KR20200066767A - Wireless charging device - Google Patents

Abstract

The present invention relates to a wireless charging device. The wireless charging device according to an embodiment of the present invention comprises: a receiving part receiving a surface signal transmitted from at least one mobile terminal and flowing along the surface of a printed circuit board; a detection part detecting a signal level of the surface signal; and a control part calculating the bandwidth of an internal communication signal transmitted by a mobile terminal placed on a charging surface based on the signal level of the surface signal, and setting the frequency band of a re-radiation antenna and an external antenna in accordance with the calculated bandwidth of the internal communication signal. Accordingly, without degrading wireless charging performance, the communication band of the mobile terminal placed on the charging surface is accurately detected, and the frequency band of the re-radiation antenna and the external antenna can be easily set by corresponding to the detected communication band.

Description

Wireless charging device

The present invention relates to a wireless charging device, and more specifically, without degrading the wireless charging performance, accurately detects the communication band of the mobile terminal placed on the charging surface, and corresponds to the detected communication band, re-radiating antenna And it relates to a wireless charging device that can be easily set the frequency band of the external antenna.

Mobile terminal wireless charging devices are on the market. Furthermore, development of a wireless charging device for a mobile terminal provided in a vehicle has been made.

On the other hand, recently, as high-rise buildings and interior spaces have become increasingly complex, shading areas with poor radio wave environments in wireless communication systems have been generated throughout the buildings. In addition, when located in a vehicle, the vehicle body is entirely made of metal, and thus the transmission/reception rate of radio waves decreases.

In order to solve this problem, in recent years, an attempt is made to retransmit a wireless communication signal by disposing a re-radiation antenna on a wireless charging device provided in a vehicle.

However, the conventional wireless charging device extracts the communication signal of the mobile terminal through the coupling antenna in order to detect the communication band of the mobile terminal placed on the charging surface, and then extracts the communication signal from the mobile terminal to the coupler structure, filter, and switching element. Through the band separation, the communication band of the mobile terminal was detected.

In this method, in order to facilitate communication between the mobile terminal and the base station, a very small portion of the communication signal of the mobile terminal is extracted into a coupler structure, but signal attenuation is caused by the coupler structure, and errors in the communication band frequently occur. Did.

For example, when signal attenuation by the coupler structure occurs seriously, the communication band cannot be detected, or the communication signal of the mobile terminal placed in the passenger seat is transferred to the printed circuit board (PCB), the printed circuit board (PCB) Since the organic signal induced in is larger than the attenuation signal by the coupler structure, the communication band of the mobile terminal placed in the passenger seat could be detected.

An object of the present invention is to provide a wireless charging device capable of more accurately calculating a communication band of a mobile terminal placed on a charging surface without reducing charging efficiency.

Another object of the present invention is to provide a wireless charging device for product miniaturization and cost reduction.

Another object of the present invention is to provide a wireless charging device capable of accurately calculating a communication band even during communication of a mobile terminal.

To achieve the above object, a wireless charging device according to an embodiment of the present invention is transmitted from at least one or more mobile terminals and receives a surface signal flowing on a surface of a printed circuit board, and a signal level of the surface signal Based on the signal level of the surface signal and the detection unit for detecting, calculates the bandwidth of the internal communication signal transmitted by the mobile terminal placed on the charging surface, and according to the calculated bandwidth of the internal communication signal, the re-radiation antenna and It includes a control unit for setting the frequency band of the external antenna.

The wireless charging device according to the embodiment of the present invention determines the communication band of the mobile terminal placed on the charging surface through the surface signal naturally induced on the printed circuit board (PCB), so that signal attenuation due to the coupler does not occur and is accurate. Communication band judgment is possible.

In addition, the conventional wireless charging device, in addition to the re-emission antenna, a coupler antenna for determining the communication band of the mobile terminal placed on the charging surface, and a coupler, filter, switching element for separating the signal received from the coupler antenna is further required However, in the wireless charging device of the present invention, since the receiver including the resonator replaces it, the product is downsized and the manufacturing cost is reduced.

In addition, since the wireless charging device of the present invention does not require a coupler antenna, a coupler, etc., there is no fear of signal reduction due to coupling loss, and a band selection error due to heat loss generated by a filter, a switching element, etc. can be eliminated. .

In addition, the conventional wireless charging device is provided with a filter, a power detector (power detector), a switching element, etc. for each communication band, but the wireless charging device of the present invention changes the resonance point to receive a surface signal, Since silver can be adjusted according to the capacitance value of a tunable capacitor, there is no need to arrange a plurality of filters, power detectors, etc. according to the band.

In addition, as the number of coupler passes increases, the interference of the signal increases, and the accuracy of the detection of the communication band decreases. However, the wireless charging device of the present invention uses a surface signal naturally induced on the printed circuit board (PCB), thereby Since it detects, it gives accuracy to the communication band selection.

In addition, since the wireless charging device of the present invention directly uses a signal that is induced on the printed circuit board (PCB), it is not placed on the charging surface, but is located close to the wireless charging device and is induced on the printed circuit board (PCB). There is no band selection error that may occur due to the organic signal.

In addition, in the wireless charging device of the present invention, the signal line for filtering and amplifying the communication signal and the signal line for determining the communication band of the mobile terminal placed on the charging surface are separated, so that communication between the mobile terminal and the base station is performed. Among them, communication band determination is possible.

In addition, since the tunable capacitor in the wireless charging device of the present invention is used only to receive a surface signal flowing through a printed circuit board (PCB), unlike a antenna using a tunable capacitor, a feeding line is unnecessary, and a signal Clearance areas for radiation are also unnecessary.

1 is a view for explaining the concept of the re-radiation antenna of the present invention.
2 is a view showing a state in which the wireless charging device of the present invention is mounted on a vehicle.
3 is a perspective view of a wireless charging device according to an embodiment of the present invention.
4 is an exploded perspective view of a wireless charging device according to an embodiment of the present invention.
5 is an example of an internal block diagram of a wireless charging device according to an embodiment of the present invention.
6 is a flowchart illustrating a communication band selection method according to an embodiment of the present invention.
7 is a view referred to in the description of FIG. 6.
8 is a view referred to in the description of FIG. 6.
9 is a view referred to in the description of FIG. 6.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

The suffixes "modules" and "parts" for components used in the following description are given simply by considering the ease of writing this specification, and do not imply any special significance or role in itself. Therefore, the "module" and the "unit" may be used interchangeably.

Terms including ordinal numbers such as first and second may be used to describe various components, but the components are not limited by the terms. The terms are used only for the purpose of distinguishing one component from other components.

In this application, terms such as "comprises" or "have" are intended to indicate the presence of features, numbers, steps, actions, components, parts or combinations thereof described in the specification, but one or more other features. It should be understood that the presence of, or the likelihood of, or addition to, numbers, steps, actions, components, parts, or combinations thereof, is not excluded in advance.

1 is a view for explaining the concept of the re-radiation antenna of the present invention.

Referring to the drawings, the mobile terminal located in the vehicle 40 (600 in FIG. 2) is a radio wave transmitted from the base station 10 collides with a building or is shielded by metal constituting the exterior of the vehicle 40. The transmission/reception rate may be significantly lowered.

The portion where radio waves are not partially transmitted is referred to as a shaded area, and the wireless charging device 100 in the vehicle 40 may include a re-radiation antenna 200 to increase the transmission/reception rate of the shaded area.

Specifically, the vehicle 40 is provided with an external antenna 30 on the outside, amplifies the external communication signal received from the external antenna 30, and through the re-radiation antenna 200 inside the vehicle 40 It can be transmitted to the terminal 600 located inside the vehicle 40.

In addition, the vehicle 40 may amplify the internal communication signal received through the re-radiation antenna 200 and transmit it to the base station 10 through the external antenna 30. Accordingly, the radio transmission/reception rate of the mobile terminal 600 may increase.

However, since the mobile terminal 600 in the vehicle 40 can communicate with the base station 10 in a specific communication band, it is essential to adjust the communication band of the re-radiation antenna 200 and the external antenna 30. Will be required.

2 is a view showing a state in which the wireless charging device of the present invention is mounted on a vehicle.

Referring to the drawings, a wireless charging device 100 for charging the mobile terminal 600 by a wireless charging method has appeared. The wireless charging method has an advantage of charging by simply placing the terminal 600 on the wireless charging device 100 without connecting the wireless charging device 100 and the mobile terminal 600 with a cable.

The wireless charging device 100 may be disposed inside the vehicle.

On the other hand, most of the mobile terminal 600 in the vehicle 40 equipped with the wireless charging device 100 is used in a state mounted on the wireless charging device 100. In addition, it is highly likely to make a hands-free call using the Bluetooth function in a mounted state during a call.

In order for the re-radiation antenna 200 to transmit a communication signal to the mobile terminal 600 while minimizing signal loss, the closer the distance between the re-radiation antenna 200 and the mobile terminal 600 is, the more advantageous it is.

Therefore, the re-radiation antenna 200 may be provided inside the wireless charging device 100 for communication efficiency. At this time, the wireless charging device 100 can wirelessly charge the mobile terminal 600 and re-emit a communication signal.

2, the wireless charging device 100 may be disposed in one area of the center console, one area of the center fascia, one area of the glove box, or one area of the dashboard, as shown in FIG. 2.

Alternatively, the wireless charging device 100 may be arranged in an area of the armrest of the rear seat.

3 is a perspective view of a wireless charging device according to an embodiment of the present invention, and FIG. 4 is an exploded perspective view of a wireless charging device according to an embodiment of the present invention.

Referring to the drawings, the wireless charging device 100 of the present invention, the housing (100a, 100b) having an electric field therein, a printed circuit board 170 mounted inside the housing, a shield can protect the printed circuit board (150), the mobile terminal 600 may include a power transmission coil 130 for wirelessly transmitting power and a re-radiation antenna 200 for receiving an antenna signal and radiating it again.

In addition, the wireless charging device 100, the printed circuit board 170, the power transmission coil 130, the heat radiation plate 191 for dissipating heat generated from the re-radiation antenna 200 and the like, circulate the air inside, wireless charging A fan module 195 for reducing heat generated in the process or the re-emission process may be further included.

In addition, the wireless charging device 100 may further include a pad 110 on which the mobile terminal 600 is mounted.

The housings 100a and 100b may be composed of an upper housing 100a and a lower housing 100b. Housings (100a, 100b), the power transmission coil 130 and the re-radiation antenna 200 is mounted therein, a terminal for supplying power to supply the power transmission coil 130 to the outside, and the vehicle 40 outside A terminal for supplying the antenna signal received through the external antenna 30 located at the re-emission antenna 200 may be exposed.

On the other hand, as described later, on the printed circuit board 170, not only the mobile terminal placed on the charging surface, but also an unwanted surface signal excited by the mobile terminal located near the wireless charging device 100 may flow, and this original value An error in band selection may be caused by an undesired surface signal.

In order to reduce the band selection error, it is preferable that the housings 100a and 100b are made of a metal material, but when the housing is made of a metal material, charging efficiency is rapidly reduced. , Housing (100a, 100b), it is reasonable to be made of a non-metallic material.

The control unit (570 in FIG. 5) receives external power from the printed circuit board 170 and supplies it to the power transmission coil 130, and transmits the signal received from the external antenna 30 to the re-radiation antenna 200. Do it.

A shield can 150 may be further provided on the upper surface of the printed circuit board 170 to radiate heat and provide a space for mounting components thereon.

The power transmission coil 130 positioned on the printed circuit board 170 forms an electromagnetic field when a current flows, and a current flows through the power receiving coil of the mobile terminal 600 by the electromagnetic field to charge the mobile terminal 600. have.

In this embodiment, the power transmission coil 130 is positioned on the shield can 150.

The wireless charging method includes a magnetic resonance method and an electromagnetic induction method. The electromagnetic induction method is a method of charging an electronic device requiring charging using the principle of induction current. The current flowing in the power transmission coil 140 mounted in the portable charging device forms an electromagnetic field, and the power receiving coil located in the electromagnetic field is Electric current may flow through the electromagnetic field.

The magnetic resonance method is a method of charging using a resonance method, which is a phenomenon that vibrates at a large amplitude at a specific frequency, and uses a strong magnetic field coupling phenomenon formed between the power transmission coil 130 having the same resonance frequency and the power reception coil.

The electromagnetic induction method has high efficiency, but the power transmitting coil 130 and the power receiving coil must be positioned adjacent to each other, and if they are spaced apart or arranged at an angle, the efficiency is greatly reduced. Therefore, in the electromagnetic induction charging, the arrangement between the power transmission coil 130 and the power reception coil is very important.

On the other hand, the magnetic resonance method has an advantage that the efficiency is not higher than that of the electromagnetic induction method, but is not limited by use because it can be charged even at a distance. In addition, the unused energy portion has the advantage of being reabsorbed by the electromagnetic field.

The wireless charging device 100 may further include a ferrite sheet on the upper or lower surface of the power transmission coil 130. The ferrite sheet can improve the circuit flow of the magnetic flux line of the coil, and reduce the amount of electromagnetic radiation emitted from the power transmission coil 130.

The heat sink 191 may radiate heat therein. The heat sink 191 may be formed of a metal material. For example, the heat sink 191 may be formed of an aluminum material.

The fan module 195 may be coupled to the heat sink 191 to discharge internal heat to the outside or suck external heat therein. Accordingly, heat generation of the wireless charging device 100 may be reduced.

The fan module 195 includes at least one fan, for example, a fan, a rotating fan, a solid state fan, a piezoelectric fan, a centrifugal fan ), an axial fan, or a fan.

On the other hand, in order to reduce the vibration and noise generated by the operation of the fan, a dustproof material may be applied to a contact portion between the fan included in the fan module 195 and other components.

The pad 110 may be formed of a material having high friction (for example, non-woven fabric, silicone, rubber, etc.) so that the mobile terminal 600 does not deviate from the wireless charging device 100.

In addition, the pad 110 may be formed of a non-metal material in consideration of wireless power transmission, communication signal radiation, and the like.

On the other hand, when the housing (100a, 100b) of Figure 4 is made of a non-metallic material, using a conventional coupler antenna, coupler, filter, switching element, etc., when selecting a communication band, near the wireless charging device 100 Due to the undesired surface signal excited on the printed circuit board 170 due to the mobile terminal, an error in band selection may occur.

Specifically, in the conventional communication band selection method, for smooth communication of a mobile terminal, a very small portion of a signal received through a coupler antenna is extracted, and a communication band is selected based on the extracted signal.

In particular, as the extracted signal passes through the coupler pass, it can be further reduced, making it less than the level of unwanted surface signals excited on the printed circuit board 170. At this time, since the unwanted surface signal has a larger noise component or a larger noise component than the extracted signal, a communication band of the unwanted signal can be selected.

In contrast, the present invention uses a surface signal naturally excited on the printed circuit board 170 without a coupler antenna, coupler, filter, switching element, and the like to calculate a communication band of the mobile terminal placed on the charging surface. Suggestions.

5 is an example of an internal block diagram of a wireless charging device according to an embodiment of the present invention.

Referring to the drawings, the receiver 510, the detector 530, the analog-to-digital converter 550, and the controller 570 may be mounted on the printed circuit board 170.

Also, the first filter unit 591a, the second filter unit 591b, the duplexer 593, the first amplifier 595a, and the second amplifier 595b may also be mounted on the printed circuit board 170.

The reception unit 510, the detection unit 530, and the analog-to-digital conversion unit 550 are for detecting a communication band of the mobile terminal placed on the charging surface, and thus may be referred to as a band selection unit.

The first filter unit 591a, the second filter unit 591b, the duplexer 593, the first amplifier 595a, and the second amplifier 595b communicate between the mobile terminal placed on the charging surface and the base station 10 Since it is for amplifying a signal, it can be referred to as a signal amplification unit, distinct from the band selection unit.

The reception unit 510 in the band selection unit may be electrically connected to the control unit 570. The tunable element in the receiver 510 may be controlled by the controller 570.

The detector 530 is electrically connected to the receiver 510 to detect the level of the surface signal. The analog-to-digital conversion unit 550 may be connected between the detection unit 530 and the control unit 570.

Meanwhile, the first filter unit 591 in the signal amplification unit may be electrically connected to the re-radiation antenna 200, and the second filter unit 591b may be electrically connected to the external antenna 30.

A duplexer 593 may be connected between the first filter unit 591a and the second filter unit 591b. Further, the first amplifier 595a and the second amplifier 595b may also be connected between the first filter portion 591a and the second filter portion 591b.

The control unit 570 may be electrically connected to the first filter unit 591a and the second filter unit 591b, respectively, to control the filter band.

As described above, the line of the band selection unit and the line of the signal amplification unit may be formed separately from the control unit 570. Accordingly, the wireless charging apparatus 100 of the present invention can determine the communication band even during communication between the mobile terminal and the base station 10.

The receiver 510 may be transmitted from at least one mobile terminal, and receive a surface signal flowing on the surface of the printed circuit board 170.

Specifically, when the communication signal transmitted from the mobile terminal collides with the metallic material, scattering of the communication signal may occur. The scattered communication signal may flow through the printed circuit board 170. At this time, when resonance occurs in the reception unit 510, the scattered communication signal may not float and may be concentrated toward the reception unit 510.

Accordingly, the receiving unit 510 may be configured to resonate with respect to electromagnetic waves of a predetermined frequency to receive electromagnetic waves of that frequency.

To this end, the receiver 510 may include a tunable capacitor C _tune mounted on the printed circuit board 170.

In order for the receiving unit 510 to cause the resonance, as well as the capacitor having a capacitance property, to an inductor having an inductor's properties must be present, inductive jaw required for this resonance seuneun the flow element that is connected to the tunable capacitor (C _tune) Can be provided by

Alternatively, the receiving unit 510 may directly connect both ends of the tunable capacitor C _tune to the ground to receive an inductance component from the ground. That is, the receiver 510 may perform a resonance function only with a tunable capacitor (C _tune ) and ground without a separate structure for providing inductance.

The tunable capacitor C _tune may be a lumped circuit device such as a chip capacitor.

On the other hand, the tunable capacitor (C _tune ) does not emit a signal, and only serves to receive a surface signal flowing through the surface of the printed circuit board 170, and therefore does not need feeding, and does not act as an antenna. Therefore, a clearance area is also unnecessary. Accordingly, the wireless charging device 100 of the present invention is easy to implement and can be miniaturized.

In addition, the wireless charging device of the present invention has an advantage that it is possible to receive a surface signal with a single tunable element even in a wide band.

Meanwhile, the control unit 570 may change the resonance point of the receiving unit 510 by adjusting the capacitance value of the tunable capacitor C _tune .

In addition, the control unit 570 may adjust the capacitance value of the tunable capacitor C _tune in a preset range. For example, the control unit 570 may continuously increase or decrease the capacitance value of the tunable capacitor C _tune from the lower limit value to the upper limit value.

The detector 530 may detect a signal level of a surface signal flowing on the surface of the printed circuit board 170.

Meanwhile, the control unit 570 adjusts the capacitance value of the tunable capacitor C _tune in a preset range, and the detection unit 530 detects the signal level of the surface signal in real time in response to the adjusted capacitance value. can do.

According to an embodiment, the wireless charging device 100 of the present invention, between the detection unit 530 and the control unit 570, converts the analog signal of the signal level detected by the detection unit 530 into a digital signal, the control unit ( 570) may further include an analog-to-digital converter 550.

For example, when the signal detected by the detector 530 is -20dbm, the analog-to-digital converter 550 outputs 0.5V to the controller 570, and the signal detected by the detector 530 is In the case of -30 dbm, 0.2 V may be output to the control unit 570.

Meanwhile, the control unit 570 may calculate the frequency band of the internal communication signal transmitted by the mobile terminal placed on the charging surface based on the signal level of the surface signal.

Specifically, the control unit 570 may calculate the surface signal having the largest level among the surface signals received by the reception unit 510 as a preliminary communication signal according to the capacitance value.

When the level of the preliminary communication signal is equal to or greater than a preset reference level, the control unit 570 may calculate the preliminary communication signal as an internal communication signal of the mobile terminal placed on the charging surface.

The controller 570 may calculate the frequency band of the mobile terminal placed on the charging surface based on the resonance frequency and bandwidth of the internal communication signal.

The first filter unit 591a may be connected to the re-radiation antenna 200. The first filter unit 591a may filter the internal communication signal transmitted from the mobile terminal placed on the charging surface.

To this end, the first filter unit 591a may include a band pass filter. The first filter unit 591a may have a variable intermediate frequency and bandwidth under control of the controller 570.

The second filter unit 591b may be connected to the external antenna 30. The second filter unit 591b may filter the external communication signal received by the external antenna 30.

To this end, the second filter unit 591b may include a band pass filter. The second filter unit 591b may have a variable intermediate frequency and bandwidth under control of the control unit 570.

The control unit 570 may set a band to be filtered by the first filter unit 591a and the second filter unit 591b according to the frequency band of the internal communication signal.

That is, the control unit 570 may set the center frequency and bandwidth of the first filter unit 591a and the second filter unit 591b in response to the frequency band of the internal communication signal. At this time, the center frequency may be the same as the resonance frequency of the internal communication signal.

The duplexer 593 is connected between the first filter part 591a and the second filter part 591b, and is connected to the internal communication signal filtered by the first filter part 591a and the second filter part 591b. Filtered external communication signal can be separated.

In FIG. 5, Tx may be an internal communication signal, and Rx may be an external communication signal.

The first amplifier 595a can amplify the separated internal communication signal. The amplified internal communication signal may be radiated through the external antenna 30.

The second amplifier 595b can amplify the separated external communication signal. The amplified external communication signal may be re-emitted through the re-emission antenna 200.

Accordingly, even in a shaded area where radio waves are not transmitted, smooth communication between the mobile terminal and the base station 10 is possible.

Meanwhile, in FIG. 5, the first amplifier 595a and the second amplifier 595b are illustrated in a configuration included in the duplexer 593, but according to an embodiment, the first amplifier 595a and the second amplifier 595b It may be provided separately from the duplexer 593.

6 is a flowchart illustrating a communication band selection method according to an embodiment of the present invention, and FIGS. 7 to 9 are diagrams referred to in the description of FIG. 6.

Referring to the drawings, first, the receiving unit 510 may be transmitted from at least one mobile terminal to receive a surface signal flowing on the surface of the printed circuit board 170 (S610).

Specifically, as in FIGS. 7 and 8, when the first mobile terminal 710 is placed on the charging surface, a part of the first internal communication signal S1 transmitted from the first mobile terminal 710 is a printed circuit It may flow on the surface of the substrate 170.

On the other hand, when the second mobile terminal 730 is located near the wireless charging device 100, a part of the second internal communication signal S2 transmitted from the second mobile terminal 730 of the printed circuit board 170 It can flow on the surface.

On the other hand, since the second internal communication signal S2 is only noise in terms of the wireless charging device 100, hereinafter, the first internal communication signal S1 is called an internal communication signal, and the second internal communication signal S2 ) May be referred to as a noise signal S2.

In FIG. 8, S1 _serface and S2 _serface illustrate surface signals flowing through the printed circuit board 170. That is, in FIG. 8, S1 _surface illustrates a surface signal through which a part of the internal communication signal S1 flows through the printed circuit board 170, and S1 _surface- indicates that a part of the noise signal S2 is a printed circuit board Illustrate the surface signal flowing through (170).

The receiving unit 510 includes a tunable capacitor C _tune mounted on the printed circuit board 170, and the control unit 570 adjusts the capacitance value of the tunable capacitor C _tune to receive the receiver The resonance point of 510 can be varied.

The control unit 570 may adjust the capacitance value of the tunable capacitor C _tune in a preset range. For example, the control unit 570 may continuously increase or decrease the capacitance value of the tunable capacitor C _tune from the lower limit value to the upper limit value.

As the resonance point of the receiving unit 510 is changed, the received surface signal may be different.

For example, when the first mobile terminal 710 communicates through the LTE high band, and the second mobile terminal 730 communicates through the GSM low band, the receiving unit 510 uses the intermediate frequency of the LTE high band. By resonating, it is possible to receive the S1 _surface and to resonate at an intermediate frequency in the GSM low band to receive the S2 _surface .

As described above, the present invention can receive a surface signal, which is induced to the printed circuit board 170 through a tunable capacitor, without a coupling antenna.

In addition, the conventional method of confirming a communication band through a coupler antenna, a coupler, a switching element, a filter, and a power detector has a lot of signal loss due to a coupling pass, but the present invention naturally leads to the printed circuit board 170 Signal is received, so signal loss is small.

In addition, since the present invention uses a signal that is naturally induced to the printed circuit board 170, there is no need to house the wireless charging device 100 in a metal material to prevent the signal being induced, and thus, the wireless charging device 100 ) Without reducing the charging efficiency, it is possible to accurately calculate the communication band of the mobile terminal placed on the charging surface.

Next, the detection unit 530 may detect the level of the surface signal (S620).

Specifically, the control unit 570 adjusts the capacitance value of the tunable capacitor C _tune in a preset range, and the detection unit 530 corresponds to the adjusted capacitance value, in real time, the signal level of the surface signal Can be detected.

The detection unit 530 may transmit the analog signal having the detected signal level to the analog-digital conversion unit 550. The analog-to-digital converter 550 may convert an analog signal of a signal level into a digital signal and transmit it to the controller 570.

For example, when the signal detected by the detector 530 is -20dbm, the analog-to-digital converter 550 outputs 0.5V to the controller 570, and the signal detected by the detector 530 is In the case of -30 dbm, 0.2 V may be output to the control unit 570.

9 is a diagram illustrating the level of the surface signal flowing through the printed circuit board 170. In FIG. 9, 910 may be a level value of the S1 _surface , and 930 may be a level value of the S2 _surface .

Since the first mobile terminal 710 is located closer to the receiver 510 than the second mobile terminal 730, the level value of the S1 _surface may be greater than the level value of the S2 _surface .

Next, the control unit 570 may calculate a surface signal having the largest level among the surface signals received by the reception unit 510 as a preliminary communication signal (S630).

Specifically, the control unit 570 may continuously increase the capacitance value of the tunable capacitor C _tune from the lower limit value to the upper limit value, and receive level values of surface signals corresponding to the capacitance change.

The level values of the surface signals corresponding to the change in capacitance may be as shown in FIG. 9 in terms of time.

Of the surface signals, since 910 has the largest level, the control unit 570 can calculate 910 as a preliminary communication signal.

Next, the control unit 570 may compare the level of the preliminary communication signal with the reference level Vref (S640).

In this case, the reference level Vref is a threshold value for an internal communication signal, and may be set based on a communication band, a distance between the first mobile terminal 710 and the receiver 510, and the like.

When the level of the preliminary communication signal is less than the preset reference level Vref, the control unit 570 may control the detection unit 530 to continuously detect the level of the surface signal (S620).

Alternatively, when the level of the preliminary communication signal is equal to or higher than a preset reference level Vref, the control unit 570 may calculate the preliminary communication signal as an internal communication signal of the mobile terminal placed on the charging surface (S650).

Next, the control unit 570 may calculate the frequency band of the internal communication signal. For example, the control unit 570 may calculate that the frequency band of the mobile terminal placed on the charging surface is an LTE high communication band.

Next, the control unit 570 may set the bands of the first filter unit 591a and the second filter unit 591b according to the calculated frequency band of the internal communication signal (S660).

For example, the control unit 570 sets the intermediate frequencies of the first filter unit 591a and the second filter unit 591b to be the same as the resonance frequency of the LTE high communication band, and the bandwidth is the same as the LTE high communication band. Can be set.

Accordingly, the wireless charging device 100 can ensure smooth communication between the mobile terminal and the base station 10 placed on the charging surface, even in a shaded area.

Meanwhile, the mobile terminal placed on the charging surface may be changed. For example, in FIG. 7, 730 may be placed on the filling surface instead of 710. In this case, the communication signal induced at 710 may be a noise signal.

Therefore, even after setting the bands of the first filter unit 591a and the second filter unit 591b, the control unit 570 may repeatedly perform steps S610 to S660.

That is, after setting the bands of the first filter unit 591a and the second filter unit 591b, the control unit 570 controls the receiver 510 to continuously receive the surface signal, and the signal level of the surface signal Based on the, it is possible to recalculate the frequency band of the internal communication signal.

For example, when 730 is placed on the charging surface instead of 710, the control unit 570 may calculate that the internal communication signal is a GSM low communication band, and corresponding to the GSM low communication band, the first filter unit 591a And a band of the second filter unit 591b.

The accompanying drawings are only for easy understanding of the embodiments disclosed in the present specification, and the technical spirit disclosed in the specification is not limited by the accompanying drawings, and all changes and equivalents included in the spirit and technical scope of the present invention It should be understood to include water to substitutes.

Likewise, although the operations are depicted in the drawings in a particular order, it should not be understood that such operations should be performed in the particular order shown or in sequential order, or that all shown actions should be performed in order to obtain the desired result. . In certain cases, multitasking and parallel processing may be advantageous.

In addition, although the preferred embodiments of the present invention have been shown and described above, the present invention is not limited to the specific embodiments described above, and the technical field to which the present invention belongs without departing from the gist of the present invention claimed in the claims. In addition, various modifications can be made by those skilled in the art, and these modifications should not be individually understood from the technical idea or prospect of the present invention.

30: external antenna
40: vehicle
100: wireless charging device
200: re-radiation antenna
510: receiver
530: detection unit
570: control unit
591a: 1st filter part
591b: second filter unit
595a: first amplifier
595b: second amplifier
593: duplexer

Claims (9)

A wireless charging device comprising a power transmission coil for wirelessly transmitting power to a mobile terminal and a re-radiation antenna for re-radiating an external communication signal received by an external antenna,
A receiving unit transmitted from at least one mobile terminal and receiving a surface signal flowing on the surface of the printed circuit board;
A detector for detecting a signal level of the surface signal; And
Based on the signal level of the surface signal, the frequency band of the internal communication signal transmitted by the mobile terminal placed on the charging surface is calculated, and according to the frequency band of the calculated internal communication signal, the re-emission antenna and the external antenna A wireless charging device comprising a; control unit for setting the frequency band. According to claim 1,
The printed circuit board,
It is disposed below the re-radiation antenna and the power transmission coil,
The receiving unit, the detecting unit and the control unit,
Wireless charging device, characterized in that mounted on the printed circuit board. According to claim 1,
The receiving unit,
A tunable capacitor mounted on the printed circuit board is provided.
The control unit,
A wireless charging device, characterized in that by adjusting the capacitance value of the tunable capacitor, the resonance point of the receiver is varied. According to claim 3,
The control unit,
Wireless charging characterized in that the capacitance value of the tunable capacitor is adjusted within a preset range, and a surface signal having the largest level among the surface signals received in the receiver is calculated as a preliminary communication signal according to the capacitance value. Device. The method of claim 4,
The control unit,
When the level of the preliminary communication signal is less than a preset reference level, the detection unit controls to continuously detect the level of the surface signal,
When the level of the preliminary communication signal is higher than a predetermined reference level, the wireless charging device, characterized in that for calculating the preliminary communication signal as the internal communication signal of the mobile terminal placed on the charging surface. According to claim 1,
A first filter unit connected to the re-radiation antenna; And
Further comprising a second filter unit connected to the external antenna,
The control unit,
Wireless charging device, characterized in that for setting the band of the first filter unit and the second filter unit, corresponding to the frequency band of the internal communication signal. The method of claim 6,
The control unit,
After setting the bands of the first filter unit and the second filter unit, the receiving unit controls to continuously receive the surface signal, and recalculates the frequency band of the internal communication signal based on the signal level of the surface signal. Wireless charging device, characterized in that. The method of claim 6,
A duplexer connected between the first filter unit and the second filter unit to separate an internal communication signal filtered by the first filter unit and an external communication signal filtered by the second filter unit; And
And a first amplifier for amplifying the separated internal communication signal and a second amplifier for amplifying the separated external communication signal. According to claim 1,
And an analog-to-digital conversion unit connected to the detection unit and converting an analog signal of a signal level detected by the detection unit into a digital signal and outputting the analog signal to the control unit.

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