Wireless power supply device and method

Abstract

To make it possible to estimate a propagation path for retrodirective transmission.SOLUTION: A wireless power supply device of the present disclosure is capable of wirelessly supplying power to a power receiver that transmits a wireless signal. The wireless power supply device includes: N antenna elements; N radio signal processing units that obtain analog signals based on radio signals received by the N antenna elements; a first signal processing unit that obtains a first digital signal based on a first analog signal that is the analog signal from a first radio signal processing unit among the N radio signal processing units; a first selection unit that selects one of second analog signals that are the analog signals from N-1 second radio signal processing units different from the first radio signal processing unit among the N radio signal processing units; a second signal processing unit that obtains a second digital signal based on the second analog signal selected by the first selection unit; and a control unit that estimates a propagation path with the power receiver based on the first digital signal and the second digital signal.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments of the present invention relate to a wireless power supply device and method.

Background Art

[0002] As a wireless power supply method, a retro-directive method is known in which a weak radio wave signal (beacon signal) transmitted by a wireless device (receiver) to be powered is received by a plurality of antenna elements on the power transmission side, and a power supply signal is transmitted in the direction of the receiver estimated based on the beacon signal. The direction of the receiver is estimated by performing propagation path estimation using the difference in phase, or the difference in phase and amplitude, of the received beacon signal among a plurality of antenna elements. On the other hand, when transmitting power, in order to prevent adverse effects on other wireless devices that are not the power supply target, it is necessary to confirm that there are no other wireless devices in the transmission direction of the power supply signal (the direction of the receiver). This confirmation can be determined by whether a radio wave signal transmitted from another wireless device is observed in the transmission direction of the power supply signal. In order to obtain an excellent signal-to-noise ratio in this observation, that is, in order to improve the accuracy in detecting other wireless devices, it is preferable to perform reception beamforming in the transmission direction of the power supply signal.

[0003] For beamforming, digital beamforming (DBF) and analog beamforming (ABF) methods are mainly used. In the DBF method, the signals received by each antenna element are converted into digital signals, and then processed such as phase shifting and synthesis, which can improve the signal-to-noise ratio. However, it is necessary to provide expensive digital signal processing elements such as quadrature mixer circuits, filters, and A / D converters for each of the plurality of antenna elements, resulting in higher costs as the number of antenna elements increases. In contrast, in a wireless power feeding device adopting the ABF method, since the signals received by each antenna element are processed such as phase shifting and synthesis in the state of analog signals, the locations where digital signal processing elements are used can be limited, and cost reduction can be achieved. However, in a wireless power feeding device adopting the ABF method, since the phase difference and amplitude difference between antenna elements cannot be obtained, propagation path estimation cannot be performed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] Embodiments of the present invention provide a wireless power feeding device and method that enable estimation of a propagation path for retro-directive transmission.

Means for Solving the Problems

[0006] The wireless power supply device of the present disclosure is a wireless power supply device capable of wirelessly supplying power to a power receiver that transmits a wireless signal, and includes N antenna elements, and N wireless signal processing units that acquire an analog signal based on the wireless signal received by the N antenna elements, a first signal processing unit that acquires a first digital signal based on a first analog signal that is the analog signal from a first wireless signal processing unit among the N wireless signal processing units, a first selection unit that selects one of second analog signals that are the analog signals from N - 1 second wireless signal processing units different from the first wireless signal processing unit among the N wireless signal processing units, a second signal processing unit that acquires a second digital signal based on the second analog signal selected by the first selection unit, and a control unit that estimates a propagation path between the power receiver based on the first digital signal and the second digital signal.

Brief Description of Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Embodiments for Carrying Out the Invention

[0008] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0009] (First Embodiment) [First Configuration Example (Propagation Path Estimation)] FIG. 1 shows a power feeding system including a wireless power feeding device 100 and a power receiving device 500 according to a first configuration example of the first embodiment. FIG. 2 shows a specific configuration example of the wireless power feeding device 100. The first configuration example realizes performing propagation path estimation for specifying the direction of the power receiving device, which is the power feeding target, with high accuracy in a simple configuration in order to perform wireless power feeding safely and reliably.

[0010] The wireless power feeding device 100 includes a plurality (N) of antenna elements 110_1 to 110_N, a plurality of RF (Radio Frequency) signal processing units 120_1 to 120_N, a selection unit 30 (first selection unit) including a plurality of switching units 130_2 to 130_N, a distribution / combiner 140, a first signal processing unit 150, a second signal processing unit 160, a signal generator 170, a switching unit 171, a control unit 180, and a wireless module or the like (not shown) that communicates with the power receiving device. The RF signal processing units 120_1 to 120_N may also be described as high-frequency signal processing units or wireless signal processing units.

[0011] At least a part of the RF signal processing unit, the selection unit 30, the distribution / combiner 140, the first signal processing unit 150, the second signal processing unit 160, the signal generator 170, the switching unit 171, and the control unit 180 may be constituted by a circuit or a processor such as an ASIC (application specific integrated circuit) or an FPGA (Field-Programmable Gate Array). Alternatively, a part or all of these elements may be executed by a CPU that executes a program.

[0012] The power receiver 500 is included in the device to be powered by the wireless power supply device 100. The device to be powered is, for example, an IoT (Internet of Things) sensor or a camera used in a facility such as a factory. The power receiver 500 may be mounted on a moving body such as a mobile robot, an AGV (Automatic Guided Vehicle), or a drone. The power receiver 500 includes a rechargeable battery 501, an antenna 502, and the like. The power receiver 500 can receive a power supply signal transmitted from the wireless power supply device 100 via the antenna 502 and charge the battery 501 based on the power supply signal. Further, the power receiver 500 can transmit a beacon signal, which is a wireless signal indicating its own presence, at regular intervals or at other timings. The power receiver 500 includes a communication circuit (not shown) for transmitting and receiving various signals via the antenna 502, a control circuit (not shown) for controlling the entire power receiver 500, a rectifier circuit (not shown) for rectifying the received RF signal into direct current, a charge control circuit (not shown), a wireless module (not shown) for communicating with the wireless power supply device 100, and the like.

[0013] The power receiver 500 transmits the beacon signal B at regular intervals. The power receiver 500 may transmit the beacon signal B or any other arbitrary signal in response to a request signal from the wireless power supply device 100. The duration of one beacon signal B is, for example, several milliseconds. The beacon signal B is, for example, a microwave.

[0014] The wireless power supply device 100 receives the beacon signal B with a plurality of antenna elements 110_1 to 110_N and performs propagation path estimation. For the propagation path estimation, the wireless power supply device 100 uses the beacon signal B received by the antenna element at the reference position (reference antenna element) as the reference signal, and at the same time, uses the beacon signal B received by the antenna element at a position different from the reference antenna element (comparison antenna element) as the comparison signal. Even if the radio wave signals from the same transmission source are the same, the radio wave signals received by each antenna element have differences in arrival time, propagation loss, etc. due to differences in the propagation path. Due to the differences in arrival time, propagation loss, etc., there are phase differences and amplitude differences between the radio wave signals received by each antenna element. The wireless power supply device 100 acquires the phase difference and amplitude difference between the reference signal and the comparison signal, and estimates the propagation path to the power receiver 500 based on the acquired phase difference between each antenna or the phase difference and amplitude difference. Thereby, the direction or position of the power receiver 500 can be estimated. The wireless power supply device 100 can check whether there are other wireless devices to be protected from communication in the direction of the power receiver 500 before performing wireless power supply by performing reception beamforming in the estimated direction of the power receiver 500 (the arrival direction of the beacon signal B). Also, the wireless power supply device 100 can perform wireless power supply to the power receiver 500 with high efficiency by transmission beamforming. In the first configuration example, the configuration and operation for performing propagation path estimation are mainly described, and other operations performed after the propagation path estimation and the configuration therefor are described in detail in the description of the second configuration example and later.

[0015] Hereinafter, with reference to FIGS. 1 and 2, the details of each component will be described.

[0016] The antenna elements 110_1 to 110_N are antenna elements used for transmitting and receiving signals with the power receiver 500. The number of the antenna elements 110_1 to 110_N is, for example, 3 or more (N ≧ 3). The antenna elements 110_1 to 110_N are arranged in an arbitrary arrangement, and their positions are different from each other. For example, the antenna elements 110_1 to 110_N are installed in an array. Hereinafter, any one of the antenna elements may be described as the antenna element 110.

[0017] Hereinafter, the antenna element 110_1 is used as a reference antenna element (first antenna element) for propagation path estimation. Also, the antenna elements 110_2 to 110_N are used as comparison antenna elements (second antenna elements) for propagation path estimation. The RF signal processing unit 120_1 connected to the reference antenna element corresponds to a first RF signal processing unit (first radio signal processing unit), and the RF signal processing units 120_2 to 120_N connected to the comparison antenna elements correspond to second RF signal processing units (second radio signal processing units).

[0018] The RF signal processing unit 120_1 performs analog processing such as amplification and phase shift on the beacon signal B, which is a radio signal received by the antenna element 110_1, to obtain an analog signal (first analog signal). The RF signal processing units 120_2 to 120_N perform analog processing such as amplification and phase shift on the beacon signal B, which is a radio signal received by the antenna elements 110_2 to 110_N, to obtain an analog signal (second analog signal). There are as many RF signal processing units 120_1 to 120_N as there are antenna elements 110_1 to 110_N, and they correspond one-to-one. For example, the RF signal processing unit 120_2 processes the beacon signal B received by the antenna element 110_2. Hereinafter, any one of the RF signal processing units may be described as the RF signal processing unit 120.

[0019] Also, although the beacon signal B is received simultaneously by the antenna elements 110_1 to 110_N, the beacon signal B received by the antenna elements 110_1 to 110_N may be described as beacon signals B_1 to B_N, respectively. For example, the beacon signal B received by the antenna element 110_2 is the beacon signal B_2.

[0020] The beacon signal B_1 is used as a reference signal for propagation path estimation, and the beacon signals B_2 to B_N are used as comparison signals for comparing with the phase and amplitude of the reference signal.

[0021] As shown in FIG. 2, the RF signal processing unit 120 includes a transmit / receive switch 121, a receive amplifier 122, a transmit variable amplifier 123, and a phase shifter 124.

[0022] The transmission / reception changeover switch 121 is switched to the transmission variable amplifier 123 side during transmission of signals such as a power feeding signal for wireless power feeding, and to the reception amplifier 122 side during reception of signals such as a beacon signal.

[0023] The reception amplifier 122 amplifies the received beacon signal B at a predetermined amplification factor. The number of reception amplifiers 122 is arbitrary.

[0024] The transmission variable amplifier 123 amplifies the signal to be output (transmitted) at the amplification factor set by the control unit 180. The transmission variable amplifier 123 may include, for example, an amplifier and a variable attenuator.

[0025] The phase shifter 124 performs phase shifting of the amplified beacon signal B input from the reception amplifier 122. The amount of phase shift of the phase shifter 124 is variable by the control unit 180.

[0026] The switching units 130_2 to 130_N in the selection unit 30 switch the ON-OFF of the connection between the RF signal processing units 120_2 to 120_N of the comparison antenna elements and the distributor / combiner 140. The number of switching units 130_2 to 130_N is the same as that of the RF signal processing units 120_2 to 120_N and they correspond one-to-one. For example, when the switching unit 130_2 is turned ON, the RF signal processing unit 120_2 and the distributor / combiner 140 are connected. The selection unit 30 has a function of selecting one of the signals (analog signals) processed by the RF signal processing units 120_2 to 120_N using the switching units 130_2 to 130_N and outputting the selected signal to the second signal processing unit 160 via the distributor / combiner 140. Hereinafter, any one of the switching units 130_2 to 130_N may be described as the switching unit 130.

[0027] The switching unit 130 includes a switch and switches the ON-OFF of the connection by the switch. Note that the switching unit 130 or the control unit 180 may include a device such as a computer that temporarily turns OFF the power supply of each RF signal processing unit 120. In this case, the processing of the switching unit 130 may be performed by an electric circuit or by a program.

[0028] The distributor / combiner 140 receives one of the signals (second analog signals) obtained by amplifying and phase-shifting the beacon signal B by the RF signal processing units 120_2 to 120_N, and sends it to the second signal processing unit 160.

[0029] The signal generator 170 includes a local oscillator (LO: Local Oscillator). The signal generator 170 generates a local oscillator signal (LO signal) for frequency conversion.

[0030] The switching unit 171 switches the output destination (connection destination) of the LO signal generated by the signal generator 170. During propagation path estimation, the switching unit 171 connects the signal generator 170 to the first signal processing unit 150 and the second signal processing unit 160. As a result, the LO signal generated by the signal generator 170 is supplied to the first signal processing unit 150 and the second signal processing unit 160. The operation of connecting the signal generator 170 to the distributor / combiner 140 will be described in the description of another configuration example described later.

[0031] The first signal processing unit 150 is connected to the RF signal processing unit of the reference antenna element. The first signal processing unit 150 receives a signal (first analog signal) obtained by amplifying and phase-shifting the reference signal (beacon signal B_1) by the RF signal processing unit of the reference antenna element. The first signal processing unit 150 performs processes such as frequency conversion and A / D conversion on the signal, thereby obtaining a digital signal (first digital signal) including information on the phase and amplitude of the beacon signal B received by the reference antenna element.

[0032] The second signal processing unit 160 is connected to the RF signal processing unit of the comparison antenna element via the switching unit 130 and the distributor / combiner 140. The second signal processing unit 160 performs processes such as frequency conversion and A / D conversion on the signal (second analog signal) input from one of the RF signal processing units of the comparison antenna element. As a result, a digital signal (second digital signal) including information on the phase and amplitude of the beacon signal B received by the comparison antenna element is obtained.

[0033] More specifically, as shown in FIG. 2, the first signal processing unit 150 includes a quadrature mixer 151 (first mixer), a low-pass filter 152, a variable gain amplifier 153, and an A / D converter 154. The second signal processing unit 160 includes a quadrature mixer 161 (second mixer), a low-pass filter 162, a variable gain amplifier 163, and an A / D converter 164.

[0034] The quadrature mixer 151 converts the signal input from the RF signal processing unit 120 of the reference antenna element into in-phase (I) and quadrature (Q) signals that are orthogonal to each other. The quadrature mixer 151 multiplies the I signal and the Q signal by the LO signal generated by the signal generator 170 to perform frequency conversion to the baseband (BB) band. Thereby, I / Q orthogonal signals in the baseband band are obtained. Using the I / Q orthogonal signals, it becomes possible to acquire the phase and the amplitude. The quadrature mixer 161 converts the signal input from the RF signal processing unit 120 of the comparison antenna element into in-phase (I) and quadrature (Q) signals that are orthogonal to each other. The quadrature mixer 161 multiplies the I signal and the Q signal by the LO signal generated by the signal generator 170 to perform frequency conversion to the baseband (BB) band. Thereby, I / Q orthogonal signals in the baseband band are obtained. Using the I / Q orthogonal signals, it becomes possible to acquire the phase and the amplitude.

[0035] The low-pass filter 152 removes unnecessary high-frequency components included in the I signal and the Q signal frequency-converted to the BB band by the quadrature mixer 151. The low-pass filter 162 removes unnecessary high-frequency components included in the I signal and the Q signal frequency-converted to the BB band by the quadrature mixer 161.

[0036] The variable gain amplifier 153 amplifies the output signals (I signal and Q signal) of the low-pass filter 152 to an appropriate magnitude. The variable gain amplifier 153 may include, for example, an amplifier and a variable attenuator. The variable gain amplifier 153 may be arranged in place of the low-pass filter 152. The variable gain amplifier 163 amplifies the output signals (I signal and Q signal) of the low-pass filter 162 to an appropriate magnitude. The variable gain amplifier 163 may include, for example, an amplifier and a variable attenuator. The variable gain amplifier 163 may be arranged in place of the low-pass filter 162.

[0037] The A / D converter 154 converts the signals (I signal and Q signal) amplified by the variable gain amplifier 153 from analog signals to digital signals. The A / D converter 164 converts the signals (I signal and Q signal) amplified by the variable gain amplifier 163 from analog signals to digital signals.

[0038] Based on the digital signals (I signal and Q signal) from the first signal processing unit 150, the control unit 180 acquires information on the phase and amplitude of the beacon signal B_1 (reference signal) received by the reference antenna element. Based on the digital signals (I signal and Q signal) from the second signal processing unit 160, the control unit 180 acquires information on the phase and amplitude of the beacon signal (comparison signal) received by the comparison antenna element, that is, the beacon signal received by the comparison antenna element of the RF signal processing unit selected by the selection unit 30. The control unit 180 repeatedly performs the acquisition of the phase and amplitude of the beacon signal (reference signal) received by the reference antenna element and the acquisition of the phase and amplitude of the beacon signal (comparison signal) received by the comparison antenna element by sequentially switching the RF signal processing unit selected by the selection unit 30. The control unit 180 performs propagation path estimation based on the information on the phase differences, or the phase differences and amplitude differences, of a plurality of sets of the reference signal and the comparison signal acquired by repetition.

[0039] That is, in the propagation path estimation, a set of a reference signal and a comparison signal observed at the same time (where "observation" means that information on phase and amplitude is acquired) is required. In the present embodiment, for a plurality of comparison antenna elements, the signal processing unit that performs frequency conversion and A / D conversion of the comparison signal is only one of the second signal processing units 160. Therefore, it is not possible to simultaneously observe the comparison signals (I signal and Q signal) from all the comparison antenna elements. Thus, the switching units 130_2 to 130_N are used to switch the comparison signals input to the second signal processing unit 160 at predetermined sampling times.

[0040] Figure 3 is a table for explaining the operation of the switching units 130_2 to 130_N. t is the time. The switching units 130_2 to 130_N are switched between ON and OFF at every arbitrary sampling time T. The sampling time T is, for example, a period of sub-milliseconds.

[0041] As shown in Figure 3, at a certain time, one switching unit 130 is selected, the selected switching unit 130 is turned ON, and the other switching units 130 are turned OFF. The switching units 130_2 to 130_N are switched in all N - 1 ON - OFF patterns. For example, in the period from t = 0 to T, only the switching unit 130_2 is turned ON, and in the period from t = T to 2T, only the switching unit 130_3 is turned ON. This is repeated, and the switching units 130_2 to 130_N are switched in order until the last switching unit 130_N is turned ON.

[0042] Thereby, the switching units 130_2 to 130_N cause only the comparison signal (the second analog signal) received by one selected comparison antenna element at a certain time to be input to the second signal processing unit 160.

[0043] Figure 4 shows the beacon signal B_1 (reference signal) processed by the first signal processing unit 150 and the beacon signals B_2 to B_N (comparison signals) processed by the second signal processing unit 160. The signals in the thick line part are the signals actually processed, and the signals in the dotted line part are discarded (not input to the second signal processing unit 160) because they are not selected by the selection unit 30.

[0044] The first signal processing unit 150 is always connected to the RF signal processing unit 120_1. Therefore, as shown in FIG. 4, the beacon signal B_1 which is a reference signal (more specifically, an analog signal obtained by processing the beacon signal B_1 by the RF signal processing unit 120) is always processed by the first signal processing unit 150 at every sampling time T by the first signal processing unit 150.

[0045] Here, for example, the beacon signal (more specifically, an analog signal obtained by processing the beacon signal by the RF signal processing unit 120) processed by the first signal processing unit 150 during the period from t = 0 to T is represented as the beacon signal B T _1.

[0046] The second signal processing unit 160 is connected to the RF signal processing unit of the comparison antenna element selected by the switching units 130_2 to 130_N only during the period of the sampling time T. Therefore, the beacon signals B_2 to B_N which are comparison signals (more specifically, analog signals obtained by processing the beacon signals B_2 to B_N by the RF signal processing unit 120) are processed by the second signal processing unit 160 only during the period when the corresponding switching unit 130 is ON.

[0047] For example, during the period from t = 0 to T, only the switching unit 130_2 is ON, so only the beacon signal B_2 (more specifically, an analog signal obtained by processing the beacon signal B_2 by the RF signal processing unit 120) is processed by the second signal processing unit 160. Similarly, during the period from t = T to 2T, only the switching unit 130_3 is ON, so only the beacon signal B_3 among the comparison signals is processed by the second signal processing unit 160.

[0048] Here, for example, the beacon signal processed by the second signal processing unit 160 during the period from t = 0 to T is represented as the beacon signal B T _2, and the beacon signal processed by the second signal processing unit 160 during the period from t = T to 2T is represented as the beacon signal B 2T _3.

[0049] As shown in FIG. 4, during the period from t = 0 to T, the beacon signal B T _1 is processed by the first signal processing unit 150, and the beacon signal B T _2 is processed by the second signal processing unit 160. Then, the information on the respective phases and amplitudes of the processed beacon signal B T _1 and the beacon signal B T _2 is acquired by the control unit 180, and the difference in amplitude and phase between the two is calculated.

[0050] Thereafter, during the period from t = T to 2T, the beacon signal B 2T _1 is processed by the first signal processing unit 150, and the beacon signal B 2T _3 is processed by the second signal processing unit 160. Then, the information on the respective phases and amplitudes of the processed beacon signal B 2T _1 and the beacon signal B 2T _3 is acquired by the control unit 180, and the difference in amplitude and phase between the two is calculated.

[0051] Similarly, during the period from t = (i - 2)T to (i - 1)T, the beacon signal B (i-1)T _1 is processed by the first signal processing unit 150, and the beacon signal B (i-1)T _i is processed by the second signal processing unit 160. Then, the information on the phases and amplitudes of the processed beacon signal B (i-1)T _1 and the beacon signal B (i-1)T _i is acquired by the control unit 180, and the difference in amplitude and phase is calculated.

[0052] By repeating the above operations, the control unit 180 acquires the information on the respective phases and amplitudes of the beacon signal B_1 and the beacon signal B_X (X = 2 to N) measured at different positions at the same time, and calculates the difference in phase and amplitude. That is, the pair of the beacon signal B T _1 and the beacon signal B T _2, the pair of the beacon signal B 2T _1 and the beacon signal B 2T _3, ···, the pair of the beacon signal B (N-1)T _1 and the beacon signal B(N-1)T For each pair with _N, the difference in phase and amplitude is calculated. The control unit 180 performs propagation path estimation based on the obtained differences.

[0053] FIG. 5 is a flowchart of the process executed during propagation path estimation in the wireless power feeding device 100.

[0054] The control unit 180 turns on only the switching unit 130_i during the period t = (i - 2)T to (i - 1)T (step S111). Here, i = 2 to N, and the initial value is i = 2.

[0055] Next, the control unit 180 obtains the phase and amplitude information of the beacon signal B (i-1)T _1 processed by the first signal processing unit 150 during the period t = (i - 2)T to (i - 1)T, and the phase and amplitude information of the beacon signal B (i-1)T _i processed by the second signal processing unit 160 during the period t = (i - 2)T to (i - 1)T. The control unit 180 calculates the difference between the two (step S112).

[0056] Next, the control unit 180 determines whether all the switching units 130_2 to 130_N have been selected (turned on). That is, it determines whether i has reached N (step S113).

[0057] If it is determined that i has not reached N, the control unit 180 switches so that only the next switching unit 130_i is turned on at the time when the sampling time T has elapsed since the time when the switching units 130_2 to 130_N were switched last time, and returns to step S111 (step S114).

[0058] If it is determined that i has reached N, the control unit 180 performs propagation path estimation based on the differences in phase and amplitude between the obtained beacon signal B_1 and the beacon signals B_2 to B_N (S116). Thereby, the control unit 180 determines the direction of the power receiver 500 which is the transmission source of the beacon signal B.

[0059] By such processing, it is possible to perform propagation path estimation using only two signal processing units, i.e., a first signal processing unit 150 and a second signal processing unit 160, for performing frequency conversion and A / D conversion.

[0060] Note that the order in which the switching unit 130 that turns on is selected is not limited to the above and may be arbitrary.

[0061] Further, the control unit 180 may perform propagation path estimation without using all of the beacon signals B_2 to B_N. For example, when a part of the RF signal processing units 110_2 to 110_N of the comparison antenna elements malfunctions and does not operate normally, the beacon signal B that should have been received by the RF signal processing unit may be ignored.

[0062] The switching units 130_2 to 130_N may change their positions within the range where the above operations can be performed. For example, the switching units 130_2 to 130_N may be located between each antenna element 110 and each RF signal processing unit 120.

[0063] As described above, according to the first configuration example of the first embodiment, by providing the first signal processing unit 150 and the second signal processing unit 160 that perform digital signal processing for observing a reference signal and a plurality of comparison signals at the same time, a wireless power feeding device that performs propagation path estimation of the beacon signal B for retro-directive transmission can be realized. Further, compared with the related art that requires providing signal processing units for the total number of the reference antenna element and the comparison antenna elements, a wireless power feeding device that performs propagation path estimation of the beacon signal B for retro-directive transmission at low cost can be realized.

[0064] [Second Configuration Example (Received Beamforming)] FIG. 6 is a block diagram of a wireless power feeding system including a wireless power feeding device 100A and a power receiving device 500 according to the second configuration example of the first embodiment. FIG. 7 is a detailed block diagram of the wireless power feeding device 100A. Elements having the same name or function as those in FIG. 1 in the above-described first embodiment are denoted by the same reference numerals. Hereinafter, the description will be omitted except for the changed or added matters.

[0065] In the second configuration example, reception beamforming is performed using the result of propagation path estimation performed in the same manner as in the first configuration example, thereby determining whether there is a wireless device other than the power receiver 500 in the direction of the power receiver 500. Thereby, before performing wireless power feeding to the power receiver 500, it is confirmed that there is no wireless device other than the power receiver 500 in the power feeding direction.

[0066] In FIGS. 6 and 7, the wireless power feeding device 100A includes a switching unit 131. The switching unit 131 switches the connection destination of the RF signal processing unit 120_1 of the reference antenna element between the first signal processing unit 150 and the distributor / combiner 140. The wireless power feeding device 100A has a function of performing propagation path estimation in the same manner as the wireless power feeding device 100 of the first configuration example described above. While performing propagation path estimation, the switching unit 131 connects the RF signal processing unit 120_1 to the first signal processing unit 150. That is, the operation of the configuration in which the RF signal processing unit 120_1 is connected to the first signal processing unit 150 is the same as that of the wireless power feeding device 100 according to the first configuration example.

[0067] The switching unit 131 includes, for example, a switch, and switches the ON-OFF of the connection by the switch.

[0068] The wireless device 600 is a wireless device that is not a power feeding target of the wireless power feeding device 100A. The wireless device 600 is, for example, a base station of a wireless LAN (Local Area Network) used in a factory or a station corresponding to a slave unit of the base station. The wireless device 600 transmits and receives radio waves having a frequency close to that of the radio wave for wireless power feeding (feeding signal R2 described later) of the wireless power feeding device 100A. Since the feeding signal R2 causes an adverse effect such as a communication failure when transmitted in the direction of the wireless device 600, the wireless power feeding device 100A must avoid transmitting the feeding signal R2 in the direction where the wireless device 600 exists.

[0069] When determining whether the wireless device 600 exists in the direction of the power receiver 500, the wireless power feeding device 100A performs reception analog beamforming (ABF) in order to improve the SN ratio of detection of the wireless device 600.

[0070] The receiving ABF is a technique for improving the signal-to-noise ratio (SNR) in receiving radio wave signals arriving from a specific direction. Phase shift processing is performed on the signals received by a plurality or all of the antenna elements based on the positions of the respective antenna elements. That is, the phases of the respective received signals are adjusted according to the positions of the respective antenna elements and a specific direction (the direction of the power receiver 500). After performing phase shift processing on each received signal, reception beamforming is achieved by combining the respective received signals. When the phase-shifted received signals are combined, the radio wave signals arriving from a specific direction have aligned phases and thus reinforce each other, while the radio wave signals arriving from directions different from that direction cancel each other out. As a result, the SNR in receiving radio wave signals arriving from a specific direction among the combined signals can be improved. During receiving ABF, unlike during the above-described propagation path estimation, there is no distinction in processing between the first antenna element 110_1 and the second to Nth antenna elements 110_2 to 110_N.

[0071] The switching units 130_2 to 130_N are all or a plurality of them are turned on. In the following description, it is assumed that all of the switching units 130_2 to 130_N are turned on. The switching unit 131 is switched to the distribution / combiner 140 side. However, when the reference antenna element 110_1 is not used for receiving ABF, the switching unit 131 does not necessarily have to be switched to the distribution / combiner 140 side.

[0072] The transmit / receive switch 121 in FIG. 2 is switched to the side of the receiving amplifier 122. The signals received by each antenna element 110 are amplified by the receiving amplifier 122 provided in each RF signal processing unit 120.

[0073] The phase shifter 124 of each RF signal processing unit 120 phase-shifts the signal amplified by the receiving amplifier 122.

[0074] As shown in FIG. 6, the control unit 180 controls the amount of phase shift of each phase shifter 124 so that the reception beam R1 faces the direction of the estimated power receiver 500.

[0075] The distributor / combiner 140 includes a combining section that combines the received signals. The distributor / combiner 140 combines each received signal that has undergone phase shift processing and is input from each RF signal processing section 120. Thereby, receive ABF is performed. The distributor / combiner 140 outputs the combined signal obtained by combining each received signal to the second signal processing section 160.

[0076] The second signal processing section 160 performs frequency conversion and A / D conversion on the combined signal input from the distributor / combiner 140. Note that the first signal processing section 150 is not used during receive ABF.

[0077] The signal generator 170 generates an LO signal for frequency conversion, similar to during propagation path estimation. Also, the switching section 171 connects between the signal generator 170 and the second signal processing section 160.

[0078] The control section 180 acquires the digital received signal (the combined signal for which receive ABF has been performed) processed by the second signal processing section 160. Based on the acquired received signal, the control section 180 determines whether the wireless device 600 is included in the direction of the power receiver 500. For example, it determines whether the received signal includes a radio wave signal transmitted from the wireless device 600. For example, when the received signal includes a signal with power equal to or greater than a threshold value, it may be determined that the received signal includes a radio wave signal transmitted by the wireless device 600. Alternatively, when the control section 180 includes a circuit capable of interpreting the protocol of the wireless LAN and a wireless LAN frame is detected from the acquired received signal, it may be determined that the received signal includes a radio wave signal transmitted by the wireless device 600. The acquired received signal has a large component of the radio wave signal arriving from the estimated direction of the power receiver 500. Therefore, the accuracy of detecting the wireless device 600 in the estimated direction of the power receiver 500 can be improved. The control section 180 may determine whether the radio wave signal of the wireless device 600 is included by other methods other than the above methods.

[0079] FIG. 8 is a flowchart of the processing executed during receive ABF in the wireless power feeding device 100A.

[0080] First, based on the result of the propagation path estimation of the beacon signal B, the control unit 180 controls the phase shift amount of the phase shifter 124 in the RF signal processing unit of each antenna element so that the received beam R1 faces the power receiver 500 (step S121).

[0081] Next, the control unit 180 acquires the digital received signal (combined signal) combined by the distributor / combiner 140 from the second signal processing unit 160 (step S122).

[0082] Next, the control unit 180 determines whether the wireless device 600 exists in the direction of the power receiver 500 based on the acquired received signal (step S123).

[0083] When the control unit 180 determines that the wireless device 600 exists in the direction of the power receiver 500, wireless power feeding is not performed (step S124). After step S124, the same sequence (steps S121 to S123) may be started again, or phase control for received beamforming based on the propagation path to a different power receiver may be performed.

[0084] When the control unit 180 determines that the wireless device 600 does not exist in the direction of the power receiver 500, wireless power feeding is performed (step S125). The details of the operation of performing wireless power feeding will be described in the description of other configuration examples described later.

[0085] When the control unit 180 determines to stop wireless power feeding to the power receiver 500 in step S124, it may perform processing to enable wireless power feeding to the power receiver 500. For example, when the power receiver 500 is mounted on a movable device such as a vehicle, the control unit 180 may transmit command data for instructing the power receiver 500 or the device to move so that the wireless device 600 is not located between the wireless power feeding device 100 and the power receiver 500. The wireless power feeding device 100 may determine the position of the moving destination of the power receiver 500. In this case, the determined position may be included in the command data. Alternatively, the control unit 180 may transmit command data for instructing a wireless power feeding device (not shown) at another position to perform wireless power feeding to the power receiver 500.

[0086] According to the second configuration example of the first embodiment as described above, it is possible to determine with high accuracy whether there is a wireless device 600 other than the power receiver 500 in the direction of the power receiver 500. As a result, since power supply can be avoided in a situation where the wireless device 600 exists in the direction of the power receiver 500, it is possible to prevent interference with the communication of the wireless device 600.

[0087] [Third Configuration Example (Human Detection)] FIG. 9 shows a wireless power supply system including a wireless power supply device 100B according to the third configuration example of the first embodiment. The illustration of the power receiver to be powered is omitted. The detailed block diagram of the wireless power supply device 100B is the same as that of FIG. 7. The same reference numerals are given to elements having the same names or functions as those in FIGS. 6 and 7 described above. Hereinafter, the description will be omitted except for the changed or added matters.

[0088] In the third configuration example, before performing wireless power supply, it is determined whether an object such as a human body exists in the direction of the power receiver 500. Thereby, before performing wireless power supply from the wireless power supply device 100B to the power receiver 500, it is confirmed that no object such as a person exists in the power supply direction.

[0089] The wireless power supply device 100B has the functions of the wireless power supply devices according to the first and second configuration examples described above, and further determines whether an object to be avoided (in this example, the human body 700) exists within the range where the wireless power supply device 100B performs wireless power supply. When the human body 700 exists, wireless power supply is not performed, and when the human body 700 does not exist, wireless power supply is performed. The object is not limited to a human body, and may be, for example, a moving body such as an automated guided vehicle, or a stationary object such as a wall or a pillar. Hereinafter, the case where the object is the human body 700 will be described, but it is not limited to the human body.

[0090] When detecting a human body, after transmitting a weak radio wave signal S1 (detection signal) from the wireless power supply device 100B, the signal S2 reflected by an object including the human body 700 is received, and based on the reflected signal S2, the presence or absence of the human body 700 is determined. For example, the presence or absence of the human body 700 is determined by whether the received signal contains vibrations peculiar to the human body (such as the swaying of the human body or the beating of the heart). Alternatively, the amplitude of the reflected signal S2 and the transmitted detection signal S1 may be compared, and when the attenuation is between the lower limit value and the upper limit value, the human body may be detected. At this time, the antenna elements 110_2 to 110_N are used as transmission antenna elements, and the antenna element 110_1 is used as a reception antenna element.

[0091] The transmission / reception changeover switch 121 (see FIG. 7) of the antenna elements 110_2 to 110_N is switched to the transmission variable amplifier 123 side, and the transmission / reception changeover switch 121 of the antenna element 110_1 is switched to the reception amplifier 122 side. Further, the switching unit 131 is switched to the first signal processing unit 150 side.

[0092] When detecting a human body, the signal generator 170 outputs a local oscillator signal as a detection signal to the distribution / synthesizer 140. At this time, the switching unit 171 connects between the signal generator 170 and the distribution / synthesizer 140.

[0093] After the detection signal S1 is output from the signal generator 170 to the distribution / synthesizer 140, the switching unit 171 is switched to connect between the signal generator 170 and the first signal processing unit 150.

[0094] The detection signal from the signal generator 170 is sequentially distributed by the distribution / synthesizer 140 to the RF signal processing units 120_2 to 120_N, and is sequentially transmitted as the detection signal S1 from one of the antenna elements 110_2 to 110_N. The detection signal S1 is, for example, a microwave.

[0095] The switching unit 171 corresponds to a first switching unit that selectively switches between supplying the local oscillator signal to the first signal processing unit 150 and the second signal processing unit 160 and providing the local oscillator signal as a detection signal to two or more RF signal processing units (second radio signal processing units).

[0096] The magnitude of the detection signal S1 transmitted from the antenna element 110 satisfies the human body protection guideline. For example, the detection signal S1 transmitted from the antenna element 110 has an effective value of the electric field strength of 137 V / m or less, an effective value of the magnetic field strength of 0.365 A / m or less, or a power flux density of 5 mW / cm 2 or less.

[0097] The detection signal S1 transmitted from the antenna element 110 does not have directivity by beamforming (i.e., has a single antenna directivity) and propagates in a direction including the direction of the human body 700 (object) from the wireless power feeding device 100B.

[0098] A part of the detection signal S1 transmitted from the antenna element 110 (here, one of the antenna elements 110_2 to 110_N) is reflected by the human body 700 and received by the antenna element 110_1 as a reflected signal S2.

[0099] The reflected signal S2 received by the antenna element 110_1 is processed by the RF signal processing unit 120_1 to be an analog received signal, and the frequency conversion and conversion to a digital signal of the received signal are performed by the first signal processing unit 150.

[0100] In this configuration example, the signal source of the detection signal S1 is the same as the signal source of the LO signal for frequency conversion (signal generator 170), but the signal source of the detection signal S1 and the signal source of the LO signal may be prepared separately.

[0101] The control unit 180 acquires the received signal of the reflected signal S2 processed by the first signal processing unit 150 for each detection signal S1 transmitted from different antenna elements. Based on the received signal, the control unit 180 determines whether a human body exists in the direction including the direction of the power receiver 500. Further, the control unit 180 may detect the position or direction of the human body and further estimate the propagation path to the human body.

[0102] FIG. 10 is a flowchart of the process executed when detecting a human body in the wireless power feeding device 100B.

[0103] First, the control unit 180 connects the signal generator 170 to the distribution / synthesizer 140 side and turns on one of the switching units 130_2 to 130_N (connects the signal generator 170 to one of the antenna elements 110_2 to 110_N). A local oscillator signal is output from the signal generator 170 as a detection signal, and the detection signal S1 is transmitted from the antenna element via the selected RF signal processing unit (step S151).

[0104] Next, the control unit 180 connects the switching unit 171 of the signal generator 170 to the first signal processing unit 150 side (step S152).

[0105] Next, the RF signal processing unit 1 receives and processes the reflected signal S2 of the detection signal S1 via the antenna element 110_1 to acquire a received signal (step S153). The first signal processing unit 150 processes the received signal to acquire a digital received signal and provides it to the control unit 180 (same step S153).

[0106] Steps S151 to S153 are repeated, and the transmission of the detection signal S1 is sequentially performed for each of the antenna elements 110_2 to 110_N. For example, the detection signal S1 is transmitted sequentially from each of the RF signal processing units 120_2 to 120_N.

[0107] Next, the control unit 180 detects a human body based on each received signal. When detecting a human body, the position or direction of the human body may be further detected. Also, the propagation path to the human body may be estimated (step S154).

[0108] When the control unit 180 determines that the human body 700 is present, in order to avoid wireless power supply to the human body 700 (transmission of the power supply signal R2), it stops the wireless power supply (step S155).

[0109] When the control unit 180 determines that the human body 700 is not present, it determines that the human body 700 is not present and performs wireless power supply (step S156).

[0110] In step S155, the control unit 180 may perform processing other than stopping the wireless power supply. For example, by performing processing such as null generation in the direction in which the human body 700 is present, transmission of the power supply signal to the human body 700 (refer to the power supply signal R2 in FIG. 11 described later) may be avoided. At this time, the magnitude of the power supply signal transmitted to the human body 700 satisfies the human body protection guideline. For example, the control unit 180 determines whether the power supply signal transmitted to the human body 700 has an effective value of the electric field strength of 137 V / m or less, an effective value of the magnetic field strength of 0.365 A / m or less, or a power flux density of 5 mW / cm 2 The following may generate a null in the direction including the direction of the human body 700 so that it becomes as follows.

[0111] In addition, after stopping the wireless power supply, the control unit 180 may issue a movement command to the human body 700. The movement command may be in any form as long as it is information recognizable by the human body 700. For example, it may be a warning sound, lighting, a message display on the terminal screen held by the human body 700, etc. Thereafter, the control unit 180 may confirm that the human body 700 has moved out of the human body detection target range and perform wireless power supply.

[0112] In addition, the control unit 180 may perform human body detection calibration by performing the above processing (the processing of the flowchart in FIG. 10) on an object other than the human body 700 (an environment where the human body 700 is not present).

[0113] According to the third configuration example of the first embodiment described above, since the presence or absence of the human body 700 can be determined, it is possible to avoid irradiating the human body 700 with a power supply signal and perform wireless power supply safely.

[0114] [Fourth Configuration Example (Wireless Power Supply)] FIG. 11 shows a wireless power supply system including a wireless power supply device 100C and a power receiver 500 according to the fourth configuration example of the first embodiment. The detailed block diagram of the wireless power supply device 100C is the same as that of FIG. 7. Elements having the same name or function as those in FIGS. 1, 6, or 9 in the first embodiment described above are denoted by the same reference numerals. Hereinafter, the description will be omitted except for the changed or added matters.

[0115] The wireless power supply device 100C has the functions of the wireless power supply devices according to the first to third configuration examples described above, and further has a function of performing wireless power supply to the power receiver 500 by transmission beamforming. That is, when performing wireless power supply, the wireless power supply device 100C performs transmission beamforming to form a transmission beam of the power supply signal R2. The power supply signal R2 is, for example, a microwave signal.

[0116] During wireless power supply, under the control of the control unit 180, the local oscillator signal generated by the signal generator 170 is used as the power supply signal. At this time, the switching unit 171 is connected to the distribution / synthesizer 140 side, and the generated power supply signal is distributed by the distribution / synthesizer 140 to the RF signal processing units 120_1 to 120_N of the antenna elements 110_1 to 110_N. During wireless power supply, there is no distinction in processing between the first antenna element 110_1 and the second to Nth antenna elements 110_2 to 110_N.

[0117] The switching unit 171 corresponds to a second switching unit that selectively switches between supplying the local oscillator signal to the first signal processing unit 150 and the second signal processing unit 160 and providing the local oscillator signal as a power supply signal to at least two RF signal processing units (wireless signal processing units).

[0118] The switching units 130_2 to 130_N are all or a plurality of them are turned on. In the following description, it is assumed that all of the switching units 130_2 to 130_N are turned on. Also, the switching unit 131 is switched to the distribution / combiner 140 side. However, when the antenna element 110_1 is not used for transmission beamforming, the switching unit 131 does not have to be switched to the distribution / combiner 140 side.

[0119] The distributed power supply signal has its phase controlled by the phase shifters 124 in each RF signal processing unit 120.

[0120] At this time, similar to the above-described reception beamforming, the control unit 180 controls the phase shift amount of each phase shifter 124 so that the transmission beam R2 is directed in the direction including the estimated direction of the power receiver 500 as shown in FIG. 11.

[0121] Each power supply signal whose phase shift amount is controlled by each phase shifter 124 has its amplitude controlled by the transmission variable amplifier 123 in each RF signal processing unit 120, and then is supplied to the plurality of antenna elements 110 (110_1 to 110_N). The power supply signal R2 is radiated from the plurality of antenna elements 110, and a transmission beam of the power supply signal R2 is formed at the power receiver 500.

[0122] As described above, according to the fourth configuration example of the first embodiment, wireless power supply can be performed with high efficiency by beam transmission to the power receiver 500.

[0123] FIG. 12 is a flowchart for explaining a series of processes performed by the wireless power supply device 100C according to the first embodiment.

[0124] First, the control unit 180 estimates the propagation path of the beacon signal B based on the phases and amplitudes of the beacon signals B_1 to B_N, and estimates or determines the direction of the transmission source (power receiver 500) of the beacon signal B (step S11).

[0125] Next, the control unit 180 performs reception beamforming in the direction estimated in step S11 (step S12).

[0126] Next, based on the signal received by reception beamforming, the control unit 180 determines whether a wireless device 600 other than the power receiver 500 to be powered exists in the estimated direction (step S13).

[0127] When the control unit 180 determines that a wireless device 600 other than the power receiver 500 exists in the estimated direction, in order to avoid interfering with the communication of the wireless device 600, wireless power feeding is not performed (step S14).

[0128] When the control unit 180 determines that the wireless device 600 does not exist in the estimated direction, the control unit 180 determines whether a human body 700 exists in the direction estimated in step S11 (step S15).

[0129] When the control unit 180 determines that the human body 700 exists in the estimated direction, in order to avoid adverse effects on the human body 700, wireless power feeding is not performed (step S14).

[0130] When the control unit 180 determines that the human body 700 does not exist in the estimated direction, the control unit 180 performs wireless power feeding, that is, transmits a power supply signal R2 (step S16).

[0131] The order in which steps S12 to S13 and step S15 are executed may be arbitrary. That is, after confirming that the human body 700 does not exist in the estimated direction, it may be determined whether the wireless device 600 exists.

[0132] As described above, according to the first embodiment, since the propagation path estimation for retro-directive transmission can be performed only by the two signal processing units 150 and 160 as the signal processing units including AD conversion, the configuration can be simplified and the cost can be reduced. In addition, reception beamforming, human body detection, etc. can be performed, and coexistence with other wireless devices and protection of the human body can be achieved.

[0133] (Second Embodiment) In the first embodiment, a predetermined one antenna element was used as the first antenna element (reference antenna element). The antenna element serving as the first antenna element was fixed and could not be changed. Therefore, when the first antenna element or the RF signal processing unit of the first antenna element becomes unusable due to a failure or the like, propagation path estimation, human body detection, etc. cannot be performed. In contrast, in the second embodiment, it is possible to change the antenna element serving as the first antenna element.

[0134] FIG. 13 shows a wireless power supply system including a wireless power supply device 200 according to the second embodiment. Illustration of the power receiving device to be powered is omitted. The detailed block diagram of the wireless power supply device 200 is the same as that of FIG. 7. Elements having the same name or function as those in FIGS. 1, 6, 9, or 11 according to the first embodiment described above are denoted by the same reference numerals. Hereinafter, the description will be omitted except for the changed or added matters.

[0135] The wireless power supply device 200 includes a switching unit 130_1 and a switching unit 132 (second selection unit).

[0136] The switching unit 130_1 switches the ON-OFF of the connection between the RF signal processing unit 1 and the distribution / combiner 140. The switching unit 130_1 has the same function as the switching units 130_2 to 130_N. The selection unit 30 (first selection unit) includes the switching units 130_1 to 130_N.

[0137] The switching unit 132 switches the ON-OFF of the connection between the RF signal processing units 1 to N and the first signal processing unit 150. The switching unit 132 is a selection unit (second selection unit) that selects one RF signal processing unit and connects the selected RF signal processing unit to the first signal processing unit 150. The RF signal processing unit selected at this time becomes the first wireless signal processing unit. The RF signal processing unit not selected becomes the second wireless signal processing unit.

[0138] The control unit 180 controls the switching units 130_1 to 130_N so as not to connect the RF signal processing unit selected by the switching unit 132 to the distributor / combiner 140. For example, when the switching unit 132 connects the RF signal processing unit 120_1 and the first signal processing unit 150, the switching unit 130_1 is turned OFF, and all or some of the switching units 130_2 to 130_N are turned ON.

[0139] The switching unit 132 is, for example, a switch circuit including a plurality of switches, and switches ON and OFF the connections by the switches. The processing of the switching unit 132 may be performed by an electric circuit or by a program. The switching unit 132 or the control unit 180 may have a function of temporarily turning OFF the power supply of the RF signal processing unit that is not used by either the first signal processing unit 150 or the second signal processing unit 160. In this case, the switching unit 132 or the control unit 180 may be a device such as a computer.

[0140] Thereby, any one of the plurality of antenna elements can be used as the first antenna element. Also, in the second embodiment as in the first embodiment, wireless power feeding can be performed by propagation path estimation, reception beamforming, human body detection, and transmission beamforming.

[0141] As described above, according to the second embodiment, any antenna element can be used as the first antenna element. Therefore, even when the RF signal processing unit of a certain antenna element used as the first antenna element becomes unusable due to a failure or the like, propagation path estimation, human body detection, etc. can be performed by newly assigning the antenna element of the normal RF signal processing unit to the first antenna element. Also, even when the antenna element itself used as the first antenna element becomes unusable due to damage or the like, propagation path estimation, human body detection, etc. can be performed by newly assigning a normal antenna element to the first antenna element.

[0142] Note that the present invention is not limited to the above-described embodiments as they are, and at the implementation stage, the components can be modified and embodied without departing from the gist thereof. Further, various inventions can be formed by appropriately combining a plurality of components disclosed in the above-described embodiments. For example, a configuration in which some components are deleted from all the components shown in each embodiment is also conceivable. Furthermore, components described in different embodiments may be appropriately combined.

[0143] Note that this embodiment can also adopt the following configuration. [Item 1] A wireless power feeding device capable of wirelessly feeding power to a power receiving device that transmits a wireless signal, N antenna elements, N wireless signal processing units that acquire an analog signal based on the wireless signal received by the N antenna elements, A first signal processing unit that acquires a first digital signal based on the first analog signal that is the analog signal acquired by the first wireless signal processing unit among the N wireless signal processing units, A first selection unit that selects one of the second analog signals that are the analog signals acquired by N - 1 second wireless signal processing units different from the first wireless signal processing unit among the N wireless signal processing units, A second signal processing unit that acquires a second digital signal based on the second analog signal selected by the first selection unit, and A control unit that estimates a propagation path between the power receiving device based on the first digital signal and the second digital signal. A wireless power feeding device comprising the above. [Item 2] The first selection unit includes a plurality of switches that connect the N - 1 second wireless signal processing units to the second signal processing unit. The wireless power feeding device according to Item 1. [Item 3] The first selection unit sequentially selects one of the plurality of second analog signals corresponding to a plurality of times, The control unit estimates a propagation path between the power receiver based on the second digital signal obtained from the second analog signal selected at each time and the first digital signal obtained from the first analog signal corresponding to each time. The wireless power feeding device according to item 1 or 2. [Item 4] The first digital signal includes information on the amplitude and phase of the wireless signal input to the first wireless signal processing unit. The second digital signal includes information on the amplitude and phase of the wireless signal input to the second wireless signal processing unit. The control unit estimates the propagation path based on the phase difference or the amplitude difference and the phase difference between the first digital signal and the second digital signal. The wireless power feeding device according to any one of items 1 to 3. [Item 5] The N wireless signal processing units include a phase shifter that performs phase shift of the wireless signal. The control unit controls the phase shift amounts of the phase shifters in at least two of the N wireless signal processing units among the phase shifters in the N wireless signal processing units based on the information on the propagation path. The apparatus further includes a combining unit that combines the analog signals obtained by the at least two wireless signal processing units. The wireless power feeding device according to item 3. [Item 6] The control unit determines whether a wireless device different from the power receiver exists in a direction including the direction of the power receiver based on a combined signal obtained by combining the analog signals by the combining unit. The wireless power feeding device according to item 5. [Item 7] When the wireless device is included in the direction including the direction of the power receiver, the control unit determines not to perform the wireless power feeding to the power receiver. When the wireless device is not included in the direction including the direction of the power receiver, the control unit determines to perform the wireless power feeding to the power receiver. The wireless power feeding device according to item 6. [Item 8] Further comprising a signal generator for generating a signal for detecting an object, The first radio signal processing unit acquires the first analog signal based on a radio signal received by a first antenna element among the N antenna elements, The N-1 second radio signal processing units acquire the second analog signal based on radio signals received by the second to Nth antenna elements among the N antenna elements, Two or more of the N-1 second radio signal processing units transmit the detection signal from the signal generator from their respective antenna elements, The first radio signal processing unit acquires a plurality of received signals based on reflected signals of the plurality of detection signals received via the first antenna element, Based on a plurality of digital signals acquired based on the plurality of received signals by the first signal processing unit, comprising a control unit for detecting at least one of the position and direction of an object existing in the power supply area The wireless power supply device according to any one of Items 1 to 7. [Item 9] The control unit controls the wireless power supply to the power receiver based on at least one of the detected position and direction of the object The wireless power supply device according to Item 8. [Item 10] The object is a human body, The detection signal has an effective value of the electric field strength of 137 V / m or less, an effective value of the magnetic field strength of 0.365 A / m or less, or a power flux density of 5 mW / cm 2 or less The wireless power supply device according to Item 8 or 9. [Item 11] The control unit determines not to perform the wireless power supply when the object is included in a direction including the direction of the power receiver, The control unit determines to perform the wireless power supply when the object is not included in a direction including the direction of the power receiver The wireless power feeding device according to any one of Items 8 to 10. [Item 12] When an object is included in the direction including the direction of the power receiver, the control unit generates a null with respect to the direction in which the object exists, and performs the wireless power feeding to the power receiver. The wireless power feeding device according to any one of Items 8 to 11. [Item 13] The object is a human body, the control unit generates the null so that the radio wave irradiated to the human body has an effective value of the electric field strength of 137 V / m or less, an effective value of the magnetic field strength of 0.365 A / m or less, or a power flux density of 5 mW / cm 2 as follows. The wireless power feeding device according to Item 12. [Item 14] The detection signal is an oscillator signal, a first switching unit that selectively switches between supplying the oscillator signal to the first signal processing unit and the second signal processing unit and providing the oscillator signal as the detection signal to two or more of the second wireless signal processing units further includes, the first wireless signal processing unit includes a first mixer that converts the frequency of the first analog signal based on the oscillator signal, the second wireless signal processing unit includes a second mixer that converts the frequency of the second analog signal based on the oscillator signal, The wireless power feeding device according to any one of Items 8 to 13. [Item 15] further includes a signal generator that generates a power feeding signal, the N wireless signal processing units include a phase shifter that performs phase shifting of the power feeding signal, the control unit controls the phase shift amounts of the phase shifters in at least two of the N wireless signal processing units based on the information on the propagation path, and performs the wireless power feeding by transmitting the power feeding signal phase-shifted by the phase shifter from each of the at least two wireless signal processing units from the antenna elements. The wireless power feeding device according to any one of Items 1 to 14. [Item 16] The power feeding signal is an oscillator signal, a second switching unit that selectively switches between supplying the oscillator signal to the first signal processing unit and the second signal processing unit and providing the oscillator signal as the power feeding signal to the at least two wireless signal processing units further comprising The first signal processing unit includes a first mixer that converts the frequency of the first analog signal based on the oscillator signal, The second signal processing unit includes a second mixer that converts the frequency of the second analog signal based on the oscillator signal. The wireless power feeding device according to Item 15. [Item 17] comprising a second selection unit that selects one of the N wireless signal processing units, the selected wireless signal processing unit being the first wireless signal processing unit, the N - 1 wireless signal processing units other than the selected wireless signal processing unit being the N - 1 second wireless signal processing units The wireless power feeding device according to any one of Items 1 to 16. [Item 18] The second selection unit includes a switch circuit that selectively connects the N wireless signal processing units to the first signal processing unit The wireless power feeding device according to Item 17. [Item 19] The wireless signal transmitted from the power receiver is a beacon signal The wireless power feeding device according to any one of Items 1 to 18. [Item 20] A method executed by a wireless power feeding device capable of feeding power to a power receiver that transmits a wireless signal, acquiring a first analog signal based on a first wireless signal received by a first antenna element among N antenna elements, and acquiring a first digital signal based on the first analog signal, Based on the second radio signal received by the N - 1 second antenna elements different from the first antenna element among the N antenna elements, a plurality of second analog signals are acquired. Select one of the second analog signals, which is an analog signal acquired by N - 1 second radio signal processing units different from the first radio signal processing unit among the N radio signal processing units. Based on the selected second analog signal, a second digital signal is acquired. A method for estimating a propagation path between the power receiver based on the first digital signal and the second digital signal.

Explanation of Signs

[0144] 30 Selection unit (first selection unit) 100, 100A, 100B, 100C Wireless power supply device 110, 110_1~110_N Antenna elements 120, 120_1~120_N RF signal processing unit (radio signal processing unit) 121 Transmission / reception changeover switch 122 Receiver amplifier 123 Transmitter variable amplifier 124 Phase shifter 130, 130_1~130_N Switching unit 131 Switching unit 132 Switching unit (first switching unit) 140 Distribution / combiner (combining unit) 150 First signal processing unit 151 Quadrature mixer (first mixer) 152 Low-pass filter 153 Variable gain amplifier 154 A / D converter 160 Second signal processing unit 161 Quadrature mixer (second mixer) 162 Low-pass filter 163 Variable gain amplifier 164 A / D converter 170 Signal generator 171 Switching unit (first switching unit, second switching unit) 180 Control unit 200 Wireless power supply device 500 Power receiver 600 Wireless device 700 Human body B, B_1 to B_N Beacon signals R1 Received beam R2 Transmitted beam, power supply signal S1 Detection signal S2 Reflected signal

Claims

1. A wireless power supply device capable of wirelessly powering a power receiver that transmits a wireless signal, N antenna elements, N wireless signal processing units that acquire analog signals based on the wireless signals received by the N antenna elements, A first signal processing unit that acquires a first digital signal based on a first analog signal that is the analog signal acquired by a first wireless signal processing unit among the N wireless signal processing units, A first selection unit that selects one of second analog signals that are the analog signals acquired by N - 1 second wireless signal processing units different from the first wireless signal processing unit among the N wireless signal processing units, A second signal processing unit that acquires a second digital signal based on the second analog signal selected by the first selection unit, And a control unit that estimates a propagation path between the power receiver based on the first digital signal and the second digital signal. A wireless power supply device comprising the above.

2. The first selection unit includes a plurality of switches that connect the N - 1 second wireless signal processing units to the second signal processing unit. The wireless power supply device according to Claim 1.

3. The first selection unit sequentially selects one of the plurality of second analog signals corresponding to a plurality of times, The control unit estimates the propagation path between the power receiver based on the second digital signal acquired from the second analog signal selected at each time and the first digital signal acquired from the first analog signal corresponding to each time. The wireless power supply device according to Claim 1.

4. The first digital signal includes information on the amplitude and phase of the wireless signal input to the first wireless signal processing unit, The second digital signal includes information on the amplitude and phase of the wireless signal input to the second wireless signal processing unit, The control unit estimates the propagation path based on the phase difference between the first digital signal and the second digital signal, or the amplitude difference and the phase difference. The wireless power supply device according to Claim 1.

5. The N wireless signal processing units include phase shifters that perform phase shifting of the wireless signal, The control unit controls the phase shift amounts of the phase shifters in at least two of the N wireless signal processing units among the phase shifters in the N wireless signal processing units based on the information on the propagation path. Further comprising a synthesizing unit that synthesizes the analog signals acquired by the at least two radio signal processing units The wireless power feeding device according to claim 3

6. Based on a composite signal obtained by synthesizing the analog signals by the synthesizing unit, the control unit determines whether a wireless device different from the power receiving device exists in a direction including the direction of the power receiving device The wireless power feeding device according to claim 5

7. When the wireless device is included in the direction including the direction of the power receiving device, the control unit determines not to perform the wireless power feeding to the power receiving device When the wireless device is not included in the direction including the direction of the power receiving device, the control unit determines to perform the wireless power feeding to the power receiving device The wireless power feeding device according to claim 6

8. Further comprising a signal generator that generates a detection signal for an object The first radio signal processing unit acquires the first analog signal based on a radio signal received by a first antenna element among the N antenna elements The N - 1 second radio signal processing units acquire the second analog signal based on radio signals received by the second to Nth antenna elements among the N antenna elements Two or more of the N - 1 second radio signal processing units transmit the detection signal from the signal generator from their respective antenna elements The first radio signal processing unit acquires a plurality of received signals based on reflected signals of the plurality of detection signals received via the first antenna element Comprising a control unit that detects at least one of the position and direction of an object existing in the power feeding area based on a plurality of digital signals acquired based on the plurality of received signals by the first signal processing unit The wireless power feeding device according to claim 1

9. Based on at least one of the detected position and direction of the object, the control unit controls the wireless power feeding to the power receiving device The wireless power feeding device according to claim 8

10. The object is a human body The detection signal has an effective value of the electric field strength of 137 V / m or less, an effective value of the magnetic field strength of 0.365 A / m or less, or a power flux density of 5 mW / cm ２ or less The wireless power feeding device according to claim 8

11. When the object is included in a direction including the direction of the power receiving device, the control unit determines not to perform the wireless power feeding When the object is not included in a direction including the direction of the power receiving device, the control unit determines to perform the wireless power feeding The wireless power feeding device according to claim 8

12. When the object is included in the direction including the direction of the power receiver, the control unit generates a null with respect to the direction in which the object exists and performs the wireless power feeding to the power receiver. The wireless power feeding device according to claim 8.

13. The object is a human body, The control unit generates the null such that the radio wave irradiated on the human body has an effective value of the electric field strength of 137 V / m or less, an effective value of the magnetic field strength of 0.365 A / m or less, or a power flux density of 5 mW / cm ２ or less The wireless power feeding device according to claim 12.

14. The detection signal is an oscillator signal, A first switching unit that selectively switches between supplying the oscillator signal to the first signal processing unit and the second signal processing unit and providing the oscillator signal as the detection signal to two or more of the second wireless signal processing units further includes, The first signal processing unit includes a first mixer that converts the frequency of the first analog signal based on the oscillator signal, The second signal processing unit includes a second mixer that converts the frequency of the second analog signal based on the oscillator signal. The wireless power feeding device according to claim 8.

15. further includes a signal generator that generates a power feeding signal, The N wireless signal processing units include a phase shifter that performs phase shifting of the power feeding signal, The control unit controls the phase shift amounts of the phase shifters in at least two of the N wireless signal processing units based on the information on the propagation path, The wireless power feeding is performed by transmitting the power feeding signals phase-shifted by the phase shifters from the at least two wireless signal processing units from the respective antenna elements. The wireless power feeding device according to claim 1.

16. The power feeding signal is an oscillator signal, A second switching unit that selectively switches between supplying the oscillator signal to the first signal processing unit and the second signal processing unit and providing the oscillator signal as the power feeding signal to the at least two wireless signal processing units further includes, The first signal processing unit includes a first mixer that converts the frequency of the first analog signal based on the oscillator signal, The second signal processing unit includes a second mixer that converts the frequency of the second analog signal based on the oscillator signal. The wireless power feeding device according to claim 15.

17. includes a second selection unit that selects one of the N wireless signal processing units, The selected wireless signal processing unit is the first wireless signal processing unit, The N - 1 wireless signal processing units other than the selected wireless signal processing unit are N - 1 second wireless signal processing units. The wireless power feeding device according to claim 1.

18. The second selection unit includes a switch circuit that selectively connects the N radio signal processing units to the first signal processing unit. The wireless power feeding device according to claim 17. **Claim 19** The wireless signal transmitted from the power receiver is a beacon signal. The wireless power feeding device according to claim 1. **Claim 20** A method executed by a wireless power feeding device capable of feeding power to a power receiver that transmits a wireless signal, comprising: acquiring a first analog signal based on a first wireless signal received by a first antenna element among N antenna elements, and acquiring a first digital signal based on the first analog signal; acquiring a plurality of second analog signals based on second wireless signals received by N - 1 second antenna elements different from the first antenna element among the N antenna elements; selecting one of the plurality of second analog signals; acquiring a second digital signal based on the selected second analog signal; estimating a propagation path between the power receiver and the first digital signal and the second digital signal.

Images