Wireless power transmitter comprising an impedance matching circuit and method for transmitting a wireless power

Abstract

The present disclosure provides a wireless power transmission device comprising an impedance matching circuit. The wireless power transmission device of the present disclosure may include: a transistor that outputs a signal corresponding to a set operating frequency based on an input signal and a driving voltage; a matching circuit connected to the transistor and converting the impedance of the signal corresponding to the operating frequency; a transmitting coil connected to the matching circuit; an LC resonant circuit connected in parallel between the transistor and the matching circuit and transmitting a signal corresponding to at least one harmonic frequency of the operating frequency; and an impedance sensing circuit connected to the LC resonant circuit and sensing the load impedance of the wireless power transmission device based on the signal corresponding to the at least one harmonic frequency transmitted through the LC resonant circuit. Various other embodiments of the wireless power transmission device comprising the impedance matching circuit of the present disclosure may be applied.

Description

Technology Field

[0001] Various embodiments of the present disclosure relate to a wireless power transmission device and a wireless power transmission method including an impedance matching circuit. Background Technology

[0002] Wireless charging technology utilizes wireless power transmission and reception, and refers to a technology that allows a mobile phone's battery to be automatically charged simply by placing the phone on a wireless power transmitting device (e.g., a charging pad) without connecting a separate charging connector. This wireless charging technology has the advantage of enhancing waterproofing capabilities by eliminating the need for a power supply connector on electronic products, and increasing the portability of electronic devices by eliminating the need for a wired charger.

[0003] With the advancement of wireless charging technology, methods for charging by supplying power from a single electronic device (wireless power transmitter) to various other electronic devices (wireless power receivers) are being researched. For example, wireless charging technologies include electromagnetic induction using coils, resonance methods utilizing resonance, and radio frequency (RF) radiation methods that convert electrical energy into microwaves for transmission.

[0004] Recently, wireless charging technology using electromagnetic induction or resonance methods has become widespread, primarily in electronic devices such as smartphones. For example, when a wireless power transmitting unit (PTU) (e.g., a wireless power transmitting device) and a wireless power receiving unit (PRU) (e.g., a smartphone or a wearable electronic device) come into contact or approach within a certain distance, power can be transferred to the wireless power receiving unit by means of electromagnetic induction or electromagnetic resonance between the transmitting coil or resonator of the wireless power transmitting unit and the receiving coil or resonator of the wireless power receiving unit, and the battery contained in the wireless power receiving unit can be charged by the transferred power.

[0005] A wireless power transmission device (or wireless power transmitter) may include an inverter and a resonator. An inverter is a device that converts direct current (DC) power into alternating current (AC) power. To increase the efficiency of the inverter, various matching circuits may be connected to the output terminal of the inverter.

[0006] An example of an inverter is a class E inverter (or class E power amplifier, PA). Since such a class E inverter operates under zero-voltage switching (ZVS) and zero-derivative voltage switching (ZDS) conditions, it has the advantage of being able to operate efficiently at high switching frequencies (e.g., 1 MHz or higher).

[0007] According to various embodiments, a Class EF in which a resonant network is added in parallel to a load network to increase the efficiency of a Class E inverter n(Here, n is an integer greater than or equal to 2) Inverter or Class E / F n An inverter is being used. The problem to be solved

[0008] According to various embodiments, a Class EF2 inverter has a form in which an LC series resonant circuit is connected in parallel to the load network of a Class E inverter. Depending on the distance between a metal (e.g., a receiving terminal) and a wireless power transmitter (or a Class EF2 inverter of a wireless power transmitter), the load impedance (Z L As ) changes, a problem may occur in which the efficiency of the Class EF2 inverter decreases.

[0009] For example, as the distance between the metal (e.g., receiving terminal) and the wireless power transmitter (or the Class EF2 inverter of the wireless power transmitter) decreases, the load impedance (Z L ) can increase. The load impedance (Z) of the above wireless power transmission device L If ) increases, the efficiency of the wireless power transmission device may be relatively lower.

[0010] In various embodiments of the present disclosure, a wireless power transmission device and a wireless power transmission method may be provided, comprising an impedance matching circuit capable of sensing a load impedance by sensing a signal corresponding to a harmonic frequency through an LC resonant circuit connected in parallel with a transistor that outputs a signal corresponding to an operating frequency.

[0011] In various embodiments of the present disclosure, a wireless power transmission device and a wireless power transmission method may be provided, comprising an impedance matching circuit capable of sensing a load impedance by sensing a signal corresponding to a harmonic frequency through an LC resonant circuit connected in parallel with a transistor that outputs a signal corresponding to an operating frequency, and adjusting the impedance based on the sensed load impedance. means of solving the problem

[0012] A wireless power transmission device according to one embodiment for solving the aforementioned problem or other problems may include: a transistor that outputs a signal corresponding to a set operating frequency based on an input signal and a driving voltage; a matching circuit connected to the transistor and converting the impedance of the signal corresponding to the operating frequency; a transmitting coil connected to the matching circuit; an LC resonant circuit connected in parallel between the transistor and the matching circuit and transmitting a signal corresponding to at least one harmonic frequency of the operating frequency; and an impedance sensing circuit connected to the LC resonant circuit and sensing the load impedance of the wireless power transmission device based on the signal corresponding to the at least one harmonic frequency transmitted through the LC resonant circuit.

[0013] A wireless power transmission method of a wireless power transmission device according to one embodiment for solving the aforementioned problem or other problems may include: an operation of outputting a signal corresponding to a set operating frequency based on an input signal and a driving voltage in a transistor; an operation of receiving a signal corresponding to the operating frequency and converting the impedance in a matching circuit connected to the transistor; an operation of receiving an impedance-converted signal from the matching circuit and forming a magnetic field based on the received signal in a transmitting coil; an operation of transmitting a signal corresponding to at least one harmonic frequency of the operating frequency in an LC resonant circuit connected in parallel between the transistor and the matching circuit; and an operation of sensing the load impedance of the wireless power transmission device based on a signal corresponding to the at least one harmonic frequency transmitted through the LC resonant circuit in an impedance sensing circuit connected to the LC resonant circuit. Effects of the invention

[0014] A wireless power transmission device and a wireless power transmission method according to various embodiments can prevent a decrease in charging efficiency due to changes in distance from a metal (e.g., a wireless power receiving device) by sensing a load impedance from a signal corresponding to a harmonic frequency and adjusting the impedance based on the sensed load impedance. Brief explanation of the drawing

[0015] FIG. 1 is a circuit diagram of a wireless power transmission device according to various embodiments of the present disclosure. FIG. 2 is a circuit diagram of a wireless power transmission device according to various embodiments of the present disclosure. FIG. 3 is a graph showing the switching waveform of a transistor according to various embodiments of the present disclosure. FIGS. 4a, FIGS. 4b, FIGS. 4c, FIGS. 4d, and FIGS. 4e are graphs showing waveforms measured at each part of a wireless power transmission device according to various embodiments of the present disclosure. FIG. 5a is a graph showing the switching waveform of a transistor according to various embodiments of the present disclosure on the time axis. FIG. 5b is a graph showing the switching waveform of a transistor according to various embodiments of the present disclosure on the frequency axis. FIG. 6a is a graph showing the switching waveform of a transistor according to various embodiments of the present disclosure on the time axis. FIG. 6b is a graph showing the switching waveform of a transistor according to various embodiments of the present disclosure on the frequency axis. FIGS. 7a, FIGS. 7b, and FIGS. 7c are graphs showing the relationship between normalized sensing values ​​and impedance according to various embodiments of the present disclosure. FIG. 8 is a circuit diagram modeling a wireless power transmission device according to various embodiments of the present disclosure. FIGS. 9a, FIGS. 9b, and FIGS. 9c are graphs showing the relationship between normalized sensing values ​​and impedance according to various embodiments of the present disclosure. FIG. 10 is a circuit diagram of a wireless power transmission device according to various embodiments of the present disclosure. FIG. 11 is a circuit diagram of a wireless power transmission device according to various embodiments of the present disclosure. FIG. 12 is a graph showing sensor gains by harmonic frequency according to various embodiments of the present disclosure. FIGS. 13a, FIGS. 13b, and FIGS. 13c are graphs showing the relationship between normalized sensing values ​​and impedance according to various embodiments of the present disclosure. FIG. 14 is a circuit diagram of a wireless power transmission device according to various embodiments of the present disclosure. FIG. 15 is a circuit diagram of a wireless power transmission device according to various embodiments of the present disclosure. FIG. 16 is a circuit diagram of a wireless power transmission device according to various embodiments of the present disclosure. FIG. 17 is a circuit diagram of a wireless power transmitting device and a wireless power receiving device according to various embodiments of the present disclosure. Specific details for implementing the invention

[0016] Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings. It should be noted that identical components in the drawings are indicated by the same reference numerals wherever possible. Detailed descriptions of known functions and configurations that could unnecessarily obscure the essence of the present invention are omitted in the following description and the accompanying drawings.

[0017] FIG. 1 is a circuit diagram of a wireless power transmission device according to various embodiments. Referring to FIG. 1, the wireless power transmission device may include an inverter (e.g., an EF2 inverter (10)), a matching circuit (15), and a resonator. According to various embodiments, the EF2 inverter (10) includes an RF choke inductor (L f )(3), gate driver(5), transistor(7), shunt capacitor(Cp It may include )(9), a first LC resonant circuit (11), and a second LC resonant circuit (13).

[0018] The transistor (7) receives a DC voltage (V) from the input power supply (1). in It can operate by receiving ) as a driving voltage. The transistor (7) can be turned on or turned off by receiving an input signal in the form of a pulse (e.g., a square wave) from the gate driver (5) through an input terminal (e.g., a gate). The transistor (7) may include a metal oxide semiconductor field effect transistor (MOSFET).

[0019] The RF choke inductor (3) can block the transmission of an RF signal from the input power source (1) to the transistor (7) so that only DC current is transmitted to the transistor (7).

[0020] The shunt capacitor (9) is connected in parallel with the transistor (7) and can be discharged or charged while the transistor (7) is turned on or turned off. The shunt capacitor (9) may be a separate capacitor connected in parallel with the transistor (7) and the internal capacitance of the transistor (2) (e.g., drain-source capacitance (C) ds It may also be explained as a concept that includes )).

[0021] An RF signal (or RF power) may be generated based on the transistor (7) receiving an input signal from the gate driver (5) and turning on or off. The generated RF signal may be a signal having an operating frequency corresponding to the input signal input from the gate driver (5) to the gate of the transistor (7). For example, when the wireless power transmission device transmits wireless power according to a standard resonant method, the operating frequency may be 6.78 MHz, but is not limited thereto. The RF signal or RF power may be transmitted to the first LC resonant circuit (11) and / or the second LC resonant circuit (13) through the output terminal of the transistor (7). More specifically, when the transistor (7) is turned on (e.g., when the transistor (7) is in a saturated state), the transistor (7) is electrically short-circuited and can be interpreted as a short circuit to ground connected to the source, and the voltage of the output terminal can be interpreted as zero. As the transistor (7) is turned on, the current flowing through the RF choke inductor (3) to the transistor (7) can gradually increase. Subsequently, when the transistor (7) is turned off, the current flowing through the RF choke inductor (3) is directed to the shunt capacitor (9), and as the shunt capacitor (9) is gradually charged, the voltage at the output terminal of the transistor (7) (e.g., the voltage across the shunt capacitor (9)) can increase until it reaches a maximum value. Subsequently, as the shunt capacitor (9) is gradually discharged, current flows from the shunt capacitor (9) through the output terminal of the transistor (7) to the first LC resonant circuit (11) and / or the second LC resonant circuit (13), and the voltage across the shunt capacitor (9) can gradually decrease.After the transistor (7) is turned off and before it is turned on again (e.g., before current starts flowing again to the transistor (7) through the RF choke inductor (3)), the transistor (7), the shunt capacitor (9), and the input signal can be configured so that the voltage at the output terminal of the transistor (7) (e.g., the voltage across the shunt capacitor (9) and the drain-source voltage of the transistor (7)) gradually decreases to zero and the amount of change in the voltage at the output terminal of the transistor (7) decreases to zero. Subsequently, when the transistor (7) is turned on again, the current flowing through the RF choke inductor (3) is directed to the transistor (7), and the voltage at the output terminal of the transistor (7) can be maintained at zero while the transistor (7) is in the ON state. As described above, while the transistor (7) is in the ON state, the voltage at the output terminal of the transistor (7) is zero, and while it is in the OFF state, the current flowing through the RF choke inductor (3) is directed toward the shunt capacitor (9), so the current flowing through the RF choke inductor (3) to the transistor (7) is zero (in other words, the period when the voltage at the output terminal of the transistor (7) is non-zero and the period when the drain-source current is non-zero do not overlap), so the power consumed by the transistor (7) can ideally be zero. However, in non-ideal cases, since RF power is generated based on the transistor (7) being turned on or turned off, the generated RF power may include not only the desired frequency component (e.g., the fundamental component of the operating frequency) but also harmonic frequency components of order 2 or higher. The duty cycle of the transistor (7) can be set to, for example, 50% based on the input signal.

[0022] The first LC resonant circuit (11) can be connected in parallel with the transistor (7). The first LC resonant circuit (11) includes a first inductor (L) connected in series with each other. mr )(11a)(e.g., coil) and the first capacitor (C mr It may include )(11b). The first inductor (11a) and the first capacitor (11b) are such that the resonant frequency of the first LC resonant circuit (11) is the operating frequency (f) of the input signal. s 2nd harmonic frequency (2f) of ) s It can have appropriate component values ​​to correspond to ). The first LC resonant circuit (11) has a second harmonic frequency (2f s ) can be interpreted as an electrical short circuit. The first LC resonant circuit (11) is at a second harmonic frequency (2f s A second harmonic filter (2) that prevents the second harmonic component of the RF power generated from the transistor (7) from being transmitted to the second LC resonant circuit (13) based on being electrically short-circuited in ). nd It can function as a harmonic filter (e.g., a band-stop filter).

[0023] The second LC resonant circuit (13) can be connected in series to the output terminal of the transistor (7). The second LC resonant circuit (13) is connected in series with a second capacitor (C o )(13a) and the second inductor (L o It may include )(13b). The second capacitor (13a) and the second inductor (13b) are such that the resonant frequency of the second LC resonant circuit (13) is the operating frequency (f) of the input signal. s Corresponds to ) (e.g., fundamental frequency (or, 1st harmonic frequency)(f s The second LC resonant circuit (13) can have appropriate component values ​​that correspond to )). The second LC resonant circuit (13) has a first harmonic frequency (f s) can be interpreted as an electrically short circuit. The second LC resonant circuit (13) is at the first harmonic frequency (f s It can operate as a band-pass filter (or low-pass filter) that passes the fundamental component (or first harmonic component) (e.g., a component corresponding to the operating frequency) of the RF power generated from the transistor (7) based on being electrically short-circuited in ).

[0024] The matching circuit (15) can be connected in series with the second LC resonant circuit (13). The matching circuit (15) has an output impedance (e.g., impedance facing the second LC resonant circuit (13)) that is connected to the load (Z L Impedance matching can be provided to match the impedance of )(17). The matching circuit (15) may include, for example, at least one low-pass filter and / or band-stop filter, and the low-pass filter may include at least one capacitor.

[0025] The load (17) (or load) may include at least one hardware component (e.g., circuit element) that receives or operates RF power generated by the EF2 inverter (10). For example, the load (17) may include a hardware component (e.g., transmitting coil) of a wireless power transmitting device (e.g., electronic device) including the EF2 inverter (10) and / or a receiving device (e.g., wireless power receiving device or wireless power receiver) that receives power from a magnetically coupled electronic device.

[0026] According to a comparative example, when a metal (e.g., a wireless power receiver) approaches an EF2 inverter (10) or a wireless power transmitter including an EF2 inverter (10), the coupling between them increases, and the impedance (Z) facing the load (17) L As ) increases, the efficiency of the EF2 inverter (10) or wireless power transmission device may decrease.

[0027] FIG. 2 is a circuit diagram of a wireless power transmission device according to various embodiments of the present disclosure. According to various embodiments, the current flowing through or the voltage applied to each element or component can be simulated by modeling the circuit of the wireless power transmission device of FIG. 1 as shown in FIG. 2. Referring to FIG. 2, a first diode may be connected between the drain and source of a transistor (7), and a voltage V applied between the drain and source of the transistor (7) ds can be measured as shown in FIG. 3. The voltage V applied between the drain and source of the transistor (7) shown in FIG. 3. ds is the point in time when the above transistor (7) becomes stabilized after being initially driven (e.g., 1×10 -5 s) It may be a waveform measured for a certain period of time thereafter. For example, the waveform is T as shown in FIG. 3. s It can have a period. Referring to Fig. 3 above, one T s A period within the cycle corresponding to the state where the transistor (7) is turned on (e.g., DT s In the interval, the voltage V applied between the drain and source of the transistor (7) ds α can be 0 or close to 0, and in the interval corresponding to the transistor (7) being off, the voltage V applied between the drain and source of the transistor (7) ds It can be close to 35~40V. The graph of Fig. 3 above is a single T s If expanded to a period and 100 samples are taken within that period and displayed as a graph, it can be represented as shown in Fig. 4a.

[0028] According to various embodiments, an RF choke inductor (L f Current I flowing through )(3) f is the corresponding T sIf 100 samples are taken within the period and plotted on a graph, it can be represented as shown in FIG. 4b. Referring to FIG. 4b, I f The magnitude of the ripple ΔI f can have a value from -4A to 4A. The above ΔI f It can be expressed as shown in <Mathematical Formula 1> below.

[0029]

[0030] According to various embodiments, current I flowing through the first LC resonant circuit (11) (e.g., first inductor (11a) and first capacitor (11b)) mr is the corresponding T s If 100 samples are taken within a period and displayed as a graph, it can be represented as shown in Fig. 4c. Referring to Fig. 4c, it can be seen that, unlike Fig. 4a, it includes harmonic frequency signals of order 2 or higher.

[0031] According to various embodiments, current I flowing through the second LC resonant circuit (13) (e.g., second capacitor (13a) and second inductor (13b)) s is the corresponding T s If 100 samples are taken within the period and displayed as a graph, it can be represented as shown in Fig. 4d.

[0032] According to various embodiments, the matching circuit (15) is a third capacitor (201) (C) connected in series with the second LC resonant circuit (13). ps ) and a fourth capacitor (202) (C) connected in parallel with the second LC resonant circuit (13) po It may include ). According to various embodiments, the transmitting coil may include a third inductor (203) (L) connected in series with the third capacitor (201). tx ) and the first resistor (204)(R tx It may include ). The third inductor (203) (L tx ) and the first resistor (204)(R tx ) is load impedance (Z LZ together with )(17) in It can be modeled as.

[0033] According to various embodiments, current i flowing through the transmitting coil tx (e.g., third inductor (203)(L tx ) and the first resistor (204)(R tx The current flowing through ) is the corresponding T s If 100 samples are taken within a period and plotted on a graph, it can be represented as shown in FIG. 4e. According to various embodiments, as the distance between the metal (e.g., a wireless power receiver) decreases, the coupling increases, and accordingly, the load impedance (Z L )(17) is R L +jX L When expressed as such, the above load impedance Z L As the real component of increases, the load impedance (Z L Resistance R of )(17) L This can increase. On the other hand, load impedance (Z L The imaginary component of )(17) is reduced, so the load impedance (Z L Reactance X of )(17) L It can decrease.

[0034] In the embodiments described below, V shown in FIG. 4a ds Based on this, we will explain how to sense the reactance of the load impedance.

[0035] FIGS. 5a and 6a are graphs showing the switching waveform of a transistor according to various embodiments of the present disclosure on the time axis, and FIGS. 5b and 6b are graphs showing the switching waveform of a transistor according to various embodiments of the present disclosure on the frequency axis. FIGS. 5a and 5b show V when a metal (e.g., a wireless power receiving device) is separated from a wireless power transmitting device by a first distance. dsIt is a waveform, and FIGS. 6a and 6b show V when a metal (e.g., a wireless power receiving device) is separated from a wireless power transmitting device by a second distance, which is closer than a first distance. ds It is a waveform. Referring to Figures 5b and 6b, it can be seen that a significant difference in Vds appears at the third harmonic. For example, when sensing the third harmonic, the metal approaches and the reactance X L This can increase. At this time, as shown in FIGS. 6a and 6b, V ds The third harmonic frequency signal V ds,3rd It can be seen that it increases from 8.07V to 14.5V. As such, V ds The reactance applied to the load can be measured by sensing the harmonic frequency signal.

[0036] FIGS. 7a, 7b, and 7c are graphs illustrating the relationship between normalized sensing values ​​and impedance according to various embodiments of the present disclosure. Referring to FIG. 7a, V ds V, which is the first harmonic frequency (or fundamental frequency or operating frequency) component of ds,1st ul V in If normalized to, V ds,1st / V in This can be, V ds,1st ul V in The value V normalized to ds,1st / V in is R L Although it has little relevance to X L It can be seen that there is a correlation. For example, X L When this increases in steps of 0.3 from -0.35 to -0.05, V ds,1st / V in It can be seen that ga decreases stepwise by 0.1 from 1.34 to 1.24. According to various embodiments, V ds,1st ul V in The value V normalized to ds,1st / V in Based on X L or XL The change in can be estimated.

[0037] According to various embodiments, referring to FIG. 7b, V ds V, the second harmonic frequency component of ds,2st ul V in If normalized to V ds,2st / V in This can be, V ds,2st ul V in The value V normalized to ds,2st / V in R, as in Fig. 7a L Although it has little relevance to X L It can be seen that there is a correlation. For example, X L When is increased in steps of 0.25 from -0.3 to -0.05, V ds,2st / V in It can be seen that ga decreases stepwise by 0.015 from 0.033 to 0.018. According to various embodiments, V ds,2st ul V in The value V normalized to ds,2st / V in Based on X L or X L The change in can be estimated.

[0038] According to various embodiments, referring to FIG. 7c, V ds V, the third harmonic frequency component of ds,3st ul V in If normalized to V ds,3st / V in This can be, V ds,3st ul V in The value V normalized to ds,3st / V in R, as in Fig. 7c L Although it has little relevance to X L It can be seen that there is a correlation. For example, X L When is increased in steps of 0.25 from -0.35 to -0.1, V ds,3st / V inIt can be seen that ga decreases stepwise by 0.3 from 0.7 to 0.4. According to various embodiments, V ds,3st ul V in The value V normalized to ds,3st / V in Based on X L or X L The change in can be estimated. As a comparative example, comparing Fig. 7a and Fig. 7c, since the normalized value of the 3rd harmonic frequency component in Fig. 7c has a relatively larger range of variation compared to the normalized value of the 1st harmonic frequency component in Fig. 7a, X L The sensing performance for may be superior.

[0039] FIG. 8 is a circuit diagram modeling a wireless power transmission device according to various embodiments of the present disclosure. Referring to FIG. 8, as described above, L tx , R tx , Z L Z IN It can be modeled as (801). Through the circuit modeled as in Fig. 8 above, V ds The sum of the harmonic frequency components of is Z as illustrated in FIGS. 9a, 9b, and 9c. IN X, the reactance component of IN It can be seen that there is a correlation.

[0040] For example, V ds V, the third harmonic frequency component of ds,3st , V ds V, the 4th harmonic frequency component of ds,4st , V ds V, the 5th harmonic frequency component of ds,5st , and V ds V, the 6th harmonic frequency component of ds,6st The sum of V h It can be represented as. The above V h ul V in The value normalized to X IN Compared to, it can be represented as shown in Figs. 9a, 9b, and 9c. Fig. 9a is L f200nH, L o 66nH, L mr Normalized V when set to 260nH h and X L It shows the relationship between, and Fig. 9b is L f 300nH, L o 300nH, L mr Normalized V when set to 600nH h and X L It shows the relationship between them, and Fig. 9c is L f 350nH, L o 116nH, L mr Normalized V when set to 455nH h and X L It represents the relationship between. In all three cases, a specific R IN Within the range of (e.g., within 10Ω) X IN As the size of decreases, the normalized V h It can be seen that the magnitude of increases. Accordingly, the normalized V regardless of the inductance value of each inductor h X by L or X L The change in can be estimated.

[0041] FIG. 10 is a circuit diagram of a wireless power transmission device according to various embodiments of the present disclosure. Referring to FIG. 10, the wireless power transmission device may include an inverter (e.g., an EF2 inverter (10)), a matching circuit (15), a resonator, and an impedance sensing circuit (1000). According to various embodiments, the EF2 inverter (10) includes an RF choke inductor (L f )(3), gate driver(5), transistor(7), shunt capacitor(C pIt may include )(9), a first LC resonant circuit (11), and a second LC resonant circuit (13). The impedance sensing circuit (1000) may include at least one of a high pass filter (HPF) (1010), an envelope detector (1020), or a controller (1030).

[0042] The first LC resonant circuit (11) can be connected in parallel with the transistor (7). The first LC resonant circuit (11) includes a first inductor (L) connected in series with each other. mr )(11a)(e.g., coil) and the first capacitor (C mr It may include )(11b). The first inductor (11a) and the first capacitor (11b) are such that the resonant frequency of the first LC resonant circuit (11) is the operating frequency (f) of the input signal. s 2nd harmonic frequency (2f) of ) s It can have appropriate component values ​​to correspond to ). The first LC resonant circuit (11) has a second harmonic frequency (2f s ) can be interpreted as an electrical short circuit. The first LC resonant circuit (11) is at a second harmonic frequency (2f s A second harmonic filter (2) that prevents the second harmonic component of the RF power generated from the transistor (7) from being transmitted to the second LC resonant circuit (13) based on being electrically short-circuited in ). nd It can operate as a harmonic filter (e.g., a band-stop filter). In FIG. 10, the same reference numerals as in FIG. 1 may perform the same or similar functions, and a detailed description thereof is omitted.

[0043] According to various embodiments, an HPF (1010) may be connected in parallel between the first inductor (11a) and the first capacitor (11b). The HPF (1010) may include at least one capacitor and at least one inductor. According to various embodiments, a voltage (hereinafter referred to as 'V') applied to the inductor included in the HPF (1010). SAC (hereinafter referred to as ') is the voltage V applied to the drain-source terminal of the transistor (7). ds It can correspond to. Accordingly, the voltage V applied to the inductor included in the HPF (1010) SAC By sensing X L or X L The change in can be estimated. Depending on various embodiments, the output signal of the HPF (1010) may be connected to an envelope detector (1020). The envelope detector (1020) may detect the envelope of the signal filtered by the HPF (1010). For example, the output signal of the envelope detector (1020) is the V SAC It may be the peak value of, and below, the above V SAC The peak value of V SDC It shall be referred to as [Name]. Accordingly, the voltage V applied to the inductor included in the HPF (1010) is [Name]. SAC By sensing X L or X L The change in can be estimated. The output value of the envelope detector (1020) (e.g., V SAC V, the peak value of SDC ) can be input to the controller (1030). The controller (1030) receives the output value of the envelope detector (1020) (e.g., V SAC V, the peak value of SDC Based on ) X L or X L The change in can be estimated. For example, the controller (1030) can estimate the output value (e.g., V) of the envelope detector (1020). SAC V, the peak value ofSDC Based on ), adjust the inductance or capacitance of the matching circuit (15), or Z L Z including (17) IN of X IN The controller (1030) can adjust the output value (e.g., V) of the envelope detector (1020). SAC V, the peak value of SDC Based on ), Z L Z including (17) IN of X IN Various embodiments for adjusting [it] will be described later in the description of FIGS. 14, 15, and 16.

[0044] FIG. 11 is a circuit diagram of a wireless power transmission device according to various embodiments of the present disclosure. Referring to FIG. 11, the wireless power transmission device may include an inverter (e.g., an EF2 inverter (10)), a matching circuit (15), a resonator, and an impedance sensing circuit (1100). According to various embodiments, the EF2 inverter (10) includes an RF choke inductor (L f )(3), gate driver(5), transistor(7), shunt capacitor(C p It may include )(9), a first LC resonant circuit (11), and a second LC resonant circuit (13). The impedance sensing circuit (1000) may include at least one of a high pass filter (HPF) or an envelope detector.

[0045] The first LC resonant circuit (11) can be connected in parallel with the transistor (7). The first LC resonant circuit (11) includes a first inductor (L) connected in series with each other. mr )(11a)(e.g., coil) and the first capacitor (C mrIt may include )(11b). The first inductor (11a) and the first capacitor (11b) are such that the resonant frequency of the first LC resonant circuit (11) is the operating frequency (f) of the input signal. s 2nd harmonic frequency (2f) of ) s It can have appropriate component values ​​to correspond to ). The first LC resonant circuit (11) has a second harmonic frequency (2f s ) can be interpreted as an electrical short circuit. The first LC resonant circuit (11) is at a second harmonic frequency (2f s A second harmonic filter (2) that prevents the second harmonic component of the RF power generated from the transistor (7) from being transmitted to the second LC resonant circuit (13) based on being electrically short-circuited in ). nd It can operate as a harmonic filter (e.g., a band-stop filter). In FIG. 11, the same reference numerals as in FIG. 1 may perform the same or similar functions, and a detailed description thereof is omitted.

[0046] According to various embodiments, an HPF may be connected in parallel between the first inductor (11a) and the first capacitor (11b). The HPF is a fifth capacitor (C sac )(1101) and the fourth inductor (L sac It may include )(1102). Depending on various embodiments, the voltage V applied to the fourth inductor (1102) included in the HPF. SAC is the voltage V applied to the drain-source terminal of the transistor (7). ds It can correspond to. Accordingly, the voltage V applied to the fourth inductor included in the HPF (1010) SAC By sensing X L or X L The change in can be estimated.

[0047] For example, the voltage V applied to the fourth inductor. SACV of each harmonic order according to the following <Equation 2> to <Equation 8> ds It can be calculated using the voltage and the gain of the sensor (e.g., impedance sensing circuit (1000, 1100)). First, the gain (G) of each harmonic order n ) can be expressed as shown in <Mathematical Formula 2> below.

[0048]

[0049] In the above <Mathematical Formula 2>, Z eq is C mr (11b), C sac (1101), L sac As the impedance of (1102), it can be calculated as shown in <Equation 3> below.

[0050]

[0051] C mr Impedance Z of (11b) cmr , L mr Impedance Z of (11a) lmr , C sac Impedance Z of (1101) cac , L sac Impedance Z of (1102) lac They can be expressed as <Equation 4>, <Equation 5>, <Equation 6>, and <Equation 7>, respectively.

[0052]

[0053]

[0054]

[0055]

[0056] Using the above mathematical formulas, the voltage V applied across the terminals of the fourth inductor (1102) SAC is V of each harmonic order ds It can be calculated using voltage and the gain of a sensor (e.g., impedance sensing circuit (1000, 1100)), and the above V SAC ul V INThe value normalized by can be expressed as shown in <Mathematical Formula 8> below.

[0057]

[0058] According to various embodiments, the fifth capacitor (C sac )(1101) and the fourth inductor (L sac An envelope detector can be connected in parallel between )(1102). For example, the fifth capacitor (C sac )(1101) and the fourth inductor (L sac A second diode (1103) may be connected in parallel between (1102). A sixth capacitor (1104) and a second resistor (1106) may be connected to one end of the second diode (1103). The sixth capacitor (1104) and the second resistor (1106) may operate as envelope detectors that detect peaks of an input signal. According to various embodiments, the voltage applied to the sixth capacitor (1104) or the second resistor (1106) is the envelope-detected value of the voltage of the fourth inductor (1102), V SAC V, the peak value of SDC It can respond to.

[0059] According to various embodiments, the impedance sensing circuit (1100) is V SDC By sensing X L or X L The change in can be estimated.

[0060] FIG. 12 is a graph showing sensor gains by harmonic frequency according to various embodiments of the present disclosure. Referring to FIG. 12, the gain (G2) at the second harmonic frequency and the gain (G) at the tenth harmonic frequency 10 It exemplifies that ) appears relatively high. Therefore, in the above <Mathematical Equation 8>, V SAC X due to the 2nd harmonic frequency component and the 10th harmonic frequency component L It can effectively sense.

[0061] FIGS. 13a, 13b, and 13c are graphs illustrating the relationship between normalized sensing values ​​and impedance according to various embodiments of the present disclosure. FIGS. 13a, 13b, and 13c show R L For these 30 values ​​between 10mΩ and 100mΩ, V SAC ul V in Value normalized by (V SAC / V in ) and X L This is a graph showing the correlation between them. Fig. 13a is a network output inductor (L 1p ) is 20nH, and C sac is 1.8pF, and L sac This is an experimental example for the case of 2.2μH. Fig. 13b shows the network output inductor (L 1p ) is 30nH, and C sac is 2.1pF, and L sac This is an experimental example for the case of 2.2μH. Fig. 13c shows the network output inductor (L 1p ) is 40nH, and C sac is 2.7pF, and L sac This is an experimental example for the case of 2.2μH.

[0062] Referring to FIGS. 13a, 13b, and 13c, R L V regardless of , sensor gain, and network output SAC ul V in Value normalized by (V SAC / V in ) and X L It can be seen that a correlation appears between them. For example, referring to Fig. 13a, X L It can be seen that it has a dynamic range in the 0.07–0.2 range, and the sensitivity is 0.98. Referring to Fig. 13b, X LIt can be seen that it has a dynamic range in the range of 0.02 to 0.13, and the sensitivity is 0.95. Referring to Fig. 13a, X L It can be seen that it has a dynamic range in the range of 0.02 to 0.33, and the sensitivity is 0.43. Referring to Figs. 13a, 13b, and 13c, C sac It can be seen that as the value increases, the gain increases, and consequently, the sensitivity increases.

[0063] FIG. 14 is a circuit diagram of a wireless power transmission device according to various embodiments of the present disclosure. Referring to FIG. 14, the wireless power transmission device may include an inverter (e.g., an EF2 inverter (10)), a matching circuit (15), a resonator, and an impedance sensing circuit. According to various embodiments, the EF2 inverter (10) includes an RF choke inductor (L f )(3), gate driver(5), transistor(7), shunt capacitor(C p It may include )(9), a first LC resonant circuit (11), and a second LC resonant circuit (13). The resonator may include a seventh capacitor (C tx )(1451) and variable coil (L tx It may include )(1450). The impedance sensing circuit may include an HPF and envelope detector (1410) including a fifth capacitor (1101) and a fourth inductor (1102), a low pass filter (LPF) (1420), an error detector (1430), and a controller (1440). In FIG. 14, the same reference numerals as in FIG. 11 may perform the same or similar functions, and a detailed description thereof is omitted.

[0064] According to various embodiments, an HPF may be connected in parallel between the first inductor (11a) and the first capacitor (11b). The HPF is a fifth capacitor (C sac )(1101) and the fourth inductor (L sac It may include )(1102). Depending on various embodiments, the voltage V applied to the fourth inductor (1102) included in the HPF. SAC is the voltage V applied to the drain-source terminal of the transistor (7). ds It can correspond to. Accordingly, the voltage V applied to the fourth inductor (1102) included in the HPF (1010) SAC By sensing X L or X L The change in can be estimated. The voltage V applied to the fourth inductor (1102). SAC V can be applied to an envelope detector (1410). The envelope detector (1410) may include a third resistor (1411), a first comparator (1412), a fourth resistor (1413), a third diode (1414), and a fourth diode (1415). The output of the envelope detector (1410) is the input voltage V SAC V, the peak value of SDC It may be possible. A fifth diode (1416) and a fifth resistor (1417) may be connected in parallel to the output terminal of the envelope detector (1410). Additionally, an LPF (1420) may be connected to the output terminal of the envelope detector (1410). The LPF (1420) may include a fifth resistor (1421) and a seventh capacitor (1422). The LPF (1420) may be connected to an error detector (1430). The error detector (1430) may include a second comparator (1431) and a feedback circuit (14132). The second comparator (1431) may have V at the first input terminal (e.g., the (-) terminal). SDC Receives as input, and applies a reference voltage (V) to the second input terminal (e.g., the (+) terminal). refIt can receive ) as input and compare two input values. For example, the second comparator (1431) V SDC and reference voltage (V ref The difference between ) can be output to the controller (1440). According to various embodiments, the controller (1440) V SDC and reference voltage (V ref Based on the difference between ), the variable coil (L of the resonator) tx The inductance of )(1451) can be adjusted. For example, the variable coil (L tx As a method for adjusting the inductance of (1451), the inductance can be adjusted by bringing a ferrite core closer to the coil using a servo motor, a microstep motor, or a piezo actuator. As another example, the inductance can be adjusted by increasing the number of turns of the coil by switching control of an auxiliary coil magnetically coupled to the coil of the resonator.

[0065] FIG. 15 is a circuit diagram of a wireless power transmission device according to various embodiments of the present disclosure. Referring to FIG. 15, the wireless power transmission device may include an inverter (e.g., an EF2 inverter (10)), a matching circuit (15), a resonator, and an impedance sensing circuit. According to various embodiments, the EF2 inverter (10) includes an RF choke inductor (L f )(3), gate driver(5), transistor(7), shunt capacitor(C p It may include )(9), a first LC resonant circuit (11), and a second LC resonant circuit (13). The resonator may include a third coil (L tx )(203) and the 7th capacitor (C txIt may include )(1451). According to various embodiments, a capacitance adjustment circuit (1500) may be connected in parallel between the third coil (203) and the seventh capacitor (1451). The capacitance adjustment circuit (1500) may have at least one capacitor (1511, 1521, 1531, 1532) connected in parallel, and a switch (e.g., MOSFET) (1512, 1522, 1532, 1542) may be connected in series to each capacitor (1511, 1521, 1531, 1532). The above impedance sensing circuit may include an HPF and envelope detector (1410) including a fifth capacitor (1101) and a fourth inductor (1102), a low pass filter (LPF) (1420), an error detector (1430), and a controller (1440). In FIG. 15, the same reference numerals as in FIG. 11 and FIG. 14 may perform the same or similar functions, and a detailed description thereof is omitted.

[0066] As described above in FIG. 14, the second comparator (1431) is V SDC and reference voltage (V ref The difference between ) can be output to the controller (1440). Depending on various embodiments, the controller (1440) may output the V as shown in FIG. 15. SDC and reference voltage (V ref The capacitance connected to the load can be adjusted by controlling at least one switch (e.g., MOSFET) (1512, 1522, 1532, 1542) included in the capacitance adjustment circuit (1500) to be in an on or off state based on the difference between ). For example, the controller (1440) can adjust the capacitance connected to the load by controlling the V SDC and reference voltage (V ref By controlling at least one switch (e.g., MOSFET) (1512, 1522, 1532, 1542) included in the capacitance adjustment circuit (1500) to be turned on based on the difference between C txThe capacitance can be increased by a capacitor connected in parallel with (1451).

[0067] FIG. 16 is a circuit diagram of a wireless power transmission device according to various embodiments of the present disclosure. Referring to FIG. 16, a fifth diode (1416) and a fifth resistor (1417) may be connected in parallel to the output terminal of an envelope detector (1410). Additionally, an LPF (1420) may be connected to the output terminal of the envelope detector (1410). The LPF (1420) may include a fifth resistor (1421) and a seventh capacitor (1422). The LPF (1420) may be connected to a comparator (1610) (e.g., a hysteresis comparator). The comparator (1431) receives the input V SDC upper threshold (V high ) and lower threshold (V low ) compare, and the above V SDC upper threshold (V high Higher than ) or lower threshold (V low If the value is lower than ), it can be determined to be an abnormal state (e.g., OVP (over voltage protection), overpower, or exceeding the allowable impedance). When the comparator (1431) determines an abnormal state, it can transmit a control signal (e.g., a disable signal) to the gate driver (5). The gate driver (5) can control the output of the wireless power transmission device based on the control signal received from the comparator (1431). For example, the gate driver (5) can control the transistor (7) to an on or off state based on the control signal received from the comparator (1431).

[0068] FIG. 17 illustrates a block diagram of a wireless power transmitter (1700) and a wireless power receiver (1750) according to various embodiments.

[0069] According to various embodiments, a wireless power transmitter (1700) (e.g., a wireless power transmitting device) may include a power transmitting circuit (1720), a control circuit (1712), a communication circuit (1730), a sensing circuit (1715) and / or a storage circuit (1716).

[0070] According to various embodiments, a wireless power transmitter (1700) can provide power to a wireless power receiver (1750) through a power transmission circuit (1720). For example, the wireless power transmitter (1700) can transmit power according to a resonant method. In the case of a resonant method, the wireless power transmitter (1700) can be implemented, for example, in a manner defined in the A4WP (Alliance for Wireless Power) standard (or the AFA (Air Fuel Alliance) standard). The wireless power transmitter (1700) may include a conductive pattern (1724) (e.g., a transmitting coil) that can generate an induced magnetic field (e.g., a Tx field) when current (e.g., alternating current) flows, depending on the resonant method or the inductive method. The process of a wireless power transmitter (1700) generating a magnetic field (e.g., Tx field) through a conductive pattern (1724) can be described as outputting wireless power, and the process of generating an induced electromotive force in a wireless power receiver (1750) based on the magnetic field (e.g., Tx field) generated through the conductive pattern (1724) can be described as receiving wireless power. Through such a process, the wireless power transmitter (1700) can be described as wirelessly transmitting power to the wireless power receiver (1750). Additionally, the wireless power receiver (1750) may include a conductive pattern (1776) (e.g., a transmitting coil) in which an induced electromotive force is generated by a magnetic field (e.g., Tx field) formed in the surroundings that changes in magnitude over time. As an induced electromotive force is generated in the conductive pattern (1776) of the wireless power receiver (1750), the process of an alternating current being output from the conductive pattern (1776) or an alternating voltage being applied to the conductive pattern (1776) can be described as the wireless power receiver (1750) receiving power wirelessly. As another example, the wireless power transmitter (1700) can transmit power according to an induction method.In the case of an inductive method, the wireless power transmitter (1700) can be implemented in a manner defined, for example, in the wireless power consortium (WPC) standard (or Qi standard).

[0071] According to various embodiments, the power transmission circuit (1720) may include a power adapter (1721), a power generation circuit (1722), a matching circuit (1723), a conductive pattern (e.g., a transmitting coil) (1724), or a first communication circuit (1731). According to various embodiments, the power transmission circuit (1720) may be configured to transmit power wirelessly to a wireless power receiver (1750) through the conductive pattern (1724). According to various embodiments, the power transmission circuit (1720) may receive power from an external source in the form of a direct current or alternating current waveform and may supply the received power to the wireless power receiver (1750) in the form of an alternating current waveform.

[0072] According to various embodiments, the power adapter (1721) may receive AC or DC power from an external source or receive a power signal from a battery device and output DC power having a set voltage value. According to various embodiments, the voltage value of the DC power output from the power adapter (1721) may be controlled by a control circuit (1712). According to various embodiments, the DC power output from the power adapter (1721) may be output to a power generation circuit (1722).

[0073] According to various embodiments, the power generation circuit (1722) may convert and output a direct current output from a power adapter (1721) into an alternating current. According to various embodiments, the power generation circuit (1722) may include a specific amplifier (not shown). According to various embodiments, if the direct current input through the power adapter (1721) is smaller than a set gain, the power generation circuit (1722) may amplify the direct current to a set gain using an amplifier (not shown). Alternatively, the power generation circuit (1722) may include a circuit that converts the direct current input from the power adapter (1721) into alternating current based on a control signal input from a control circuit (1712). For example, the power generation circuit (1722) may convert the direct current input from the power adapter (1721) into alternating current through a specific inverter (not shown). Alternatively, the power generation circuit (1722) may include a gate driver (not shown). The gate driver (not shown) may convert the DC current into AC by controlling the DC current input from the power adapter (1721) by turning it on / off. Alternatively, the power generation circuit (1722) may generate an AC power signal through a wireless power generator (e.g., an oscillator).

[0074] According to various embodiments, the matching circuit (1723) can perform impedance matching. For example, when an alternating current (e.g., an alternating signal) output from the power generation circuit (1722) is transmitted to the conductive pattern (1724), an electromagnetic field can be formed in the conductive pattern (1724) by the transmitted alternating signal. By adjusting the impedance of the matching circuit (1723), the frequency band of the formed electromagnetic field (e.g., an electromagnetic field signal) can be adjusted. According to various embodiments, the matching circuit (1723) can control the output power transmitted to the wireless power receiver (1750) through the conductive pattern (1724) to be high efficiency or high output by adjusting the impedance. According to various embodiments, the matching circuit (1723) can adjust the impedance based on the control of the control circuit (1712). The matching circuit (1723) may include at least one of an inductor (e.g., a coil), a capacitor, or a switching device. The control circuit (1712) may control the connection state with at least one of the inductor or capacitor through the switching device, and thereby perform impedance matching.

[0075] According to various embodiments, the first communication circuit (1731) (e.g., resonant circuit) can perform communication (e.g., data communication) in an in-band format using electromagnetic waves generated by the conductive pattern (1724).

[0076] According to various embodiments, the sensing circuit (1715) can sense a change in current / voltage applied to the conductive pattern (1724) of the power transmission circuit (1720). Depending on the change in current / voltage applied to the conductive pattern (1724), the amount of power to be transmitted to the wireless power receiver (1750) may change. Alternatively, the sensing circuit (1715) can sense a change in temperature of the wireless power transmitter (1700). According to various embodiments, the sensing circuit (1715) may include at least one of a current / voltage sensor or a temperature sensor.

[0077] According to various embodiments, the control circuit (1712) can control the operation of the wireless power transmitter (1700). For example, the control circuit (1712) can control the operation of the wireless power transmitter (1700) using an algorithm, program, or application required for control stored in the storage circuit (1716). The control circuit (1712) can be implemented in the form of a CPU, a microprocessor, or a minicomputer. For example, the control circuit (1712) can display the status of the wireless power receiver (1750) on the display module (1717) based on a message received from the wireless power receiver (1750) through the communication circuit (1730).

[0078] According to various embodiments, the control circuit (1712) can control to wirelessly transmit power to a wireless power receiver (1750) through a power transmission circuit (1720). According to various embodiments, the control circuit (1712) can control to wirelessly receive information from a wireless power receiver (1750) through a communication circuit (1730).

[0079] According to one embodiment, information received from a wireless power receiver (1750) may include at least one of charging setting information related to the battery status of the wireless power receiver (1750), power amount control information related to the control of the amount of power transmitted to the wireless power receiver (1750), environment information related to the charging environment of the wireless power receiver (1750), or time information of the wireless power receiver (1750). According to one embodiment, the charging setting information may be information related to the battery status of the wireless power receiver (1750) at the time of wireless charging between the wireless power transmitter (1700) and the wireless power receiver (1750). For example, the charging setting information may include at least one of the total battery capacity, remaining battery capacity, number of charges, battery usage, charging mode, charging method, or wireless reception frequency band of the wireless power receiver (1750). According to one embodiment, the power amount control information may include information for controlling the amount of initial power transmitted according to a change in the amount of power charged in the wireless power receiver (1750) during wireless charging between the wireless power transmitter (1700) and the wireless power receiver (1750). According to one embodiment, the environment information is information obtained by measuring the charging environment of the wireless power receiver (1750) by the sensing circuit (1755) of the wireless power receiver (1750), and may include, for example, at least one of temperature data including at least one of the internal temperature or external temperature of the wireless power receiver (1750), illuminance data indicating the illuminance (brightness) around the wireless power receiver (1750), or sound data indicating the sound (noise) around the wireless power receiver (1750). According to one embodiment, the control circuit (1712) may control the generation or transmission of power to be transmitted to the wireless power receiver (1750) based on the charging setting information among the information received from the wireless power receiver (1750).Alternatively, the control circuit (1712) may determine or change the amount of power transmitted to the wireless power receiver (1750) based on at least some of the information received from the wireless power receiver (1750) (e.g., at least one of power amount control information, environment information, or time information). Alternatively, the control circuit (1712) may control the matching circuit (1723) to change the impedance.

[0080] According to various embodiments, the display module (1717) can display overall information related to the status, environment information, or charging status of the wireless power transmitter (1700).

[0081] According to various embodiments, the communication circuit (1730) can communicate with the wireless power receiver (1750) in a predetermined manner. The communication circuit (1730) can perform data communication with the communication circuit (1780) of the wireless power receiver (1750). For example, the communication circuit (1730) can unicast, multicast, or broadcast a signal.

[0082] According to one embodiment, the communication circuit (1730) may include at least one of a first communication circuit (1731) which is implemented in one hardware with the power transmission circuit (1720) so that the wireless power transmitter (1700) can perform communication in an in-band format, or a second communication circuit (1732) which is implemented in a different hardware from the power transmission circuit (1720) so that the wireless power transmitter (1700) can perform communication in an out-of-band format.

[0083] According to one embodiment, if the communication circuit (1730) includes a first communication circuit (1731) capable of performing communication in an in-band format, the first communication circuit (1731) can receive the frequency and signal level of an electromagnetic field signal received through the conductive pattern (1724) of the power transmission circuit (1720). The control circuit (1712) can extract information received from the wireless power receiver (1750) by decoding the frequency and signal level of the electromagnetic field signal received through the conductive pattern (1724). Alternatively, the first communication circuit (1731) may apply a signal regarding information of the wireless power transmitter (1700) to be transmitted to the wireless power receiver (1750) to the conductive pattern (1724) of the power transmission circuit (1720) (e.g., changing the impedance of the load (e.g., conductive pattern (1724)) according to an on / off keying modulation method), or add a signal regarding information of the wireless power transmitter (1700) to the electromagnetic field signal generated by the signal output from the matching circuit (1723) being applied to the conductive pattern (1724) to transmit information of the wireless power transmitter (1700) to the wireless power receiver (1750). The control circuit (1712) may control the output of information of the wireless power transmitter (1700) by changing the connection state with at least one of the inductor and capacitor of the matching circuit (1723) through on / off control of a switch device included in the matching circuit (1723).

[0084] According to one embodiment, if the communication circuit (1730) includes a second communication circuit (1732) capable of performing communication in an out-of-band format, the second communication circuit (1732) can communicate with the communication circuit (1780) (e.g., the second communication circuit (1782)) of the wireless power receiver (1750) using NFC (near field communication), Zigbee communication, infrared communication, visible light communication, Bluetooth communication, BLE (Bluetooth Low Energy) communication method, or UWB communication method.

[0085] The communication method of the communication circuit (1730) described above is merely exemplary, and the scope of the embodiments of the present disclosure is not limited to a specific communication method performed in the communication circuit (1730).

[0086] According to various embodiments, a wireless power receiver (1750) (e.g., a wireless power receiving device) may include a power receiving circuit (1770), a control circuit (1752), a communication circuit (1780), a sensing circuit (1755), and / or a display module (1757).

[0087] According to various embodiments, the power receiving circuit (1770) may receive power from the power transmitting circuit (1720) of the wireless power transmitter (1700). The power receiving circuit (1770) may be implemented in the form of a built-in battery, or may be implemented in the form of a power receiving interface to receive power from an external source. The power receiving circuit (1770) may include a matching circuit (1771), a rectification circuit (1772), an adjustment circuit (1774), a battery (1775), and / or a conductive pattern (1776).

[0088] According to various embodiments, the power receiving circuit (1770) can receive wireless power in the form of electromagnetic waves generated in response to the current / voltage applied to the conductive pattern (1724) of the power transmitting circuit (1720) through the conductive pattern (1776). For example, the power receiving circuit (1770) can receive power using the induced electromotive force formed in the conductive pattern (1724) of the power transmitting circuit (1720) and the conductive pattern (1776) of the power receiving circuit (1770).

[0089] According to various embodiments, the matching circuit (1771) can perform impedance matching. For example, power transmitted through the conductive pattern (1724) of the wireless power transmitter (1700) can be transferred to the conductive pattern (1776) to form an electromagnetic field. According to various embodiments, the matching circuit (1771) can adjust the frequency band of the formed electromagnetic field (e.g., electromagnetic field signal) by adjusting the impedance. According to various embodiments, the matching circuit (1771) can control the input power received from the wireless power transmitter (1700) through the conductive pattern (1776) to be high efficiency and high output by such impedance adjustment. According to various embodiments, the matching circuit (1771) can adjust the impedance based on the control of the control circuit (1752). The matching circuit (1771) may include at least one of an inductor (e.g., a coil), a capacitor, or a switch device. The control circuit (1752) can control the connection state with at least one of an inductor or a capacitor through a switch device, and accordingly, can perform impedance matching.

[0090] According to various embodiments, the rectifier circuit (1772) can rectify wireless power received by the conductive pattern (1776) into a direct current form and can be implemented, for example, in the form of a bridge diode.

[0091] According to various embodiments, the adjustment circuit (1773) can convert rectified power to a set gain. The adjustment circuit (1773) may include a DC / DC converter (not shown). For example, the adjustment circuit (1773) can convert rectified power so that the voltage at the output terminal becomes 5V. Alternatively, a minimum or maximum value of the voltage that can be applied may be set at the front end of the adjustment circuit (1773).

[0092] According to various embodiments, the switch circuit (1774) can be connected to the adjustment circuit (1773) and the battery (1775). According to various embodiments, the switch circuit (1774) can be maintained in an on / off state under the control of the control circuit (1752).

[0093] According to various embodiments, the battery (1775) can be charged by receiving power input from the adjustment circuit (1773).

[0094] According to various embodiments, the sensing circuit (1755) can sense changes in the power state received by the wireless power receiver (1750). For example, the sensing circuit (1755) can periodically or non-periodically measure the current / voltage value received by the conductive pattern (1776) through a predetermined current / voltage sensor (not shown). According to various embodiments, the wireless power receiver (1750) can calculate the amount of power received by the wireless power receiver (1750) based on the current / voltage measured through the predetermined current / voltage sensor (not shown). According to various embodiments, the sensing circuit (1755) can sense changes in the charging environment of the wireless power receiver (1750). For example, the sensing circuit (1755) can periodically or non-periodically measure at least one of the internal temperature or external temperature of the wireless power receiver (1750) through a predetermined temperature sensor (not shown).

[0095] According to various embodiments, the display module (1757) may display overall information related to the charging status of the wireless power receiver (1750). For example, the display module (1757) may display at least one of the total battery capacity, remaining battery capacity, battery charge amount, battery usage, or estimated charging time of the wireless power receiver (1750).

[0096] According to various embodiments, the communication circuit (1780) can communicate with the wireless power transmitter (1700) in a predetermined manner. The communication circuit (1780) can perform data communication with the communication circuit (1730) of the wireless power transmitter (1700). According to various embodiments, the communication circuit (1780) can operate similarly or identically to the communication circuit (1730) of the wireless power transmitter (1700).

[0097] According to various embodiments, the control circuit (1752) can transmit charging setting information to the wireless power transmitter (1700) to receive the required amount of power based on information related to the battery status of the wireless power receiver (1750) through the communication circuit (1780). For example, when the control circuit (1752) identifies a wireless power transmitter (1700) capable of transmitting wireless power, it can transmit charging setting information to the wireless power transmitter (1700) through the communication circuit (1780) to receive the required amount of power based on at least one of the total battery capacity, remaining battery capacity, number of charges, battery usage, charging mode, charging method, or wireless reception frequency band of the wireless power receiver (1750).

[0098] According to various embodiments, the control circuit (1752) can transmit power amount control information to the wireless power transmitter (1700) to control the amount of power received from the wireless power transmitter (1700) according to a change in the amount of power charged in the wireless power receiver (1750) through the communication circuit (1780).

[0099] According to various embodiments, the control circuit (1752) can transmit environmental information regarding changes in the charging environment of the wireless power receiver (1750) to the wireless power transmitter (1700) via the communication circuit (1780). For example, the control circuit (1752) can transmit the measured temperature data to the wireless power transmitter (1700) if the temperature data value measured by the sensing circuit (1755) is greater than or equal to a set temperature reference value.

[0100] Although FIG. 17 illustrates that the wireless power transmitter (1700) and the wireless power receiver (1750) each include only the power transmission circuit (1720) and the power reception circuit (1770), the wireless power transmitter (1700) and the wireless power receiver (1750) may each include both the power transmission circuit (1720) and the power reception circuit (1770). Accordingly, the wireless power transmitter (1700) and the wireless power receiver (1750) according to various embodiments may perform both the functions of a power transmitter and a power reception device.

[0101] A wireless power transmission device according to any one of the various embodiments may include: a transistor that outputs a signal corresponding to a set operating frequency based on an input signal and a driving voltage; a matching circuit connected to the transistor and converting the impedance of the signal corresponding to the operating frequency; a transmitting coil connected to the matching circuit; an LC resonant circuit connected in parallel between the transistor and the matching circuit and transmitting a signal corresponding to at least one harmonic frequency of the operating frequency; and an impedance sensing circuit connected to the LC resonant circuit and sensing the load impedance of the wireless power transmission device based on the signal corresponding to the at least one harmonic frequency transmitted through the LC resonant circuit.

[0102] According to various embodiments, the signal corresponding to the at least one harmonic frequency may include at least one harmonic frequency signal among a second harmonic frequency signal to a 20th harmonic frequency signal.

[0103] According to various embodiments, the LC resonant circuit includes at least one coil and at least one capacitor connected in series with the at least one coil, and the impedance sensing circuit may be connected between the at least one coil and the at least one capacitor.

[0104] According to various embodiments, the impedance sensing circuit includes a first capacitor connected in parallel with at least one capacitor of the LC resonant circuit; and a first inductor connected in series with the first capacitor, and can sense the load impedance based on the voltage across the first inductor.

[0105] According to various embodiments, the voltage across the first inductor can be determined based on the voltage across the LC resonant circuit and the gain of the impedance sensing circuit for each harmonic frequency.

[0106] According to various embodiments, the impedance sensing circuit further includes an envelope detector connected in parallel between the first capacitor and the first inductor and detecting a peak value of the voltage across the first inductor, and can sense the load impedance based on the peak value detected by the envelope detector.

[0107] According to various embodiments, the impedance sensing circuit further includes an error detector connected to the envelope detector, wherein the error detector receives an output signal of the envelope detector through a first input terminal and receives a reference voltage signal through a second input terminal, and can output an error signal corresponding to the difference between the two input signals.

[0108] According to various embodiments, the wireless power transmission device may receive an error signal from the error detector and adjust the load impedance based on the received error signal.

[0109] According to various embodiments, the impedance sensing circuit can sense the load impedance based on a value in which the voltage across the first inductor is normalized by the driving voltage.

[0110] According to various embodiments, the wireless power transmission device may further include a controller that receives a sensing value corresponding to a load impedance output from the impedance sensing circuit.

[0111] According to various embodiments, the wireless power transmission device further includes a variable coil connected in series to the matching circuit, and the controller can control the variable coil based on the sensing value.

[0112] According to various embodiments, the wireless power transmission device further includes a variable capacitor connected to the matching circuit, and the controller can control the variable capacitor based on the sensing value.

[0113] According to various embodiments, the variable capacitor includes at least one capacitor and at least one switch connected in series with the at least one capacitor, and the controller can adjust the capacitance of the variable capacitor by controlling the at least one switch.

[0114] A wireless power transmission method of a wireless power transmission device according to any one of various embodiments may include: an operation of outputting a signal corresponding to a set operating frequency based on an input signal and a driving voltage in a transistor; an operation of receiving a signal corresponding to the operating frequency and converting the impedance in a matching circuit connected to the transistor; an operation of receiving an impedance-converted signal from the matching circuit in a transmitting coil and forming a magnetic field based on the received signal; an operation of transmitting a signal corresponding to at least one harmonic frequency of the operating frequency in an LC resonant circuit connected in parallel between the transistor and the matching circuit; and an operation of sensing the load impedance of the wireless power transmission device based on a signal corresponding to the at least one harmonic frequency transmitted through the LC resonant circuit in an impedance sensing circuit connected to the LC resonant circuit.

[0115] According to various embodiments, the signal corresponding to the at least one harmonic frequency may include at least one harmonic frequency signal among a second harmonic frequency signal to a 20th harmonic frequency signal.

[0116] According to various embodiments, the method can sense the load impedance based on the voltage across the LC resonant circuit.

[0117] According to various embodiments, the method can sense the load impedance based on the voltage across the first inductor among a first capacitor and a first inductor connected in parallel between at least one coil and at least one capacitor included in an LC resonant circuit.

[0118] According to various embodiments, the method can sense the load impedance based on the peak value of the voltage across the first inductor.

[0119] According to various embodiments, the method may further include an operation of outputting an error signal based on the result of a comparison between the peak value and a reference voltage signal.

[0120] According to various embodiments, the method may further include an operation of adjusting the load impedance based on the output error signal.

[0121] The various embodiments of this document and the terms used therein are not intended to limit the technical features described in this document to specific embodiments, and should be understood to include various modifications, equivalents, or substitutions of said embodiments. In connection with the description of the drawings, similar reference numerals may be used for similar or related components. The singular form of a noun corresponding to an item may include one or more of said items unless the relevant context clearly indicates otherwise. In this document, phrases such as "A or B," "at least one of A and B," "at least one of A or B," "A, B or C," "at least one of A, B and C," and "at least one of A, B, or C" may each include any one of the items listed together in the corresponding phrase, or all possible combinations thereof. Terms such as "first," "second," or "first" or "second" may be used simply to distinguish said components from other said components and do not limit said components in any other aspect (e.g., importance or order). Where any (e.g., first) component is referred to as “coupled” or “connected” to another (e.g., second) component, with or without the terms “functionally” or “communicationly,” it means that said any component may be connected to said other component directly (e.g., by wire), wirelessly, or through a third component.

[0122] According to various embodiments, each component (e.g., module or program) of the components described above may include a singular or multiple entities, and some of the multiple entities may be separated and placed in other components. According to various embodiments, one or more of the components or operations of the aforementioned components may be omitted, or one or more other components or operations may be added. Generally or additionally, multiple components (e.g., module or program) may be integrated into a single component. In this case, the integrated component may perform one or more functions of each of the multiple components in the same or similar manner as those performed by the corresponding component among the multiple components prior to integration. According to various embodiments, operations performed by the module, program, or other components may be executed sequentially, in parallel, iteratively, or heuristically, or one or more of the operations may be executed in a different order, omitted, or one or more other operations may be added. Explanation of the symbols

[0123] 3: RF choke inductor 5: Gate driver 7 : Transistor 9 : Shunt capacitor 10: Inverter 11: First LC resonant circuit 13: Second LC Resonant Circuit 15: Matching Circuit 17 : Subordinate

Claims

Claim 1 A wireless power transmission device comprising: a transistor that outputs a first signal corresponding to a set operating frequency based on an input signal and a driving voltage; a matching circuit connected to the transistor; a transmitting coil connected to the matching circuit; an LC resonant circuit connected in parallel between the transistor and the matching circuit and transmitting a second signal corresponding to at least one harmonic frequency of the operating frequency to an impedance sensing circuit; and an impedance sensing circuit connected to the LC resonant circuit and sensing a load impedance of the wireless power transmission device corresponding to an impedance in the direction facing the transmitting coil relative to the matching circuit based on the second signal corresponding to the at least one harmonic frequency transmitted through the LC resonant circuit; wherein the matching circuit is configured to adjust the impedance of the matching circuit or the impedance of the transmitting coil based on the sensed load impedance. Claim 2 A wireless power transmission device according to claim 1, wherein the second signal corresponding to the at least one harmonic frequency comprises at least one harmonic frequency signal among a second harmonic frequency signal to a 20th harmonic frequency signal. Claim 3 A wireless power transmission device according to claim 1, wherein the LC resonant circuit comprises at least one coil and at least one capacitor connected in series with the at least one coil, and the impedance sensing circuit is connected between the at least one coil and the at least one capacitor. Claim 4 A wireless power transmission device according to claim 1, wherein the impedance sensing circuit comprises: a first capacitor connected in parallel with at least one capacitor of the LC resonant circuit; and a first inductor connected in series with the first capacitor, and senses the load impedance based on a first voltage applied across the first inductor. Claim 5 A wireless power transmission device according to claim 4, wherein the first voltage applied across the terminals of the first inductor is determined based on the second voltage applied across the terminals of the LC resonant circuit and the gain of the impedance sensing circuit for each harmonic frequency. Claim 6 A wireless power transmission device according to claim 4, wherein the impedance sensing circuit further includes an envelope detector connected in parallel between the first capacitor and the first inductor and detecting a peak value of the first voltage applied across the first inductor, and sensing the load impedance based on the peak value detected by the envelope detector. Claim 7 A wireless power transmission device according to claim 6, wherein the impedance sensing circuit further includes an error detector connected to the envelope detector, and the error detector is configured to receive an output signal of the envelope detector through a first input terminal and receive a reference voltage signal through a second input terminal, and output an error signal corresponding to the difference between the two input signals. Claim 8 In claim 7, the wireless power transmission device is configured to receive an error signal from the error detector and adjust the impedance of the transmission coil based on the received error signal. Claim 9 A wireless power transmission device according to claim 4, wherein the impedance sensing circuit is configured to sense the load impedance based on a value obtained by normalizing the first voltage across the first inductor by the driving voltage. Claim 10 A wireless power transmission device according to claim 1, wherein the wireless power transmission device further comprises a controller configured to receive a sensing value corresponding to the sensed load impedance. Claim 11 In claim 10, the wireless power transmission device further comprises a variable coil connected in series to the matching circuit, and the controller controls the variable coil based on the sensing value. Claim 12 In claim 10, the wireless power transmission device further comprises a variable capacitor connected to the matching circuit, and the controller controls the variable capacitor based on the sensing value. Claim 13 A wireless power transmission device according to claim 12, wherein the variable capacitor comprises at least one capacitor and at least one switch connected in series with the at least one capacitor, and the controller controls the at least one switch to adjust the capacitance of the variable capacitor. Claim 14 A wireless power transmission method of a wireless power transmission device, comprising: an operation of outputting a first signal corresponding to a set operating frequency based on an input signal and a driving voltage in a transistor; an operation of transmitting a second signal corresponding to at least one harmonic frequency of the operating frequency, provided in an LC resonant circuit connected in parallel between a matching circuit connected to the transistor and the transistor, to an impedance sensing circuit; an operation of sensing a load impedance of the wireless power transmission device corresponding to an impedance in the direction facing a transmitting coil connected to the matching circuit relative to the matching circuit, based on the second signal corresponding to the at least one harmonic frequency transmitted through the LC resonant circuit in the impedance sensing circuit connected to the LC resonant circuit; and an operation of adjusting the impedance of the matching circuit or the impedance of the transmitting coil based on the sensed load impedance. Claim 15 A wireless power transmission method of a wireless power transmission device, wherein the second signal corresponding to the at least one harmonic frequency comprises at least one harmonic frequency signal among a second harmonic frequency signal to a 20th harmonic frequency signal. Claim 16 A wireless power transmission method of a wireless power transmission device according to claim 14, wherein the operation of sensing the load impedance includes the operation of sensing the load impedance based on a first voltage applied across the terminals of the LC resonant circuit. Claim 17 A wireless power transmission method of a wireless power transmission device according to claim 14, wherein the operation of sensing the load impedance includes the operation of sensing the load impedance based on a second voltage applied across the terminals of a first inductor among a first capacitor and a first inductor connected in parallel between at least one coil and at least one capacitor included in an LC resonant circuit. Claim 18 A wireless power transmission method of a wireless power transmission device, wherein, in claim 17, the operation of sensing the load impedance includes the operation of sensing the load impedance based on the peak value of the second voltage applied across the first inductor. Claim 19 A wireless power transmission method of a wireless power transmission device according to claim 18, wherein the method further comprises the operation of outputting an error signal based on the result of comparison between the peak value and the reference voltage signal. Claim 20 A wireless power transmission method of a wireless power transmission device according to claim 19, wherein the method further comprises the operation of adjusting the impedance of the transmitting coil based on the output error signal.

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