Power receivers, systems, programs, and methods

Abstract

To improve power supply efficiency in spatial transmission type wireless power supply systems. [Solution] The power receiver is equipped with a receiving means that can change the frequency band in which the frequency characteristics are approximately at their maximum value, using either the first frequency band or the second frequency band.

Description

Technical Field

[0001] The present disclosure relates to a power receiver, a system, a program, and a method.

Background Art

[0002] Patent Document 1 discloses an apparatus and method in a communication system, and a method for controlling power in wireless power transmission. The apparatus of the communication system receives, from at least one terminal device, information related to a power conversion window of the wireless power transmission requested by the terminal device, determines a power level of the wireless power transmission based at least in part on the received information, and controls the wireless power transmission based on the determination.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Patent Document 1, power transmission is performed using a signal for power transmission that is separate from signals used for information transmission. Therefore, in Patent Document 1, the terminal device is not supplied with power by information transmission.

[0005] A power receiver used in a space transmission type wireless power supply system may be disposed within the area of a communication system that allows use of mobile phones. There is a demand for the power receiver to also receive power from wireless signals transmitted from the communication system.

[0006] An objective of the present disclosure is to improve the power supply efficiency of a power receiver that is supplied with power by wireless non-contact energy related technology, and to increase power reception opportunities.

Means for Solving the Problems

[0007] To solve the above problems, the receiver is equipped with a receiving means that can change the frequency band in which the frequency characteristics are approximately at their maximum value, between the first frequency band and the second frequency band. [Effects of the Invention]

[0008] According to this disclosure, it is possible to improve the power supply efficiency of a power receiver powered by wireless / contactless energy-related technologies, increase the opportunities for receiving power, or achieve both. [Brief explanation of the drawing]

[0009] [Figure 1] This figure shows the overall configuration of the WPT system 1 according to this embodiment. [Figure 2] This is a schematic diagram illustrating an example of a WPT system 1 located within a mobile phone communication area. [Figure 3] Figure 1 is a block diagram showing an example configuration of a power transmitter 100 and a power receiver 200. [Figure 4] This is a schematic diagram showing the frequency response shift of a rectenna. [Figure 5] This is a schematic diagram illustrating the change in impedance. [Figure 6] This figure illustrates an example of the operation of the WPT system 1 according to this embodiment. [Figure 7] This figure illustrates another example of the operation of the WPT system 1 according to this embodiment. [Figure 8] This figure illustrates another example of the operation of the WPT system 1 according to this embodiment. [Modes for carrying out the invention]

[0010] The embodiments of this disclosure will be described below with reference to the drawings. In all the drawings illustrating the embodiments, common components are denoted by the same reference numerals, and repeated explanations are omitted. The following embodiments are not intended to unduly limit the content of this disclosure as described in the claims. Not all components shown in the embodiments are necessarily essential components of this disclosure. Also, each drawing is a schematic diagram and is not necessarily a strict illustration.

[0011] Furthermore, in the following description, "processor" refers to one or more processors. A processor may be expressed, for example, as processing circuitry. At least one processor is typically a microprocessor such as a CPU (Central Processing Unit), but may be other types of processors such as a GPU (Graphics Processing Unit). At least one processor may be single-core or multi-core. Also, at least one processor may be a general-purpose processor or a purpose-specific processor.

[0012] Furthermore, at least one processor may be a broad-sense processor, such as a hardware circuit that performs some or all of the processing (e.g., an FPGA (Field-Programmable Gate Array), an ASIC (Application Specific Integrated Circuit)).

[0013] Furthermore, in the following explanation, we may use expressions such as "xxx table" to describe information that yields an output for a given input. This information can be data with any structure, or it can be a learning model such as a neural network that generates an output for a given input. Therefore, "xxx table" can be referred to as "xxx information."

[0014] Furthermore, in the following explanation, the structure of each table is just an example; one table may be divided into two or more tables, or all or part of two or more tables may be a single table.

[0015] The program may be pre-installed on the information processing device described below, or, for example, the information processing device may be on a readable (e.g., non-temporary) recording medium and the program may be installed on the information processing device. Alternatively, the program may be sent from a program distribution server to the information processing device and installed there. Furthermore, in the following description, two or more programs may be implemented as a single program, or one program may be implemented as two or more programs.

[0016] Furthermore, while various types of identification information are used in the following description, the identification information only needs to be information that indicates a predetermined object, and the specific data is not limited to the embodiments. The identification information may be an identification number, or an identifier that includes letters or symbols.

[0017] <Overview> The present disclosure relates to a power receiver capable of efficiently receiving power from radio waves of both a mobile phone system and a space transmission type wireless power feeding system in an environment where these two systems coexist. The power receiver according to the present disclosure is fed with power by wireless and contactless energy related technologies. In the present embodiment, the wireless and contactless energy related technologies refer to technologies including transmission and reception of information and / or power using electromagnetic induction, magnetic field resonance, radio waves (RF) / microwaves, infrared rays, visible light, etc. (e.g., wireless communication, wireless power transmission, simultaneous information and power transmission), as well as energy harvesting from radio waves, vibration, heat, light, etc. in the environment. The power receiver includes a receiving unit (for example, a rectenna) and a load (for example, an SoC and a sensor) connected to the receiving unit. The frequency characteristic of the receiving unit is designed to vary depending on the impedance of the connected load. The load can actively change its impedance, for example, by switching the operation mode (e.g., sleep mode, active mode, on / off state) of the SoC or the sensor. Thereby, the power receiver can selectively make the substantially maximum value of the frequency characteristic of the receiving unit substantially coincide with the frequency band of the power feeding system (the first frequency band) and the frequency band of the mobile phone system (the second frequency band), making it possible to improve the power feeding efficiency.

[0018] <1 Overall Configuration Diagram of System> Figure 1 is a diagram showing the overall configuration of the WPT system 1 according to the present embodiment.

[0019] The WPT system 1 shown in Figure 1 is used, for example, in a building, a factory, or the like. The WPT system 1 is, for example, a space transmission type wireless power feeding system. The WPT system 1 includes, for example, a power transmitter 100, a power receiver 200, a first information processing apparatus 300, and a second information processing apparatus 400. Note that the connection between the power transmitter 100 and the first information processing apparatus 300, and the connection between the first information processing apparatus 300 and the second information processing apparatus 400 may be wired or wireless.

[0020] Figure 1 shows an example where the WPT system 1 includes three power transmission units 100, but the number of power transmission units 100 included in the WPT system 1 is not limited to three. The WPT system 1 may include two or fewer power transmission units 100, or four or more power transmission units 100.

[0021] Figure 1 shows an example where the WPT system 1 includes seven power receivers 200, but the number of power receivers 200 included in the WPT system 1 is not limited to seven. The number of power receivers 200 included in the WPT system 1 may be six or fewer, or eight or more.

[0022] In this specification, the power receiver 200 may transmit, for example, information regarding the status of the power receiver 200 or information regarding measurement results from a sensor connected to the power receiver 200 as a data signal to the power transmitter 100, and the power transmitter 100 may receive such data signals. In this case, the power transmitter 100 functions as a receiver that receives data signals, and the power receiver 200 functions as a transmitter that transmits data signals.

[0023] Figure 1 shows an example where the WPT system 1 includes two first information processing devices 300, but the number of first information processing devices 300 included in the WPT system 1 is not limited to two. The WPT system 1 may include one first information processing device 300, or it may include three or more.

[0024] The transmitter 100 transmits, for example, a power supply signal or a data signal to the receiver 200. Based on control from the first information processing device 300, the transmitter 100 transmits a power supply signal to the receiver 200, for example, using radio waves in the 920 MHz band, which is the first frequency band. The transmitter 100 is, for example, an example of a first transmitting device. The transmitter 100 transmits a data signal to the receiver 200, for example, using radio waves in the 2.4 GHz band. The transmitter 100 may transmit the data signal using radio waves in the 920 MHz band.

[0025] The feed signal transmitted from the power transmitter 100 may, for example, be a continuous wave (CW) with a predetermined power. The frequency bands that can be used for the feed signal are not limited to those mentioned above, and for example, radio waves in the 430MHz band (433.05MHz~434.79MHz), 860MHz band (865MHz~868MHz), 920MHz band (902MHz~928MHz (915MHz±13MHz)), 2.4GHz band (2.4GHz~2.5GHz), 5.7GHz band (5.725GHz~5.875GHz), and 24GHz band (24GHz~24.25GHz) can also be used. In this case, the laws of the country where the WPT system 1 is installed may impose restrictions on the intermittent transmission of the feed signal with a predetermined power. For example, if the power supply signal from the power transmitter 100 falls under the provisions for radio stations as defined in Japan's Radio Law (regardless of whether a license is in place), it may be necessary to set a certain pause period for the power supply signal in accordance with the Radio Law. In this case, considering it over a certain time axis, the power supply signal cannot be said to be a continuous wave. However, it is important to set a pause period, and since this pause period only needs to be short, the power supply signal transmitted from the power transmitter 100 can be considered to be a nearly continuous wave. The ratio of the duration of the power supply signal to the duration of the pause period should be such that the power supply signal transmitted from the power transmitter 100 can be considered to be a nearly continuous wave, as described above. For example, the duration of the pause period is about 1 / 50 to 1 / 100 of the duration of the power supply signal.

[0026] The power transmitter 100 may, for example, supply power to one power receiver 200, or to multiple power receivers 200. The power transmitter 100 may, for example, transmit a data signal to one power receiver 200, or to multiple power receivers 200. The power transmitter 100 may, for example, transmit the same data signal as other power transmitters 100, or transmit a different data signal from other power transmitters 100. The power transmitter 100 may, for example, transmit a predetermined command signal as a data signal to the power receiver 200, or transmit a pre-set signal as a data signal to the power receiver 200.

[0027] The power transmitter 100 receives, for example, data signals transmitted from the power receiver 200. The power transmitter 100 may receive data signals transmitted from, for example, one power receiver 200, or it may receive data signals transmitted from multiple power receivers 200. The power transmitter 100 transmits the data signals transmitted from the power receiver 200 to the first information processing device 300. The power transmitter 100 transmits information regarding the status of the power transmitter 100 to the first information processing device 300.

[0028] The power receiver 200 receives, for example, a power supply signal or a data signal transmitted from the power transmitter 100. If the power receiver 200 has, for example, a power storage unit, it converts the power supply signal transmitted from the power transmitter 100 into power and stores the converted power in the power storage unit. If the power receiver 200 has, for example, a predetermined sensor, it converts the power supply signal transmitted from the power transmitter 100 into power and drives the sensor with the converted power.

[0029] The power receiver 200 transmits, for example, information regarding the status of the power receiver 200 (such as the power reception level) or information regarding measurement results from sensors as a data signal to the first information processing device 300.

[0030] As an example of its operational configuration, the WPT system 1 may be located within the communication area of ​​a mobile phone network. More specifically, at least one of the receivers 200 included in the WPT system 1 may be located within the communication area. Figure 2 is a schematic diagram showing an example of a WPT system 1 located within the communication area of ​​a mobile phone network. In the example shown in Figure 2, the transmitter 100 and the receiver 200 included in the WPT system 1 are located within the communication area formed by the base station 2, which acts as a second transmitting device.

[0031] In a 3GPP® cellular phone system, a radio signal for wireless communication is emitted from base station 2. This radio signal corresponds to the signal in the second frequency band in this embodiment. The frequency bands of the radio signal are 925MHz to 960MHz for the downlink of band 8, 869MHz to 894MHz for the downlink of band 5, and 859MHz to 8949MHz for the downlink of band 26. Note that the bands are not limited to these, and may also be band 6, band 19, band 18, band 27, etc.

[0032] The receiver 200 selectively receives the power supply signal in the first frequency band transmitted from the transmitter 100 and the radio signal for wireless communication in the second frequency band transmitted from the base station 2, and converts the received signals into power. The receiver 200 is configured to receive radio signals in, for example, one or more preset frequency bands from the above frequency bands as radio signals for wireless communication.

[0033] Specifically, for example, the receiver 200 has a first mode for efficiently receiving power supply signals transmitted from the transmitter 100, and a second mode for efficiently receiving radio signals for wireless communication transmitted from the base station 2. Furthermore, if it is capable of receiving radio signals in multiple frequency bands, the receiver 200 can be configured with a number of modes corresponding to the types of radio signals it can receive, such as a third mode, a fourth mode, and so on.

[0034] The first information processing device 300 is an information processing device that monitors the operation of the power transmitter 100 and power receiver 200 housed in the WPT system 1. The first information processing device 300 is, for example, a gateway. The first information processing device 300 may also be referred to as Sumit (registered trademark). For example, the first information processing device 300 determines whether the power transmitter 100 or the power receiver 200 is in a preset state based on information about the status of the power transmitter 100 and the power receiver 200 transmitted from the power transmitter 100. If it determines that the power transmitter 100 or the power receiver 200 is in a preset state, the first information processing device 300 transmits predetermined information to the second information processing device 400.

[0035] Furthermore, the first information processing device 300 stores information about the power transmitter 100 and power receiver 200 housed in the WPT system 1. For example, the first information processing device 300 stores information about the status of the power transmitter 100 and power receiver 200, transmitted from the power transmitter 100, in a storage unit provided in the first information processing device 300.

[0036] Furthermore, the first information processing device 300 controls the operation of the power transmitter 100, which is housed in the WPT system 1. For example, the first information processing device 300 transmits a predetermined instruction or information to the power transmitter 100. This instruction may include a command signal to switch the operating mode (first mode, second mode, etc.) of the power receiver 200.

[0037] Furthermore, the first information processing device 300 controls the operation of the second information processing device 400.

[0038] The second information processing device 400 is, for example, an information processing device operated by the administrator of the WPT system 1. The second information processing device 400 is, for example, a PLC. When the second information processing device 400 receives a notification from the first information processing device 300 that the power transmitter 100, the power receiver 200, or both thereof, which are housed in the WPT system 1, are in a predetermined state, it informs the user that the power transmitter 100, the power receiver 200, or both thereof are in a predetermined state.

[0039] Furthermore, the second information processing device 400 analyzes the information regarding the status of the power transmitter 100 and the power receiver 200 stored in the first information processing device 300 and presents predetermined information to the user. The predetermined information is, for example, the following: • Information regarding the placement of the power transmission unit 100 • Information regarding the placement of the power receiver 200 • Information regarding power consumption • Information regarding the amount of electricity

[0040] <2. Transmitter and Receiver Configuration> Figure 3 is a block diagram showing an example configuration of the transmitter 100 and receiver 200 shown in Figure 1. As shown in Figure 3, the transmitter 100 and receiver 200 are separated from each other by a predetermined distance, for example. For example, the transmitter 100 and receiver 200 are installed at a distance of several meters apart. Specifically, for example, the transmitter 100 is fixed and installed at a predetermined high position indoors, for example, on the ceiling or wall. The receiver 200 is installed in a predetermined device indoors or placed near a device that requires power supply. The receiver 200 may also be carried by the user. The transmitter 100 transmits a power supply signal to the receiver 200 using radio waves at a predetermined frequency, for example, in the 920 MHz band. The receiver 200 converts the power supply signal transmitted from the transmitter 100 into power, and either charges with the converted power or supplies the converted power to a predetermined device.

[0041] The power transmitter 100 includes, for example, an oscillator 101, a transmitting antenna 102, a microcontroller 103, a data transceiver 104, and a data transceiver antenna 105. The oscillator 101, microcontroller 103, data transceiver 104, data transceiver antenna 105, or at least a combination of these, may be mounted on a PCB (printed circuit board), for example.

[0042] The oscillator 101 generates a signal in a frequency band corresponding to the control of the microcontroller 103, or in a predetermined frequency band, for example, the 920 MHz band. The generated signal may be amplified as needed to remove unwanted frequency components.

[0043] The transmitting antenna 102 is configured to efficiently transmit, for example, radio waves in the frequency band oscillated by the oscillator 101. The transmitting antenna 102 radiates the signal oscillated by the oscillator 101 as a feed signal.

[0044] The microcontroller 103 controls the operation of the power transmitter 100. The microcontroller 103 is implemented, for example, by a semiconductor element equipped with an ARM processor. The microcontroller 103 controls, for example, the transmission of radio waves by the transmitting antenna 102.

[0045] The data transceiver 104 performs processing such as converting digital data to analog and modulating analog data. The data transceiver 104 also performs processing such as demodulating the data signal received by the data transmission antenna 105 and digitizing the demodulated data. For example, the data transceiver 104 extracts a predetermined signal from the data signal received by the data transmission antenna 105, converts it to digital data, and transmits it to the microcontroller 103.

[0046] The data transmission antenna 105 is configured to efficiently transmit and receive radio waves in the 2.4GHz band, for example. The data transmission antenna 105 radiates data signals supplied from the data transceiver 104. The data transmission antenna 105 also receives data signals transmitted from the receiver 200.

[0047] The receiver 200 includes a receiving means that can change the frequency band in which the frequency characteristics are approximately at their maximum value between a first frequency band and a second frequency band. This can be rephrased as, for example, the receiver 200 includes a receiving means that can switch between the first frequency band and the second frequency band to approximately match the approximately maximum value of the frequency characteristics. This receiving means includes, for example, a receiving antenna 201, a rectifier circuit 202, a power management unit 203, a power storage unit 204, a microcontroller (SoC: System on Chip) 205, a data transceiver 206, and a data transceiver antenna 207. The receiving antenna 201, the rectifier circuit 202, the power management unit 203, the power storage unit 204, the microcontroller 205, the data transceiver 206, the data transceiver antenna 207, or at least a combination of these, may be mounted on, for example, a PCB or FPC (flexible printed circuit board).

[0048] In this disclosure, "approximately maximum value of frequency response" is a concept that includes not only the maximum value that the frequency response in question can take, but also values ​​that fall within a predetermined tolerance range from that maximum value. The predetermined tolerance range may include, for example, a range that is approximately 3 dB to 6 dB lower than the maximum value. Alternatively, it may be defined as a predetermined percentage or more of the maximum value (for example, approximately 80% or more, or approximately 80% to 95% or more).

[0049] Furthermore, the "frequency band where the frequency response is approximately at its maximum value" refers to a set of frequencies (including a continuous frequency range) that satisfy the condition of the frequency response being approximately at its maximum value. For example, in a 920MHz band WPT, a bandwidth of approximately 30MHz, such as from 902MHz to 928MHz, can be set as the first frequency band. In addition, the frequency band of radio waves for wireless communication transmitted from base station 2 can be set as the second frequency band. These frequency bands may be changed as appropriate depending on the standard, country / region, or system design.

[0050] Furthermore, the statement that "the frequency or frequency band at which the frequency response reaches approximately its maximum value approximately coincides with the first frequency band (or second frequency band)" may include the relationship between the frequency or frequency band at which the frequency response reaches approximately its maximum value and the said first frequency band (or second frequency band), taking into consideration a predetermined tolerance range, satisfying at least one of the following: that is, (i) the boundaries (ends) of the two frequency bands coincide, (ii) the two frequency bands overlap in at least part, or (iii) one frequency band encompasses (or is encompassed by) the other frequency band.

[0051] The receiving antenna 201 is formed to receive, for example, radio waves being emitted. The rectifier circuit 202 rectifies the radio waves received as a power supply signal and converts them into a DC voltage.

[0052] The receiving antenna 201 and the rectifier circuit 202 are treated as a single unit, a rectenna that receives radio waves and converts them into DC power. In this embodiment, the frequency at which the rectenna's power receiving efficiency is maximized is not fixed but variable. In other words, the frequency characteristics of the rectenna can be set to multiple values. Switching between frequency characteristics is achieved by changing the impedance of the circuit connected downstream of the rectifier circuit 202, i.e., the load.

[0053] Since the rectifier circuit 202 is a nonlinear circuit including diodes, etc., when the impedance of the load connected to its "output side" changes, the impedance on the "input side" also changes in conjunction. By utilizing this property and intentionally switching the impedance of the subsequent circuit, the input impedance of the rectifier circuit 202 can be changed. As a result, the impedance between the receiving antenna 201 and the rectifier circuit 202 (input side) is matched, and the frequency band in which the power reception performance is maximized can be shifted to the intended frequency.

[0054] In this embodiment, the power receiver 200 is configured to be switchable between at least a first mode and a second mode. The frequency characteristics of the rectenna are different in the first mode and the second mode. Figure 4 is a schematic diagram showing the shift in the frequency characteristics of the rectenna.

[0055] In the first mode, the impedance of the stage after the rectifier circuit 202 is set to a predetermined first value, optimizing the rectenna's frequency response so that its approximate maximum value approximately matches the first frequency band, i.e., the frequency band of the WPT radio waves transmitted from the power transmitter 100 (e.g., the 920 MHz band). In the second mode, the impedance of the stage after the rectifier circuit 202 is switched to a second value different from the first value, optimizing the rectenna's frequency response so that its approximate maximum value approximately matches the second frequency band, i.e., the frequency band of the radio waves for wireless communication transmitted from the base station 2 (e.g., the downlink frequency of band 8, 925 MHz to 960 MHz). Figure 4 shows this shift in frequency response, illustrating how the rectenna's frequency response approximately matches the frequency band of the WPT radio waves and the frequency band of the radio waves for wireless communication, respectively. Note that if multiple different frequency bands of radio waves for wireless communication are to be supported, even more modes (third mode, fourth mode, etc.) may be set and the impedance value corresponding to each mode may be switched.

[0056] The power management unit 203 manages the DC voltage output from the rectifier circuit 202. For example, the power management unit 203 generates a charging voltage based on the DC voltage and controls it to charge the energy storage unit 204. Also, for example, when the energy storage unit 204 has stored more than a predetermined capacity, the power management unit 203 supplies the DC voltage to the microcontroller 205 or connected components such as the sensor 208.

[0057] Furthermore, the power management unit 203 releases the power stored in the energy storage unit 204 to the sensor 208 and other devices in response to control from the microcontroller 205.

[0058] The energy storage unit 204 is implemented by, for example, a battery such as a lithium-ion secondary battery, or a capacitor such as an electric double-layer capacitor. The energy storage unit 204 stores power in response to instructions from the power management unit 203. The energy storage unit 204 also releases the stored power in response to instructions from the power management unit 203.

[0059] The microcontroller 205 is a processor that comprehensively controls the operation of the entire power receiver 200 and is implemented as an SoC. The microcontroller 205 is driven by the DC voltage supplied from the power management unit 203 or the power stored in the energy storage unit 204. The microcontroller 205 controls the power management unit 203 to release the power stored in the energy storage unit 204. In this embodiment, the microcontroller 205 is responsible for switching the load impedance in a manner that will be described later.

[0060] Various sensors 208 can be connected to the power receiver 200. For example, heat sensors, temperature sensors, light sensors, humidity sensors, vibration sensors, magnetic sensors, etc. can be connected to the power receiver 200. Force sensors, proximity sensors, gas sensors, acceleration sensors, human presence sensors, infrared sensors, illuminance sensors, flow sensors, current sensors, pressure sensors, etc. may also be connected to the power receiver 200. The sensors 208 connected to the power receiver 200 are driven, for example, by a DC voltage supplied from the power management unit 203 or by power released from the energy storage unit 204. The sensors 208 may be built into the circuit board of the power receiver 200.

[0061] To switch the frequency characteristics of the rectenna (receiving antenna 201 and rectifier circuit 202), it is necessary to actively control the impedance of the load connected downstream of the rectifier circuit 202. In the power receiver 200, this load mainly includes a microcontroller 205 and at least one sensor 208. Impedance control (switching) is achieved by changing the power consumption of the microcontroller 205 and the sensor 208.

[0062] Figure 5 is a schematic diagram illustrating the change in impedance. Generally, the impedance Z of a load is expressed as Z = V / I, where V is the voltage and I is the current. Assuming that the voltage V is relatively constant, increasing the current I decreases the impedance Z, and decreasing the current I increases the impedance Z. Figure 5 shows, for example, that increasing the current to the load decreases the load impedance, and returning the load impedance to its original value also returns the load impedance to its original value.

[0063] The microcontroller 205 switches its own operating mode and the sensor 208's operating mode at predetermined timings. Specifically, the microcontroller 205 has multiple operating modes with different power consumption, such as normal mode, sleep mode, and deep sleep mode. Normal mode is a high-power mode in which, for example, predetermined functions are in operation. Sleep mode is a mode that reduces power consumption by suspending some functions, such as stopping the microcontroller 205's operating clock. Deep sleep mode is a mode that further reduces power supply to more functions than sleep mode, or minimizes it, thereby suppressing power consumption (load) to the absolute minimum. The microcontroller 205 may also have an active mode in which more functions are in operation and the clock speed is faster than in normal mode. On the other hand, the sensor 208 has an ON state (operating state) in which it performs measurement operations and an OFF state (stopped state) in which it stops operating.

[0064] The microcontroller 205 performs switching control by combining its multiple operating modes, such as "normal mode," "sleep mode," and "deep sleep mode," with the "on state" and "off state" of the sensor 208. This makes it possible to actively change the impedance of the downstream load as seen from the rectifier circuit 202 to multiple patterns, and as a result, enables switching of the frequency characteristics of the rectenna.

[0065] For example, the microcontroller 205 can change the load impedance into multiple patterns by varying the combination of the microcontroller 205's operating mode and the state of the sensor 208, as follows. (1) Microcontroller: Deep sleep mode + Sensor: Off state (the state with the lowest power consumption and highest impedance) (2) Microcontroller: Sleep mode + Sensor: Off state (3) Microcontroller: Normal mode + Sensor: Off state (4) Microcontroller: Deep sleep mode + Sensor: On state (5) Microcontroller: Sleep mode + Sensor: On state (6) Microcontroller: Normal mode + Sensor: On state (the state with the highest power consumption and lowest impedance)

[0066] Since each of the above combinations has a different power consumption (load), the load impedance for each combination also takes on a different value. During the design phase of the rectenna, these impedance values ​​are pre-optimized so that the power receiving performance is approximately maximized in different specific frequency bands.

[0067] For example, in one instance, the rectenna is designed such that the impedance of the above combination, "microcontroller: normal mode + sensor: on state," provides approximately maximum power reception performance in the 920MHz band of the first frequency band, which is the transmitter 100. Furthermore, the impedance of the above combination, "microcontroller: sleep mode + sensor: off state," is pre-optimized so that it provides approximately maximum power reception performance in the second frequency band, which is the Band 8 downlink frequency band of base station 2.

[0068] As a result, the receiver 200 can efficiently handle multiple types of wireless communication radio waves (different frequency bands) solely through purely electrical control, such as switching the operating modes of downstream devices (e.g., the microcontroller 205 and the sensor 208), while using a single rectenna configuration.

[0069] The "predetermined timing" at which the microcontroller 205 switches modes can be determined in various ways. For example, the modes can be switched periodically based on a timer inside the microcontroller 205. For instance, it is possible to operate in the first mode for N seconds to receive power from the transmitter 100, and then switch to the second mode for M seconds to receive communication signals from the base station 2. Alternatively, the mode may be switched triggered by receiving a specific command signal as a data signal from the transmitter 100. Furthermore, autonomous control is possible, such as monitoring the voltage level of the energy storage unit 204 and switching modes to receive a stronger radio source when the voltage falls below a predetermined threshold.

[0070] The microcontroller 205 continuously or intermittently monitors the voltage value at a predetermined location on the power receiver 200, the status of the sensor 208 connected to the power receiver 200, and information detected by the sensor 208. The microcontroller 205 transmits this information as digital data to the data transceiver 206.

[0071] The data transceiver 206 performs processing such as converting digital data supplied from the microcontroller 205 to analog and modulating analog data. The data transceiver 206 also performs processing such as demodulating the data signal received by the data transceiver antenna 207 and digitizing the demodulated data. The data transceiver 206 is driven, for example, by a DC voltage supplied from the power management unit 203 or power emitted from the energy storage unit 204.

[0072] The data transmission antenna 207 is configured to efficiently transmit and receive radio waves in the 2.4 GHz band, for example. The data transmission antenna 207 radiates data signals supplied from the data transceiver 206. The data transmission antenna 207 also receives data signals transmitted from the power transmitter 100. For example, the data transmission antenna 207 is driven by a DC voltage supplied from the power management unit 203 or power emitted from the energy storage unit 204.

[0073] <3 operations> A first example of operation in the WPT system 1 according to this embodiment will be described with reference to the drawings. This example of operation shows the basic sequence when the power receiver 200 actively switches between receiving wireless power transmission (WPT) and receiving mobile communications (Mobile).

[0074] (Example of operation 1) Figure 6 is a diagram illustrating an example of the operation of the WPT system 1 according to this embodiment. First, the microcontroller 205 of the power receiver 200 detects, for example, when a predetermined timing has arrived. Specifically, the microcontroller 205 detects a periodic charging timing based on an internal timer, for example. The microcontroller 205 may also detect, for example, when the charge level of the built-in energy storage unit 204 falls below a predetermined threshold. Triggered by this detection, the microcontroller 205 transmits a WPT power reception start signal to the power transmitter 100 via the data transceiver 206 and the data transceiver antenna 207, requesting the start of wireless power transmission (step S11). The WPT power reception start signal may include identification information for the power receiver 200, or it may include information regarding the requested power amount.

[0075] After transmitting the WPT power reception start signal, the microcontroller 205 transitions to the WPT power reception standby state. Specifically, the microcontroller 205 performs a process to optimize the frequency characteristics of the receiving means, including the receiving antenna 201 and the rectifier circuit 202, to the frequency band (first frequency band) of the wireless power transmission signal transmitted from the transmitter 100. This optimization process is achieved by adjusting the impedance of the entire receiving means by controlling the operating mode of the microcontroller 205 itself, which is the load, and the operating state of the connected sensor 208. For example, the microcontroller 205 increases its own processing clock or transitions from sleep mode, which stops some functions, to normal mode. The microcontroller 205 also operates the sensor 208 as needed to acquire new data. These operations increase the power consumption of the microcontroller 205 and sensor 208, and decrease the load impedance. This change in impedance adjusts the approximate maximum value of the frequency characteristics of the receiving means to approximately match the first frequency band.

[0076] Meanwhile, the transmitter 100 receives a WPT power reception start signal from the receiver 200 using the data transmission antenna 105. The microcontroller 103 of the transmitter 100 controls the oscillator 101 and the transmitting antenna 102 in response to the WPT power reception start signal to begin transmitting radio power in the first frequency band (step S12). The level of transmitted power and the transmission time are determined, for example, based on a request from the receiver 200 or a predetermined profile.

[0077] When power transmission begins from the transmitter 100, the receiver 200 switches to WPT power receiving operation (step S13). Specifically, the receiving antenna 201 and rectifier circuit 202, which are optimized for the first frequency band, efficiently receive the feed signal. The received feed signal is converted into a DC voltage by the rectifier circuit 202. The converted DC voltage is input to the power management unit 203. The power management unit 203 uses the input power to charge the energy storage unit 204 and also supplies the necessary operating power to each part of the receiver 200, such as the microcontroller 205 or the sensor 208. During charging, the microcontroller 205 monitors the voltage and current of the energy storage unit 204 to understand the charging status.

[0078] When the microcontroller 205 detects, based on information from the power management unit 203, that a predetermined charging time has elapsed or that the energy storage unit 204 has reached a fully charged state, the power receiver 200, for example, sends a charging completion notification to the power transmitter 100. Upon receiving this notification, the microcontroller 103 of the power transmitter 100 stops the power transmission operation (step S14). The microcontroller 103 may also operate autonomously to stop power transmission even without notification from the power receiver 200, for example, after the power transmitter 100 has transmitted power for a predetermined time. Alternatively, the microcontroller 103 may also operate to stop power transmission in response to a notification from another predetermined power receiver 200, for example.

[0079] When the transmission of power supply signals from the power transmitter 100 stops, the microcontroller 205 transmits a Mobile Power Start signal to the base station 2 (second transmitting device) of the mobile communication network via the data transceiver 206 and the data transceiver antenna 207, requesting the start of power supply via communication signals (step S15). The microcontroller 205 may also transmit the Mobile Power Start signal to the base station 2 via the first information processing device 300.

[0080] After transmitting the Mobile Power Reception Start signal, the microcontroller 205 transitions to a Mobile Power Reception standby state. Specifically, the microcontroller 205 performs a process to optimize the frequency characteristics of the receiving device to the frequency band (second frequency band) of the wireless communication signals transmitted from the base station. Unlike during WPT power reception, this optimization process reduces power consumption by, for example, lowering the microcontroller 205's processing clock or entering a sleep mode that disables some functions. This increases the load impedance, and as a result, the approximate maximum value of the receiving device's frequency characteristics is adjusted to approximately match the second frequency band.

[0081] Base station 2 responds to the start request from receiver 200 and begins transmitting radio signals in the second frequency band (step S16).

[0082] When base station 2 begins transmitting a wireless signal, the receiver 200 switches to mobile power reception operation (step S17). Specifically, the receiving antenna 201, optimized for the second frequency band, and the rectifier circuit 202 efficiently receive the wireless signal for communication. The received signal is converted into a DC voltage by the rectifier circuit 202. The converted DC voltage is input to the power management unit 203. The power management unit 203 uses the input power to charge the energy storage unit 204 and also supplies the necessary operating power to each part of the receiver 200, such as the microcontroller 205 or the sensor 208. During charging, the microcontroller 205 monitors the voltage and current of the energy storage unit 204 to understand the charging status.

[0083] When the microcontroller 205 detects, based on information from the power management unit 203, that a predetermined charging time has elapsed or that the energy storage unit 204 has reached a fully charged state, the power receiver 200, for example, sends a charging completion notification to the base station 2. Upon receiving this notification, the base station 2 stops the power transmission operation (step S18). The base station 2 may also operate autonomously to stop power transmission after transmitting power for a predetermined time, even without notification from the power receiver 200. Alternatively, the base station 2 may operate to stop power transmission in response to a notification from another predetermined power receiver 200, for example. Thereafter, when a predetermined timing arrives again, the charging sequence from step S11 is repeated.

[0084] In this way, the receiver 200 efficiently performs both power supply via a power supply signal from the transmitter 100 and power supply via a wireless signal from the base station 2 by switching the load impedance, using a single receiving antenna 201. Furthermore, since the start of power transmission can be decided at the discretion of the receiver 200, optimization according to the energy storage status and other factors is possible.

[0085] (Second example of operation) Next, a second example of operation in the WPT system 1 according to this embodiment will be described. In this example of operation, the power transmitter 100 takes the lead in power supply, and the power transmitter 100 and the base station 2 operate in cooperation with each other.

[0086] Figure 7 is a diagram illustrating another example of the operation of the WPT system 1 according to this embodiment. First, the microcontroller 103 determines, based on an internal timer or instructions from an external system, that the timing for supplying power to the power receiver 200 has arrived. Then, via the data transmission antenna 105, it transmits a WPT power transmission start signal to the power receiver 200 to inform it that power transmission will begin (step S21).

[0087] The receiver 200 receives a WPT power transmission start signal from the transmitter 100 using the data transmission antenna 207. The microcontroller 205 switches to WPT power receiving mode triggered by the reception of the WPT power transmission start signal (step S22). Specifically, the microcontroller 205 switches the impedance of the microcontroller 205, the sensor 208, or a combination thereof. As a result, the microcontroller 205 performs a switching operation that optimizes the frequency characteristics of the receiving means, including the receiving antenna 201 and the rectifier circuit 202, for the first frequency band used for power transmission transmitted from the transmitter 100.

[0088] After transmitting the WPT transmission start signal, the transmitter 100 controls the oscillator 101 and transmitting antenna 102, for example, after a predetermined waiting time for the receiver 200 to switch frequency characteristics, and transmits a feed signal for the first frequency band (step S23). The level of the feed signal and the transmission time are determined, for example, based on a predetermined profile.

[0089] When power transmission begins from the transmitter 100, the receiver 200 switches to WPT power receiving operation (step S24). Specifically, the receiving antenna 201 and rectifier circuit 202, which are optimized for the first frequency band, efficiently receive the feed signal. The received feed signal is converted into a DC voltage by the rectifier circuit 202. The converted DC voltage is input to the power management unit 203. The power management unit 203 uses the input power to charge the energy storage unit 204 and also supplies the necessary operating power to each part of the receiver 200, such as the microcontroller 205 or the sensor 208. During charging, the microcontroller 205 monitors the voltage and current of the energy storage unit 204 to understand the charging status.

[0090] When the microcontroller 205 detects, based on information from the power management unit 203, that a predetermined charging time has elapsed or that the energy storage unit 204 has reached a fully charged state, the power receiver 200, for example, sends a charging completion notification to the power transmitter 100. Upon receiving this notification, the microcontroller 103 of the power transmitter 100 stops the power transmission operation (step S25). The microcontroller 103 may also operate autonomously to stop power transmission after the power transmitter 100 has transmitted power for a predetermined time, even without notification from the power receiver 200. Alternatively, the microcontroller 103 may operate to stop power transmission in response to a notification from another predetermined power receiver 200, for example.

[0091] For example, triggered by the termination of WPT power transmission, the microcontroller 103 transmits a Mobile power transmission request signal to the base station 2 of the mobile communication network via its own communication function or the first information processing device 300, requesting the start of power supply via a communication signal (step S26).

[0092] Base station 2 responds to the start request from transmitter 100 and transmits a Mobile power transmission start signal to indicate the start of power supply via a communication signal (step S27).

[0093] The power receiver 200 receives the Mobile power transmission start signal. The microcontroller 205 transitions to the Mobile power reception standby state (step S28). Specifically, the microcontroller 205 performs a process to optimize the frequency characteristics of the receiving means to the frequency band (second frequency band) of the wireless communication signal transmitted from the base station.

[0094] After transmitting the Mobile Power Transmission Start signal, base station 2 transmits a radio signal in the second frequency band after a predetermined waiting time for the receiver 200 to switch its frequency characteristics (step S29).

[0095] When base station 2 begins transmitting a wireless signal, the receiver 200 switches to mobile power reception operation (step S210). Specifically, the receiving antenna 201, optimized for the second frequency band, and the rectifier circuit 202 efficiently receive the wireless signal for communication. The received signal is converted into a DC voltage by the rectifier circuit 202. The converted DC voltage is input to the power management unit 203. The power management unit 203 uses the input power to charge the energy storage unit 204 and also supplies the necessary operating power to each part of the receiver 200, such as the microcontroller 205 or the sensor 208. During charging, the microcontroller 205 monitors the voltage and current of the energy storage unit 204 to understand the charging status.

[0096] When the microcontroller 205 detects, based on information from the power management unit 203, that a predetermined charging time has elapsed or that the power storage unit 204 has reached a fully charged state, the power receiver 200, for example, sends a charging completion notification to the base station 2. Upon receiving this notification, the base station 2 stops the power transmission operation (step S211). The base station 2 may also operate autonomously to stop power transmission after transmitting power for a predetermined time, even without notification from the power receiver 200. Alternatively, the base station 2 may operate to stop power transmission in response to a notification from another predetermined power receiver 200, for example. Thereafter, when the predetermined timing arrives again, the charging sequence from step S21 is repeated.

[0097] In this way, the receiver 200 can efficiently perform both power supply via a power supply signal from the transmitter 100 and power supply via a wireless signal from the base station 2 by switching the load impedance, using a single receiving antenna 201. Furthermore, since the start of power transmission can be determined according to the needs of the power transmission side, optimization can be performed according to the status of resource blocks, etc.

[0098] (Third example of operation) Next, a third example of operation in the WPT system 1 according to this embodiment will be described. This example of operation shows a sequence in which the transmitter 100, the receiver 200, and the base station 2 actively switch the receiving mode based on an autonomous schedule without waiting for an external signal.

[0099] Figure 8 is a diagram illustrating another example of the operation of the WPT system 1 according to this embodiment. The microcontroller 103 of the power transmitter 100 operates according to an internally set operating schedule. For example, the schedule is defined as "repeat transmission of power supply signals every X minutes." The microcontroller 103 may also be defined to stop transmitting power supply signals a minutes after the initial transmission.

[0100] The microcontroller 205 of the power receiver 200 operates according to an internally set operating schedule. For example, the schedule is defined as "after N minutes of WPT power receiving mode, transition to M minutes of Mobile power receiving mode, and repeat this cycle."

[0101] Base station 2 operates according to an internally configured operating schedule. For example, the schedule is defined as "repeat transmission of a communication signal every Y minutes." Base station 2 may also be defined to stop transmitting a communication signal b minutes after the initial transmission.

[0102] The operating schedules of the transmitter 100, the receiver 200, and the base station 2 are set in conjunction with each other to ensure efficient operation of the entire system. For example, the schedules are set so that the period during which the transmitter 100 transmits a power supply signal (a minutes) and the period during which the base station 2 transmits a communication signal (b minutes) do not overlap. The mode switching schedule of the receiver 200 is set so that the WPT receiving mode period (N minutes) overlaps with the transmission period (a minutes) of the transmitter 100, and the Mobile receiving mode period (M minutes) overlaps with the transmission period (b minutes) of the base station 2. By synchronizing the schedules of each device in advance in this way, the receiver 200 can switch receiving modes at the optimal timing and efficiently receive power from both sources without the need for direct communication between the devices.

[0103] At the start of operation, the microcontroller 205 first determines that it will enter WPT power reception mode. The microcontroller 205 adjusts the load impedance to optimize the receiving frequency characteristics for the first frequency band (switching operation, step S31).

[0104] The microcontroller 103 starts WPT power transmission using a power supply signal in the first frequency band based on an internally set operating schedule (step S32). The power receiver 200 receives the power supply signal from the power transmitter 100 using a receiving means optimized for the first frequency band (step S33).

[0105] The microcontroller 103 terminates WPT power transmission when a predetermined time has elapsed or a predetermined condition has been met, based on an internally set operating schedule (step S34).

[0106] After a predetermined interval, for example N minutes, has elapsed since switching to WPT power reception mode, the microcontroller 205 starts the process of switching to Mobile power reception mode according to its internal schedule. The microcontroller 205 readjusts the load impedance and optimizes the receiving frequency characteristics for the second frequency band (switching operation, step S35).

[0107] Base station 2 starts transmitting a radio signal in the second frequency band (Mobile power transmission) based on an internally set operating schedule (step S36). Receiver 200 receives the radio signal from base station 2 using a receiving means optimized for the second frequency band (step S37).

[0108] Based on an internally configured operating schedule, base station 2 terminates the transmission of radio signals when a predetermined time has elapsed or when predetermined conditions are met (step S38).

[0109] After transitioning to Mobile Power Reception Mode, if a predetermined interval, for example M minutes, has elapsed, the microcontroller 205 optimizes the load impedance to the first frequency band in order to transition back to WPT Power Reception Mode according to its internal schedule (switching operation, step S39).

[0110] Based on the internally set operating schedule, the microcontroller 103 starts transmitting the power supply signal (step S32), and after X minutes have elapsed, it starts WPT power transmission using the power supply signal (step S310). The microcontroller 103 repeats the process of starting to transmit the power supply signal at X-minute intervals.

[0111] Based on the internally configured operating schedule, base station 2 starts transmitting a radio signal (step S36), and after Y minutes have elapsed, it starts transmitting a radio signal (mobile power transmission) (step S311). Base station 2 repeats the process of starting to transmit a radio signal every Y minutes.

[0112] In this example, the transmitter 100, receiver 200, and base station 2 operate autonomously based on a pre-set schedule (preset), without necessarily communicating with each other. This allows the receiver 200 to periodically switch between WPT power reception mode and Mobile power reception mode at regular intervals, enabling efficient power acquisition from both sources. Furthermore, pre-determining the intervals makes the system easier to implement. Additionally, since communication between each device is unnecessary, the system is easy to implement.

[0113] (Fourth example of operation) Next, a fourth example of operation in the WPT system 1 according to this embodiment will be described. This example of operation is a sequence in which the power receiver 200 switches between WPT power reception mode and Mobile power reception mode at random timings.

[0114] The microcontroller 205 randomly determines, for example, the duration of the WPT power reception mode, the duration of the Mobile power reception mode, or both, using a random number generator. Based on the determined random time, the microcontroller 205 performs load impedance switching control (steps S31, S35, etc.).

[0115] Specifically, the microcontroller 205 varies the duration of each operation, for example, performing WPT power reception for N1 minutes in one cycle and N2 minutes (N1 ≠ N2) in the next. This prevents the "worst-case scenario" where the power reception timing of the power receiver 200 becomes perfectly synchronized with the periodic noise or interference in the surrounding environment. As a result, it prevents a situation where power reception efficiency continues to drop significantly under specific conditions and ensures average power reception performance.

[0116] As described above, in the above embodiment, the power receiver 200 has a receiving means, and the receiving means can change the frequency band in which the frequency characteristics are approximately at their maximum value between the first frequency band and the second frequency band. This makes it possible to efficiently receive radio waves of different frequency bands, such as power supply signals for wireless power transmission (WPT) and wireless signals for mobile phone communication, with a single receiving means. Furthermore, it is possible to reduce the number of power transmitters 100 installed, thereby reducing the cost of introducing the WPT system 1.

[0117] Therefore, according to this embodiment, the power supply efficiency in a spatial transmission type wireless power supply system can be improved.

[0118] Furthermore, in the above embodiment, the power receiver 200 is used in a spatial transmission type wireless power supply system. This enables efficient power reception as part of a spatial transmission type wireless power supply system, for example, in buildings or factories.

[0119] Furthermore, in the above embodiment, the receiving means includes a rectenna. The receiving means includes a load whose impedance is adjusted so that the approximate maximum value of the rectenna's frequency characteristics approximately matches the first frequency band or the second frequency band, and whose impedance is switchable. This makes it possible to shift the frequency characteristics of the rectenna to the intended frequency band (first frequency band or second frequency band) by electrical control of switching the impedance of the load.

[0120] Furthermore, in the above embodiment, the load includes an SoC (microcontroller 205) and at least one sensor 208. This makes it possible to actively control the impedance of the entire load by changing the power consumption of components that the power receiver originally possesses, such as the SoC and sensors.

[0121] Furthermore, in the above embodiment, the impedance of the SoC is adjusted so that the approximate maximum value of the rectenna's frequency characteristics approximately matches the first frequency band or the second frequency band, depending on the SoC's operating mode, and the impedance is switched by switching the operating mode at a predetermined timing. As a result, by switching the SoC to deep sleep mode, sleep mode, normal mode, etc., the load impedance can be specifically changed, and a shift in the frequency characteristics can be achieved.

[0122] Furthermore, in the above embodiment, the SoC switches the impedance by switching the operation or deactivation of at least one sensor at predetermined timings. By combining this with switching the operating mode of the SoC, the number of control patterns for the load impedance can be increased, enabling optimization for a wider variety of frequency characteristics.

[0123] Furthermore, in the above embodiment, the first frequency band is the frequency band for the power supply signal of the wireless power transmission system, and the second frequency band is the frequency band for the communication signal of the communication system. This makes it possible to efficiently receive power (energy harvesting) by switching between dedicated wireless power transmission (WPT) radio waves and radio waves for communication signals from widely available mobile phone base stations, etc., depending on the situation.

[0124] <Variation> In the above embodiment, the load impedance was controlled by a combination of the operating modes of the microcontroller 205 and the sensor 208, but the present invention is not limited thereto.

[0125] (Impedance control using resistance) In addition to varying the load by switching the modes of operating components such as the microcontroller 205 and the sensor 208, the load also has resistance, and the microcontroller 205 may switch the impedance by switching the state of this resistance (resistance value or connection state) at predetermined timings.

[0126] Specifically, the microcontroller 205 switches (changes) the resistance value of a resistor included in the load at a predetermined timing. In this case, the load has a variable resistance value of a predetermined element, such as a sensor. As a specific method for changing the resistance value, for example, a technique in which the resistance value changes due to the applied magnetic force (magnetic field) may be used. In this configuration, the predetermined element in the load includes a magnetoresistive element (MR element, GMR element, etc.) and a magnetic field generating unit (coil, etc.) capable of applying magnetic force to the element. The microcontroller 205 changes the resistance value of the magnetoresistive element to a desired value by controlling the magnetic field generating unit and changing the magnetic force applied to the element. This makes it possible to adjust the impedance of the entire load in steps or continuously.

[0127] Specifically, the microcontroller 205 may switch the impedance by, for example, switching the connection or disconnection of a resistor at predetermined timings. For example, one or more resistors and a switch circuit such as a MOSFET can be provided after the rectifier circuit 202. The microcontroller 205 connects or disconnects the resistor as a load by controlling the on / off state of this switch circuit. This makes it possible to intentionally change the impedance of the entire load. By providing multiple resistors and switches, it is possible to realize a wider range of impedance values ​​and to finely respond to three or more different frequency bands. This configuration has the advantage of being able to control the impedance independently, without depending on the operating state of the microcontroller or sensor.

[0128] (Multiband antenna) In another embodiment, the receiving means may be an antenna designed so that its frequency characteristics are approximately at their maximum in the first frequency band and the second frequency band. In this case, the receiving antenna 201 itself is configured as a multiband antenna having good receiving characteristics in multiple frequency bands. For example, a dipole antenna that combines multiple antenna elements of different lengths, or a fractal antenna that achieves broadband and multi-frequency characteristics by utilizing a self-similar shape, can be considered. In this configuration, since the antenna itself corresponds to multiple frequency bands, the adjustment range for the load impedance can be more lenient, or may not be necessary at all. However, matching the load impedance for each frequency band is still effective in obtaining optimal power reception efficiency, and by combining this with the impedance control technology described above, an even higher-performance power receiver can be realized.

[0129] (Receiving uplink signals) In the above embodiment, a base station 2 was used as an example of a second transmitting device, and the case in which the receiver 200 receives a radio signal (downlink signal) transmitted from the base station 2 was described. However, the present invention is not limited to this. The second transmitting device may be a terminal device other than the base station 2 that is capable of wireless communication (for example, a mobile phone terminal or other communication device). In this case, the receiver 200 receives a radio signal (i.e., an uplink signal) transmitted from the terminal device and converts it into power. The frequency band of this uplink signal (for example, the uplink frequency band in 3GPP band 8: 880MHz to 915MHz) corresponds to the second frequency band, and the receiver 200 switches the impedance of the load so that the power receiving performance is approximately maximum in this frequency band.

[0130] (Support for multiple frequency bands) The power receiver 200 may operate to support not only the two frequency bands of WPT and Mobile, but also third and fourth frequency bands. In that case, the microcontroller 205 performs control to switch the load impedance in three or more stages. This can be achieved by setting the operating mode of the microcontroller 205 in multiple stages, operating it in combination with multiple sensors 208, or by digitally combining and connecting multiple resistive elements.

[0131] (Switching timing) The timing for switching impedances can be determined autonomously by the receiver 200, or it can be executed after receiving a control command from the transmitter 100 or base station 2. For example, the microcontroller 205 may receive an emergency command from base station 2 and interrupt the WPT power reception mode to forcibly switch to Mobile power reception mode (impedance switching).

[0132] (Dynamic feedback control) The power receiver 200 may monitor the received strength of the power supply signal from the power transmitter 100 or the received strength of the radio signal from the base station 2 and perform feedback control to dynamically fine-tune the impedance. For example, during WPT power reception and mobile power reception, the microcontroller 205 adjusts its own clock frequency or the value of the variable resistor to search for the optimal impedance value so that the received power is maximized. This can increase robustness against environmental changes and aging.

[0133] (Implementation as a program or method) The frequency characteristic switching control in the power receiver 200 described in this embodiment is realized by a program executed on the microcontroller 205. This program causes the power receiver 200 to "detect a predetermined trigger (internal timer, external command, voltage drop, etc.), determine a target operating mode, and switch the microcontroller's own mode, the sensor state, or the connection state of a dedicated resistor to achieve the load impedance corresponding to that mode." This series of processes can also be considered as a "method" implemented by a power receiver equipped with a receiving means that can switch the approximate maximum value of the frequency characteristic between a first frequency band and a second frequency band (or higher).

[0134] (Ambient IoT mode) The power receiver 200 may receive power by receiving ambient radio waves (e.g., mobile communication waves, Wi-Fi, short-range radio, broadcast waves, etc.) present in the space, without making a power transmission request to the power transmitter 100 or base station 2. In this case, the microcontroller 205 may search for a state in which the DC output voltage, DC output power, or received power is high by switching the load impedance in multiple stages or continuously fine-tuning it, and perform control to maintain the searched state (e.g., maximum power point tracking control).

[0135] Furthermore, the power receiver 200 may perform duty cycle control, which involves measuring with the sensor 208 or transmitting data when the voltage of the energy storage unit 204 exceeds a predetermined threshold, and maintaining a sleep state when it falls below the threshold.

[0136] (Other variations) In the above embodiment, a configuration in which the power receiver switches frequency characteristics at a predetermined timing was described as an example, but the trigger for switching is not limited to this. For example, the power receiver may be configured to dynamically switch from WPT power reception mode (optimized for the first frequency band) to Mobile power reception mode (optimized for the second frequency band) when it receives a specific wake-up signal or command transmitted from the second transmitter (base station 2) as a trigger.

[0137] Furthermore, the timing of the switch may be determined autonomously based on the internal state of the power receiver itself. For example, the SoC mounted on the power receiver monitors the voltage of the built-in secondary battery or capacitor. Depending on this voltage value, the SoC may switch the load impedance to a state that maximizes power reception efficiency in the first frequency band and transition to WPT power reception mode, or switch the load impedance to a state that maximizes power reception efficiency in the second frequency band and transition to Mobile power reception mode. In addition, the timing of the switch may be based on the detection results of sensors mounted on the power receiver. For example, if the power receiver is equipped with a motion sensor, it may be configured to switch to Mobile power reception mode when it detects the approach of a person.

[0138] In the above embodiment, an example was described in which the load impedance is switched by switching the operating mode of the SoC or by starting and stopping the sensor, but the method of switching the impedance is not limited to these. For example, if the power receiver 200 is equipped with a display device such as an LED, the SoC may actively change the load impedance by changing the brightness or by controlling the power on / off of the display device itself.

[0139] The above embodiment describes a WPT system in which a power supply signal is transmitted by radio waves from a power transmitter 100, a power receiver 200 receives the power supply signal, and power is generated based on the received power supply signal. However, the power receiver according to this embodiment is not limited to use in a WPT system. The power receiver according to this embodiment may be a device related to an RFID tag. That is, for example, the frequency characteristic switching function of the present invention can be used to receive a carrier wave (corresponding to a power supply signal) and a command signal (corresponding to a communication signal) transmitted from an RFID reader / writer. This is particularly effective in systems where the power supply frequency and the communication frequency are different.

[0140] The system according to the above embodiment is compliant with 3GPP (3rd generation partnership project) (registered trademark), IEEE, WPT Alliance, AirPlug (registered trademark) Alliance, Airfuel Alliance, WPC (Wireless Power Consortium), A4WP (Alliance for Wireless Power), PMA (Power Matters Alliance), ARIB (Association of Radio Industries and Businesses), ETSI (European Telecommunications Standards Institute), CISPR (International Special Committee on Radio Interference), ANSI (American National Standards Institute), ISO (International Organization for Standardization), IEC (International Electrotechnical Commission), etc. Within 3GPP, it is compliant with RAN (Radio Area Network) 1, RAN2, RAN3, RAN4, and RAN5, and within IEEE, it is compliant with the 802.11 series of standards (e.g., 802.11ax) and the 802.15 series of standards (e.g., 802.15.4), but is not limited to these.

[0141] In the above embodiment, the power receiver 200 may have an interface accessible to the user. The user accesses the power receiver via the interface. The interface includes, for example, buttons, switches, LEDs, a small display, or a combination thereof, connected to an SoC or microcontroller mounted on the power receiver. The user can, for example, forcibly switch the operating mode of the power receiver to WPT power mode or Mobile power mode by operating a button. The power receiver 200 may also notify the user of the current operating mode, the strength of the received radio waves, or the battery level by the color or flashing pattern of the LEDs, or by a display on a small display.

[0142] Furthermore, while the embodiments described above described a configuration in which a receiver receives a wireless signal consisting of an AC signal, it is naturally possible to apply this to systems that receive energy by other methods. Since such systems are already known, a detailed explanation will be omitted, but as an example, the functions described in this embodiment may be used in a system that utilizes electricity generated by solar power generation. In this case, for example, a hybrid energy utilization is possible, such as actively adopting the Mobile power receiving mode during the daytime when the amount of power generated from the solar cells is sufficient, and adopting the WPT power receiving mode at night or in environments with low illumination. In addition, the functions described in this embodiment may also be used in energy harvesters that convert vibration or acoustic energy into electricity.

[0143] In this disclosure, the term "frequency band" can be interpreted as "wavelength band" when the energy transmission medium is light or heat.

[0144] Furthermore, the power receiver 200 relating to this disclosure may not only convert and utilize a radio signal in the second frequency band into power, but may also acquire information contained in the radio signal (so-called simultaneous information-power transmission).

[0145] Specifically, the power receiver 200 may split the radio signal received by the receiving antenna 201 into a path for power conversion and a path for information acquisition. For example, the power receiver 200 may split the received signal using a directional coupler, power divider, or switch circuit, inputting one side to the rectifier circuit 202 and the other side to a detection circuit or demodulation circuit (e.g., a data transceiver 206, or a separate receiving circuit). This makes it possible to acquire DC power and information in parallel from the same radio signal. The splitting method may be a power split method in which a portion of the power of the received signal is always allocated to information acquisition, or a time switch method in which a predetermined period is allocated to information acquisition and other periods are allocated to power reception.

[0146] In this embodiment, "connection" refers to a relationship in which information, power, signals, or electric / magnetic fields influence each other, regardless of whether there is physical contact, and includes not only direct connections but also indirect connections through other elements or materials.

[0147] For example, if circuit element A and circuit element C are connected, and circuit element B is inserted between them, then A and C are considered connected if electrical signal transmission, current flow, or influence via electric and magnetic fields is maintained between A and C. In this embodiment, "connection" includes the following forms: (1) Communicable Connection A connection is considered to exist if the output terminal of a rectenna and the load (e.g., the power input terminal of an SoC) are electrically connected, and even if a filter capacitor, inductor, protective diode, or impedance switching element is inserted between them, the relationship in which DC power is supplied is maintained. (2) Network Connection Even if the rectifier circuits of the antenna and the rectenna belong to the same network and an impedance matching circuit is inserted between them, if they have an electrical influence on each other, this is considered a connection. For example, a relationship in which the impedance of the antenna and the input impedance of the rectenna side, including the matching circuit, are designed to be conjugate matched is one form of connection. (3) Connection as an electrical path ("Electrical Pathway") A connection is made when the control port of the SoC and the gate terminal of the impedance switching element form an electrical path, regardless of whether a level shifter or buffer is interposed between them.

[0148] Furthermore, the definition of a connection may differ depending on the type of semiconductor circuit and its operating principle. For example, the concept of connection is applied as follows in bulk CMOS, SOI CMOS, compound semiconductor circuits, and wide-bandgap semiconductor circuits. (1) Connections in CMOS circuits In an SoC composed of bulk CMOS, the internal CPU core and various peripherals (sensor interfaces, communication blocks, etc.) are electrically connected by metal or polysilicon wiring formed on the silicon substrate. Switching the operating modes of these peripherals changes the load impedance of the entire SoC, indirectly affecting the connection state with the rectenna. (2) Connections in wide-bandgap semiconductor circuits When using wide-bandgap semiconductor diodes such as SiC or GaN in the rectifier circuit of a rectenna, it is necessary to consider connections via vertical current paths and electron transfer through barrier layers in order to adapt to high-frequency and high-power operation. (3) Connections in high-frequency circuits In high-frequency circuits to which the present invention applies, the influence may include not only physical wire connections but also coupling via parasitic inductance and capacitance, signal transmission by electromagnetic induction, and the effects of resonant circuits. In particular, the connection between the antenna and the rectenna consists of a microstrip line or coplanar line, and its characteristic impedance is a crucial factor in determining the overall performance.

[0149] In this embodiment, the definition of "connection" is applied according to the circuit configuration and operating conditions, and is not limited to mere physical conductivity. In a broad sense, coupling via electric and magnetic fields, optical coupling, and electromagnetic coupling can also be included as connections. On the other hand, when defined as a connection in a narrow sense, it can refer only to direct conductivity or specific physical contact. This should be interpreted appropriately according to the embodiment of the present invention.

[0150] Although several embodiments of this disclosure have been described above, these embodiments can be implemented in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. For example, configurations and processes in one embodiment may be combined with configurations and processes in another embodiment, or a modification of one embodiment may be applied to another embodiment. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents.

[0151] (Note) The details described in each of the above embodiments are noted below.

[0152] (Note 1) A power receiver equipped with a receiving means that allows the frequency band in which the frequency characteristics are approximately at their maximum value to be changed between the first frequency band and the second frequency band. (Note 2) A power receiver as described in (Appendix 1) used in a spatial transmission type wireless power supply system. (Note 3) The receiving means comprises a rectenna and a load whose impedance is adjusted so that the approximate maximum value of the frequency characteristics of the rectenna approximately matches that of the first frequency band or the second frequency band, and whose impedance is switchable. (Appendix 1) or (Appendix 2) (Note 4) The load is a power receiver, including an SoC (System on Chip), as described in Appendix 3. (Note 5) The SoC has an impedance adjusted so that the approximate maximum value of the rectenna's frequency characteristics approximately matches the first or second frequency band, depending on the SoC's operating mode, and the impedance is switched by switching the operating mode at a predetermined timing (as described in Appendix 4). (Note 6) The load includes at least one sensor, and the SoC switches the impedance by switching the operation or deactivation of at least one sensor at predetermined timings, as described in (Appendix 4). (Note 7) The load has a switchable resistance value, and the SoC switches the impedance by switching the resistance value at predetermined timings (as described in Appendix 4). (Note 8) The receiving means is an antenna designed to achieve approximately maximum frequency characteristics in the first frequency band and the second frequency band, as described in (Appendix 1). (Note 9) The first frequency band is the frequency band for the power supply signals of a wireless power transmission system, and the second frequency band is the frequency band for the communication signals of a communication system. A power receiver as described in any of (Appendix 1) to (Appendix 8). (Note 10) A system comprising a receiver equipped with a receiving means capable of switching between a first frequency band and a second frequency band, wherein the frequency band in which the frequency characteristics are approximately at their maximum value is the first frequency band; a first transmitting device that transmits a radio signal in the first frequency band; and a second transmitting device that transmits a radio signal in the second frequency band. (Note 11) A program executed on a power receiver equipped with a receiving means capable of changing the frequency band in which the frequency characteristics are approximately at their maximum value between a first frequency band and a second frequency band, wherein the program causes the power receiver to execute a step of switching the approximately maximum value of the frequency characteristics of the receiving means from the first frequency band to the second frequency band at a predetermined timing. (Note 12) A method implemented by a power receiver equipped with a receiving means capable of changing the frequency at which the frequency characteristics are approximately maximum in either a first frequency band or a second frequency band, wherein the approximately maximum frequency of the frequency characteristics of the receiving means is switched from the first frequency band to the second frequency band at a predetermined timing. [Explanation of symbols]

[0153] 1…WPT System 100... Power transmission 101...Oscillator 102... Transmitting antenna 103... Microcontroller 104...Data Transmitter / Receiver 105...Data transmission antenna 200…Power receiver 201... Receiving antenna 202... Rectifier circuit 203…Power management department 204... Energy storage unit 205... Microcontroller 206...Data Transmitter / Receiver 207...Data transmission antenna 300...First Information Processing Device 400...Second Information Processing Device

Claims

1. The system includes a receiving means that can change the frequency band in which the frequency characteristics are approximately at their maximum value, between a first frequency band, which is the frequency band of the power supply signal of the wireless power transmission system, and a second frequency band, which is the frequency band of the communication signal of the communication system. The receiving means is A rectenna including a rectifier circuit, A load provided downstream of the rectifier circuit and Equipped with, The load is a power receiver whose impedance is adjusted such that the approximate maximum value of the frequency characteristics of the rectenna falls within the first frequency band or the second frequency band, and whose impedance is adjustable.

2. A power receiver according to claim 1, used in a spatial transmission type wireless power supply system.

3. The load is a power receiver according to claim 1, which includes a System on Chip (SoC).

4. The SoC has an impedance adjusted such that the approximate maximum value of the frequency characteristics of the rectenna falls within a first frequency band or a second frequency band, depending on the operating mode of the SoC, and the impedance is changed by switching the operating mode at a predetermined timing, as described in claim 3.

5. The load includes at least one sensor, The power receiver according to claim 3, wherein the SoC changes the impedance by switching the operation or shutdown of at least one sensor at a predetermined timing.

6. The aforementioned load has a switchable resistance value. The power receiver according to claim 3, wherein the SoC changes the impedance by switching the resistance value at a predetermined timing.

7. A power receiver equipped with a receiving means that can change the frequency band in which the frequency characteristics are approximately at their maximum value between a first frequency band, which is the frequency band of the power supply signal of a wireless power transmission system, and a second frequency band, which is the frequency band of the communication signal of a communication system. A first transmitting device that transmits a radio signal in the first frequency band, A second transmitting device that transmits the wireless signal in the second frequency band and Equipped with, The receiving means is A rectenna including a rectifier circuit, A load provided downstream of the rectifier circuit and Equipped with, The load is a system in which the impedance is adjusted so that the approximate maximum value of the frequency characteristics of the rectenna falls within the first frequency band or the second frequency band, and the impedance is changeable.

8. A program executed on a power receiver equipped with a receiving means that can change the frequency band in which the frequency characteristics are approximately at their maximum value between a first frequency band, which is the frequency band of the power supply signal of a wireless power transmission system, and a second frequency band, which is the frequency band of the communication signal of a communication system, The receiving means is A rectenna including a rectifier circuit, A load provided downstream of the rectifier circuit and Equipped with, The load includes a processor, and its impedance is adjusted so that the approximate maximum value of the frequency characteristics of the rectenna falls within the first frequency band or the second frequency band. The program is provided to the processor: A program that causes a program to execute a step of changing the impedance at a predetermined timing so as to change the approximate maximum value of the frequency characteristics of the rectenna from the first frequency band to the second frequency band.

9. A method implemented by a power receiver equipped with a receiving means that can change the frequency band in which the frequency characteristics are approximately at their maximum value between a first frequency band, which is the frequency band of the power supply signal of a wireless power transmission system, and a second frequency band, which is the frequency band of the communication signal of a communication system, The receiving means is A rectenna including a rectifier circuit, A load provided downstream of the rectifier circuit and Equipped with, The load includes a processor, and its impedance is adjusted so that the approximate maximum value of the frequency characteristics of the rectenna falls within the first frequency band or the second frequency band. A method for changing the impedance at a predetermined timing such that the processor changes the substantially maximum value of the frequency characteristics of the rectenna from the first frequency band to the second frequency band.

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