Patent Description:
Wireless power may refer to energy transmitted from a wireless power transmitter to a wireless power receiver via magnetic coupling. A wireless power charging system may include a wireless power transmitter configured to wirelessly transmit power, and a wireless power receiver configured to wirelessly receive power. The wireless power transmitter may include a source resonator, and the wireless power receiver may include a target resonator. Magnetic coupling or resonance coupling may occur between the source resonator and the target resonator, and power may be wirelessly transmitted from the wireless power transmitter to the wireless power receiver via the magnetic coupling or the resonance coupling.

<CIT> discloses that a first alternating current is generated in a resonant receiving coil at a resonant frequency in a self-resonant circuit tuned to resonate at substantially the same resonant frequency as a resonant transmitting coil in a self-resonant circuit of a wireless charger, the resonant receiving coil operating as a magnetically coupled resonator with the resonant transmitting coil. The separation distance between the two coils may be several times larger than geometric sizes of the coils. The embodiments convert the first alternating current in a power control circuit to a second alternating current at a different frequency than the resonant frequency. The embodiments drive a the power transmitting coil using the second alternating current to inductively couple with a proximately located power receiving coil in a user's device, to provide power to the power receiving coil in the user's device by contact-less electromagnetic induction.

<CIT> discloses that a power control apparatus includes a calculating unit that calculates contactless transmission efficiency of power from each of a plurality of devices when the power is received from one device of the plurality of devices and a control unit that controls contactless power transmission from a device in which the transmission efficiency is high.

<CIT> discloses a non-contact power supply system and control method for non-contact power supply system.

It is therefore the object of the present invention to provide an improved power relay apparatus for transmitting an AC power signal, a corresponding wireless power transmission system, and a corresponding wireless power relay method.

In one general aspect, a wireless power relay apparatus includes: a first antenna configured to wirelessly receive an alternating current (AC) power signal of a first frequency from a wireless power transmission apparatus; a rectifier configured to convert the received AC power signal into a direct current (DC) power; a storage device configured to store electric energy of the DC power output from the rectifier; a power oscillator configured to generate an AC power signal of a second frequency based on an output current of the rectifier and electric energy of a DC voltage stored in the storage device; and a second antenna configured to transmit the AC power signal of the second frequency to a wireless power reception apparatus.

The power oscillator may be configured to start to oscillate, in response to a reception of the AC power signal of the first frequency and the DC voltage stored in the storage device reaching a reference value.

The power oscillator may be configured to remain in an off state until the DC voltage reaches the reference value, start to oscillate at a point in time at which the DC voltage reaches the reference value, and generate the AC power signal of the second frequency, without being controlled by a control signal.

The power oscillator may be configured to oscillate at the second frequency based on the DC voltage supplied from the storage device and the current supplied from the rectifier.

The rectifier, the storage device, and the second antenna may be connected to a common node.

The storage device may be a capacitor, and an end of the capacitor may be connected to a ground terminal, and another end of the capacitor may be connected to the rectifier and the second antenna.

The wireless power relay apparatus may be configured to be detachably mounted on a surface of the wireless power transmission apparatus.

The first antenna may be configured to wirelessly receive the AC power signal of the first frequency from the wireless power transmission apparatus when the wireless power relay apparatus is detachably mounted on the surface of the wireless power transmission apparatus.

The wireless power transmission apparatus may be a mobile electronic device, and the AC power signal of the first frequency may be generated from electric energy stored in a battery of the mobile electronic device.

The wireless power reception apparatus may be an implantable apparatus or a body attachment apparatus.

The second frequency may be different from the first frequency, and the second frequency may be equal to an operating frequency for a wireless power reception of the wireless power reception apparatus.

The rectifier may include a plurality of diodes, and the power oscillator may include two transistors and a capacitor connected to an end of each of the two transistors.

The apparatus may include: a circuit board in which the rectifier and the power oscillator are disposed; a first insulating layer disposed between the first antenna and the circuit board; and a second insulating layer disposed between the circuit board and the second antenna.

A wireless power transmission system may include: the wireless power relay apparatus; and the wireless power transmission apparatus.

In another general aspect, a wireless power transmission system includes: a wireless power transmission apparatus configured to wirelessly transmit an alternating current (AC) power signal of a first frequency; and a wireless power relay apparatus configured to receive the AC power signal of the first frequency, convert the received AC power signal into a direct current (DC) power, generate an AC power signal of a second frequency based on the DC power, and transmit the generated AC power signal of the second frequency to a wireless power reception apparatus.

The wireless power relay apparatus may include: a rectifier configured to convert the received AC power signal into the DC power; a storage device configured to store electric energy of the DC power output from the rectifier; and a power oscillator configured to generate the AC power signal of the second frequency based on an output current of the rectifier and electric energy of a DC voltage stored in the storage device.

The wireless power transmission apparatus may be a mobile electronic device, and the wireless power reception apparatus may be an implantable apparatus or a body attachment apparatus.

In another general aspect, a wireless power relay method includes: wirelessly receiving, using a first antenna, an alternating current (AC) power signal of a first frequency from a wireless power transmission apparatus; converting, using a rectifier, the received AC power signal into a direct current (DC) power; storing, in a storage device, electric energy of the DC power output from the rectifier; generating, using a power oscillator, an AC power signal of a second frequency based on an output current of the rectifier and electric energy of a DC voltage stored in the storage device; and transmitting, using a second antenna, the AC power signal of the second frequency to a wireless power reception apparatus.

The generating of the AC power signal of the second frequency may include the power oscillator starting to oscillate, in response to a reception of the AC power signal of the first frequency and the DC voltage reaching a reference value.

The wireless power transmission apparatus may be a mobile electronic device, the AC power signal of the first frequency may be generated from electric energy stored in a battery of the mobile electronic device, and the wireless power reception apparatus may be an implantable apparatus or a body attachment apparatus.

The second frequency may be different from the first frequency and may be identical to an operating frequency for a wireless power reception of the wireless power reception apparatus.

Also, descriptions of features that are known in the art, after an understanding of the disclosure of this application, may be omitted for increased clarity and conciseness.

The following structural or functional descriptions of examples disclosed in the present disclosure are merely intended for the purpose of describing the examples and the examples may be implemented in various forms. The examples are not meant to be limited, but it is intended that various modifications, equivalents, and alternatives are also covered within the scope of the claims.

Although terms of "first" or "second" are used to explain various members, components, regions, layers, or sections, the members, components, regions, layers, or sections are not limited to the terms. These terms should be used only to distinguish one member, component region, layer, or section from another member, component region, layer, or section. Thus, a first member, component, region, layer, orsection referred to in examples described herein may also be referred to as a second member, component, region, layer, orsection without departing from the teachings of the examples.

Likewise, expressions, for example, "between" and "immediately between" and "adjacent to" and "immediately adjacent to" may also be construed as described in the foregoing.

The terminology used herein is for the purpose of describing particular examples only and is not to be limiting of the present disclosure. As used herein, the terms "include," "comprise," and "have" specify the presence of stated features, integers, steps, operations, elements, components, numbers, and/or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, numbers, and/or combinations thereof. The use of the term "may" herein with respect to an example or embodiment (for example, as to what an example or embodiment may include or implement) means that at least one example or embodiment exists where such a feature is included or implemented, while all examples are not limited thereto.

Unless otherwise defined herein, all terms used herein including technical or scientific terms have the same meanings as those generally understood. Terms defined in dictionaries generally used should be construed to have meanings matching with contextual meanings in the related art and the present disclosure, and are not to be construed as an ideal or excessively formal meaning unless otherwise defined herein.

<FIG> illustrates an example of a wireless power transmission system (for example, a wireless power transmission system <NUM>).

Referring to <FIG>, the wireless power transmission system <NUM> may be a system configured to wirelessly transmit power of a wireless power transmission apparatus <NUM> to a wireless power reception apparatus <NUM>. The wireless power transmission system <NUM> may include a wireless power relay apparatus <NUM> configured to relay power between the wireless power transmission apparatus <NUM> and the wireless power reception apparatus <NUM>, in addition to the wireless power transmission apparatus <NUM> and the wireless power reception apparatus <NUM>. In an example, the wireless power transmission system <NUM> may be a system in which the wireless power transmission apparatus <NUM> located outside a body wirelessly transmits power to the wireless power reception apparatus <NUM> that is located in the body or attached to the body, through the wireless power relay apparatus <NUM>.

The wireless power transmission apparatus <NUM> may be an apparatus configured to wirelessly transmit power. The wireless power transmission apparatus <NUM> may be or include, for example, a smartphone, a tablet, a mobile phone, a netbook, an electronic notebook, a wearable device, and/or a wireless power charger. In an example, the wireless power transmission apparatus <NUM> may wirelessly transmit an alternating current (AC) power signal of a first frequency using a near field communication (NFC).

The wireless power relay apparatus <NUM> may be an apparatus configured to relay power received from the wireless power transmission apparatus <NUM> to the wireless power reception apparatus <NUM>. In an example, the wireless power relay apparatus <NUM> may receive an AC power signal of a first frequency from the wireless power transmission apparatus <NUM>, and may convert the received AC power signal into a direct current (DC) power. The wireless power relay apparatus <NUM> may generate an AC power signal of a second frequency based on the DC power, and may transmit the generated AC power signal of the second frequency to the wireless power reception apparatus <NUM>. In this example, the second frequency may be different from the first frequency.

The wireless power reception apparatus <NUM> may be an apparatus configured to wirelessly receive power and to perform a predetermined function based on the received power, and may be or include, for example, an implantable apparatus or a body attachment apparatus. For example, the wireless power reception apparatus <NUM> may be a medical device that is inserted into a body or attached to the body and configured to sense biometric information or provide biostimulation for treatment. However, a type of the wireless power reception apparatus <NUM> is not limited to the medical device, and all apparatuses capable of wirelessly receiving power may be used without a limitation. The wireless power reception apparatus <NUM> may be, for example, a sensor, or an internet of Things (IoT) apparatus.

In an example, when the wireless power reception apparatus <NUM> is an implantable apparatus, power may need to be wirelessly transmitted from an external device to a device inserted into a body. In this example, a unique optimized wireless power transmission frequency is often used in consideration of a rate of power transfer to a body and a size of a receiver of the wireless power reception apparatus <NUM>. In general, when a wireless power transmission frequency decreases, the rate of power transfer to the body and the size of the receiver may tend to increase. Also, an optimal wireless power transmission frequency for the implantable apparatus may be set based on power used for charging, an allowable size of the receiver, and/or a depth of insertion of the wireless power reception apparatus <NUM> into the body.

When a wireless power transmission frequency of the wireless power transmission apparatus <NUM> is fixed (as may typically be the case), the wireless power transmission frequency of the wireless power transmission apparatus <NUM> may not match an optimal wireless power transmission frequency for the wireless power reception apparatus <NUM>. In this example, it may be difficult to achieve an optimal efficiency of a wireless power transmission. In this example, the wireless power reception apparatus <NUM> may need to use a dedicated charger for the optimal wireless power transmission frequency, which may lead to a reduction in a user's convenience because the dedicated charger needs to be carried and managed.

In contrast, the wireless power relay apparatus <NUM> of one or more embodiments may convert wireless power of a first frequency received from the wireless power transmission apparatus <NUM> into wireless power of a second frequency, and may transmit the wireless power of the second frequency to the wireless power reception apparatus <NUM>, and thus the wireless power relay apparatus <NUM> of one or more embodiments may prevent a decrease in a power conversion efficiency due to a difference in characteristics of wireless power transmission frequencies between the wireless power transmission apparatus <NUM> and the wireless power reception apparatus <NUM>. Also, the wireless power relay apparatus <NUM> may be implemented in a form of an accessory, and thus may be easily carried and may wireless transmit power even without a dedicated charger for the wireless power reception apparatus <NUM>, thereby enhancing user convenience.

<FIG> and <FIG> illustrate examples of a wireless power relay apparatus (for example, a wireless power relay apparatus <NUM>).

Referring to <FIG> and <FIG>, a wireless power transmission apparatus <NUM> may be a mobile electronic device (for example, a smartphone). A widely used apparatus such as a smartphone may operate as the wireless power transmission apparatus <NUM>, and the wireless power transmission apparatus <NUM> may generate an AC power signal of a first frequency for a wireless power transmission, and may transmit the AC power signal via an antenna of the wireless power transmission apparatus <NUM> to the outside of the wireless power transmission apparatus <NUM>.

In an example, the wireless power relay apparatus <NUM> may be detachably implemented on one surface of the wireless power transmission apparatus <NUM>. For example, in <FIG> and <FIG>, the wireless power relay apparatus <NUM> may be attached to a rear side of the wireless power transmission apparatus <NUM> and may operate. The wireless power relay apparatus <NUM> may be implemented in the form of a portable accessary, for example, a coin, a card, a card holder, and/or a collapsible grip, however, the implementation form is not limited. In order to supply power to a wireless power reception apparatus, a user carrying the wireless power transmission apparatus <NUM> may only need to additionally carry the wireless power relay apparatus <NUM> of one or more embodiments in the form of an accessory for a wireless power relay, and thus portability may be enhanced and user convenience may increase.

<FIG> illustrates an example of an operation of a wireless power relay apparatus (for example, a wireless power relay apparatus <NUM>).

Referring to <FIG>, a wireless power transmission apparatus <NUM> (for example, a smartphone) may generate an AC power signal of a first frequency based on electric energy stored in an internal battery of the wireless power transmission apparatus <NUM> or an external battery, and may output the AC power signal of the first frequency to the outside. In an example, the wireless power relay apparatus <NUM> may receive the AC power signal of the first frequency from the wireless power transmission apparatus <NUM> via mutual coupling between coils (for example, between a coil of the wireless power transmission apparatus <NUM> and a coil of the wireless power relay apparatus <NUM>), may convert the received AC power signal of the first frequency into an AC power signal of a second frequency, and may transmit the AC power signal of the second frequency to a wireless power reception apparatus <NUM>.

In an example, the wireless power reception apparatus <NUM> may be a medical apparatus inserted into a body of a user <NUM>. In this example, the wireless power reception apparatus <NUM> may be, for example, an implantable medical apparatus, such as a deep brain neurostimulator configured to sense a biosignal in a body or output a stimulation signal, a pacemaker, a cochlear implant, an insulin pump, or a gastric stimulator. However, the wireless power reception apparatus <NUM> is not limited to the implantable medical apparatus, and may correspond to various electronic apparatuses capable of wirelessly receiving power.

In a wireless power transmission between the wireless power transmission apparatus <NUM> and the wireless power reception apparatus <NUM>, operating frequencies may be different from each other. The wireless power relay apparatus <NUM> of one or more embodiments may enhance an efficiency of the wireless power transmission by reducing a difference between the operating frequencies through a frequency conversion.

The wireless power relay apparatus <NUM> of one or more embodiments may change a frequency of wireless power so that various types of wireless power transmission apparatuses <NUM> may operate as a charger of the wireless power reception apparatus <NUM> inserted into the body without using a dedicated charger separate from the wireless power transmission apparatus <NUM>, as may be used by a typical wireless power relay apparatus. Since such various types of wireless power transmission apparatuses <NUM> may operate as a charger of the wireless power reception apparatus <NUM> when used with the wireless power relay apparatus <NUM> of one or more embodiments, user convenience may be enhanced. The wireless power relay apparatus <NUM> of one or more embodiments may provide a great advantage to a wireless power charging system that uses an optimal frequency different from a frequency that is widely used for wireless power charging due to constraints such as a size or a location of use and a difficulty in freely relacing a battery in an implantable medical apparatus.

Since the wireless power relay apparatus <NUM> uses the wireless power transmission apparatus <NUM> as a power source, the wireless power relay apparatus <NUM> of one or more embodiments may transmit powerto the wireless power reception apparatus 340without including a processor and a battery that a typical wireless power relay apparatus may use to communicate with a wireless power reception apparatus. Also, the wireless power relay apparatus <NUM> implemented in the form of an accessory may be attached to one surface of the wireless power transmission apparatus <NUM> to be easily used. The wireless power relay apparatus <NUM> of one or more embodiments may output an AC power signal of an optimal operating frequency used by the wireless power reception apparatus <NUM> and may efficiently perform wireless power charging, regardless of a wireless power transmission frequency used by the wireless power transmission apparatus <NUM>.

Also, the wireless power relay apparatus <NUM> of one or more embodiments may reduce a loss caused by penetration of the body of the user <NUM>, through a frequency optimization. Various types of mobile electronic apparatuses may be used as the wireless power transmission apparatus <NUM> without a need for a dedicated charger in addition to the wireless power transmission apparatus <NUM>, and thus the user convenience may be enhanced.

<FIG> illustrates an example of a configuration of a wireless power relay apparatus (for example, a wireless power relay apparatus <NUM>).

Referring to <FIG>, the wireless power relay apparatus <NUM> may include a first antenna <NUM>, a rectifier <NUM>, a storage device <NUM>, a power oscillator <NUM>, and a second antenna <NUM>. In examples described herein, the term "antenna" may be referred to as a "coil".

The first antenna <NUM> may wirelessly receive power from a wireless power transmission apparatus. In a wireless power charging mode, the wireless power transmission apparatus may generate an AC power signal of a first frequency based on electric energy stored in a battery (for example, a battery included in the wireless power transmission apparatus), and may radiate the generated AC power signal of the first frequency to the outside. When the wireless power relay apparatus <NUM> is attached to or located near the wireless power transmission apparatus that is in the wireless power charging mode, the first antenna <NUM> may wirelessly receive the AC power signal of the first frequency from the wireless power transmission apparatus.

The rectifier <NUM> may convert the AC power signal of the first frequency received via the first antenna <NUM> into a DC power. The rectifier <NUM> may generate a DC voltage by rectifying the AC power signal, and may output the DC voltage. The rectifier <NUM> may be, for example, an active rectifier or a passive rectifier, and there is no limitation to a type of the rectifier <NUM>.

The storage device <NUM> may store electric energy of the DC power output from the rectifier <NUM>, and may be, for example, a capacitor. The storage device <NUM> may store the DC voltage output from the rectifier <NUM>.

The power oscillator <NUM> may generate an AC power signal of a second frequency based on an output current of the rectifier <NUM> and electric energy of the DC voltage stored in the storage device <NUM>. The second frequency may be different from the first frequency and may be identical to, or substantially similar to, an optimal operating frequency for a wireless power reception of a wireless power reception apparatus. The power oscillator <NUM> may oscillate at the second frequency based on the DC voltage supplied from the storage device <NUM> and a current supplied from the rectifier <NUM>. The power oscillator <NUM> may have its own reference value for oscillation by a characteristic of a structure of an internal circuit thereof.

In an example, when a reception of the AC power signal of the first frequency occurs and when the DC voltage stored in the storage device <NUM> reaches the reference value, the power oscillator <NUM> may start to oscillate. For example, the power oscillator <NUM> may remain in an off state until the DC voltage reaches the reference value, may start to oscillate at a point in time at which the DC voltage reaches the reference value and may generate the AC power signal of the second frequency, without being controlled by a control signal.

The second antenna <NUM> may transmit the AC power signal of the second frequency generated by the power oscillator <NUM> to the wireless power reception apparatus.

As described above, the wireless power relay apparatus <NUM> may receive a wireless power signal of the first frequency from the wireless power transmission apparatus, may store the received wireless power signal in a form of an AC voltage in the storage device <NUM>, may convert the wireless power signal into a wireless power signal of the second frequency, and may transmit the wireless power signal of the second frequency to the wireless power reception apparatus. The wireless power relay apparatus <NUM> of one or more embodiments may not require a separate battery to relay a wireless power transmission, and accordingly use of the wireless power relay apparatus <NUM> of one or more embodiments may reduce a size and a production cost, and increase a power conversion efficiency by minimizing a process of converting power.

Also, whether the power oscillator <NUM> is activated may be determined based on whether the wireless power relay apparatus <NUM> wirelessly receives power, and accordingly the power oscillator <NUM> may be activated without a separate configuration, for example, a processor, to control the power oscillator <NUM>. In other words, the wireless power relay apparatus <NUM> of one or more embodiments may include active devices, instead of including a separate processor and a battery configured to operate the processor, and accordingly the wireless power relay apparatus <NUM> of one or more embodiments may be implemented as a compact accessory. Due to such a structure of the wireless power relay apparatus <NUM> of one or more embodiments, the wireless power relay apparatus <NUM> may relay a wireless power transmission, by changing a frequency for wireless power charging, instead of changing a structure of each of the wireless power transmission apparatus and the wireless power reception apparatus in an existing wireless power charging system.

The wireless power relay apparatus <NUM> may operate without being inserted into a body, and may easily change a frequency by changing the first antenna <NUM>. Accordingly, any number of apparatuses (smartphones, wearable devices, etc., for example) may be used as a wireless power transmission apparatus.

<FIG> illustrates an example of a circuit to implement a wireless power relay apparatus (for example, a wireless power relay apparatus <NUM>).

Referring to the circuit of <FIG>, the wireless power relay apparatus <NUM> may include a first antenna <NUM> configured to receive an AC power signal of a first frequency from a wireless power transmission apparatus, a rectifier <NUM> configured to convert the AC power signal of the first frequency received via the first antenna <NUM> into a DC power, a storage device <NUM> configured to store the DC power output from the rectifier <NUM> in a form of a DC voltage, a power oscillator <NUM> configured to oscillate at a second frequency based on a DC voltage stored in the storage device <NUM> and a current supplied from the rectifier <NUM> and to generate an AC power signal of the second frequency, and a second antenna <NUM> configured to transmit the AC power signal of the second frequency generated by the power oscillator <NUM>.

The storage device <NUM> may be a capacitor, and one end of the capacitor may be connected to a ground terminal and another end of the capacitor may be connected to the rectifier <NUM> and the second antenna <NUM>. The storage device <NUM> may store a DC voltage VRECT rectified by the rectifier <NUM>. In an example, the rectifier <NUM> may include a plurality of diodes, and the power oscillator <NUM> may include two transistors and a capacitor that is connected to one end of each of the two transistors. In the circuit, the power oscillator <NUM> may be implemented without a separate control circuit, because the power oscillator <NUM> has its own reference value for the DC voltage VRECT supplied from the storage device <NUM>.

The wireless power relay apparatus <NUM> may be implemented with a compact structure as shown in the circuit of <FIG>, and thus the wireless power relay apparatus <NUM> of one or more embodiments may be manufactured with a small size and produce the wireless power relay apparatus <NUM> at a relatively low unit cost of production. Also, the wireless power relay apparatus <NUM> of one or more embodiments may enhance a power efficiency of a wireless power charging system through a frequency conversion of an AC power signal for wireless power charging. Even when it is difficult to change an operating frequency for wireless power charging of a wireless power reception apparatus, or when such operating frequency cannot be changed, the wireless power relay apparatus <NUM> may generate an AC power signal of a second frequency optimized for the wireless power charging of the wireless power reception apparatus, by changing the second antenna.

<FIG> illustrates an example of a structure of a wireless power relay apparatus (for example, a wireless power relay apparatus <NUM>).

Referring to <FIG>, the wireless power relay apparatus <NUM> may be implemented in the form of an accessory disposed (for example, detachably mounted) on one surface of a wireless power transmission apparatus <NUM> (for example, a smartphone). The wireless power relay apparatus <NUM> may include a first antenna <NUM> configured to receive an AC power signal of a first frequency from the wireless power transmission apparatus <NUM>, a circuit board <NUM> in which a rectifier and a power oscillator are disposed and/or included, a second antenna <NUM> configured to transmit an AC power signal of a second frequency generated by the power oscillator, a first insulating layer <NUM> disposed between the first antenna <NUM> and the circuit board <NUM>, and a second insulating layer <NUM> disposed between the circuit board <NUM> and the second antenna <NUM>. The first antenna <NUM> and the circuit board <NUM> may be connected to each other through a wiring, and the circuit board <NUM> and the second antenna <NUM> may be connected to each other through a wiring. In an example, the first antenna <NUM> is disposed closer to the one surface of the wireless power transmission apparatus <NUM> than the second antenna <NUM> when the wireless power relay apparatus <NUM> is disposed on the one surface.

Through the above structure, the wireless power relay apparatus <NUM> of one or more embodiments may be implemented with a relatively high power conversion efficiency by reducing a size and a unit cost of production.

<FIG> illustrates an example of an operation of a power oscillator (for example, the power oscillator <NUM>).

Referring to <FIG>, reference numeral <NUM> represents a change in the DC voltage stored in the storage device <NUM> over time, and reference numeral <NUM> represents a change in a voltage signal output from the power oscillator <NUM> over time. Charges may start to accumulate in the storage device <NUM> by a current supplied from the rectifier <NUM> to the storage device <NUM>, and a magnitude of the DC voltage may gradually increase over time as the current is supplied. When the DC voltage stored in the storage device <NUM> reaches (for example, is greater than or equal to) a predetermined reference value (for example, a threshold), the power oscillator <NUM> may start to oscillate. For example, when the magnitude of the DC voltage stored in the storage device <NUM> reaches the reference value at a point A in time, the power oscillator <NUM> may be automatically activated at the point A in time and start to oscillate by the structure of the circuit of <FIG>. The power oscillator <NUM> may remain in an off state until the DC voltage stored in the storage device <NUM> reaches the reference value, may start to oscillate at the point A in time at which the DC voltage reaches the reference value, and may generate an AC power signal of a second frequency, without being controlled by a control signal. As described above, the wireless power relay apparatus <NUM> may not require a configuration to actively control the power oscillator <NUM> and may fully passively operate.

<FIG> illustrates an example of a wireless power relay method. The wireless power relay method may be performed by, for example, a wireless power relay apparatus described above (for example, the wireless power relay apparatus <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and/or <NUM>).

Referring to <FIG>, in operation <NUM>, the wireless power relay apparatus may receive, using a first antenna, an AC power signal of a first frequency from a wireless power transmission apparatus. The first antenna may be implemented as a coil, and may receive the AC power signal of the first frequency from the wireless power transmission apparatus through mutual coupling between coils.

In operation <NUM>, the wireless power relay apparatus may convert, using a rectifier, the AC power signal of the first frequency into a DC power. By converting the AC power signal into the DC power, a DC voltage may be generated. In operation <NUM>, the wireless power relay apparatus may store electric energy of the DC power output from the rectifier in a storage device, for example, a capacitor.

In operation <NUM>, the wireless power relay apparatus may generate, using a power oscillator, an AC power signal of a second frequency based on an output current of the rectifier and electric energy of a DC voltage stored in the storage device. The second frequency may be different from the first frequency and may be identical to an operating frequency for a wireless power reception of a wireless power reception apparatus. For example, when a reception of the AC power signal of the first frequency is started and when the DC voltage stored in the storage device reaches a reference value, the power oscillator may start to oscillate to generate the AC power signal of the second frequency. In operation <NUM>, the wireless power relay apparatus may transmit the AC power signal of the second frequency via a second antenna to the wireless power reception apparatus.

The wireless power transmission systems, wireless power transmission apparatuses, wireless power relay apparatuses, wireless power reception apparatuses, first antennas, rectifiers, storage devices, power oscillators, second antennas, second antennas, first insulating layers, circuit boards, second insulating layers, wireless power transmission system <NUM>, wireless power transmission apparatus <NUM>, wireless power relay apparatus <NUM>, wireless power reception apparatus <NUM>, wireless power transmission apparatus <NUM>, wireless power relay apparatus <NUM>, wireless power transmission apparatus <NUM>, wireless power relay apparatus <NUM>, wireless power reception apparatus <NUM>, wireless power relay apparatus <NUM>, first antenna <NUM>, rectifier <NUM>, storage device <NUM>, power oscillator <NUM>, second antenna <NUM>, wireless power relay apparatus <NUM>, first antenna <NUM>, a rectifier <NUM>, storage device <NUM>, second antenna <NUM>, power oscillator <NUM>, wireless power transmission apparatus <NUM>, wireless power relay apparatus <NUM>, first antenna <NUM>, first insulating layer <NUM>, circuit board <NUM>, second insulating layer <NUM>, second antenna <NUM>, apparatuses, units, modules, devices, and other components described herein with respect to <FIG> are implemented by or representative of hardware components. Examples of hardware components that may be used to perform the operations described in this application where appropriate include controllers, sensors, generators, drivers, memories, comparators, arithmetic logic units, adders, subtractors, multipliers, dividers, integrators, and any other electronic components configured to perform the operations described in this application. In other examples, one or more of the hardware components that perform the operations described in this application are implemented by computing hardware, for example, by one or more processors or computers. A processor or computer may be implemented by one or more processing elements, such as an array of logic gates, a controller and an arithmetic logic unit, a digital signal processor, a microcomputer, a programmable logic controller, a field-programmable gate array, a programmable logic array, a microprocessor, or any other device or combination of devices that is configured to respond to and execute instructions in a defined manner to achieve a desired result. In one example, a processor or computer includes, or is connected to, one or more memories storing instructions or software that are executed by the processor or computer. Hardware components implemented by a processor or computer may execute instructions or software, such as an operating system (OS) and one or more software applications that run on the OS, to perform the operations described in this application. The hardware components may also access, manipulate, process, create, and store data in response to execution of the instructions or software. For simplicity, the singular term "processor" or "computer" may be used in the description of the examples described in this application, but in other examples multiple processors or computers may be used, or a processor or computer may include multiple processing elements, or multiple types of processing elements, or both. For example, a single hardware component or two or more hardware components may be implemented by a single processor, or two or more processors, or a processor and a controller. One or more hardware components may be implemented by one or more processors, or a processor and a controller, and one or more other hardware components may be implemented by one or more other processors, or another processor and another controller. One or more processors, or a processor and a controller, may implement a single hardware component, or two or more hardware components. A hardware component may have any one or more of different processing configurations, examples of which include a single processor, independent processors, parallel processors, single-instruction single-data (SISD) multiprocessing, single-instruction multiple-data (SIMD) multiprocessing, multiple-instruction single-data (MISD) multiprocessing, and multiple-instruction multiple-data (MIMD) multiprocessing.

Forexample, a single operation or two or more operations may be performed by a single processor, or two or more processors, or a processor and a controller.

The instructions or software may be written using any programming language based on the block diagrams and the flow charts illustrated in the drawings and the corresponding descriptions used herein, which disclose algorithms for performing the operations that are performed by the hardware components and the methods as described above.

Claim 1:
A wireless power relay apparatus (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>; <NUM>) comprising:
a first antenna (<NUM>; <NUM>; <NUM>) configured to wirelessly receive (<NUM>) an alternating current, AC, power signal of a first frequency from a wireless power transmission apparatus (<NUM>; <NUM>; <NUM>; <NUM>);
a rectifier (<NUM>; <NUM>) configured to convert (<NUM>) the received AC power signal into a direct current, DC, power;
a storage device (<NUM>; <NUM>) configured to store (<NUM>) electric energy of the DC power output from the rectifier; characterised by
a power oscillator (<NUM>; <NUM>) configured to generate (<NUM>) an AC power signal of a second frequency in response to receiving an output current of the rectifier and a DC voltage stored in the storage device reaching a reference value, wherein the power oscillator (<NUM>; <NUM>) includes two transistors and a capacitor of a second antenna (<NUM>) that is connected to one end of each of the two transistors, and wherein the power oscillator (<NUM>; <NUM>) is further configured to remain in an off state until the DC voltage reaches the reference value, and to start to oscillate, in response to the reception of the AC power signal of the first frequency and the DC voltage stored in the storage device (<NUM>; <NUM>) reaching the reference value; and
the second antenna (<NUM>; <NUM>; <NUM>) configured to transmit (<NUM>) the AC power signal of the second frequency to a wireless power reception apparatus (<NUM>),
wherein the storage device is a capacitor, and an end of the capacitor is connected to a ground terminal, and another end of the capacitor is connected to the rectifier and the second antenna.