Power receiving device, power supply device, and wireless power supply system

Abstract

To improve the efficiency of power reception. [Solution] The power receiving device comprises an antenna section, a power receiving circuit, a rectifier circuit, and a transmission circuit. The antenna section has one or more first antennas on its first surface for receiving radio waves from the outside and two or more second antennas for transmitting radio waves to the outside. The power receiving circuit is connected to the first antenna and receives power signals via the first antenna. The rectifier circuit rectifies the power signals received by the power receiving circuit. The transmission circuit is connected to the second antenna and transmits radio signals via the second antenna. The first surface of the antenna section includes a first region and a second region which is at least a part of the region surrounding the first region, and the second antennas are located in the second region.

Description

Technical Field

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[0001] Embodiments of the present invention relate to a power receiving device, a power feeding device, and a wireless power feeding system.

Background Art

[0002] With the development of electrical products, the development and research of wireless power feeding technology that enables charging without using a physical interface such as a charging pad or a plug have been widely carried out. As one of the wireless power feeding methods, there is a method using microwaves. In this implementation, power transmission is performed by estimating the position where a beacon signal is transmitted from a beacon device by a power transmitter having a microwave array emitter.

[0003] Therefore, power transmission from the transmitter is concentrated at the position where the beacon signal is transmitted in the receiver. The rectenna in the device to be charged receives and rectifies the microwave energy, which is used for charging the battery and / or used as the main power. However, in this method, there has been insufficient discussion about which position among the positions of the beacon transmission antenna and the plurality of antenna elements that receive power is to receive power transmission, and there is a problem that the received power becomes small.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

[0007] [Figure 1] A schematic diagram showing a wireless power supply system according to one embodiment. [Figure 2] A schematic block diagram showing a power receiving device according to one embodiment. [Figure 3] A diagram showing an example of antenna arrangement in an antenna array according to one embodiment. [Figure 4] A diagram showing an example of antenna arrangement in an antenna array according to one embodiment. [Figure 5] A diagram showing an example of antenna arrangement in an antenna array according to one embodiment. [Figure 6] A schematic block diagram showing a power supply device according to one embodiment. [Figure 7] A schematic block diagram showing a power receiving device according to one embodiment. [Figure 8] A diagram showing an example of antenna arrangement in an antenna array according to one embodiment. [Modes for carrying out the invention]

[0008] The embodiments will now be described with reference to the drawings. The problems to be solved by these embodiments are not limited to those described above; they may also include at least one of the problems corresponding to the effects described below. In other words, any problem corresponding to at least one of the effects described in the description of the embodiments may be the problem that the embodiments aim to solve.

[0009] (First Embodiment)

[0010] Figure 1 is a schematic diagram showing a wireless power supply system according to one embodiment. The wireless power supply system 1 comprises a power receiving device 10 and a power supply device 20. In the drawing, one power receiving device 10 and one power supply device 20 are shown, but the system is not limited to these. The wireless power supply system 1 may, for example, have one power supply device 20 for multiple power receiving devices 10, or multiple power supply devices 20 for one power receiving device 10, or multiple power supply devices 20 for multiple power receiving devices 10.

[0011] The wireless power supply system 1 is a system for charging the power receiving device 10. The wireless power supply system 1 supplies power to the power receiving device 10 without contact between the power receiving device 10 and the power supply device 20 by transmitting a power signal from the power supply device 20 to the power receiving device 10. However, the wireless power supply system 1 can also operate as a system that supplies power to electronic equipment including the power receiving device 10, or to electronic equipment connected to the power receiving device 10.

[0012] The power receiving device 10 transmits a wireless signal to the power supply device 20. The power supply device 20 receives the wireless signal transmitted from the power receiving device 10, estimates the location of the power receiving device 10, and transmits a power signal toward the location of the power receiving device 10.

[0013] Alternatively, the power supply device 20 may broadcast a wireless signal. In this case, the power receiving device 10 can determine that it is located within a range where power can be supplied, triggered by the reception of the wireless signal, and then transmit a wireless signal to the power supply device 20 in order to receive power.

[0014] In this disclosure, more specifically, the power supply device 20 estimates an appropriate position in the receiving antenna or receiving antenna array located in the receiving device 10 based on the wireless signal output from the power receiving device 10, and outputs a power signal toward the estimated position. A specific implementation for performing this operation will be described.

[0015] Figure 2 is a schematic block diagram showing an example of a power receiving device 10 according to one embodiment. The power receiving device 10 includes, for example, an antenna section (antenna array 100) having an antenna on its first surface, a power receiving circuit 120, a transmitting circuit 122, a rectifier circuit 124, a control circuit 126, and a battery 128. The power receiving device 10 is a device that receives power signals via the antenna provided on the antenna array 100 and supplies power to the battery 128.

[0016] The antenna array 100 is formed by arranging multiple antennas that transmit or receive radio waves in the power receiving device 10 in an array. The detailed arrangement will be described later. The antenna array 100 has a first surface and comprises a first antenna 102 and a second antenna 104 formed on this first surface.

[0017] One or more first antennas 102 are provided in the power receiving device 10. The first antenna 102 is an antenna that receives radio waves, and the power receiving device 10 receives power signals supplied from an external source via this first antenna 102. Although multiple first antennas 102 are shown in the diagram, the configuration may consist of at least one first antenna 102.

[0018] Two or more second antennas 104 are provided in the power receiving device 10. The second antenna 104 is an antenna that transmits radio waves, and the power receiving device 10 transmits a wireless signal via the second antenna 104.

[0019] The power receiving circuit 120 receives at least a power signal from outside the power receiving device 10 via the first antenna 102. Also, although the power receiving circuit 120 is a circuit that receives a power signal, in addition to this, it may be configured to receive a data signal. The power signal to be received is not limited to a specific type in terms of its frequency band, communication standard, etc., and a form and means capable of appropriate power supply (and data signal reception) can be used.

[0020] The transmission circuit 122 transmits a wireless signal to the outside of the power receiving device 10 via the second antenna 104. The wireless signal to be transmitted is not limited to a specific type in terms of its frequency band, communication standard, etc. As an example without limitation, the wireless signal may be a beacon signal that notifies the presence of a power receiving side wireless power feeding device (power receiving device 10). Also, the wireless signal may include at least one of information related to a power signal transmission request, identifier information of the power receiving side wireless power feeding device (power feeding device 20), or position information of each of the second antennas 104.

[0021] The transmission circuit 122 may transmit a wireless signal by attaching the position information of the second antenna 104 to the signal transmitted from each second antenna 104. Also, the transmission circuit 122 may transmit a wireless signal by attaching the position information corresponding to each of the plurality of second antennas from at least one of the plurality of second antennas 104. In this case, the transmission circuit 122 can transmit by associating the identification information and the position information of each second antenna 104.

[0022] This location information may be global location information, local location information, or relative location information from a reference point in the power receiving device 10 or antenna array 100.

[0023] Local position information may be, for example, the relative position of the power supply device 20 with respect to a reference point in the space in which it is located. The reference point in the power receiving device 10 or the antenna array 100 may be, for example, the relative position from the central point of the antenna array 100 (one or more first antennas 102 arranged therein), or the relative position from a reference point in the coordinate system including the antenna array 100.

[0024] Thus, location information is not limited to any particular means of acquisition, but can be acquired by any means, for example, by global means such as highly accurate GPS, by means of acquiring information from wireless information such as Wi-Fi, or by means based on information such as the antenna mounting arrangement in the power receiving device 10.

[0025] The transmitting circuit 122 may transmit the radio signals from each second antenna 104 at different timings, i.e., in time division multiplexing. By transmitting the radio signals from each power receiving device 10 and / or second antenna 104 at different timings, when the power supply device 20 receives the radio signals, multiple radio signals are not combined, and can be distinguished as independent signals from each antenna.

[0026] The rectifier circuit 124 converts the power signal received by the power receiving circuit 120 from AC to DC and outputs it. The rectifier circuit 124 may be a bridge-type rectifier circuit, including, but is not limited to, a full-bridge circuit or a half-bridge circuit, but other configurations are not excluded. The rectifier circuit 124 rectifies the power signal and stores it in the battery 128.

[0027] The control circuit 126 controls the power receiving circuit 120, the transmission circuit 122, and the rectifier circuit 124. The battery 128 may include hardware circuits such as a general-purpose processor, an ASIC (Application Specified Integrated Circuit), an FPGA (Field Programmable Gate Array), or a PLD (Programmable Logic Device), as well as memory circuits. For example, when the power receiving circuit 120 receives a control signal containing information requesting the transmission of a wireless signal via the antenna array 100, the control circuit 126 can control the transmission of a wireless signal to the transmission circuit 122 via the second antenna 104. The control circuit 126 can also control or monitor the charging and discharging of the battery 128. Information related to control and monitoring can also be stored in a memory circuit (not shown).

[0028] Furthermore, if a general-purpose circuit is used as the control circuit 126, it is also possible to store the data related to the software, which is used to concretely implement the software-based information processing by the control circuit 126, which is a hardware resource, in a memory circuit not shown above.

[0029] Battery 128 is the battery to be supplied with power by the power receiving device 10. Battery 128 is a rechargeable battery, such as a lithium-ion battery, lead-acid battery, or nickel-metal hydride battery. Battery 128 may be any other battery capable of providing suitable power.

[0030] Furthermore, although Figure 2 shows the battery 128 as a structure installed inside the power receiving device 10, it is not limited to this. The battery 128 may be, for example, a standalone battery connected to the power receiving device 10. Alternatively, the battery 128 may be, for example, a battery placed inside an electronic device that includes the power receiving device 10. The battery 128 may be a battery that supplies power for the operation of the power receiving device 10, or for the operation of an electronic device that includes the power receiving device 10.

[0031] Next, the arrangement of antennas in antenna array 100 will be explained using several diagrams.

[0032] Figures 3, 4, and 5 show some examples of the arrangement of the first antenna 102 and the second antenna 104 in an antenna array 100 according to one embodiment. The first antenna 102, which receives power signals, is arranged in an array along, for example, a first direction and a second direction intersecting the first direction. By arranging them in this way, the radiated power signals are received as a surface on the first surface, and the power supplied by the power signals can be efficiently acquired. Furthermore, by not arranging the second antenna 104 in a position where power signals can be efficiently received, the efficiency of power supply can be further improved.

[0033] As shown in the figure, the first antenna 102 is positioned to occupy a location near the center of the array. More specifically, the first antenna 102 is positioned so that it can properly receive radio waves in the area near the center of the antenna array 100. In other words, the second antenna 104 is not positioned near the center of the antenna array 100.

[0034] In other words, the antenna array 100 is provided on the first surface of the antenna section and includes a first region and a second region which is at least a part of the region surrounding the first region. The first antenna 102 is located in the first region. The second antenna 104 is located in the second region. In Figures 3, 4, and 5, the region where the first antenna 102 is located is the first region, and the region where the second antenna 104 is located is the second region.

[0035] Furthermore, the distance between the second antenna 104 and the center of the antenna array 100 is longer than the distance between at least one first antenna 102 and the center of the antenna array 100. While it is desirable that the distance between the second antenna 104 and the center of the antenna array 100 be longer than the distance between all the first antennas 102 and the center of the antenna array 100, as shown in Figures 3 to 5, this is not limited to this arrangement. In some cases, the distance may be shorter than the distance between some of the first antennas 102 and the center of the antenna array 100, provided that the arrangement allows for adequate power reception.

[0036] Preferably, the second antenna 104 is positioned at the location furthest from the center of the array, as shown in Figure 3 or Figure 4. However, it is not limited to these configurations, and as shown in Figure 5, the second antenna 104 can be positioned at a location far from the center, such that the first antenna 102 is positioned near the center of the array. Preferably, the second antenna 104 is positioned symmetrically with respect to the center (or a position close to the center) of the array.

[0037] The transmitting circuit 122 transmits radio signals at different timings (time-division multiplexing) for each of the multiple second antennas 104. The feeding device 20 receives the radio signals from the second antennas 104 and uses these radio signals to estimate the center position of the array. The feeding device 20 can efficiently supply power to the receiving device 10 by transmitting a power signal towards the estimated center position of the antenna array 100, or a position close to the center.

[0038] Furthermore, the transmitting circuit 122 may transmit a radio signal via the second antenna 104 that includes information indicating the position of the second antenna 104 in the array. The transmitting circuit 122 can, for example, transmit data indicating the position of each second antenna 104 on the radio signal. The power supply device 20 can estimate the central position or a position close to the center of the antenna array 100 based not only on the information regarding the radio wave reception status in the radio signal acquired from the second antenna 104, but also on the information indicating the position of the second antenna 104 included in the radio signal.

[0039] In this disclosure, the second antenna 104 is positioned relative to an array of first antennas 102 arranged in a 5 × 5 grid, but the configuration is not limited to this. For example, the number of first antennas 102 forming the array may be fewer, such as 1 × 1 or 2 × 2, or more, such as 6 × 6, or they may be in a number that does not form a square, such as 2 × 3 or 5 × 7. Furthermore, the shape does not have to be rectangular; it may be any shape that can efficiently receive power signals radiated towards the center of the array, such as a circle or an ellipse.

[0040] Furthermore, although the description described an configuration with two second antennas 104, the configuration is not limited to this. The number of second antennas 104 may be three or more, and they should be arranged so that they are not located near the center of the array, as described above. In this case, it is desirable for the second antennas 104 to be arranged symmetrically with respect to the center of the array, as described above, but the configuration is not limited to this, and any arrangement that allows the center position (or a position near the center) to be appropriately estimated using the radio signals transmitted from multiple second antennas 104 is acceptable.

[0041] As described above, according to this embodiment, the antenna array 100 in the power receiving device 10 can transmit data for transmitting power signals to the appropriate location. Furthermore, by positioning the second antenna 104 away from the center of the antenna array 100, it becomes possible to efficiently receive the beam of the power signal transmitted towards the appropriate location (ideally the center of the antenna array 100) at one or more first antennas 102.

[0042] Generally, the power intensity in a transmitted beam is highest at the target location from which the beam is transmitted, and decreases towards the periphery. In this embodiment, the first receiving antenna 102 is positioned near the center, i.e., at the target location from which the beam is transmitted. Furthermore, multiple first receiving antennas 102 are positioned, and the second transmitting antenna 104 is not positioned at a location with high power in the beam. This allows for efficient power supply via power signals, that is, enables the reception of a large overall power.

[0043] The emission of such a beam will be described in the following embodiment.

[0044] (Second Embodiment)

[0045] Figure 6 is a schematic block diagram showing an example of a power supply device 20 according to one embodiment. The power supply device 20 includes, for example, a third antenna 202, a fourth antenna 204, a power transmission circuit 220, a receiving circuit 222, an arithmetic circuit 224, a control circuit 226, a memory circuit 228, and a power supply circuit 230. The power supply device 20 receives a wireless signal from the power receiving device 10 of the first embodiment via the fourth antenna 204 and radiates a power signal to an appropriate location via the third antenna 202.

[0046] The third antenna 202 is an antenna that outputs a signal for supplying power to the feeder 20. It is desirable that there be multiple third antennas 202. The power transmission circuit 220 outputs the power signal used for feeding via the third antenna 202 to the outside, for example, to a position close to the center of the antenna of the receiving device 10. By using multiple third antennas 202, the feeder 20 can transmit power signals in the direction it wants to transmit, for example, by beamforming. Furthermore, the feeder 20 is not limited to beamforming, and can also transmit power signals by mechanically moving the beam.

[0047] The fourth antenna 204 is an antenna in the power supply device 20 that receives signals from the outside. The fourth antenna 204 may be provided in one or more configurations. The receiving circuit 222 receives signals from the outside, such as radio signals transmitted from the power receiving device 10, via the fourth antenna 204. These received signals may, but are not limited to, beacon signals.

[0048] The power transmission circuit 220 transmits power signals via multiple third antennas 202. The power transmission circuit 220 outputs power signals in an appropriate direction and position, for example, based on beamforming techniques or mechanical methods.

[0049] The receiving circuit 222 receives radio signals via one or more fourth antennas 204. The receiving circuit 222 receives multiple radio signals in a time-division multiplexing manner, for example. The receiving circuit 222 outputs data related to the multiple received radio signals to the arithmetic circuit 224.

[0050] The arithmetic circuit 224 estimates the central or near-central position of the antenna array 100 of the power receiving device 10 based on the radio signal received by the receiving circuit 222. The arithmetic circuit 224 estimates the direction of arrival for each of the multiple radio signals transmitted through the multiple second antennas 104. If the transmitting circuit 122 transmits radio signals from each of the second antennas 104 at different timings, the arithmetic circuit 224 can obtain information about the signals transmitted through each of the second antennas 104 by having the receiving circuit 222 receive the radio signals at different timings.

[0051] The arithmetic circuit 224 can acquire the direction of arrival of the signals output through each of the second antennas 104. Based on the direction of arrival of the radio signals acquired from these multiple second antennas 104, the arithmetic circuit 224 can estimate the central position or a position close to the center of the antenna array 100. In this case, the memory circuit 228 may pre-store data relating to the position of each of the second antennas 104, and the arithmetic circuit 224 can estimate the central position or a position close to the center based, for example, on the data indicating the position of each of the second antennas 104 stored in the memory circuit 228.

[0052] In the following, the expression "position near the center" (or "position near the center") will be used, but this expression may be reinterpreted as either the central position of the antenna array 100 estimated by the arithmetic circuit 224, or the transmission position of the power signal (feed signal) relative to this estimated central position. The phrase "transmission position of the power signal" can be interpreted, depending on the context, as either the position where the feeder 20 is scheduled to transmit the power signal, or the actual arrival position of the power signal at the antenna array 100 of the receiving device 10 of the power receiving device 20, or both.

[0053] Furthermore, if the radio signal transmitted from the power receiving device 10 contains data indicating the position information of the second antenna 104, the arithmetic circuit 224 can use this position information to obtain the position of each second antenna 104. By obtaining the position information, the arithmetic circuit 224 can perform a more detailed estimation of the center or near-center position of the antenna array 100 based on the direction of arrival of the radio signal transmitted through each second antenna 104 and the position information of the second antenna 104 in the antenna array 100. Of course, even in this case, the arithmetic circuit 224 may use the position data of the second antenna 104 stored in the memory circuit 228.

[0054] The arithmetic circuit 224 may further estimate the position of the first antenna 102 that is closest to the center of the antenna array 100 based on the above estimation. If the second antenna 104 is arranged symmetrically in the antenna array 100, the arithmetic circuit 224 can make the estimated center of the direction of arrival of the radio signal a position close to the center of the multiple first antennas 102, making it easier to perform the calculation to estimate the position close to the center in the antenna array 100.

[0055] The arithmetic circuit 224 determines the transmission center based on the radio signals transmitted from two or more antennas. The transmission center is, for example, one.

[0056] If the second antenna 104 is positioned symmetrically with respect to the center of the first region where the first antenna 102 is located, the transmission center is the center of the second antenna 104. Alternatively, if the calculation circuit 224 has previously obtained the relationship between the second antenna 104 and the center of the first region, the transmission center is determined based on this relationship.

[0057] The arithmetic circuit 224 can employ methods such as the beamformer method, Capon method, linear prediction method, MUSIC (Multiple Signal Classification) method, and ESPRIT (Estimation of Signal Parameters via Rotational Invariance Techniques), but is not limited to these methods; any method that can appropriately acquire the position can be used.

[0058] The calculation circuit 224 outputs information regarding the estimated central or near-central position of the antenna array 100 to the control circuit 226.

[0059] The control circuit 226 controls the components of the power supply device 20. The control circuit 226 may include, for example, a general-purpose processor, ASIC, FPGA, PLD or other hardware circuits, as well as memory circuits. The control circuit 226 can control, for example, the phase and amplitude of the power signal, as well as the orientation of the third antenna 202. The control circuit 226 can control the transmission of the power signal so that it targets the position estimated by the arithmetic circuit 224.

[0060] Furthermore, if the wireless signal contains information such as a power signal transmission request or an identifier for the power receiving device 10, the control circuit 226 can control the power transmission circuit 220 to transmit a power signal to the power receiving device 10 corresponding to this identifier. If there are multiple power receiving devices 10, the control circuit 226 can control the transmission of a power signal to the appropriate power receiving device 10 based on a pre-set algorithm or a predetermined processing flow.

[0061] If there are multiple third antennas 202, a variable phase circuit may be provided at each third antenna 202, or before and after the interface connecting the power transmission circuit 220 to the third antenna 202. The variable phase circuit may be provided at some of the third antennas 202, or at all of the third antennas 202. The power transmission circuit 220 can transmit a power signal towards the position closest to the center of the antenna array 100 estimated by the calculation circuit 224, using the phase of the variable phase circuit controlled by the control circuit 226.

[0062] For example, the system may have a mechanism to change the direction of the third antenna 202 using a motor or the like. The power transmission circuit 220 can transmit a power signal towards the position closest to the center of the antenna array 100 estimated by the calculation circuit 224, according to the direction of the third antenna 202 controlled by the control circuit 226.

[0063] The memory circuit 228 provides a memory area capable of storing various types of data. The memory circuit 228 may be, for example, volatile memory or non-volatile memory, a storage device such as a hard disk, or an external storage device; there are no particular limitations on the type. The memory circuit 228 may, for example, pre-store data such as the identifier of each power receiving device 10 and the position of the second antenna 104 in each power receiving device 10, as described above. Furthermore, if information processing by software is implemented by at least some of the circuits in the power supply device 20, which is a hardware resource, information related to that software can be stored.

[0064] The power supply circuit 230 supplies power to the other components of the power supply device 20. The power supply circuit 230 may perform conversions based on the power supplied from an external power source to supply power to the other components of the power supply device 20. The power supply circuit 230 may include a configuration that achieves voltage boosting or bucking, for example, by a DC-DC converter. Furthermore, the power supplied from this power supply circuit 230 allows the power transmission circuit 220 to acquire power used for supplying power wirelessly via the third antenna 202.

[0065] As described above, the power supply device 20 according to this embodiment makes it possible to transmit an appropriate power signal based on the data acquired from the power receiving device 10 in the previously described embodiment. In other words, when using the power receiving device 10 in the first embodiment, the power supply device 20 according to this embodiment can operate as a power supply device for efficiently supplying power, as one example of which is not limited to this embodiment. That is, the power supply device 20 according to this embodiment makes it possible to supply a large amount of power.

[0066] It should be noted that the configuration in this embodiment is shown as an example, and does not preclude other configurations for the power supply device in the power receiving device 10 in the previously described embodiment or other embodiments. Furthermore, the power supply device 20 in this embodiment can operate similarly with the power receiving device 10 in the following embodiments and can achieve similar effects.

[0067] (Third embodiment)

[0068] In the embodiments described above, the power receiving device 10 is equipped with a first antenna 102 and a second antenna 104, with the second antenna 104 being a transmitting antenna. However, the embodiment is not limited to this configuration. For example, the second antenna 104 can also be used as a receiving antenna.

[0069] Figure 7 is a schematic block diagram showing a power receiving device according to one embodiment. In addition to the configuration of the embodiment described above, the power receiving device 10 may include a switch 130.

[0070] Switch 130 is provided between the second antenna 104 and the transmitting circuit 122. Switch 130 is also connected to the power receiving circuit 120. Switch 130 can switch whether the second antenna 104 is connected to the transmitting circuit 122 or to the power receiving circuit 120. In other words, the configuration of switch 130 allows the second antenna 104 to be used for both receiving power signals and transmitting radio signals.

[0071] The second antenna 104 is switched by the switch 130 so that when the power receiving device 10 transmits a wireless signal, it is connected to the transmitting circuit 122 and functions as a transmitting antenna, and when the power receiving device 10 receives a power signal, it is connected to the power receiving circuit 120 and functions as a receiving antenna.

[0072] The antenna array 100 can have the same configuration as the embodiment described above, or it can achieve power reception just as efficiently with other configurations as described below.

[0073] Figure 8 shows an example of antenna arrangement in an antenna array according to one embodiment. As shown in this figure, preferably, the second antenna 104, which is used for both receiving and transmitting, can be positioned, for example, diagonally in a two-dimensional array arrangement along the first and second directions. In Figure 8, the region where the first antenna 102 is provided is the first region, and the region where the second antenna 104 is provided is the second region.

[0074] Preferably, the second antenna 104 can be positioned at the position furthest from the center of the antenna array 100 (the diagonal position shown in the figure). This arrangement allows the power receiving device 10 to receive power from the entire antenna array 100, and minimizes the impact of power signals radiated towards the center of the antenna array 100 on the receiving device at the position with the least impact within the antenna array 100, thereby suppressing the impact of power loss in the switch 130.

[0075] For example, in a configuration with a switch 130, if there is only one second antenna 104, positioning the second antenna 104 in the center of the antenna array 100 allows for the transmission of positional information to the power supply device 20. However, in this configuration, power loss occurs in the switch 130 at the antenna at the position where the power intensity is strongest, which can lead to significant power loss. According to this embodiment, such significant power loss can be suppressed, and a greater power supply can be achieved.

[0076] The contents of this disclosure can also be summarized as follows:

[0077] (1) An antenna section having one or more first antennas that receive radio waves from the outside, and two or more second antennas that transmit radio waves to the outside, on its first surface, A power receiving circuit connected to the first antenna and receiving a power signal via the first antenna, A rectifier circuit that rectifies the power signal received by the power receiving circuit, A transmitting circuit connected to the second antenna and transmitting a wireless signal via the second antenna, Equipped with, The first surface of the antenna portion includes a first region and a second region which is at least a part of the region surrounding the first region, and the second antenna is located in the second region. Power receiving device.

[0078] (2) The aforementioned external radio waves are signals transmitted based on the aforementioned wireless signals. (1) The power receiving device described above.

[0079] (3) The aforementioned wireless signal is a beacon signal. (1) or (2) the power receiving device described above.

[0080] (4) The transmitting circuit transmits the radio signal from each of the second antennas at different timings. A power receiving device as described in any of (1) to (3).

[0081] (5) The transmitting circuit transmits the wireless signal including the position information of the second antenna. A power receiving device as described in any of (1) to (4).

[0082] (6) The second antenna is positioned symmetrically with respect to the center of the antenna array on which the first antenna is provided. A power receiving device as described in any of (1) to (5).

[0083] (7) A switch is connected between the aforementioned second antenna and the transmitting circuit. Equipped with, The switch is further connected to the power receiving circuit, A power receiving device as described in any of (1) to (6).

[0084] (8) The aforementioned switch is The second antenna and the transmitting circuit are connected at the timing when the transmitting circuit transmits the wireless signal. The second antenna and the power receiving circuit are connected at the timing when the power receiving circuit receives the power signal. (7) The power receiving device described above.

[0085] (9) The distance between the second antenna and the center of the antenna array is longer than the distance between the first antenna and the center of the antenna array. A power receiving device as described in any of (1) to (8).

[0086] (10) One or more antennas, A power transmission circuit connected to at least one of the aforementioned antennas, which transmits a power signal to a power transmission center via the at least one aforementioned antenna, A receiving circuit connected to at least one of the aforementioned antennas and receiving a wireless signal via said at least one antenna, A calculation circuit that determines a single transmission center based on the radio signals transmitted from two or more antennas, Equipped with, The power transmission circuit performs control to transmit the power signal toward a position close to the power transmission center estimated by the calculation circuit. Power supply device.

[0087] (11) A power receiving device as described in any of (1) to (9), (10) The power supply device described above, Equipped with, The power receiving device transmits a wireless signal via the second antenna. The power supply device transmits the power signal based on the information of the wireless signal transmitted by the transmitting circuit. Wireless power supply system.

[0088] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents. [Explanation of symbols]

[0089] 1: Wireless power supply system, 10: Power receiving equipment, 100: Antenna array, 102: First antenna, 104: Second antenna, 120: Power receiving circuit, 122: Transmitter circuit, 124: Rectifier circuit, 126: Control circuit, 128: Batteries, 130: Switch, 20: Power supply device, 202: Third antenna, 204: Fourth antenna, 220: Power transmission circuit, 222: Receiving circuit, 224: Arithmetic circuit, 226: Control circuit, 228: Memory circuit, 230: Power supply circuit

Claims

1. An antenna section having one or more first antennas that receive radio waves from the outside, and two or more second antennas that transmit radio waves to the outside, on its first surface, A power receiving circuit connected to the first antenna and receiving a power signal via the first antenna, A rectifier circuit that rectifies the power signal received by the power receiving circuit, A transmitting circuit connected to the second antenna and transmitting a wireless signal via the second antenna, Equipped with, The first surface of the antenna portion includes a first region and a second region which is at least a part of the region surrounding the first region, and the second antenna is located in the second region. Power receiving device.

2. The aforementioned external radio waves are signals transmitted based on the aforementioned wireless signals. The power receiving device according to claim 1.

3. The aforementioned wireless signal is a beacon signal. The power receiving device according to claim 1.

4. The transmitting circuit transmits the radio signal from each of the second antennas at different timings. The power receiving device according to claim 1.

5. The transmitting circuit transmits the wireless signal including the position information of the second antenna. The power receiving device according to claim 1.

6. The second antenna is positioned symmetrically with respect to the center of the antenna array on which the first antenna is provided. The power receiving device according to claim 1.

7. A switch is connected between the aforementioned second antenna and the transmission circuit. Equipped with, The switch is further connected to the power receiving circuit. The power receiving device according to claim 1.

8. The aforementioned switch is The second antenna and the transmitting circuit are connected at the timing when the transmitting circuit transmits the wireless signal. The second antenna and the power receiving circuit are connected at the timing when the power receiving circuit receives the power signal. The power receiving device according to claim 7.

9. The distance between the second antenna and the center of the antenna array is longer than the distance between the first antenna and the center of the antenna array. The power receiving device according to claim 1.

10. One or more antennas, A power transmission circuit connected to at least one of the aforementioned antennas, which transmits a power signal to a power transmission center via the at least one aforementioned antenna, A receiving circuit connected to at least one of the aforementioned antennas and receiving a wireless signal via said at least one antenna, A calculation circuit that determines a single transmission center based on the radio signals transmitted from two or more antennas, Equipped with, The power transmission circuit performs control to transmit the power signal toward a position close to the power transmission center estimated by the calculation circuit. Power supply device.

11. The power receiving device according to claim 1, The power supply device according to claim 10, Equipped with, The power receiving device transmits a wireless signal via the second antenna. The power supply device transmits the power signal based on the information of the wireless signal transmitted by the transmitting circuit. Wireless power supply system.

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