Patent Description:
Currently, an increasing quantity of electronic devices, such as a smartphone, a smartwatch, and a smart wristband, have a near field communication (NFC) function. The NFC function is widely used. For example, it can be used for payment. How to perform NFC wireless charging on a wearable product such as a watch, a wristband, and a wireless headset by using an existing NFC communication module in an electronic device has received attention and started to be studied.

Usually, wireless communication and wireless charging have different requirements for circuits. To solve this problem, a technical solution of adding additional circuits has been proposed. For example, two sets of coils and matching circuits are used. However, such an NFC apparatus requires a larger printed circuit board (PCB) area and more NFC coil mounting space. In addition, the use of two sets of coils and circuits increases costs.

<CIT> discloses a protection device and a method for a power transmitter. <CIT> discloses a power transmission control device, a power transmitting device, a non-contact power transmission system, and a secondary coil positioning method. <CIT> discloses a power transmission control device, a power transmission device, an electronic instrument, and a non-contact power transmission system.

In general, embodiments of the present disclosure provide a technical solution for power regulation in near field communication. The scope of protection is defined by the claims appended hereto.

It may be understood from the following description of example embodiments that an NFC power regulation circuit having active power and/or reactive power that are arbitrarily controllable in a magnitude and a direction is added according to the technical solutions proposed herein. The NFC power regulation circuit may inject corresponding required active power and/or reactive power into an NFC circuit based on an NFC receive end type and an operating state of an NFC apparatus that are detected, thereby implementing improved performance of wireless communication or wireless charging for the NFC apparatus.

Other features of the present disclosure will be readily understood through the following description.

Some example embodiments are described with reference to the accompanying drawings, where:.

In all the accompanying drawings, identical or similar reference signs denote identical or similar elements.

The principles of the present disclosure are described with reference to some example embodiments. It should be understood that these embodiments are described for illustrative purposes only and to assist persons skilled in the art in understanding and implementing the present disclosure without imposing any limitation on the scope of the present disclosure. In addition to the manners described below, the implementations described in this specification may be implemented in various manners.

In the following descriptions and claims,
<IMG>
s otherwise defined, all technical and scientific terms used in this specification have the same meanings as those generally understood by persons of ordinary skill in the art to which the present disclosure belongs.

References to "an embodiment", "one embodiment", "example embodiment", and the like in the present disclosure indicate that the embodiment described may include particular features, structures, or characteristics, but it is not necessary that each embodiment includes the particular features, structures, or characteristics. Moreover, such phrases do not necessarily refer to a same embodiment. In addition, when a particular feature, structure, or characteristic is described in combination with an embodiment, it may be considered that combination of another embodiment affecting the feature, structure, or characteristic is well known to the persons killed in the art. There is no explicit description.

It should be understood that the terms "first", "second", and the like may be used in this specification to describe various elements, but these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from a scope of an example embodiment, a first element may be referred to as a second element, and similarly, the second element may be referred to as the first element. As used in this specification, the term "and/or" includes any and all combinations of one or more of listed terms.

The terms used in this specification are for the purpose of describing particular embodiments only and are not intended to limit example embodiments. As used in this specification, the singular forms "a", "an", and "the" are also intended to include plural forms unless the context expressly indicates otherwise. It will be further understood that, when used in this specification, the terms "include", "including", "have", "having", "comprise", and/or "comprising" designate the presence of the feature, element, component, and/or the like without excluding the presence or addition of one or more other features, elements, components and/or combinations thereof.

The term "circuit" used herein refers to one or more of the following:.

The definition of a circuit is applicable to all scenarios of use of the term in this application (including any claim). As another example, the term "circuit" used herein also covers implementations of only a hardware circuit or processor (or a plurality of processors), a part of a hardware circuit or processor, or software or firmware accompanying a hardware circuit or processor. For example, if applicable to a particular claim element, the term "circuit" further covers a baseband integrated circuit, a processor integrated circuit, or a similar integrated circuit in another computing device.

In the embodiments of the present disclosure, the term "wireless charging" refers to that without electrical contact between a power transmit apparatus and a power receive apparatus, wireless energy transfer is performed across space (by using an electromagnetic field between the power transmit apparatus and the power receive apparatus). The term "near field communication" refers to communication applying magnetic coupling operation principles and may also be used for wireless charging. For example, an operating frequency for the near field communication and the wireless charging may be <NUM> or another suitable frequency. Wireless power transfer may refer to transfer of any form of energy associated with an electric field, a magnetic field, an electromagnetic field, or another wireless field from a transmitter to a receiver without use of a physical electrical conductor (for example, power may be transferred through free space). Power output into a wireless field (for example, a magnetic field) may be received, captured, or coupled by a "receive coil" to implement power transfer.

The term "alternating-current resistance (ACR)" used in this specification refers to an alternating-current internal resistance value measured by a device port at a corresponding alternating-current operating frequency. The term "coil quality factor" is also referred to as a "Q value". A larger Q value indicates smaller coil loss, and a smaller Q value indicates greater coil loss. The term "active power" refers to alternating-current energy emitted or consumed per unit time. The "active power" is average power within a period and has a characteristic that a phase of an alternating-current voltage and a phase of an alternating-current current are in a same direction or opposite directions. The term "reactive power" refers to constant exchange of energy between a power supply and a reactance element (a capacitor or an inductor) with average power of zero within a period. A maximum value of the exchanged energy is the "reactive power". The reactive power has a characteristic that a phase of an alternating-current voltage lags behind or leads a phase of an alternating-current current by <NUM> degrees.

Wireless communication (for example, NFC communication) and wireless charging (for example, NFC charging) are very similar in terms of a circuit structure. As shown in <FIG>, a circuit <NUM> of a wireless communication/charging transmitter includes a power converter/controller <NUM>, an electromagnetic compatibility (EMC) network <NUM>, a matching network <NUM>, and a transmit coil <NUM>. The power transmit/controller <NUM> is configured to generate a high-frequency alternating-current signal. The EMC network <NUM> may be configured to remove a higher-order harmonic component from a high-frequency square wave. The matching network <NUM> may be configured to reduce an alternating-current signal reflected by a load.

Wireless communication and wireless charging have different requirements for a circuit. For example, to be compatible with requirements of different wireless communication rates, a transmit coil used for wireless communication usually has a comparatively small Q value. If a wireless communication circuit and the transmit coil are directly used for NFC wireless charging, the comparatively small Q value of the coil will lead to great loss of a transmit coil for NFC wireless charging, low charging efficiency, and poor user experience. To achieve higher NFC wireless charging efficiency, it is usually required that a Q value of the transmit coil for NFC wireless charging be as large as possible, for example, Q > <NUM>. Therefore, there is a contradiction between Q values required for wireless communication and for wireless charging.

When an electronic device performs wireless charging, a Q value of an entire NFC apparatus is comparatively large, which causes that the NFC apparatus is comparatively sensitive to changes in coil inductance and capacitance parameters. When tolerances or offsets exist in these parameters, the NFC apparatus produces a comparatively large change in an imaginary part of impedance. This results in a comparatively large reactive current generated in the NFC apparatus, thereby reducing wireless charging power and efficiency. Therefore, it is difficult to achieve consistency in wireless charging characteristics.

According to some conventional technologies, a plurality of coils and circuits may be used to achieve compatibility between wireless communication and NFC wireless charging. For example, <FIG> is a schematic diagram of a structure of an NFC apparatus <NUM> according to some conventional solutions. The NFC apparatus <NUM> is an embodiment of the circuit <NUM> of a wireless communication/charging transmitter. The NFC apparatus <NUM> includes an NFC communication/charging chip <NUM>, an EMC circuit <NUM>, matching networks <NUM>-<NUM> and <NUM>-<NUM>, and NFC transmit coils <NUM>-<NUM> and <NUM>-<NUM>. The NFC transmit coil <NUM>-<NUM> may be set to have a comparatively small Q value for wireless communication. The NFC transmit coil <NUM>-<NUM> may be set to have a comparatively large Q value for NFC wireless charging. Compatibility between wireless communication and NFC wireless charging may be achieved by using two sets of coils and matching circuits. However, such an NFC apparatus requires a larger printed circuit board (PCB) area and more NFC coil mounting space. In addition, the use of two sets of coils and circuits increases costs.

In some other conventional technologies, an NFC coil may be regulated by resistors connected in series to achieve compatibility between wireless communication and NFC wireless charging. An NFC apparatus <NUM> is another embodiment of the circuit <NUM> of a wireless communication/charging transmitter. As shown in <FIG>, the NFC apparatus <NUM> includes an NFC communication/charging chip <NUM>, an EMC network <NUM>, a matching network <NUM>, a Q-value switching circuit <NUM>, and an NFC coil <NUM>. The Q-value switching circuit may include short-circuit resistors Rd1 and Rd2, and switches S1 and S2. Switching of a Q value may be implemented by connecting or disconnecting the switches S1 and S2. For example, in a wireless communication mode, the switches S1 and S2 are open, and the resistors Rd1 and Rd2 are connected in series to the circuit, so that an equivalent Q value of the NFC coil decreases to meet a wireless communication requirement. In a wireless charging mode, the resistors Rd1 and Rd2 may be short-circuited by closing the switches S1 and S2, so that the equivalent Q value of the NFC coil increases to meet a wireless charging requirement. However, driving the switches S1 and S2 is very complicated, and technical implementation is difficult.

The foregoing technologies are conventional solutions to solve a difference in Q value requirements between NFC wireless charging and wireless communication. It is difficult to solve the difference or implement the foregoing technologies if a resonance state changes due to an offset that exists in the inductance and capacitance parameters of the circuit, or if different impedance requirements of wireless communication and wireless charging are to be compatible. In some other conventional technologies, circuit parameters are regulated by changing capacitance to achieve compatibility between wireless communication and wireless charging. As shown in <FIG>, an NFC apparatus <NUM> includes an NFC communication/charging chip <NUM>, an EMC network <NUM>, a matching network <NUM>, a capacitance regulation circuit <NUM>, and an NFC coil <NUM>. Capacitance may be regulated so that the NFC apparatus is in a required impedance state. However, such technical solutions require an additional circuit, which increases costs and occupies a PCB.

Therefore, new technical solutions are required to achieve compatibility between wireless communication and NFC wireless charging. According to embodiments of the present disclosure, compatibility between wireless communication and NFC wireless charging can be achieved by adding a power regulation circuit having active power and/or reactive power that are controllable in a magnitude and a direction. In some embodiments, an excellent wireless communication or NFC wireless charging effect can be achieved by injecting correspondingly required active power and/or reactive power into an NFC circuit based on an NFC receive end type and an operating state of an NFC apparatus that are detected.

<FIG> is a schematic diagram of a structure in a wireless communication/charging scenario <NUM>. The wireless communication/charging scenario <NUM> includes an NFC transmit end apparatus <NUM> and an NFC receive end apparatus <NUM> that may communicate with each other. The NFC transmit end apparatus <NUM> may provide input power from a power supply to a transmitter to generate a wireless (such as magnetic or electromagnetic) field for performing wireless power transfer. The NFC transmit end apparatus <NUM> and the NFC receive end apparatus <NUM> may be separated by a specific distance. The NFC receive end apparatus <NUM> may be coupled to the wireless field and generate, based on received wireless power, output power for storage and consumption.

The wireless field may be corresponding to a "near field" of the NFC transmit end apparatus <NUM>. The near field may be corresponding to a region in which a strong reactance field is present. The strong reactance field is caused by a current and a charge in a transmit antenna of the NFC transmit end apparatus <NUM> and minimally radiates power from the transmit antenna. The near field may be corresponding to a region within about one wavelength (or fraction thereof) of the transmit antenna. The embodiments of the present disclosure may be applied to the NFC transmit end apparatus <NUM>. In addition, the embodiments of the present disclosure may further be applied to the NFC receive end apparatus <NUM>. Although <FIG> illustrates an NFC scenario as an example for description, it should be understood that the embodiments of the present disclosure may also be used in other suitable environments or systems that are currently known or developed in the future.

<FIG> is a schematic diagram of a wireless communication/charging system <NUM> according to an example embodiment of the present disclosure. The wireless communication/charging system <NUM> includes the NFC transmit end apparatus <NUM> and the NFC receive end apparatus <NUM> shown in <FIG>. It may be understood that the system structure shown in <FIG> is merely an example and does not impose a restriction. The wireless communication/charging system <NUM> may include other additional components not shown or omit some of the components shown, which is not limited in this embodiment of the present disclosure.

As an example, the NFC transmit end apparatus <NUM> includes a transmit converter <NUM>, a transmit coil <NUM>, a power regulator <NUM>, a signal control processor <NUM>, a matching circuit <NUM>, an EMC circuit <NUM>, a direct-current converter <NUM>, a system processor <NUM>, and a direct-current power supply <NUM>. It may be understood that the NFC transmit end apparatus <NUM> may include another suitable unit or module.

The direct-current power supply <NUM> may supply power to each component of the NFC transmit end apparatus <NUM>. The direct-current power supply <NUM> may be a power supply, such as a battery, located inside the NFC transmit end apparatus <NUM>. Alternatively, the direct-current power supply <NUM> may be an external power supply externally connected to the NFC transmit end apparatus <NUM>. The embodiments of the present disclosure are not limited in this respect. The direct-current converter <NUM> may be powered by the direct-current power supply <NUM>. After direct-current voltage conversion is performed on a supply voltage output by the power supply <NUM>, the direct-current converter <NUM> supplies a required voltage to the signal control processor <NUM>. The transmit converter <NUM> may be powered by the direct-current power supply <NUM>, or powered by the direct-current power supply <NUM> through the direct-current converter <NUM>, and a direct current is converted into a high-frequency alternating current.

Because the transmit converter <NUM> emits a high-frequency square wave, the high-frequency square wave includes more higher-order harmonic components. If the high-frequency square wave is transmitted by the NFC transmit coil <NUM> without any processing, serious electromagnetic interference is caused. The higher-order harmonic waves pass through the EMC circuit <NUM> (for example, including a series/parallel network of inductors/capacitors) and then become comparatively complete sine waves. The matching circuit <NUM> may include devices of a capacitor and/or an inductor and reduce an alternating-current signal reflected by a load, to meet a power output requirement of the direct-current converter <NUM>. The NFC transmit coil <NUM> is configured to generate/receive an NFC high-frequency magnetic field and transmit/receive an NFC signal.

In some embodiments, the power regulator <NUM> may be configured to generate power of any magnitude and phase. Specific examples are described in detail below. An interface circuit <NUM> includes an inductor and a capacitor, and is configured to connect the power regulator <NUM>, the matching circuit <NUM>, and the EMC circuit <NUM>. The transmit coil <NUM> generates a high-frequency magnetic field to transmit energy to the NFC receive end apparatus <NUM> in a wireless manner. The signal control processor <NUM> is configured to process a signal generated in a communication/charging process, and control and drive the power regulator <NUM> in the NFC transmit end apparatus <NUM>. The system processor <NUM> is configured to process information of another process and the like.

As an example, the NFC receive end apparatus <NUM> includes a receive coil <NUM>, a receive power device <NUM>, a signal control processor <NUM>, a direct-current converter <NUM>, an electric energy storage apparatus <NUM>, and a matching circuit <NUM>. Some components of the NFC receive end apparatus <NUM> and some components of the NFC transmit end apparatus <NUM> have same or similar names, and also have same or similar operations and functions.

The receive coil <NUM> may be configured to receive a wireless signal and/or power in the high-frequency magnetic field. The receive power device <NUM> may convert a high-frequency alternating current received by the receive coil <NUM> into a direct current. The matching circuit <NUM> includes devices that are mainly an inductor and a capacitor and performs matching on impedance characteristics. For example, impedance at a receive end may be matched to resistive impedance, inductive impedance, or capacitive impedance.

In some embodiments, a direct current obtained through conversion by the receive power device <NUM> may be used to provide electric energy to the signal control processor <NUM>. In other embodiments, a direct current obtained through conversion by the receive power device <NUM> may be processed by the direct-current converter <NUM> or charge the electric energy storage apparatus <NUM>.

The signal control processing unit is configured to process a signal generated in a communication/charging process, and control and drive a power circuit in the receive power device <NUM>. The direct-current converter <NUM> converts a direct current received from the receive power device <NUM> to charge the electric energy storage apparatus <NUM>. The electric energy storage apparatus <NUM> may be configured to store energy received from the receive coil <NUM>.

<FIG> is a schematic diagram of a structure of a terminal device <NUM> according to an embodiment of the present disclosure. For example, when the terminal device <NUM> is a mobile phone, as shown in <FIG>, the terminal device <NUM> mainly includes a display panel (display panel, DP) <NUM>. The display panel <NUM> may be a liquid crystal display (liquid crystal display, LCD) panel or an organic light emitting diode (organic light emitting diode, OLED) display panel. This is not limited in this application. The terminal device <NUM> further includes a middle frame <NUM> and a housing <NUM> shown in <FIG>. The display panel <NUM> and the housing <NUM> are respectively located on two sides of the middle frame <NUM>. A back surface of the display panel <NUM> faces the housing <NUM>, and the display panel <NUM> and the housing <NUM> are connected through the middle frame <NUM>. The NFC transmit end apparatus <NUM> shown in <FIG> as an example may be disposed on a side of the middle frame <NUM>.

<FIG> is a diagram of a structure of an NFC apparatus <NUM> as an example according to an embodiment of the present disclosure. The NFC apparatus <NUM> may include other additional components not shown or omit some of the components shown, which is not limited in this embodiment of the present disclosure. Some components in <FIG> and some components in <FIG> have same or similar names, and have similar operations and functions. The NFC apparatus <NUM> may be implemented in the terminal device <NUM> shown in <FIG>. For example, the NFC apparatus <NUM> may be disposed on a side that is of the middle frame <NUM> and that faces the housing <NUM>. It may be understood that connection manners of elements in the NFC apparatus <NUM> that are shown in <FIG> are merely an example and do not impose a restriction.

The NFC apparatus <NUM> includes a direct-current power supply <NUM>, an NFC power converter <NUM>, an NFC circuit <NUM>, and an NFC coil <NUM>. In some implementations, the NFC power converter <NUM> may include a direct-current/direct-current converter <NUM> and a direct-current/alternating-current converter <NUM>. In some embodiments, the NFC circuit <NUM> may further include the EMC circuit <NUM> and the matching circuit <NUM> that are shown in <FIG>. The direct-current/direct-current converter <NUM> and the direct-current/alternating-current converter <NUM> may be combined to form the direct-current converter <NUM> shown in <FIG>.

The NFC apparatus <NUM> further includes an interface circuit <NUM>, a controller <NUM>, and a power regulator <NUM>. In some embodiments, the NFC apparatus <NUM> further includes a detector <NUM>. The interface circuit <NUM> may include an inductor and a capacitor. In some embodiments, the interface circuit <NUM> may be the same as the interface circuit <NUM> shown in <FIG>. In some embodiments, the detector <NUM> and the controller <NUM> may be implemented in the signal control processor <NUM>. Therefore, in the embodiments of the present disclosure, existing NFC chips, circuits, and coils may be reused, thereby reducing costs and reducing mounting space. Compared with conventional technologies, the NFC apparatus according to the embodiments of the present disclosure implements Q value switching and impedance regulation by using the controller <NUM> and the power regulator <NUM>, and can meet different requirements of wireless communication/charging. In addition, injected power is regulated by the power regulator <NUM>, so that compatibility between wireless communication and NFC charging is achieved, and mode switching is efficient.

The controller <NUM> is configured to generate different power control signals based on different operating modes of the NFC apparatus <NUM> to regulate at least one of a magnitude or a phase of power generated by the power regulator <NUM>. One end of the power regulator <NUM> is connected to the direct-current power supply <NUM>, and the other end is connected to the NFC circuit <NUM>. The power regulator <NUM> regulates, based on the different power control signals, at least one of a magnitude and a phase of power output to the NFC circuit <NUM>. In some embodiments, the power regulator may include a direct-current/alternating-current converter <NUM>. Additionally, in some embodiments, the power regulator <NUM> may further include a direct-current/direct-current converter <NUM>, thereby further implementing control of the magnitude of the power output to the NFC circuit <NUM>. In some embodiments, the detector <NUM> is connected to the NFC circuit <NUM> through the interface circuit <NUM>. The detector <NUM> is configured to detect an operating mode of the NFC apparatus <NUM>. For example, the detector <NUM> may determine whether the NFC apparatus <NUM> is in a wireless communication mode or an NFC wireless charging mode. If the NFC apparatus <NUM> is in the wireless communication mode, the NFC circuit <NUM> requires a small Q value. If the NFC apparatus <NUM> is in the NFC charging mode, the NFC circuit <NUM> requires a large Q value. In some embodiments, the detector <NUM> may determine the operating mode of the NFC apparatus <NUM> based on a communication protocol format used by the NFC apparatus <NUM>. Additionally or alternatively, an operating manner of the NFC circuit <NUM> may be determined by using impedance information and/or power information (that is, power during an operation of the NFC circuit) of the NFC apparatus <NUM>. In this way, impedance and/or power of the NFC apparatus may be regulated based on the different operating modes, so that the NFC apparatus is in a suitable operating state. It may be understood that the operating mode of the NFC apparatus <NUM> may be determined by any suitable component.

In some embodiments, the power regulator <NUM> may obtain active power from the NFC circuit <NUM> through the interface circuit <NUM>, thereby forming an equivalent load on the NFC circuit <NUM>. In some embodiments, the power regulator <NUM> may perform direct-current/alternating-current power conversion on the active power obtained. The power obtained after conversion by the power regulator <NUM> may be transmitted backward, to be supplied as auxiliary power to the NFC power converter <NUM>. As an example for illustration only, if power required by the NFC power converter <NUM> is P1, in the absence of the power that is obtained after conversion by the power regulator <NUM> and that is transmitted backward, the direct-current power supply <NUM> needs to supply the power P1 to the NFC power converter <NUM>. If the power (represented as P2) obtained after conversion by the power regulator <NUM> is transmitted backward, the direct-current power supply <NUM> needs to supply power P1 - P2 to the NFC power converter <NUM>. In this way, power recovery is implemented, and power consumption of the NFC apparatus <NUM> is reduced. In other embodiments, the active power obtained may be directly consumed by the power regulator <NUM> without being transmitted backward. As shown in <FIG>, the controller <NUM> may be connected to an NFC clock <NUM> and be at a same frequency as the NFC clock <NUM>. In some embodiments, the controller <NUM> may generate a power control signal to control phase leading or lagging. The power control signal serves as a drive signal (frequency and phase) of a power switching transistor in the direct-current/alternating-current converter <NUM>, thereby controlling a relative phase of an alternating-current port voltage/current of the direct-current/alternating-current converter <NUM>. Additionally, the controller <NUM> may further regulate an output voltage of the direct-current/direct-current converter <NUM>, or regulate a drive duty ratio or a phase shift angle of the direct-current/alternating-current converter <NUM>, thereby controlling an amplitude of the alternating-current port voltage/current of the direct-current/alternating-current converter <NUM>. In this way, more convenient and more accurate Q value regulation and impedance regulation of the NFC apparatus are implemented.

The direct-current/direct-current converter <NUM> is configured to receive a current from the power supply <NUM>, perform conversion, and supply power to the direct-current/alternating-current converter <NUM>. In other embodiments, the direct-current/direct-current converter <NUM> may further be configured to receive electric energy from the direct-current/alternating-current converter <NUM> and transmit backward the electric energy to the power supply <NUM>. The direct-current/direct-current converter <NUM> may be a buck regulator. Alternatively, a boost regulator may be used as the direct-current/direct-current converter <NUM>. In other embodiments, the direct-current/direct-current converter <NUM> may be a bidirectional buck-boost regulator or a low dropout regulator, and the embodiments of the present disclosure are not limited in this respect.

In the wireless communication mode, the direct-current/alternating-current converter <NUM> may be configured to convert a direct current into an alternating current, and transmit the alternating current to the NFC circuit <NUM> through the interface circuit <NUM>. In the NFC charging mode, the direct-current/alternating-current converter <NUM> may further be configured to convert an alternating current obtained from the NFC circuit <NUM> through the interface circuit <NUM> into a direct current, and transmit the direct current back to the direct-current/direct-current converter <NUM>. In some embodiments, the direct-current/alternating-current converter <NUM> may be a direct-current/alternating-current full-bridge converter. Alternatively, a full-bridge inverter may also be used as the direct-current/alternating-current converter <NUM>. In other embodiments, the direct-current/alternating-current converter <NUM> may be a half-bridge converter.

The embodiments of the present disclosure are further described below with reference to <FIG> and <FIG> is a flowchart of a power regulation method <NUM> according to an example embodiment of the present disclosure. The method shown in <FIG> may be implemented by the NFC apparatus <NUM> shown in <FIG>. It should be understood that the method shown in <FIG> may include other additional steps not shown, or some of the steps shown may be omitted. The scope of the present disclosure is not limited thereto.

In block <NUM>, the NFC power converter <NUM> generates a high-frequency alternating-current output. As described above, the NFC power converter <NUM> may include the direct-current/direct-current converter <NUM> and the direct-current/alternating-current converter <NUM>. For example, the direct-current/direct-current converter <NUM> is configured to receive a current from the power supply <NUM>, perform conversion, and supply power to the direct-current/alternating-current converter <NUM>. The direct-current/alternating-current converter <NUM> may be configured to convert a direct current into an alternating current, and transmit the alternating current to the NFC circuit <NUM>.

In block <NUM>, the NFC coil <NUM> generates/receives an NFC high-frequency magnetic field and transmits/receives NFC power or an NFC signal.

In block <NUM>, the NFC circuit <NUM> transmits/receives the high-frequency alternating-current output. For example, when the NFC circuit <NUM> is in a wireless communication mode, the NFC circuit <NUM> may transmit a high-frequency alternating-current electrical signal to the NFC receive end apparatus <NUM> and the like. In other embodiments, if the NFC circuit <NUM> is in an NFC charging mode, the NFC circuit <NUM> may further receive a high-frequency alternating-current electrical signal used for charging the direct-current power supply <NUM>.

In some embodiments, an operating mode of the NFC apparatus <NUM> may be determined. For example, the operating mode may include the wireless communication mode. The operating mode may further include the wireless charging mode. In some embodiments, the detector <NUM> may determine the operating mode of the NFC apparatus <NUM> based on a communication protocol format used by the NFC apparatus <NUM>. Because signals used for wireless communication and NFC charging use different communication protocols, the detector <NUM> may determine the operating mode by using the communication protocol format. In some embodiments, the detector <NUM> may detect impedance information of the NFC apparatus <NUM>. Alternatively, impedance information of the NFC apparatus <NUM> may be detected by the detector <NUM>.

In some embodiments, circuit parameters used for different operating modes of the NFC apparatus <NUM> may be set. These circuit parameters may be set to default parameter values. As an example, when the detector <NUM> determines that the NFC apparatus <NUM> is in the wireless communication mode, a magnitude and a phase of default injected power in the communication mode (for example, injected by the power regulator <NUM>) may be applied to the NFC circuit. For example, a phase of injected power and a phase of power of the NFC circuit <NUM> are in opposite directions. In other embodiments, when the detector <NUM> determines that the NFC apparatus <NUM> is in the wireless charging mode, a magnitude and a phase of default injected power in the charging mode may be applied to the NFC circuit. For example, a phase of injected power and a phase of power of the NFC circuit <NUM> may be in a same direction by default.

In block <NUM>, the controller <NUM> generates different power control signals based on the different operating modes of the NFC apparatus <NUM>. In some embodiments, as described above, default circuit parameters used for the different operating manners of the NFC circuit <NUM> may be set, and the controller <NUM> may generate, based on information about the NFC circuit <NUM> determined by the detector <NUM>, a power control signal used for updating the default circuit parameters. In other embodiments, the controller <NUM> may generate, based on information about the NFC circuit <NUM> determined by the detector <NUM>, a power control signal without a need for default circuit parameters. In this way, more convenient and more accurate Q value regulation and impedance regulation can be implemented. Further, the controller <NUM> may determine a magnitude and a direction of the injected power based on the operating mode, to implement a wireless communication function or an NFC wireless charging function, so that the NFC apparatus operates in an optimal state.

In some embodiments, the controller <NUM> may generate power control signals (referred to as a "first group of power control signals") used for the direct-current/alternating-current converter <NUM> based on the operating mode, for regulating a magnitude and a phase of an alternating-current voltage output by the direct-current/alternating-current converter <NUM>. When the power regulator <NUM> may further include the direct-current/direct-current converter <NUM>, in some embodiments, the controller <NUM> may generate power control signals (referred to as a "second group of power control signals") used for the direct-current/direct-current converter <NUM> based on the operating mode, for regulating a magnitude of a direct-current voltage output by the direct-current/direct-current converter <NUM>.

As described above, the wireless communication mode and the NFC charging mode have different requirements for a circuit. For example, if the NFC apparatus <NUM> is in the wireless communication mode, the NFC apparatus <NUM> requires a small Q value. If the NFC apparatus <NUM> is in the NFC charging mode, the NFC apparatus <NUM> requires a large Q value. The Q value of the NFC apparatus <NUM> may be regulated by using a magnitude and a direction of injected active power.

As an example, if the operating mode of the NFC apparatus <NUM> is the wireless charging mode, active power in a same direction as active power in the NFC circuit <NUM> needs to be injected. In this case, the controller <NUM> may generate a power control signal (referred to as a" first type of power control signal") so that a phase of power output to the NFC circuit <NUM> is regulated to be in a same direction as a phase of power of the NFC circuit <NUM>. In this way, an equivalent quality factor of the NFC circuit <NUM> and the NFC coil are increased and NFC charging efficiency is improved. In some embodiments, the controller <NUM> may update the first type of power control signal. For example, the controller <NUM> may update the first type of power control signal based on power of the NFC circuit <NUM> in the wireless charging mode. Alternatively, the first power control signal may be updated by the controller <NUM> based on impedance of the NFC apparatus <NUM> in the wireless charging mode.

If the operating mode of the NFC apparatus <NUM> is the wireless communication mode, active power in an opposite direction as the NFC circuit <NUM> needs to be injected. In this case, the controller <NUM> may generate a power control signal (referred to as a" second type of power control signal") so that a phase of power output to the NFC circuit <NUM> is regulated to be in an opposite direction as a phase of power of the NFC circuit <NUM>. In this way, equivalent Q values of the NFC circuit <NUM> and the NFC coil are decreased and a Q value required for NFC communication is achieved. That is, active power is obtained from the NFC circuit <NUM>, and is consumed or recovered to a direct-current source. Specifically, the power regulator <NUM> may obtain the active power of the NFC circuit <NUM> through the interface circuit <NUM>, to form an equivalent load on the NFC circuit <NUM>. In some embodiments, the power regulator <NUM> may perform direct-current/alternating-current power conversion on the active power obtained. The power obtained after conversion by the power regulator <NUM> may be transmitted backward, to be supplied as auxiliary power to the NFC power converter <NUM>. In this way, power recovery is implemented, and power consumption of the NFC apparatus <NUM> is reduced. In other embodiments, the active power obtained may be directly consumed by the power regulator <NUM> without being transmitted backward. In some embodiments, the controller <NUM> may update the second type of power control signal. For example, the controller <NUM> may update the second type of power control signal based on power, impedance, or both of the NFC apparatus <NUM> in the wireless communication mode.

Impedance of the NFC circuit <NUM> may be regulated by changing a magnitude and a direction of injected reactive power. As an example, if the detector <NUM> determines that the NFC apparatus <NUM> is an inductive circuit, leading reactive power, that is, capacitive reactive power, needs to be injected. In this case, the controller <NUM> may generate a power control signal (referred to as a "third type of power control signal"), so that a phase difference between a phase of power output to the NFC circuit <NUM> and a phase of power of the NFC circuit <NUM> is regulated to a first predetermined phase difference, thereby changing the NFC apparatus <NUM> into a resistive circuit.

If the detector <NUM> determines that the NFC apparatus <NUM> is a capacitive circuit, lagging reactive power, that is, inductive reactive power, needs to be injected. In this case, the controller <NUM> may generate a power control signal (referred to as a "fourth type of power control signal"), so that a phase difference between a phase of power output to the NFC circuit <NUM> and a phase of power of the NFC circuit <NUM> is regulated to a second predetermined phase difference, thereby changing the NFC apparatus <NUM> into a resistive circuit.

The controller <NUM> may generate any suitable power control signal based on the circuit parameters of the NFC apparatus <NUM>, to regulate the phase of the power output to the NFC circuit <NUM>, thereby achieving required injected power. Table <NUM> shows a relationship between injected power and a phase difference. It may be understood that values shown in Table <NUM> are merely an example and do not impose a restriction.

In block <NUM>, the power regulator <NUM> regulates, based on the power control signals, at least one of a magnitude and a phase of the power output to the NFC circuit <NUM>. In some implementations, the direct-current/alternating-current converter <NUM> in the power regulator <NUM> may perform mutual conversion between a first direct-current voltage and a first alternating-current power supply and regulate a magnitude and a phase of an output alternating-current voltage based on the first group of power control signals. Alternatively, if the power regulator <NUM> includes the direct-current/direct-current converter <NUM>, the direct-current/direct-current converter <NUM> may implement mutual conversion between a second direct-current voltage and a first direct-current voltage that is provided to the direct-current/alternating-current converter <NUM>. The direct-current/direct-current converter <NUM> may further regulate a magnitude of the first direct-current voltage based on the second group of power control signals.

<FIG> is a diagram of a structure of an NFC apparatus <NUM> according to an example embodiment of the present disclosure. The NFC apparatus <NUM> shown in <FIG> is merely an example and does not impose a restriction. The NFC apparatus <NUM> may be an example embodiment of the NFC apparatus <NUM>. The NFC apparatus <NUM> may simultaneously regulate a Q value and impedance of the NFC apparatus, so that the NFC apparatus <NUM> can not only operate in an efficient NFC wireless charging mode, but also operate in a wireless communication mode that meets a compatibility requirement.

As shown in <FIG>, the NFC apparatus <NUM> includes an NFC power converter <NUM>, an NFC circuit <NUM>, a controller <NUM>, a direct-current/direct-current converter (shown as a bidirectional buck-boost converter <NUM>), a direct-current/alternating-current converter (shown as a DC/AC full-bridge converter <NUM>), and an interface circuit <NUM>. <FIG> further includes other devices not shown, such as a detector.

Referring to <FIG>, the bidirectional buck-boost converter <NUM> is configured to control bidirectional flow of energy and control a direct-current port voltage Vdc of the post-stage DC/AC full-bridge converter <NUM>. For example, the bidirectional buck-boost converter <NUM> converts a direct-current voltage Vsys into the direct-current voltage Vdc. The DC/AC full-bridge converter <NUM> is configured to invert the direct-current voltage Vdc into an alternating-current voltage Ur for output, and may also rectify the alternating-current voltage Ur to the direct-current voltage Vdc. The interface circuit <NUM> is configured to inject the port voltage Ur of the DC/AC full-bridge converter <NUM> into the NFC circuit <NUM>. The interface circuit <NUM> may include an inductor and a capacitor, for example, L31, C31, C32, and L32. A power supply to the NFC power converter <NUM> also provides the direct-current voltage Vsys.

The controller <NUM> is configured to control an amplitude of the port voltage Vdc of the bidirectional buck-boost converter <NUM> and an amplitude of the port voltage Ur of the DC/AC full-bridge converter <NUM>. The controller <NUM> may be further configured to control a phase difference of the port voltage Ur of the DC/AC full-bridge converter <NUM> relative to the NFC circuit <NUM>. Therefore, a phase and an amplitude of power of the NFC circuit <NUM> can be arbitrarily controlled through phase/amplitude control. The bidirectional buck-boost converter <NUM>, the DC/AC full-bridge converter <NUM>, the controller <NUM>, and the NFC power converter <NUM> may be integrated into an NFC chip by using a semiconductor process. In addition, arbitrary regulation of a Q value and impedance can be implemented by adding only a few passive devices (inductors and capacitors) at the periphery. This manner can save a PCB board surface and effectively control costs.

According to the NFC apparatus <NUM> shown in <FIG>, if circuit impedance of the NFC circuit <NUM> is to be regulated, only reactive power needs to be injected into the NFC circuit <NUM>. Because average power of the reactive power is zero, energy is exchanged between a device that rectifies an alternating current to a direct current and a passive device, and theoretically, active power is not obtained from a direct-current source. If a Q value of the NFC circuit <NUM> is to be regulated, active power of the NFC circuit <NUM> may be obtained by using the DC/AC full-bridge converter <NUM>, and the active power is fed back to the direct-current source to form load resistance R that is arbitrarily regulated. As shown in <FIG>, an equivalent resistor of the full-bridge converter may be expressed as R. To simplify analysis, a parasitic inductor, a parasitic capacitor, and an equivalent resistor of an EMC network and a matching network are ignored first. Through circuit-based equivalent conversion, they can be equivalent to a resistor Req and a capacitor Ceq that are connected in series, as shown in <FIG>. Then, they are connected to a transmit coil Ltx in parallel (as shown in <FIG> and <FIG>). When the resistor R does not exist, the Q value of the system is Q = <NUM> × π × f × Ltx/(Rac1 + Rac2), and the Q value is large, which is used in the NFC wireless charging mode. When the resistor R exists, the Q value of the system is Q = <NUM> × π × f × Ltx/(Rac1 + Rac2 + Req), and the Q value is small, which is used in the wireless communication mode.

<FIG> is a diagram of a structure of an NFC apparatus according to another example embodiment of the present disclosure. The NFC apparatus <NUM> shown in <FIG> is merely an example and does not impose a restriction. The NFC apparatus <NUM> may be an example embodiment of the NFC apparatus <NUM>. The NFC apparatus <NUM> may simultaneously regulate a Q value and impedance of the NFC apparatus, so that the NFC apparatus <NUM> can not only operate in an efficient NFC wireless charging mode, but also operate in a wireless communication mode that meets a compatibility requirement.

As shown in <FIG>, the NFC apparatus <NUM> includes an NFC power converter <NUM>, an NFC circuit <NUM>, a controller <NUM>, a direct-current/direct-current converter (shown as an LDO <NUM> through which a unidirectional current flows), a direct-current/alternating-current converter (shown as a full-bridge inverter <NUM>), and an interface circuit <NUM>. It should be understood that the NFC apparatus <NUM> shown in <FIG> is merely an example and does not impose a restriction. <FIG> may further include other devices not shown, such as a detector.

Referring to <FIG>, the LDO <NUM> is configured to control bidirectional flow of energy and control a direct-current port voltage Vdc2 of the post-stage full-bridge inverter <NUM>. For example, the LDO <NUM> converts a direct-current voltage Vsys2 into the direct-current voltage Vdc2. The full-bridge inverter <NUM> is configured to invert the direct-current voltage Vdc2 into an alternating-current voltage Ur2 for output, and may also rectify the alternating-current voltage Ur2 to the direct-current voltage Vdc2. The interface circuit <NUM> is configured to inject the port voltage Ur2 of the full-bridge inverter <NUM> into the NFC circuit <NUM>.

The controller <NUM> is configured to control the LDO <NUM> to output the voltage Vdc2 or control a drive duty ratio or a phase shift angle of the full-bridge inverter <NUM>. The controller <NUM> is further configured to control phases of a drive signal of the full-bridge inverter <NUM> and a master clock.

According to the NFC apparatus <NUM> shown in <FIG>, if circuit impedance of the NFC circuit <NUM> is to be regulated, only reactive power needs to be injected into the NFC circuit <NUM>. Because average power of the reactive power is zero, energy is exchanged between a device that rectifies an alternating current to a direct current and a passive device, and theoretically, active power is not obtained from a direct-current source. The NFC apparatus <NUM> implements Q value regulation of the NFC circuit in an energy consumption manner. If a Q value of the NFC circuit <NUM> is to be regulated, regulation of the Q value may be implemented by using arbitrarily regulated resistance that is achieved through a power device of the full-bridge inverter <NUM> and resistors connected in series.

In addition, similarly, the LDO <NUM>, the full-bridge inverter <NUM>, the controller <NUM>, and the NFC power converter <NUM> may be integrated into an NFC chip by using a semiconductor process. In addition, arbitrary regulation of a Q value and impedance can be implemented by adding only a few passive devices (inductors and capacitors) at the periphery. This manner can save a PCB board surface and effectively decrease costs.

In general, the various example embodiments of the present disclosure may be implemented in hardware or dedicated circuits, software, logic, or any combination thereof. Some aspects may be implemented in hardware. Other aspects may be implemented in firmware or software that may be executed by controllers, microprocessors, or other computing devices. When various aspects of the embodiments of the present disclosure are illustrated or described as block diagrams, flowcharts, or using some other graphical representation, it is appreciated that the blocks, apparatuses, systems, technologies, or methods described herein may be implemented as non-restrictive examples in hardware, software, firmware, dedicated circuits or logic, general-purpose hardware or controllers, or other computing devices, or some combination thereof. Examples of hardware devices that may be used to implement the embodiments of the present disclosure include but are not limited to: a field programmable gate array (FPGA), an application-specific integrated circuit (ASIC), an application-specific standard product (ASSP), a system-on-chip (SOC), a complex programmable logic device (CPLD), and the like.

As an example, the embodiments of the present disclosure may be described in context of machine executable instructions. The machine executable instructions are, for example, included in program modules executed in a device of a target real or virtual processor. In general, the program modules include routines, programs, libraries, objects, classes, components, data structures, and the like, and perform specific tasks or implement specific abstract data structures. In various embodiments, functions of the program modules may be merged or split between the described program modules. The machine executable instructions used for the program modules may be executed locally or in a distributed device. In the distributed device, the program modules may be located in both local and remote storage media.

Computer program code used to implement the method of the present disclosure may be written in one or more programming languages. The computer program code may be provided to a processor of a general-purpose computer, a dedicated computer, or another programmable data processing apparatus. In this case, when the program code is executed by the computer or the another programmable data processing apparatus, the program code causes functions/operations specified in the flowcharts and/or block diagrams to be implemented. The program code may be executed entirely on the computer, partially on the computer, as a standalone software package, partially on the computer and partially on a remote computer, or entirely on a remote computer or server.

In the context of the present disclosure, the computer program code or associated data may be carried by any suitable carrier to enable a device, an apparatus, or a processor to execute the various processing and operations described above. Examples of the carrier include a signal, a computer readable medium, and the like.

Examples of the signal may include a propagating signal in an electrical, optical, radio, sound, or other form, such as a carrier or an infrared signal.

Claim 1:
A near field communication NFC apparatus(<NUM>), comprising:
an NFC power converter (<NUM>), configured to connect to a direct-current power supply (<NUM>) and generate a high-frequency alternating-current output;
an NFC coil (<NUM>), configured to generate/receive an NFC high-frequency magnetic field and transmit/receive NFC power or an NFC signal;
an NFC circuit (<NUM>) connected to the NFC power converter and the NFC coil, configured to transmit/receive the high-frequency alternating-current output;
a controller(<NUM>), configured to generate different power control signals based on different operating modes of the NFC apparatus; and
a power regulator(<NUM>), coupled one end of the power regulator to the direct-current power supply and the other end of the power regulator to the NFC circuit, and configured to regulate, based on the different power control signals, at least one of a magnitude and a phase of power output to the NFC circuit and characterised in that the power regulator comprises:
a direct-current/alternating-current converter(<NUM>), coupled between the direct-current power supply and the NFC circuit; and
a direct-current/direct-current converter (<NUM>), coupled between the direct-current power supply and the direct-current/alternating-current converter.