of first information processing devices 61 included in the WPT system is not limited to two. The number of first information processing devices 61 included in the WPT system may be one, or may be three or more.

[0035] The power transmitting device 4 transmits, for example, a power supply signal or a data signal to the power receiving devices 1 and 2. The power transmitting device 4 transmits the power supply signal to the power receiving devices 1 and 2 by radio waves in the 920 MHz band, for example. The power transmitting device 4 transmits the data signal to the power receiving devices 1 and 2 by radio waves in the 2.4 GHz band, for example. The power transmitting device 4 may transmit the data signal by radio waves in the 920 MHz band.

[0036] The power transmitting device 4 may transmit a power supply signal to one of the power receiving devices 1 and 2, for example, or may transmit a power supply signal to multiple power receiving devices 1 and 2. The power transmitting device 4 may transmit a data signal to one of the power receiving devices 1 and 2, for example, or may transmit a data signal to multiple power receiving devices 1 and 2. The power transmitting device 4 may transmit the same data signal as other power transmitting devices 4, for example, or may transmit a data signal different from other power transmitting devices 4. The power transmitting device 4 may transmit a predetermined command signal as a data signal to the power receiving devices 1 and 2, for example, or may transmit a preset signal as a data signal to the power receiving devices 1 and 2.

[0037] The power transmitting device 4 receives, for example, a data signal transmitted from the power receiving devices 1 and 2. The power transmitting device 4 may receive, for example, a data signal transmitted from one of the power receiving devices 1 and 2, or may receive data signals transmitted from a plurality of the power receiving devices 1 and 2. The power transmitting device 4 transmits the data signals transmitted from the power receiving devices 1 and 2 to the first information processing device 61. The power transmitting device 4 transmits information related to the state of the power transmitting device 4 to the first information processing device 61.

[0038] The power receiving devices 1 and 2 receive, for example, a power supply signal or a data signal transmitted from the power transmitting device 4. For example, if the power receiving devices 1 and 2 have a power storage unit, they convert the power supply signal transmitted from the power transmitting device 4 into power and store the converted power in the power storage unit. For example, if the power receiving devices 1 and 2 have a specified sensor, they convert the power supply signal transmitted from the power transmitting device 4 into power and drive the sensor with the converted power. The power storage unit can be a battery, a capacitor, or the like.

[0039] The power receiving devices 1 and 2 transmit, for example, information on the states of the power receiving devices 1 and 2 or information on the results of measurements by sensors to the power transmitting device 4 as a data signal.

[0040] The first information processing device 61 is an information processing device that monitors the operation of the power transmission device 4 and the power receiving devices 1 and 2 contained in the WPT system. For example, the first information processing device 61 determines whether the power transmission device 4 or the power receiving devices 1 and 2 are in a preset state based on information about the states of the power transmission device 4 and the power receiving devices 1 and 2 transmitted from the power transmission device 4. If it is determined that the power transmission device 4 or the power receiving devices 1 and 2 are in a preset state, the first information processing device 61 transmits predetermined information to the second information processing device 62.

[0041] In addition, the first information processing device 61 accumulates information about the power transmission device 4 and the power receiving devices 1 and 2 accommodated in the WPT system. For example, the first information processing device 61 stores information about the states of the power transmission device 4 and the power receiving devices 1 and 2 transmitted from the power transmission device 4 in a storage unit provided in the first information processing device 61.

[0042] Moreover, the first information processing device 61 controls the operation of the power transmitting device 4 contained in the WPT system.

[0043] In addition, the first information processing device 61 controls the operation of the power transmission device 4 accommodated in the WPT system. For example, the first information processing device 61 transmits a predetermined instruction or information to the power transmission device 4.

[0044] In addition, the first information processing device 61 controls the operation of the second information processing device 62 .

[0045] The second information processing device 62 is, for example, an information processing device operated by an administrator of the WPT system. When the second information processing device 62 receives a notification from the first information processing device 61 that the power transmission device 4, the power receiving devices 1 and 2, or both of them accommodated in the WPT system are in a predetermined state, the second information processing device 62 presents to the user that the power transmission device 4, the power receiving devices 1 and 2, or both of them are in the predetermined state.

[0046] Moreover, the second information processing device 62 analyzes information on the states of the power transmitting device 4 and the power receiving devices 1 and 2, which is stored in the first information processing device 61, and presents predetermined information to the user. The predetermined information is, for example, the following. Information regarding the arrangement of the power transmission device 4 Information regarding the placement of power receiving devices 1 and 2 Power consumption information Power intensity information

[0047] <Basic configuration of power transmitting device and power receiving device> FIG. 2 is a block diagram showing a configuration example of the power transmitting device 4 and the power receiving devices 1 and 2 shown in FIG. 1. As shown in FIG. 2, the power transmitting device 4 and the power receiving devices 1 and 2 are, for example, spaced apart from each other at a predetermined interval. For example, the power transmitting device 4 and the power receiving devices 1 and 2 are installed at a distance of about several meters. Specifically, for example, the power transmitting device 4 is fixed and installed at a predetermined high position provided on a high place indoors, for example, a ceiling or a wall. The power receiving devices 1 and 2 are installed on a predetermined device indoors, or placed near a device that requires power supply. The power receiving devices 1 and 2 may be carried by a user. The power transmitting device 4 transmits a power supply signal to the power receiving devices 1 and 2 by radio waves of a predetermined frequency, for example, 920 MHz band. The power receiving devices 1 and 2 convert the power supply signal transmitted from the power transmitting device 4 into power, and charge the converted power or supply the converted power to a predetermined device.

[0048] The power transmitting device 4 includes, for example, an oscillator 401, a transmitting antenna 402, a microcomputer (controller or MCU) 403, a data transceiver 404, and a data transmitting / receiving antenna 405. The oscillator 401, the microcomputer 403, the data transceiver 404, and the data transmitting / receiving antenna 405, or at least any combination of these, may be mounted on, for example, a PCB (printed circuit board).

[0049] The oscillator 401 oscillates a signal in a predetermined frequency band, for example, the 920 MHz band. The oscillated signal may be amplified and unnecessary frequency components may be removed, if necessary.

[0050] The transmitting antenna 402 is formed so as to be capable of efficiently transmitting radio waves in the 920 MHz band, for example. The transmitting antenna 402 radiates a signal oscillated by an oscillator 401 as a power supply signal.

[0051] The microcomputer 403 controls the operation of the power transmitting device 4. The microcomputer 403 is realized by, for example, a single board computer equipped with an ARM processor. The microcomputer 403 controls the transmission of radio waves by the transmitting antenna 402, for example.

[0052] The data transceiver 404 performs processes such as converting digital data to analog data, modulating analog data, etc. The data transceiver 404 also performs processes such as demodulating a data signal received by the data transceiver antenna 405, and digitizing the demodulated data. For example, the data transceiver 404 extracts a predetermined signal from the data signal received by the data transceiver antenna 405, converts it into digital data, and transmits it to the microcomputer 403.

[0053] The data transmission / reception antenna 405 is formed to be capable of efficiently transmitting and receiving radio waves in the 2.4 GHz band, for example. The data transmission / reception antenna 405 radiates a data signal supplied from the data transceiver 404. In addition, the data transmission / reception antenna 405 receives data signals transmitted from the power receiving devices 1 and 2.

[0054] Fig. 3A is a top view of the main body of the power receiving device 1. Fig. 3B is a side view of the main body of the power receiving device 1. Fig. 4 is a top view of the substrate 10 built into the main body of the power receiving device 1.

[0055] The power receiving device 1 includes, for example, a multi-antenna 11, a rectifier 14, a power management unit 141, a power storage unit 142, a microcomputer 145, a data transceiver 144, and a data transmission / reception antenna 143. The multi-antenna 11, the connection line 111, the rectifier 14, the power management unit 141, the power storage unit 142, the microcomputer 145, the data transceiver 144, and the data transmission / reception antenna 143, or at least any combination of these, may be mounted on, for example, a PCB or an FPC (flexible printed circuit board). The power management unit 141, the power storage unit 142, the microcomputer 145, the data transceiver 144, and the data transmission / reception antenna 143 arranged on the substrate 10 form a circuit 12 as a whole. The connection line 111 is a signal line that connects the two linear antennas 1122 and 1132 via the rectifier 14. The connection line 111 is an output line for outputting a signal (rectified signal) rectified via the rectifier 14 in response to a power signal received from the multi-antenna 11. The connection line 111 is composed of two connection lines: a first connection line that outputs a positive power signal, and a second connection line that outputs a negative power signal. Two combinations are allowed for the method of connecting the first connection line and the second connection line of the linear antennas 1122 and 1132 (FIGS. 4A and 4B). Specifically, the signal line connecting linear antenna 1122A via rectifier 14 is connection line 111A, the signal line connecting linear antenna 1122B via rectifier 14 is connection line 111B, the signal line connecting linear antenna 1132A via rectifier 14 is connection line 111C, and the signal line connecting linear antenna 1132B via rectifier 14 is connection line 111D. In this case, in Fig. 4A, connection line 111C is connected to connection line 111A, and connection line 111D is connected to connection line 111B. In Fig. 4B, connection line 111D is connected to connection line 111A, and connection line 111C is connected to connection line 111B. In either case, the power signal received by linear antennas 1122 and 1132 can be extracted from connection line 111.

[0056] The multi-antenna 11 is formed so as to be able to efficiently receive radio waves in the 920 MHz band, for example. The multi-antenna 11 receives a power feed signal radiated from the transmitting antenna 402.

[0057] The rectifier 14 rectifies the radio waves received as a power supply signal and converts them into a DC voltage.

[0058] The power management unit 141 manages the DC voltage. For example, the power management unit 141 controls a charging voltage based on the DC voltage. The power management unit 141 charges the power storage unit 142 by controlling the charging voltage. In addition, for example, when the power storage unit 142 stores power equal to or greater than a predetermined capacity, the power management unit 141 supplies the DC voltage to a connected member.

[0059] Furthermore, the power management unit 141 releases the power stored in the power storage unit 142 in response to control from the microcomputer 145 .

[0060] The power storage unit 142 stores power in response to an instruction from the power management unit 141. Moreover, the power storage unit 142 releases the stored power in response to an instruction from the power management unit 141.

[0061] The microcomputer 145 controls the operation of the power receiving devices 1 and 2. The microcomputer 145 is driven by a DC voltage supplied from the power management unit 141 or by power stored in the power storage unit 142. The microcomputer 145 controls the power management unit 141 to cause the power storage unit 142 to release the power stored therein.

[0062] For example, various sensors can be connected to the power receiving devices 1 and 2. For example, a heat sensor, a temperature sensor, a light sensor, a humidity sensor, a vibration sensor, etc. are connected to the power receiving devices 1 and 2. The sensors connected to the power receiving devices 1 and 2 are driven by, for example, a DC voltage supplied from a power management unit 141 or power discharged from a power storage unit 142. The microcomputer 145 continuously or intermittently monitors the voltage value at a predetermined portion of the power receiving devices 1 and 2, the status of the sensor connected to the power receiving devices 1 and 2, information detected by the sensor, etc. The microcomputer 145 transmits the voltage value at a predetermined portion of the power receiving devices 1 and 2, the status of the sensor connected to the power receiving devices 1 and 2, information detected by the sensor, etc. as digital data to the data transceiver 144. The sensor may be built into the power receiving devices 1 and 2.

[0063] The data transceiver 144 performs processes such as converting digital data supplied from the microcomputer 145 into analog data and modulating the analog data. The data transceiver 144 also performs processes such as demodulating a data signal received by the data transceiver antenna 143 and digitizing the demodulated data. The data transceiver 144 is driven by, for example, a DC voltage supplied from the power management unit 141 or power discharged from the power storage unit 142.

[0064] The data transmission / reception antenna 143 is formed to be capable of efficiently transmitting and receiving radio waves in the 2.4 GHz band, for example. The data transmission / reception antenna 143 radiates a data signal supplied from the data transceiver 144. In addition, the data transmission / reception antenna 143 receives a data signal transmitted from the power transmitting device 4. For example, the data transmission / reception antenna 143 is driven by a DC voltage supplied from the power management unit 141 or power discharged from the power storage unit 142.

[0065] <Power receiving device (Example 1)> The configuration of the power receiving device 1 according to the first embodiment will be described below. The power receiving device 1 is a power receiving device that receives energy wirelessly transmitted in a three-dimensional space based on wireless power transmission (WPT). Specifically, the power receiving device 1 is a wireless power transmission (WPT) power receiving device used to receive energy transmitted from a power transmitting device using microwaves. The power receiving device 1 includes a main body, a substrate 10 built into the main body, a multi-antenna 11 built into the main body, a circuit 12 for performing the function of the multi-antenna 11 built into the main body, and a device 13. The power receiving device 1 is capable of receiving microwaves transmitted from a power transmitting device via the multi-antenna 11 and supplying power to the circuit 12, the device 13, etc. The circuit 12 is functionally coupled to a rectifier 14. The circuit 12 is connected to the multi-antenna 11 via the rectifier 14. The multi-antenna 11 includes a connecting line 111 , a first antenna element 112 , and a second antenna element 113 .

[0066] The power receiving device 1 is connected to a controller (MCU) by wire and can transmit data related to power reception to the MCU. For example, the power receiving device may feed back the amount of power received to the MCU. The circuit 12 may have the function of the MCU. Alternatively, the circuit 12 may be configured to be capable of data communication with the MCU (not shown).

[0067] <Configuration of the Substrate 10> Specifically, the main body of the power receiving device 1 is configured in a multi-layered structure. A printed wiring board (substrate) can be provided on an FPC (flexible printed circuit board), which is a type of substrate 10. In particular, the FPC is provided with a multi-antenna 11 capable of receiving energy wirelessly transmitted within a three-dimensional space.

[0068] The FPC can be flexible. For example, the FPC can be made of a thin insulating material (plastic film). This allows the sheet-shaped power receiving device 1 to be rolled up together with the built-in FPC.

[0069] <Configuration of Multi-Antenna 11> FIG. 5 is a perspective view of a single multi-antenna disposed on an FPC. FIG. 6 is a diagram showing a configuration according to a first embodiment of a multi-antenna (first example). The FPC may be provided with only one multi-antenna 11 . The FPC may be provided with a plurality of multi-antennas 11 .

[0070] The multi-antenna is composed of a linear antenna, such as a linear dipole antenna, arranged on the FPC (substrate 10).

[0071] The first antenna element 112 includes a first feed point 1121 and two linear antennas 1122 extending in two different directions from the first feed point 1121. The second antenna element 113 includes a second feed point 1131 and two linear antennas 1132 extending in two different directions from the second feed point 1131. It should be noted that the number of antenna elements provided in the multi-antenna 11 does not necessarily have to be two, and it may include more than two antenna elements; in other words, the multi-antenna 11 according to the present disclosure is a multi-antenna that includes at least two or more antenna elements.

[0072] The two linear antennas 1122 of the first antenna element 112 are preferably orthogonal to each other at an angle of 90 degrees at the first feeding point 1121. The two linear antennas 1132 of the second antenna element 113 are preferably orthogonal to each other at an angle of 90 degrees at the second feeding point 1131. Specifically, the two linear antennas 1122, 1132 included in the first antenna element 112 and the second antenna element 113 are bent into an L shape with the first feeding point 1121 and the second feeding point 1131 as apexes, and are formed by extending in two directions at 90 degree angles perpendicular to each other from the first feeding point 1121 and the second feeding point 1131. Preferably, the linear antennas 1122, 1132 extend by substantially equal lengths from the first feeding point 1121 and the second feeding point 1131, respectively. This makes it possible to improve the power receiving efficiency by suppressing electromagnetic coupling caused by mutual interference between the linear antennas 1122 and 1132. Furthermore, by reducing the number of linear antennas, the manufacturing cost can be reduced.

[0073] Although the linear antennas 1122 and 1132 are configured symmetrically, they may be configured partially asymmetrically when mounted. The linear antennas 1122 and 1132 do not necessarily have to be straight. For example, they may be curved as shown in Figures 4, 12, 13, and 15A.

[0074] The first antenna element 112 and the second antenna element 113 are arranged to surround one area 101 of the substrate 10. Specifically, the first antenna element 112 and the second antenna element 113 extend along the four sides of the area 101 which is a substantially regular polygon. Two linear antennas 1122, 1132 formed in an L-shaped bent shape with first feeding point 1121 and second feeding point 1131 as vertices are arranged point-symmetrically with respect to the center of area 101 so as to surround one area 101 of substrate 10. As a result, first antenna element 112 and second antenna element 113 are arranged opposite each other so as to surround approximately square area 101. For example, the length of one side of the substrate 10 is about 8 cm, and the lengths of the linear antennas 1122, 1132 of the first antenna element 112 and the second antenna element 113 are configured to be about 7 cm. The circuit 12 is formed in a square shape, and the length of one side is about 3.5 cm.

[0075] It is not necessary that the first feeding point 1121 and the second feeding point 1131 are located at the apexes of the L-shaped bent two linear antennas 1122 and 1132. For example, they may be located at positions on the linear antennas 1122 and 1132 that are offset from the bent apexes, as in the multi-antenna of FIG.

[0076] FIG. 7 is a diagram showing a configuration according to a second embodiment of the multi-antenna (first embodiment). The area 101 surrounded by the first antenna element 112 and the second antenna element 113 does not have to be square, and may be rectangular. By arranging them so as to surround the approximately square area 101, a multi-antenna with a small board area, low manufacturing costs, and excellent reception performance can be realized compared to the case where they are arranged so as to surround the rectangular area 101.

[0077] Furthermore, it is preferable that the distance from one end of the first antenna element to one end of the second antenna element adjacent to the one end of the first antenna element is λ / 64 or more, where λ is the operating wavelength of the power receiving device. In particular, it is preferable that the distance from one end of the first antenna element to one end of the second antenna element adjacent to the one end of the first antenna element is λ / 32 or more. 5, one end of the linear antenna 1132 of the first antenna element is spaced apart from one end of the linear antenna 1122 of the second antenna element by a distance L. Similarly, the other end of the linear antenna 1132 of the first antenna element is spaced apart from the other end of the linear antenna 1122 of the second antenna element by a distance L. If the separation distance L is too small, the first antenna element and the second antenna element will interfere with each other, causing electromagnetic coupling and reducing the power receiving efficiency, whereas if the separation distance L is too large, the board area will increase, resulting in high manufacturing costs. Specifically, it is desirable that L is λ / 64 or more, more preferably λ / 32 or more, where λ is the operating wavelength of the power receiving device. Also, L may be a distance smaller than λ or any integer multiple of λ. It may also be a distance of λ / 16 or more.

[0078] FIG. 8 is a diagram showing a configuration according to a third embodiment of the multi-antenna (first embodiment). The basic configuration of the first antenna element 112, the second antenna element 113, the connection line 111, etc. is similar to that of the multi-antenna (first embodiment) and the multi-antenna (second embodiment), so a detailed description thereof will be omitted. In the third embodiment of the multi-antenna (first example), a connection line 111 linearly connects a first feed point 1121 and a second feed point 1131 of a first antenna element 112 and a second antenna element 113 which are arranged to surround a rectangular area 101. In this case, the connection line 111 is connected to the first feed point of the first antenna element without following the bisector of the interior angle formed by the two linear antennas with the first feed point of the first antenna element as a vertex. The connection line 111 is connected to the second feed point of the second antenna element without following the bisector of the interior angle formed by the two linear antennas with the second feed point of the second antenna element as a vertex. In the first antenna element 112 and the second antenna element 113 arranged to surround the square area 101, the connection line 111 may also be connected to the first feed point of the first antenna element without following the bisector of the interior angle formed by the two linear antennas with the first feed point of the first antenna element as a vertex. Similarly, the connection line 111 may also be connected to the second feed point of the second antenna element without following the bisector of the interior angle formed by the two linear antennas with the second feed point of the second antenna element as a vertex. 13, the connection line 111 may be connected to the first feed point of the first antenna element without being aligned along the bisector of the interior angle formed by the two linear antennas with the first feed point of the first antenna element as a vertex. Similarly, the connection line 111 may be connected to the second feed point of the second antenna element without being aligned along the bisector of the interior angle formed by the two linear antennas with the second feed point of the second antenna element as a vertex. In this case too, it is possible to realize a multi-antenna for use in a WPT power receiving device that uses microwaves, which is inexpensive and has excellent power receiving efficiency.

[0079] FIG. 9 is a diagram showing a configuration according to a fourth embodiment of the multi-antenna (first embodiment). The basic configuration of the first antenna element 112, the second antenna element 113, the connection line 111, etc. is similar to that of the multi-antenna (first embodiment) and the multi-antenna (second embodiment), so a detailed description thereof will be omitted. In the fourth embodiment of the multi-antenna (first example), a connection line 111 linearly connects a first feed point 1121 and a second feed point 1131 of a first antenna element 112 and a second antenna element 113, which are arranged to surround a diamond-shaped or rectangular area 101. The first antenna element 112 extends in a first direction toward the first end and in a second direction toward the second end. The second antenna element 113 extends in a third direction toward the third end and in a fourth direction toward the fourth end. The interior angle between the first direction and the second direction and the interior angle between the third direction and the fourth direction are less than 90 degrees. Specifically, the interior angle of the bent vertices of the two linear antennas 1122, 1132 is an acute angle less than 90 degrees. The first feed point 1121 and the second feed point 1131 do not have to be located at the bent vertices of the two linear antennas 1122, 1132, and may be provided at positions offset from the bent vertices. This makes it possible to realize a multi-antenna that requires a small board area, is inexpensive to manufacture, and has excellent reception performance.

[0080] FIG. 10 is a diagram showing a configuration according to a fifth embodiment of the multi-antenna (first embodiment). The basic configuration of the first antenna element 112, the second antenna element 113, the connection line 111, etc. is similar to that of the fourth embodiment of the multi-antenna (first example), and therefore a detailed description thereof will be omitted. The interior angle formed by the two linear antennas having the first feed point of the first antenna element 112 as a vertex and the interior angle formed by the two linear antennas having the second feed point of the second antenna element 113 as a vertex are less than 90 degrees. Specifically, the first feeding point 1121 and the second feeding point 1131 are disposed at the vertices of the bent two linear antennas 1122 and 1132, respectively. This makes it possible to realize a suitable multi-antenna having better reception performance than the fourth embodiment of the multi-antenna (first embodiment) with a similar base area.

[0081] FIG. 11 is a diagram showing a configuration according to the sixth embodiment of the multi-antenna (first embodiment). The basic configuration of the first antenna element 112, the second antenna element 113, the connection line 111, etc. is similar to that of the multi-antenna (first embodiment) and the multi-antenna (second embodiment), so a detailed description thereof will be omitted. In the sixth embodiment of the multi-antenna (first embodiment), a connection line 111 linearly connects a first feed point 1121 and a second feed point 1131 of a first antenna element 112 and a second antenna element 113, which are arranged to surround a diamond-shaped or rectangular area 101. The first antenna element 112 extends in a first direction toward the first end and in a second direction toward the second end. The second antenna element 113 extends in a third direction toward the third end and in a fourth direction toward the fourth end. The interior angle between the first direction and the second direction and the interior angle between the third direction and the fourth direction are equal to or greater than 90 degrees. The interior angle formed by the two linear antennas having the first feed point of the first antenna element 112 as a vertex, and the interior angle formed by the two linear antennas having the second feed point of the second antenna element 113 as a vertex are an angle of 90 degrees or more. Specifically, the interior angle of the bent vertices of the two linear antennas 1122, 1132 is formed to be an obtuse angle of 90 degrees or more. The first feed point 1121 and the second feed point 1131 do not have to be located at the bent vertices of the two linear antennas 1122, 1132, and may be provided at positions offset from the bent vertices. The first feeding point 1121 and the second feeding point 1131 may be disposed at the vertices of the bent two linear antennas 1122 and 1132, respectively. This allows for a small number of antennas, low manufacturing costs, and the ability to receive radio waves over a wide area, resulting in the realization of a compact, highly efficient multi-antenna with excellent reception performance.

[0082] FIG. 12 is a diagram showing a configuration according to a seventh embodiment of the multi-antenna (first embodiment). The basic configuration of the first antenna element 112, the second antenna element 113, the connection line 111, etc. is similar to that of the third embodiment of the multi-antenna (first example), and therefore a detailed description thereof will be omitted. In the present disclosure, of the linear antennas 1122 and 1132 constituting the first antenna element 112 and the second antenna element 113, the linear antennas provided along the long sides are formed in a shape that is repeatedly bent in a wavy line. Also, of the linear antennas 1122 and 1132, the linear antennas provided along the short sides may be formed in a shape that is repeatedly bent in a wavy line. It should be noted that the linear antennas 1122 and 1132 do not necessarily need to be formed in a dashed line shape with a fixed wavelength, and may be in any curved shape. This allows, for example, the substrate 10 to be formed along the shapes of the linear antennas 1122 and 1132. The linear antennas 1122 and 1132 can be freely arranged along the outer shape of the receiving device. For example, the substrate and the housing (case) may be formed in a wavy line shape according to the shapes of the linear antenna 1122 and the linear antenna 1132. For example, when the power receiving devices 1 and 2 are portable devices held by a user, the housing formed in a wavy line shape may be used as a grip when the user holds it.

[0083] FIG. 13 is a diagram showing a configuration according to an eighth embodiment of the multi-antenna (first embodiment). The basic configuration of the first antenna element 112, the second antenna element 113, the connection line 111, etc. is similar to that of the multi-antenna (first embodiment) and the multi-antenna (second embodiment), so a detailed description thereof will be omitted. The connection line 111 is bent and connected to a first feed point of the first antenna element, and the connection line 111 is bent and connected to a second feed point of the second antenna element. In the present disclosure, the connection line 111 is bent with a predetermined curvature, and is bent and connected to the first feed point and the second feed point. Even in such a case, the number of antennas is small, the manufacturing costs are low, and radio waves can be received over a wide area. A compact, highly efficient multi-antenna with excellent reception performance can be realized.

[0084] <Configuration of multi-antenna 11 (modified example)> FIG. 15A is a diagram showing a configuration according to a first modified example of the multi-antenna (first embodiment). FIG. 15B is a diagram showing a configuration according to a second modified example of the multi-antenna (first embodiment). FIG. 15C is a diagram showing a configuration according to a third modified example of the multi-antenna (first embodiment). FIG. 15D is a diagram showing a configuration according to a fourth modified example of the multi-antenna (first embodiment). FIG. 15E is a diagram showing a configuration according to a fifth modified example of the multi-antenna (first embodiment). The number of antenna elements 112, 113 included in the multi-antenna 11 according to the present disclosure is not limited to two. Furthermore, the linear antennas 1122, 1132 included in the antenna elements 112, 113 may be arranged line-symmetrically, not point-symmetrically, so as to surround the area 101. Furthermore, the area surrounded by the linear antennas does not need to be polygonal, and may be circular or elliptical. As shown in FIG. 15A, the linear antennas 1122, 1132 of the first antenna element 112 and the second antenna element 113 may extend in a curved shape along the four sides of the substantially square area 101 in which the circuit 12 is arranged. 15B, the linear antennas 1122, 1132, and 1142 may be arranged to surround the approximately equilateral triangular region 101 in which the circuit 12 is arranged. The linear antennas 1122, 1132, and 1142 form an equilateral triangle that is symmetrical with respect to an axis. 15C, the linear antennas 1122 to 1162 may be arranged to surround the substantially regular pentagonal region 101 in which the circuit 12 is arranged. The linear antennas 1122 to 1162 form a regular pentagon that is symmetrical with respect to a line. 15D, the linear antennas 1122 to 1172 may be arranged to surround the substantially regular hexagonal region 101 in which the circuit 12 is arranged. The linear antennas 1122 to 1172 form a regular hexagon that is symmetrical with respect to a line and a point. 15E, the linear antennas 1122, 1132, and 1142 may be disposed so as to surround the substantially circular area 101 in which the circuit 12 is disposed. The linear antennas 1122, 1132, and 1142 form a circle.

[0085] <Configuration of connection line 111> The connection line 111 is a DC connection line connecting the dipole antennas. Preferably, each antenna element has equal length on the left and right to form a balanced circuit. A rectifier is provided in the center. Each antenna is connected to the rectifier, and they are connected by the connection line 111. At this time, the polarity of the rectifier is assumed to be the same. This also applies to all embodiments relating to a multi-antenna. It should be understood that any type of rectifier may be applied in this embodiment. In general, the connection lines 111 connecting the antenna elements are arranged so as not to create a complex configuration. It is preferable that the connection lines 111 connect the power supply points of the antenna elements in the shortest distance.

[0086] One end of the connection line 111 is connected to a first feeding point 1121 of the first antenna element 112, and the other end of the connection line 111 is connected to a second feeding point 1131 of the second antenna element 113. When the number of antenna elements constituting the multi-antenna 11 is more than two, the connection line 111 connects the feeding points of the respective antenna elements.

[0087] The connection line 111 is connected to the first feed point 1121 and the second feed point 1131 of the first antenna element 112 and the second antenna element 113 along the bisector of the interior angle formed by the first feed point 1121 and the second feed point 1131 of the first antenna element 112 and the second antenna element 113 as vertices. Specifically, the connection line 111 is connected to a first feed point 1121 of the first antenna element 112 along the bisector of the interior angle formed by the two linear antennas of the first antenna element 112. The connection line 111 is connected to a second feed point 1131 of the second antenna element 113 along the bisector of the interior angle formed by the two linear antennas of the second antenna element 113.

[0088] In addition, the connection line 111 may be connected to the first feed point 1121 and the second feed point 1131 of the first antenna element 112 and the second antenna element 113 without following the bisector of the interior angle formed by the first feed point 1121 and the second feed point 1131 of the first antenna element 112 and the second antenna element 113 as vertices. Specifically, the connection line 111 is connected to a first feeding point 1121 of the first antenna element 112 without following the bisector of the interior angle formed by the two linear antennas of the first antenna element 112. The connection line 111 is connected to a second feeding point 1131 of the second antenna element 113 without following the bisector of the interior angle formed by the two linear antennas of the second antenna element 113.

[0089] Specifically, the connection line 111 is connected to a first feeding point 1121 and a second feeding point 1131 of the first antenna element 112 and the second antenna element 113 via the connection line 111 and rectifiers 1123 and 1133, respectively. FIG. 29 illustrates the connection relationship between antenna elements 112 and 113, connection line 111, and rectifiers 1123 and 1133. This allows a large potential difference between the multi-antenna and GND, improving the performance of the multi-antenna. Also, connection line 111 can be understood as a signal line for extracting output from a rectenna that combines antenna element 112 and rectifier 1123, and antenna element 113 and rectifier 1133. Specifically, connection line 111 is a signal line that extracts the radio wave energy received by the rectenna as a current.

[0090] <Configuration of circuit 12> A circuit 12 for realizing the function of the multi-antenna built into the FPC is built into the main body of the power receiving device 1. The FPC and the circuit can be connected by wire. Any device can be added to the circuit 12 in order to improve the flow of balanced currents in the multi-antennas, such as a filter or a mixer.

[0091] The circuit 12 is provided at a position that does not overlap any antenna element included in the multi-antenna 11 when viewed from a direction perpendicular to the surface of the substrate 10. This is the same for all the embodiments relating to the multi-antenna. For example, the circuit 12 may be provided in a central region of one area 101 of the substrate 10 surrounded by a first antenna element 112 and a second antenna element 113 . It is preferable that the distance from the first feeding point 1121 of the first antenna element 112 to the circuit 12 be approximately equal to the distance from the second feeding point 1131 of the second antenna element 113 to the circuit 12 . In this way, by utilizing the area of ​​the circuit 12 as a means for suppressing electromagnetic coupling, it is possible to realize a power receiving device that has a small board area, is inexpensive to manufacture, and has excellent power receiving efficiency.

[0092] There are cases where the multi-antenna 11 includes antenna elements other than the first antenna element 112 and the second antenna element 113. Even in such cases, it is preferable that the circuit 12 is provided at a position that does not overlap any antenna element including the other antenna elements. This is because if the antenna element and the circuit 12 overlap, electromagnetic coupling between the antenna element and the circuit 12 reduces the power receiving efficiency.

[0093] Specifically, it is preferable that the first antenna element 112 and the second antenna element 113 are spaced apart from the circuit 12 by a distance of λ / 8 or more. In particular, it is preferable that the first antenna element 112 and the second antenna element 113 are spaced apart from the circuit 12 by a distance of λ / 4 or more. Here, λ is the wavelength (operating wavelength) of the electromagnetic wave (microwave) for receiving energy. The wavelength λ can be calculated based on the operating frequency f (Hz) as λ (m) = c (m / s) ÷ f (Hz). c (m / s) is the speed of light. This makes it possible to effectively suppress electromagnetic coupling between the antenna element and the circuit 12, thereby realizing a power receiving device with excellent power receiving efficiency.

[0094] The circuit 12 may be formed in a shape that is away from the direction opposite to the direction of the first antenna element 112 and the second antenna element 113 . The directivity of first antenna element 112 is oriented in an outward direction from inside area 101 through first feed point 1121. The directivity of second antenna element 113 is oriented in an outward direction from area 101 through second feed point 1131. In this case, the circuit 12 is formed in a quadrangular shape when viewed from a direction perpendicular to the surface of the substrate 10. In the present disclosure, the first vertex 121 and the second vertex 122 of the quadrangular circuit 12 may be recessed in a direction away from the first feeding point 1121 of the first antenna element 112 and the second feeding point 1131 of the second antenna element 113, respectively, or may be formed in a notched shape. Also, the circuit 12 may be arranged in the area 101 by rotating it by 45 degrees.

[0095] <Power receiving device (Example 2)> The configuration of the power receiving device 2 according to the second embodiment will be described below. Note that the basic configuration is common to the power receiving device 1 according to the first embodiment, and therefore the description of the common configuration will be omitted. The power receiving device 2 is a power receiving device that receives energy wirelessly transmitted in a three-dimensional space based on wireless power transmission (WPT). Specifically, the power receiving device 2 is a wireless power transmission (WPT) power receiving device used to receive energy transmitted from a power transmitting device using microwaves. The power receiving device 2 includes a main body, a substrate 20 built into the main body, a multi-antenna 21 built into the main body, a circuit 22 for exerting the function of the multi-antenna 21 built into the main body, and a device 23. The power receiving device 2 is capable of receiving microwaves transmitted from the power transmitting device via the multi-antenna 21 and supplying power to the circuit 22, the device 23, etc. The multi-antenna 21 includes a connection line 211 and linear antennas 212 to 217 .

[0096] <Configuration of Multi-Antenna 21> FIG. 16 is a diagram showing a configuration according to a first embodiment of the multi-antenna (second embodiment). The multi-antenna 21 includes two linear antennas 212, 213 arranged in a roughly cross shape to divide the substrate 20 into four regions 201, 202, 203, 204, and four linear antennas 214-217 arranged on the four sides of a roughly quadrangle at the outermost side on the substrate to surround the four regions 201, 202, 203, 204. This allows the linear antenna to have a longer antenna length with the same board area, thereby achieving a power receiving device with excellent power receiving efficiency. It should be noted that the linear antennas 212 to 217 do not necessarily have to be straight lines, and may be curved, for example.

[0097] Specifically, two linear antennas 212, 213 having equal lengths are orthogonal to each other at an angle of 90 degrees at the center. Four linear antennas 214-217 are arranged to surround the two orthogonally arranged linear antennas 212, 213 from the outside, and are each arranged at an angle of 45 degrees to the two linear antennas 212, 213. This makes it possible to realize a power receiving device with superior power receiving efficiency compared to the power receiving device (embodiment 1).

[0098] FIG. 17 is a diagram showing a configuration according to a second embodiment of the multi-antenna (second embodiment). At least one end of at least a part of the four linear antennas 214 to 217 is bent toward the inside or outside of the four regions. Specifically, both ends of the four linear antennas 214 to 217 have bent portions 2141, 2142, 2151, 2152, 2161, 2162, 2171, and 2172 that are bent toward the inside of the four regions. In the present disclosure, as an example, an embodiment in which both ends of all of the four linear antennas 214 to 217 are bent toward the inside of the four regions is disclosed, but it is also possible to have one end or both ends of some or all of the four linear antennas 214 to 217 bent toward the inside of the four regions. Specifically, the four linear antennas 214 to 217 provided outside the linear antennas 212 and 213 are bent inward at 45 degree angles at both ends, thereby forming bent portions 2141, 2142, 2151, 2152, 2161, 2162, 2171, and 2172. In addition, in the present disclosure, the bent portions 2141, 2142, 2151, 2152, 2161, 2162, 2171, and 2172 may be bent toward the outside of the four regions.

[0099] FIG. 18 is a diagram showing a configuration according to a third embodiment of the multi-antenna (second embodiment). At least one end of at least a part of the four linear antennas 214 to 217 is folded back twice toward the inside or outside of the four regions. Specifically, both ends of the four linear antennas 214 to 217 have folded-back portions 2143, 2144, 2153, 2154, 2163, 2164, 2173, and 2174 that are folded back twice toward the inside of the four regions. The four linear antennas 214 to 217 provided outside the linear antennas 212 and 213 are folded back twice toward the inside at angles of 45 degrees and 90 degrees at both ends, thereby forming folded back portions 2143, 2144, 2153, 2154, 2163, 2164, 2173, and 2174. This allows the linear antenna to have a longer antenna length with the same board area, thereby achieving a power receiving device with excellent power receiving efficiency. It should be noted that the folded portions 2143, 2144, 2153, 2154, 2163, 2164, 2173, and 2174 may be folded back twice toward the outside of the four regions.

[0100] <Configuration of multi-antenna 21 (modified example)> FIG. 20 is a diagram showing a configuration according to a modified example of the multi-antenna (second embodiment). The number of linear antennas 212 to 217 included in the multi-antenna 21 according to the present disclosure is not limited to six. The four linear antennas 214 to 217 arranged on the four sides of the approximate rectangle do not necessarily have to be straight lines. For example, they may be curved lines. The two linear antennas 212 and 213 arranged in a substantially cross shape do not necessarily have to be straight lines. For example, they may be curved lines.

[0101] <Configuration of connection line 211> The connection line 211 connects all six of the linear antennas 212 to 217 in a single stroke clockwise or counterclockwise. When the number of linear antennas constituting the multi-antenna 21 is more than six, the connection line 211 connects each linear antenna. The connecting line 211 connects at an angle of 90 degrees from the orthogonal portion of the two linear antennas 212, 213 to approximately the center of the linear antenna 215. The linear antennas 212, 213 and the connecting line 211 form an angle of 45 degrees.

[0102] As an example, a case will be described in which the connection line 211 connects all six of the linear antennas 212 to 217 in a single stroke clockwise. The connecting line 211 connects at an angle of 90 degrees from the orthogonal portion of the two linear antennas 212, 213 to approximately the center of the linear antenna 216. The linear antennas 212, 213 and the connecting line 211 form an angle of 45 degrees. The connection line 211 is connected to approximately the center of the linear antenna 216 at an angle of 45 degrees, and is connected to approximately the center of the linear antenna 217 at an angle of 45 degrees. The connection line 211 is connected to approximately the center of the linear antenna 217 at an angle of 45 degrees, and is connected to approximately the center of the linear antenna 214 at an angle of 45 degrees. The connection line 211 is connected to approximately the center of the linear antenna 214 at an angle of 45 degrees, and is connected to approximately the center of the linear antenna 215 at an angle of 45 degrees.

[0103] <Configuration of circuit 22> The circuit 22 is provided at a position that does not overlap any of the linear antennas included in the multi-antenna 21 when viewed from a direction perpendicular to the surface of the substrate 20 . For example, the circuit 22 may be provided inside any one of the four regions 201, 202, 203, and 204 defined by the linear antennas 212 to 217, at a position not overlapping with the linear antennas. In this way, by utilizing the area of ​​the circuit 22 as a means for suppressing electromagnetic coupling, it is possible to realize a power receiving device that requires a small board area, is inexpensive to manufacture, and has excellent power receiving efficiency.

[0104] <Modification> As shown in Figures 14 and 19, multiple multi-antennas 11, 21 may be arranged in the vertical direction (y-axis direction) and / or horizontal direction (x-axis direction). In this case, adjacent multi-antennas 11, 21 may be arranged with an offset (shift) from each other. The offset interval is arbitrary. When multiple multi-antennas 11, 21 are arranged side by side in the vertical direction (y-axis direction) and / or horizontal direction (x-axis direction), the multi-antenna 11 according to Example 1 and the multi-antenna 21 according to Example 2 may be combined and arranged in any desired manner.

[0105] Adjacent multi-antennas 11 and 21 may be offset from each other. Any of the multiple multi-antennas 11, 21 may be rotated clockwise or counterclockwise. When multiple multi-antennas 21 are arranged side by side, they may be arranged so as to share at least a part of any one of the outermost linear antennas 214 to 217.

[0106] As mentioned above, a dipole antenna is generally called a 1 / 2λ (half wavelength) dipole antenna, and its length d can be calculated based on the operating frequency f (Hz) as follows: d = 3 × 108 / 2f(m), or d={3×108 / 2f}×(0.96~0.97)(m). Therefore, from the above description, a person skilled in the art would be able to roughly understand the dimensions of each of the linear antennas included in the multi-antennas 11 and 21 of this embodiment. However, it should be understood that the dimensions of each of the linear antennas included in the multi-antennas 11 and 21 can be modified in various ways depending on the embodiment.

[0107] <Multi-antenna configuration> FIG. 21 is a diagram showing a configuration according to a first embodiment of the multi-antenna (third embodiment). The basic configuration of the first antenna element 312, the second antenna element 313, the connection line 311, the substrate 30, etc. is similar to that of the first antenna element 112, the second antenna element 113, the connection line 111, and the substrate 10 in the multi-antenna (first embodiment) and the multi-antenna (second embodiment), so detailed description will be omitted. Note that a circuit may be arranged inside the region 301. In the first embodiment of the multi-antenna (third embodiment), the first antenna element 312 and the second antenna element 313 are inverted-F antennas. The connection line 311 is connected to a first feed point 3121 of the first antenna element 312 and a second feed point 3131 of the second antenna element 313. In addition, the first ground point 3122 of the first antenna element 312 and the second ground point 3132 of the second antenna element 313 are each connected to the ground (substrate 31). Note that the first ground point 3122 and the second ground point 3132 do not need to be connected to a common ground, and may be connected to independent grounds. For example, the first ground point 3122 and the second ground point 3132 may each be connected to a ground line that is divided independently into a plurality of regions. The connection line 311 is wired so as not to be connected to the ground (substrate 31). Note that the connection line 311 does not necessarily need to connect the first feeding point 3121 and the second feeding point 3131 over the shortest distance. They may be connected over any route. The first antenna element 312 and the second antenna element 313 are disposed opposite to each other so as to surround the area 301. The first antenna element 312 and the second antenna element 313 are formed three-dimensionally in the vertical direction relative to the substrate 30.

[0108] FIG. 22 is a diagram showing a configuration according to a second embodiment of the multi-antenna (third embodiment). The third antenna element 314 and the fourth antenna element 315 are inverted-F antennas. The connection line 311 connects a first feeding point 3121 of the first antenna element 312, a second feeding point 3131 of the second antenna element 313, a third feeding point 3141 of the third antenna element 314, and a fourth feeding point 3151 of the fourth antenna element 315. The second embodiment of the multi-antenna (third embodiment) includes a third antenna element 314 and a fourth antenna element 315, which are inverted-F antennas, in addition to the first embodiment of the multi-antenna (third embodiment). The connection line 311 is connected to a third feed point 3141 of the third antenna element 314 and a fourth feed point 3151 of the fourth antenna element 315. Also, a third ground point 3142 of the third antenna element 314 and a fourth ground point 3152 of the fourth antenna element 315 are each connected to the ground (substrate 31). Note that the first ground point 3122, the second ground point 3132, the third ground point 3142, and the fourth ground point 3152 do not need to be connected to a common ground, and may each be connected to an independent ground. For example, the first ground point 3122, the second ground point 3132, the third ground point 3142, and the fourth ground point 3152 may each be connected to a ground line that is independently divided into multiple regions (FIGS. 23 and 24). The connection line 311 is wired so as not to be connected to the ground (substrate 31). The connection line 311 does not necessarily need to connect the first feed point 3121, the second feed point 3131, the third feed point 3141, and the fourth feed point 3151 over the shortest distance. The connection line 311 may be connected to each feed point in any order. The connection line 311 may be connected to the first feed point 3121, the second feed point 3131, the third feed point 3141, and the fourth feed point 3151 over any route. The third antenna element 314 and the fourth antenna element 315 are disposed opposite each other so as to surround the area 301. The first antenna element 312, the second antenna element 313, the third antenna element 314, and the fourth antenna element 315 are disposed so as to surround the area 301. The first antenna element 312 and the second antenna element 313 are formed three-dimensionally in the vertical direction with respect to the substrate 30. As a result, even if the receiver is installed in an environment such as on a metal conductor desk, the multi-antenna can be spaced away from the conductor surface to efficiently receive radio waves. In addition, the thickness can be reduced, making it possible to realize a compact, highly efficient multi-antenna with excellent reception performance. The first to fourth antenna elements 312 to 315 do not necessarily have to be provided at the end of the substrate 31 (substrate end), but may be provided in an area inward from the end of the substrate 31 so as to surround the area 301. Furthermore, the number of antenna elements is not limited to two or four. It is possible to realize a multi-antenna composed of any number of inverted-F antenna elements provided to surround the area 301.

[0109] FIG. 25 is a side view of the main body of the power receiving devices 1 and 2 including a multi-antenna (third embodiment). The housing 35 is an exterior (case) that surrounds the multi-antenna (third embodiment). The housing 35 houses and accommodates the substrate 30 and the multi-antenna inside. The housing 35 has a role of protecting the built-in circuit board 30 and wireless devices such as the multi-antenna. The housing 35 is made of a combination of impact-resistant and durable plastic (ABS resin) and metal materials. In addition, ventilation parts such as ventilation holes and ventilation slits may be provided to effectively diffuse internal heat to the outside. The housing 35 is formed so that the thickness in the vertical direction of the area 301 of the multi-antenna is smaller than the thickness in the plane direction of the area 301, and it is possible to accommodate the board 10 and the multi-antenna in a compact manner. The housing 35 is formed in a protruding shape having an inclination in the vertical direction of the substrate from the periphery toward the center of the substrate. Specifically, the thickness of the vertical direction of the housing 35 becomes thinner from the center of the region 301 toward the circumferential direction of the region 301, with an inclined surface 351 being formed. Specifically, the central region of the region 301 has a built-in inverted F antenna (for example, the first antenna element 312) that protrudes in the vertical direction from the region surface of the region 301, so the housing 35 is also formed to protrude outward from the region surface of the region 301 along the inclined surface 351 accordingly. This allows the thickness of the receiving device to decrease in the circumferential direction, making it possible to realize a compact, highly efficient multi-antenna with excellent receiving performance.

[0110] <Configuration of power receiving device (stand)> FIG. 26 is a perspective view of the power receiving devices 1 and 2 (fourth embodiment). The housing 35 has a stand 352 that supports the housing 35 so that the direction perpendicular to the area intersects with the placement surface when the housing 35 is placed. The housing 35 has a stand 352 that supports the housing 35 so that the direction perpendicular to the area intersects with the placement surface when the housing 35 is placed. The stand 352 is made of a durable and weather-resistant plastic material or the like. 26A, the housing 35 of the power receiving devices 1 and 2 is supported by a stand 352 capable of supporting the substrate 30 and the region 301 built into the housing 35 approximately perpendicular to the arrangement surface. The stand 352 may be formed as a part of the housing 35 of the power receiving devices 1 and 2, or may be formed as a separate body. The housing 35 of the power receiving devices 1 and 2 may be formed so as to be detachable from the stand 352. The housing 35 of the power receiving devices 1 and 2 is not necessarily supported perpendicularly, and the housing 35 may be supported at any angle as long as the support member can arrange the multi-antenna at least partly away from the arrangement surface as shown in FIGS. 26B, 26C, and 26D. 26B and 26C, it is preferable that the stand 352 supports the housing 35 of the power receiving devices 1 and 2 so that the multi-antenna area 301 is non-parallel (orthogonal) to the arrangement surface. Note that, if the multi-antenna area 301 can be spaced far enough to allow the multi-antenna to exhibit its performance, the stand 352 may support the housing 35 parallel to (opposite) the arrangement surface as shown in FIG. 26D. As a result, even if the receiving device is installed in an environment such as on a metal conductive desk, the multi-antenna can be spaced away from the conductive surface to efficiently receive radio waves, thereby realizing a receiving device that can efficiently receive radio waves.

[0111] In addition, the stand 352 may include a pillar portion supporting the housing 35, which allows the height of the housing 35 (the distance from the surface on which the multi-antenna is placed) to be adjusted, an arm portion having a multi-joint structure or a ball joint structure connected to the housing 35, which allows the angle of the housing 35 (the angle relative to the surface on which the multi-antenna is placed) to be adjusted, and an attachment portion consisting of a fixing device such as a bracket or clamp for connecting the arm portion to the housing 35. The multi-antenna built into the housing 35 supported by the stand 352 is applicable to the multi-antennas according to all the embodiments of the present disclosure.

[0112] <Configuration of the power receiving device (hanging support part)> FIG. 27 is a top view, a side view, and a perspective view of the main body of the power receiving devices 1 and 2 (fifth embodiment). The housing 35 has a hanging support portion 353 that can be hung. Specifically, the hanging support 353 is a support member that supports the housing 35 by suspending it from the left and right ends of an electronic device such as a monitor placed on a desk. For example, the housing 35 is fixed to an arm (hanging support 353) fixed to the left and right ends of an electronic device such as a monitor, and the housing 35 is supported at a distance from the metal desk. The hanging support 353 may include an adjustment member such as a wire, chain, or nylon strap that can adjust the distance to the housing 35. The hanging support 353 may support the housing 35 in a manner that allows it to be suspended by engaging an attachment hook with the hanging hook. The multi-antenna built into the housing 35 supported by the hanging support portion 353 is applicable to the multi-antennas according to all the embodiments of the present disclosure.

[0113] <Configuration of Multi-Antenna 41> FIG. 28 is a diagram showing a configuration according to a first embodiment of the multi-antenna (sixth embodiment). The first antenna 412 and the second antenna 413 are formed as slits (gaps, slots) formed on a metal substrate. The slits formed on the metal substrate function as antenna elements capable of receiving radio waves. In the first embodiment of the multi-antenna (sixth embodiment), a gap or slit, which is a long and narrow gap (slit), is formed on a conductive substrate such as a metal. Specifically, a groove having a width of about several mm is provided on the conductive substrate. The slit extends in two different directions, similar to the linear antennas in the multi-antenna (first embodiment), multi-antenna (second embodiment), and multi-antenna (third embodiment). Moreover, the extension direction of the slit in the first embodiment of the multi-antenna (sixth embodiment) is allowed to be formed in any shape, similar to the linear antennas in the multi-antenna (first embodiment), multi-antenna (second embodiment), and multi-antenna (third embodiment). Moreover, the connection line 411 is provided so as to connect the vertices of the L-shaped bend. Note that the connection line 411 does not necessarily have to be provided at the vertex, and may be provided at a position offset from the vertex. In the present disclosure, the radio wave energy received by the first antenna 412 and the second antenna 413 can be obtained from the connection line 411. In the present disclosure, the number of slits is not limited to 2. It is possible to realize a multi-antenna composed of an antenna with any number of slits provided so as to surround the region 401. In the first embodiment of the multi-antenna (sixth embodiment), the slits provided in the conductive substrate can function as a magnetic current type antenna for receiving power. This makes it possible to configure the power receiving devices 1 and 2. This makes it possible to realize a magnetic current type antenna that has a small board area, is inexpensive to manufacture, and has excellent reception performance.

[0114] <Interface Board (Seventh Example)> 30A and 30B are diagrams showing a configuration of an interface board (seventh embodiment). FIG. 30C is a diagram showing an example of application of an interface board to a multi-antenna consisting of multiple linear antennas. 30A and 30B, an interface board (small board) 51 that assists in the arrangement and connection of the linear antennas 1122, 1132, 212 to 217, the connection lines 111, 211, etc. included in the multi-antennas 11 and 21 is illustrated.

[0115] The main body 52 of the interface board 51 is constructed based on a polygon model. In this embodiment, it is formed based on a regular octagon. In a regular octagon, all sides are the same length, and each interior angle is constant at 135 degrees, with the central angle being 45 degrees. A main body 52 of the interface board 51 is configured in a generally regular polygonal shape, and connectors that enable two-terminal connection can be arranged at each corner 54 of the main body.

[0116] This interface substrate 51 facilitates application to each connection portion of the multi-antennas 11, 21 which may be configured geometrically symmetrically or fractally. As illustrated in FIGS. 30A and 30B, the interface board 51 can variably configure the current flow within the body 52 by utilizing connectors located at multiple corners. The interface board 51 illustrated in FIGS. 30A and 30B can be used in combination with a linear antenna (dipole antenna) related to the multi-antennas 11 and 21, a rectifier integrated with the linear antenna, and an FPC cable.

[0117] By using multiple interface boards, it is possible to configure multiple antennas of various shapes. Referring to FIG. 30C, there is shown an example in which the interface board 51 is applied to a multi-antenna consisting of a plurality of linear antennas. Each linear antenna has a rectifier in the center, which allows it to be connected to a connector on the interface board. The interface board has other connectors that allow it to be connected to an FPC cable, a controller, etc. The interface board has an internal switch mechanism that allows the connection to the linear antenna, FPC cable, and controller to be freely switched and selected.

[0118] The interface board 51 illustrated in FIGS. 30A and 30B can also be configured with a switch so that connections can be freely changed inside the main body 52. As shown in FIGS. 30A and 30B, all interface boards 51 can have two inputs when connected to each antenna, and one input and one output when only setting two output angles.

[0119] The multi-antenna can be reconfigured by controlling the switches inside the interface board from the controller. By using an interface board, any pattern can be connected using only three types of board patterns (component mounting can be switched each time). In this case, all of the boards can be flexible and mounted on one side, which is advantageous in terms of design and manufacturing.

[0120] By using the interface board 51, it becomes easy to adapt to design changes of the multi-antenna. Furthermore, by using the interface board 51, it is possible to increase the resistance of the multi-antenna even when it is subjected to a strong load such as stress or heat. Furthermore, by joining the interface board 51 with solder, connectors, tape, etc. and housing it in a housing, it becomes easier for it to blend in with the environment.

[0121] The multi-antenna and flexible substrate according to this embodiment have been described above with reference to FIGS. Next, with reference to FIGS. 33A and 33B, a power receiving device 1 including the multi-antenna and the flexible substrate exemplified in FIGS. 5 to 19 will be described.

[0122] <Comparative test of various multi-antennas> The following describes comparative tests of various multi-antennas of the prior art carried out by the applicant. There are various ways to configure a multi-antenna using multiple linear antennas. FIG. 32A shows examples of the radiation efficiency of various multi-antennas, indicated by (1) to (3). FIG. 32B is an example illustrating a multi-antenna. Referring to FIG. 32A, various multi-antenna configurations and radiation efficiencies are illustrated as (1) to (3). In each of (1) to (3), a multi-antenna is formed by combining six linear antennas within a square frame with each side measuring 12 cm.

[0123] In the figure (1), a multi-antenna is shown in which multiple linear antennas such as dipole antennas are arranged radially so that they cross at their center points. In this example, a total of six antennas are arranged so that two adjacent antennas form an angle of 30 degrees. In this case, each antenna can be connected at the center point, making connection easy.

[0124] In the figure (2), a multi-antenna is shown in which multiple linear antennas such as dipole antennas are arranged in parallel. In this example, a total of six antennas are arranged so that two adjacent antennas are spaced a specified distance apart. Each antenna can be connected in a meandering shape bent in a zigzag pattern. In (3) of the same figure, six linear antennas such as dipole antennas are arranged in a more complicated manner compared to the above cases (1) and (2). This example was devised by the applicant.

[0125] As shown enlarged in Figure 32B, in the embodiment (3), two linear antennas are arranged in a cross shape at approximately the center of the board, and linear antennas are arranged along the four sides of a rectangle surrounding the cross. Both ends of the outer linear antennas are folded back twice toward the inside, at angles of 45 degrees and 90 degrees. Each antenna can be connected relatively easily along the black connecting wires.

[0126] Referring to FIG. 32A, the radiation efficiency of the various multi-antennas (1), (2), and (3) above is compared. Considering the practical range, when comparing within the frequency range of 0.8 GHz to 1.0 GHz, it was confirmed that the radiation efficiency of the multi-antenna of (3) above is the highest, and for example, at a frequency of 0.92 GHz, when the ideal performance of the antenna is taken as 100%, it exceeds approximately 90%. In contrast, it was confirmed that the radiation efficiency of the multi-antennas of (1) and (2) above is approximately 85% at a frequency of 0.92 GHz, when the ideal performance of the antenna is taken as 100%.

[0127] In this way, when a multi-antenna is configured by combining a number of linear antennas, there are various ways of configuring the antenna. It was confirmed that when multiple antennas are arranged as shown in Figure 32B, power reception can be performed with relatively high efficiency. In this case, it may be possible to further increase the power reception efficiency by increasing the number of antennas.

[0128] However, there is an issue that the number of antennas is proportional to the board area (the more antennas there are, the higher the board cost). In other words, multi-antennas, which have a small component mounting area but a large board area, tend to have high manufacturing costs. Furthermore, when multiple linear antennas are densely packed within a limited area, there is a risk that interference between adjacent antennas will occur, resulting in a deterioration in power receiving efficiency. Furthermore, there is a trade-off between the amount of power received by a multi-antenna (optimally arranging multiple antennas over a large area) and aesthetics (humans not being aware of the antennas).

[0129] In this embodiment, in consideration of the results of the above tests, improvements were made to reduce manufacturing costs while suppressing the degradation of the performance of the multi-antenna exemplified in (3). In particular, a multi-antenna is provided in which multiple linear antennas are arranged close to each other to improve space efficiency, and a circuit is arranged between the multiple linear antennas to avoid or suppress problems with electromagnetic coupling.

[0130] The term "multi-antenna" refers to multiple linear antennas (such as dipole antennas) placed close to each other to increase spatial efficiency. In order to avoid or reduce problems with electromagnetic coupling, it is advisable to connect the antennas by a connection line (such as a DC connection line). The term "power receiving device" refers to a device that receives energy wirelessly from a separate power transmitting device within a three-dimensional space using a built-in multiple antennas.

[0131] <Application example of power receiving devices 1 and 2> As described above, in this embodiment, WPT (wireless power transmission) can be used to wirelessly transmit energy to a PC, a sensor, an actuator, a robot, the devices 13, 23, etc. The embodiment can be configured in various ways.

[0132] FIG. 33A is a diagram illustrating an example in which a power receiving device is applied in a building management area. FIG. 33B is a schematic diagram showing a usage pattern of the power receiving device. Referring to FIG. 33A, an application example of WPT power receiving devices 1 and 2 is illustrated. As shown in the figure, a power transmitting device is provided outside the power receiving devices 1 and 2, and the power transmitting device transmits energy E to the outside. Multi-antennas 11 and 21 built into the power receiving devices 1 and 2 are configured to be able to receive energy E wirelessly transmitted from the outside. The power receiving devices 1 and 2 can be connected to a MCU (controller) by wire and can transmit data related to power reception to the MCU. For example, the power receiving device can feed back the amount of power received to the MCU.

[0133] Referring to Fig. 33B, a schematic diagram is shown of the usage form of the power receiving devices 1 and 2. As described above, the power receiving devices 1 and 2 including the multi-antennas 11 and 21 configured in a planar, curved or three-dimensional manner can be used in various forms such as a desk mat or an objet d'art. In Fig. 33B, examples of other forms of the power receiving device 1 are illustrated using the reference numerals 1 and 2.

[0134] For example, the power receiving devices 1 and 2 may be configured as a desk mat, a mouse pad, a table mat, a vinyl mat, a protective mat, or the like. The power receiving devices 1 and 2 are installed, for example, on an office desk, a dining table, or the top surface of a shelf. The power receiving devices 1 and 2 receive transmission power from a power transmitting device outside the desk, and can use this power to supply power to electronic devices such as a personal computer, a mouse, a smartphone, and a camera that are placed on the power receiving devices 1 and 2. Power can be supplied from the power receiving devices 1 and 2 to these electronic devices wirelessly or by wire. By adopting such a configuration, the wiring on the power receiving devices 1 and 2 can be eliminated or reduced. The main body of the power receiving device 1, 2 is preferably configured in a multi-layered manner and includes a front surface and a back surface. Either one of the two opposite surfaces (e.g., the back surface) can be abutted against the surface of a desk, and the other surface (e.g., the front surface) can be used as a work surface on the desk. The power receiving devices 1 and 2 can be configured so that either the front or back surface can be used as a work surface (reversible type). The front and back surfaces may each have the same color or the same material, or the front and back surfaces may each have different colors or materials, for example. For example, the front and back surfaces can each be configured using resin, etc. Between the front and back surfaces, an FPC (flexible printed circuit board) 4 is sandwiched. A printed wiring board (substrate) can be provided on the FPC. In particular, the FPC is provided with a multi-antenna capable of receiving energy wirelessly transmitted within a three-dimensional space. In this way, the multi-antennas cannot be seen from the outside, making it possible to place the multi-antennas without spoiling the aesthetic look of the surrounding environment.

[0135] For example, the power receiving devices 1 and 2 may be suspended from a ceiling in a three-dimensional space. For example, the power receiving devices 1 and 2 may be arranged in the form of lighting suspended from a ceiling by a cord or chain. A multi-antenna may be arranged using the flat or curved surface of a lighting shade or umbrella. The power receiving devices 1 and 2 may be any form suspended from a ceiling other than lighting.

[0136] For example, the power receiving devices 1 and 2 may be mounted on a wall of a room in a three-dimensional space. For example, the power receiving devices 1 and 2 may be arranged like a wall clock mounted on a wall or a pillar with a nail or the like. A multi-antenna may be arranged using the face of the wall clock. The power receiving devices 1 and 2 may be any form that can be mounted on a wall or a pillar other than a clock.

[0137] For example, the power receiving devices 1 and 2 may be in a form that stands on a leg or stands on its own on a floor in a three-dimensional space. For example, the power receiving devices 1 and 2 may be arranged like a frame or board for a picture, poster, etc. on a stand provided on the floor, such as a tripod. A multi-antenna may be arranged inside a frame such as a picture frame. The power receiving devices 1 and 2 may be in any form that stands on its own on the floor, other than a picture or board.

[0138] For example, the power receiving devices 1 and 2 may be in a form placed on a floor in a three-dimensional space. For example, the power receiving devices 1 and 2 may be arranged as a shelf or a desk. A multi-antenna may be arranged using at least one side surface of the shelf or desk. The power receiving devices 1 and 2 may be in any form placed on a floor, other than a shelf or a desk. For example, the power receiving devices 1 and 2 may be configured so that a multi-antenna is arranged on the side surface of a sheet or an object placed on a desk.

[0139] For example, the power receiving devices 1 and 2 may be in a form movable in three-dimensional space. For example, the power receiving devices 1 and 2 may be arranged on one side of a business bag or a handbag. For example, a multi-antenna may be arranged on the rear surface of a business bag or a handbag that has a substantially rectangular shape. The power receiving devices 1 and 2 may be in any movable form other than a bag. For example, the power receiving devices 1 and 2 may be configured so that a multi-antenna is arranged on the side of a mobile phone. Alternatively, the power receiving devices 1 and 2 may be placed at the four corners of a desk, or on the side, ceiling, or floor of a room in which the desk is placed.

[0140] As described above, the power receiving devices 1 and 2 can transmit energy wirelessly to a PC (personal computer), a sensor, an actuator, a robot, a device, and the like, by using WPT (wireless power transmission). The targets of this power transmission may also be mobile phones, PDAs (personal digital assistants), wireless microphones, wireless USBs, wireless theaters, wireless televisions, wireless cameras, wireless headphones, wireless mice, wireless keyboards, wireless routers, wireless printers, and the like. The power receiving devices 1 and 2 can be connected to these targets by wires. Any type of power storage device or the like may be interposed between them. Furthermore, the power receiving devices 1 and 2 may be integrated with these targets.

[0141] The power receiving devices 1, 2 have a main body configured in a flexible sheet shape or in any other shape, and the multi-antennas 11, 21 can be arranged on an FPC built into the main body. Flexible boards can be bent and folded freely, and can also form circuit patterns. Flexible boards are also called FPCs (Flexible Printed Circuits). There are also FFCs (Flexible Flat Cables), which cannot mount components but can be wired.

[0142] In this embodiment, the multi-antennas 11 and 21 are disposed on the substrates 10 and 20, for example, on the flexible substrates 10 and 20. The flexible substrates 10 and 20 may include an FPC and an FFC. Referring to Fig. 31, the flexible boards 10 and 20 are compared between FPC and FFC from the viewpoints of appearance, form, component mounting pattern, shape change, cost, and lead time. As can be seen from this figure, FPC and FFC each have advantages and disadvantages. In this embodiment, FPC and FFC can be used depending on the implementation environment. It should be understood that in this embodiment, the shape, dimensions, material, etc. of the substrate on which the multi-antennas 11 and 21 are arranged can be selected arbitrarily.

[0143] The FPC or FFC can be attached by any means inside the main body or housing of the power receiving devices 1 and 2. For example, the attachment can be performed by soldering, attaching a connector, or bonding with copper foil tape. Although solder bonding has the advantage of being highly suitable for mass production, it has the problem that the heat generated during bonding can cause deterioration of the board. Although the connector mounting has the advantage of easy reconfiguration, it has the problem that the thickness tends to increase due to the use of the connector. Copper foil tape bonding has the advantage of being thin and not subject to heat, but there are issues with mass production. In this embodiment, these can be used depending on the implementation environment.

[0144] Although the multi-antenna according to the present embodiment has been described above with reference to the drawings, it should be understood that the present embodiment is not limited to the form shown in the drawings. For example, the multi-antenna according to this embodiment can be combined with a cover called a radome that protects the antenna. Additionally, a metal plate may be placed inside the radome behind the antenna to generate reflected waves and increase the directivity of the antenna. Alternatively, the multi-antenna according to this embodiment may use a metal plate installed on the wall or ceiling of a room to create a reflection situation.

[0145] In the above description, a dipole antenna has been described as a suitable example of a linear antenna, but it should be understood that the present embodiment is not limited to this form. For example, some or all of the multi-antennas according to this embodiment may be replaced with other linear conductors such as a bow-tie dipole, a monopole antenna, an inverted F-shaped antenna, or the like, or may be used in combination.

[0146] Furthermore, the multi-antenna according to this embodiment does not necessarily have to be entirely made up of straight linear antennas, and some or a plurality of the multi-antennas according to this embodiment may be replaced with a meandering shape folded in a zigzag pattern, a star-shaped pattern extending radially from a substantially curved line, or the like, or may be used in combination.

[0147] Furthermore, a part or a plurality of the multi-antennas according to the present embodiment may be replaced with or combined with an antenna utilizing the concept of metamaterials. A metamaterial is an artificial medium that artificially creates characteristic physical phenomena related to the wavelength of electromagnetic waves by periodically arranging regular structures of metals, dielectrics, or magnetic materials.

[0148] It should be understood that the multi-antenna according to this embodiment can be added with any device to improve the flow of balanced current. For example, depending on the embodiment, any device that can be used in conventional antenna technology, such as a blocking tube (schwertop) or a balun, can be added.

[0149] Although the above description relates to receiving energy transmitted wirelessly, the communication method may be any method. For example, it should be understood that any communication method such as wireless LAN, Bluetooth (registered trademark), etc. may be adopted.

[0150] The present invention is not limited to the above-described embodiments, and includes various modified examples. 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 configurations described. It is also possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. It is also possible to add, delete, or replace a part of the configuration of each embodiment with another configuration.

[0151] In addition, the control lines and information lines shown are those that are considered necessary for the explanation, and not all control lines and information lines in the product are necessarily shown. In reality, it can be considered that almost all components are connected to each other. The above-described embodiments disclose at least the configurations described in the claims.

[0152] <Additional Notes> The matters described in the above embodiments will be supplemented below.

[0153] (Appendix 1) A multi-antenna comprising: a substrate; a first antenna element (112) arranged to surround one area of ​​the substrate and consisting of two linear antennas extending in two different directions from a first feed point; a second antenna element (113) consisting of two linear antennas extending in two different directions from a second feed point; and a connecting line (111) connecting the first feed point of the first antenna element and the second feed point of the second antenna element, wherein the connecting line (111) is connected to the first feed point of the first antenna element without following the bisector of the interior angle formed by the two linear antennas with the first feed point of the first antenna element as a vertex, and the connecting line (111) is connected to the second feed point of the second antenna element without following the bisector of the interior angle formed by the two linear antennas with the second feed point of the second antenna element as a vertex. This makes it possible to realize a multi-antenna system with a small number of antennas, low manufacturing costs, and excellent reception performance.

[0154] (Appendix 2) A multi-antenna comprising: a substrate; a first antenna element (112) arranged to surround one region of the substrate and consisting of two linear antennas extending from a first feed point in two different directions; a second antenna element (113) consisting of two linear antennas extending from a second feed point in two different directions; and a connecting line (111) connecting the first feed point of the first antenna element and the second feed point of the second antenna element, wherein the first antenna element (112) extends in a first direction toward a first end and extends in a second direction toward a second end, the second antenna element (113) extends in a third direction toward a third end and extends in a fourth direction toward a fourth end, and an interior angle between the first direction and the second direction and an interior angle between the third direction and the fourth direction are less than 90 degrees. This makes it possible to realize a multi-antenna that requires a small board area, is inexpensive to manufacture, and has excellent reception performance.

[0155] (Appendix 3) A multi-antenna as described in Appendix 2, wherein the interior angle formed by the two linear antennas having the first feed point of the first antenna element (112) as a vertex and the interior angle formed by the two linear antennas having the second feed point of the second antenna element (113) as a vertex are an angle less than 90 degrees. This makes it possible to realize a multi-antenna that requires a small board area, is inexpensive to manufacture, and has superior reception performance.

[0156] (Appendix 4) 2. A multi-antenna as described in appended claim 1, comprising: a substrate; a first antenna element (112) arranged to surround one region of the substrate and consisting of two linear antennas extending from a first feed point in two different directions; a second antenna element (113) consisting of two linear antennas extending from a second feed point in two different directions; and a connecting line (111) connecting the first feed point of the first antenna element and the second feed point of the second antenna element, wherein the first antenna element (112) extends in a first direction toward a first end and extends in a second direction toward a second end, the second antenna element (113) extends in a third direction toward a third end and extends in a fourth direction toward a fourth end, and an interior angle between the first direction and the second direction and an interior angle between the third direction and the fourth direction are an angle of 90 degrees or more. This allows for a small number of antennas, low manufacturing costs, and the ability to receive radio waves over a wide area, resulting in the realization of a compact, highly efficient multi-antenna with excellent reception performance.

[0157] (Appendix 5) A multi-antenna comprising: a substrate; a first antenna element (112) arranged to surround one area of ​​the substrate and consisting of two linear antennas extending from a first feed point in two different directions; a second antenna element (113) consisting of two linear antennas extending from a second feed point in two different directions; and a connecting wire (111) connecting the first feed point of the first antenna element and the second feed point of the second antenna element, the connecting wire (111) being bent and connected to the first feed point of the first antenna element, and the connecting wire (111) being bent and connected to the second feed point of the second antenna element. This allows for a small number of antennas, low manufacturing costs, and the ability to receive radio waves over a wide area, resulting in the realization of a compact, highly efficient multi-antenna with excellent reception performance.

[0158] (Appendix 6) A multi-antenna comprising: a substrate; a first antenna element (112) arranged to surround one region of the substrate and having a first feed point; a second antenna element (113) having a second feed point; and a connecting line (111) connecting the first feed point of the first antenna element and the second feed point of the second antenna element, wherein the first antenna element (112) and the second antenna element (113) are inverted-F antennas. As a result, even if the receiver is installed in an environment such as on a metal conductor desk, the multi-antenna can be spaced away from the conductor surface to efficiently receive radio waves. In addition, the thickness can be reduced, making it possible to realize a compact, highly efficient multi-antenna with excellent reception performance.

[0159] (Appendix 7) A multi-antenna as described in Appendix 6, comprising: a substrate; a third antenna element (114) arranged to surround one region of the substrate and having a third feed point; and a fourth antenna element (115) having a fourth feed point, wherein the third antenna element (114) and the fourth antenna element (115) are inverted-F antennas; and a connecting line (111) connects the first feed point of the first antenna element, the second feed point of the second antenna element, the third feed point of the third antenna element, and the fourth feed point of the fourth antenna element. As a result, even if the receiver is installed in an environment such as on a metal conductor desk, the multi-antenna can be spaced away from the conductor surface to efficiently receive radio waves. In addition, the thickness can be reduced, making it possible to realize a compact, highly efficient multi-antenna with excellent reception performance.

[0160] (Appendix 8) A multi-antenna as described in Appendix 6, comprising a housing (35) surrounding the multi-antenna, the housing (35) being formed in a protruding shape having an inclination from the periphery of the substrate toward the center of the substrate in the vertical direction of the substrate. As a result, even if the receiver is installed in an environment such as on a metal conductor desk, the multi-antenna can be spaced away from the conductor surface to efficiently receive radio waves. In addition, the thickness of the receiver becomes thinner in the circumferential direction, making it possible to realize a compact, highly efficient multi-antenna with excellent reception performance.

[0161] (Appendix 9) A multi-antenna comprising: a substrate; a first antenna (112) arranged to surround one region of the substrate and having a first feed point; a second antenna (113) having a second feed point; and a connecting line (111) connecting the first feed point of the first antenna and the second feed point of the second antenna, wherein the first antenna and the second antenna are formed as slits in a metal substrate. This makes it possible to realize a magnetic current type antenna that has a small board area, is inexpensive to manufacture, and has excellent reception performance.

[0162] (Appendix 10) 10. A multi-antenna according to any one of claims 1 to 9, used in a wireless power transmission (WPT) power receiving device for receiving energy transmitted from a power transmitting device using microwaves. This makes it possible to realize a multi-antenna system with a small number of antennas, low manufacturing costs, and excellent reception performance.

[0163] (Appendix 11) A wireless power transmission (WPT) receiving device comprising: a substrate; a first antenna element (112) arranged to surround one area of ​​the substrate and consisting of two linear antennas extending from a first feed point in two different directions; a second antenna element (113) consisting of two linear antennas extending from a second feed point in two different directions; a connection wire (111) connecting a first feed point of the first antenna element and a second feed point of the second antenna element; and a housing (35), wherein the housing (35) has a stand (352) that supports the housing (35) so that, when placed, a direction perpendicular to the area is spaced apart from the placement surface by a predetermined distance or more. As a result, even if the receiving device is installed in an environment such as on a metal conductive desk, the multi-antenna can be spaced away from the conductive surface to efficiently receive radio waves, thereby realizing a receiving device that can efficiently receive radio waves.

[0164] (Appendix 12) The power receiving device according to claim 11, wherein the housing (35) has a stand (352) that supports the device so that a direction perpendicular to the area intersects with the placement surface when the device is placed. As a result, even if the receiving device is installed in an environment such as on a metal conductive desk, the multi-antenna can be spaced away from the conductive surface to efficiently receive radio waves, thereby realizing a receiving device that can efficiently receive radio waves.

[0165] (Appendix 13) 12. The power receiving device according to claim 11, wherein the housing (35) has a stand (352) that supports the device so that a direction perpendicular to the area is approximately vertical to the placement surface when the device is placed. This allows the multi-antenna to be placed away from the receiving device and the environment, such as a metal conductive desk, and allows the realization of a receiving device that can receive radio waves efficiently. [Explanation of symbols]

[0166] 1 power receiving device, 10 board, 11 multi-antenna, 12 circuit, 13 equipment, 2 power receiving device, 20 board, 21 multi-antenna, 22 circuit, 23 equipment, 4 power transmitting device

Claims

[Claim 1] circuit board and A first antenna element is formed by two linear antennas arranged to surround one region of the substrate and extending in two different directions from a first feed point, and a second antenna element is formed by two linear antennas extending in two different directions from a second feed point. A connecting wire that connects the first feed point of the first antenna element and the second feed point of the second antenna element, Equipped with, The connecting line is connected to the first feed point of the first antenna element, without following the angle bisector of the interior angle formed by the two linear antennas, with the first feed point of the first antenna element as its vertex. The connecting line is connected to the second feed point of the second antenna element, without following the angle bisector of the interior angle formed by the two linear antennas, with the second feed point of the second antenna element as its vertex. Multi-antenna.

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