WO2021137367A1

WO2021137367A1 - Antenna for wireless power transmission

Info

Publication number: WO2021137367A1
Application number: PCT/KR2020/007731
Authority: WO
Inventors: 이왕상; 안성협
Original assignee: 경상국립대학교산학협력단
Priority date: 2019-12-30
Filing date: 2020-06-15
Publication date: 2021-07-08
Also published as: KR102355945B1; KR20210085399A; KR20210086579A; KR102302764B1

Abstract

The present invention relates to a wireless power transmission technology and, more specifically, to a wireless power transmission device antenna using multiple two-dimensional planar coils so as to enable wireless charging of a mobile device arranged in various three-dimensional directions. To this end, an antenna for wireless power transmission, according to the present invention, comprises: a first coil which is the base coil; a second coil arranged inside the first coil; and a third coil arranged to overlap on the second coil.

Description

Antenna for wireless power transmission

The present invention relates to a wireless power transmission technology, and more particularly, to an antenna of a wireless power transmission device capable of wireless charging for mobile devices arranged in various three-dimensional directions using multiple two-dimensional planar coils.

The magnetic induction type wireless power transmission method currently used in real life can transmit a high-power signal, but it is 1:1 power transmission and has a short transmission distance.

In the case of the magnetic resonance method, it can be applied to most modern electronic devices, can transmit multiple power of 1:N, and has a transmission distance of several meters. power transmission is required.

In the case of a general magnetic induction method, wireless power transmission is possible only when the mobile device is placed in parallel on a charging pad with a two-dimensional transmitting coil.

On the other hand, although cup-type wireless charging technologies are being developed for three-dimensional wireless power transmission, there is a problem in that the advantage of multiple power transmission disappears because multiple charging is impossible.

The present invention has been devised to solve the above problems, and an object of the present invention is to realize a transmission coil for wireless charging in a two-dimensional plane, so that wireless power transmission for mobile devices arranged in various three-dimensional directions is performed. To provide a possible system.

To this end, the antenna for wireless power transmission according to the present invention includes a first coil that is a basic coil, a second coil disposed in the first coil, and a third coil overlapped with the second coil.

An antenna for wireless power transmission according to the present invention includes a first coil that is a basic coil in which a magnetic field is formed in one direction, and a second coil that is disposed in the first coil and has a magnetic field formed in the first direction in the other direction in the first direction. and a third coil disposed together with the second coil in the first coil and configured to generate a magnetic field in the other direction along a second direction different from the first direction in the one direction.

In addition, the antenna for wireless power transmission according to the present invention includes a first coil that is a basic coil in which a magnetic field is formed in one direction, and is disposed together with the first coil in the one direction along a specific direction in the direction opposite to the one direction. and a second coil in which a magnetic field is formed in the other direction.

As described above, the present invention combines multiple coils of a two-dimensional planar structure to provide high efficiency to the receiving coil of the mobile device even when the mobile devices are placed in parallel on a two-dimensional flat plate as well as in various three-dimensional directions. There is an effect of wireless power transmission.

1 is a view showing a schematic configuration of a wireless power transmitter according to the present invention.

2 is a diagram showing the structure of an antenna for wireless power transmission according to the first embodiment of the present invention.

3 is a view showing the distribution of current and magnetic field in each transmitting coil constituting the antenna for wireless power transmission according to the first embodiment of the present invention.

4 is a view showing the distribution of current and magnetic field in the second coil according to the first embodiment of the present invention.

5 is a view showing the distribution of current and magnetic field in the third coil according to the first embodiment of the present invention.

6 is a view showing the structure of an antenna according to a second embodiment of the present invention.

7 is a view showing the distribution of current and magnetic field in each transmitting coil constituting the antenna according to the second embodiment of the present invention.

8 is a view showing the structure of an antenna according to a third embodiment of the present invention.

9 is a view showing an antenna structure according to a fourth embodiment of the present invention.

10 is a view showing an antenna structure according to a fifth embodiment of the present invention.

11 is a view showing a state that a mobile device is placed on a wireless charging plate composed of an antenna for wireless power transmission according to the present invention.

12 to 14 are diagrams showing simulation analysis and measurement results for an antenna for wireless power transmission according to the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily implement them.

However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein.

And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated.

In addition, the terms "... unit" and "... module" described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software.

Hereinafter, a structure of an antenna for wireless power transmission according to an embodiment of the present invention will be described in detail with reference to the drawings.

1 shows a schematic configuration of a wireless power transmitter according to the present invention.

Referring to FIG. 1 , the wireless power transmitter includes an antenna 10 , a matching circuit 20 , a transmitter 30 , a controller 40 , and the like.

The antenna 10 is composed of a plurality of coils. The antenna 10 according to the present invention has a structure in which three transmitting coils are combined. The three transmitting coils include a first coil 10-1, a second coil 10-2, and a third coil 10-3.

Here, the first coil 10-1 is a basic coil, and the second coil 10-2 and the third coil 10-3 are additional coils combined with the basic coil. Each coil may consist of a rectangular or circular loop antenna.

The matching circuit 20 is disposed in each coil to match the impedance of the transmitter 30 with each coil. That is, the impedance of the transmitter 30 is matched with the first coil 10-1 by the first matching circuit 20-1, and similarly, the second coil 10- by the second matching circuit 20-2 2) and matched with the third coil 10-3 by the third matching circuit 20-3.

The transmitter 30 applies transmit power to each coil and performs phase control. To this end, the controller 40 controls the operation of the transmitter 30 while adjusting the transmit power and phase.

2 shows the structure of the antenna according to the first embodiment of the present invention.

Referring to FIG. 2 , the antenna according to the first embodiment includes a rectangular coil 101 as a first coil (basic coil), a reclining figure 8 coil 102 as a second coil, and a figure 8 coil 103 as a third coil. This is a combined structure.

The figure-eight coil 102 and figure-eight coil 103 lying down have an intersection region C (refer to FIGS. 4 and 5) passing current flowing from the first side in the opposite direction from the second side to the first coil 101 ) is formed vertically or horizontally with respect to

The size of the rectangular coil 101 is such that the lying figure 8 coil 102 or the figure 8 coil 103 does not overlap and can be placed inside the rectangular coil 101. The figure 8 coil 102 or the figure 8 coil ( 103) is greater.

P1 of the square coil 102, P2 of the figure-eight coil 102 lying down, and P3 of the figure-eight coil 103 are respectively the feeding ports of the coil. When a voltage is applied through the power supply ports (P1, P2, P3), a current flows along the coil and a magnetic field is formed.

When the figure-eight coil 103 is disposed in the square coil 102 and the figure-eight coil 102 lying on the figure eight coil 103 is overlapped to form one wireless power transmission antenna, the square coil ( The feeding port (P1) of 102), the feeding port (P2) of the lying figure-eight coil (102), and the feeding port (P3) of the figure-eight coil (103) are arranged at the same corner, so that the wiring for feeding can be done efficiently have.

3 shows the distribution of current and magnetic field in each transmitting coil constituting the antenna for wireless power transmission according to the first embodiment of the present invention, and FIG. 4 shows the distribution of current and magnetic field in a lying figure 8 coil, FIG. 5 shows the distribution of current and magnetic field in a figure 8 coil.

3 to 5, when a voltage is applied to the feeding port (P2) of the lying figure 8 coil 102, a constant current flows, but the current is transferred in the opposite direction in the crossing region (C) to the left and right currents As the direction is reversed, the magnetic field M is formed from left to right.

Since the magnetic field passes from left to right in the figure 8 coil 102 lying down like this, even if the receiving coil of the mobile device 100 is disposed in the vertical direction on the wireless charging plate 200 as shown in FIG. 11 ( b ), wireless power transmission becomes possible.

In addition, when a voltage is applied to the power supply port (P3) of the 8th coil 103, a constant current also flows, but the current is transferred in the opposite direction in the crossing region (C) so that the direction of the current in the upper and lower sides is reversed and the magnetic field ( M) is formed from top to bottom.

As such, since the magnetic field passes from the top to the bottom in the figure 8 coil 103, wireless power transmission is performed even when the receiving coil of the mobile device 200 is disposed in the vertical direction on the wireless charging plate 200 as shown in FIG. 11(c). it becomes possible

6 shows the structure of an antenna according to a second embodiment of the present invention.

Referring to FIG. 6 , the antenna according to the second embodiment includes a rectangular coil 101 as a first coil (basic coil), a -45 degree coil 104 as a second coil, and a +45 degree coil 105 as a third coil. ) is a combined structure.

The -45 degree coil 104 and the +45 degree coil 105 have an intersecting region C, which transmits a current flowing from the first side in the opposite direction at the second side, is inclined with respect to the first coil 101, that is, It is formed with an inclination of 45 degrees.

The size of the square coil 101 is such that the -45 degree coil 104 or the +45 degree coil 105 can be disposed inside the square coil 101 without overlapping the -45 degree coil 104 or the +45 degree coil. larger than the coil 105 .

P1 of the rectangular coil 102, P2 of the -45 degree coil 104, and P3 of the 8 and +45 degree coil 105 are the feed ports of the coil, respectively. When a voltage is applied through the power supply ports (P1, P2, P3), a current flows along the coil and a magnetic field is formed.

When the -45 degree coil 104 is disposed in the rectangular coil 102 and the +45 degree coil 105 is overlapped on the -45 degree coil 104 to constitute one antenna for wireless power transmission, a rectangular The feeding port (P1) of the coil 102, the feeding port (P2) of the -45 degree coil 104, and the feeding port (P3) of the +45 degree coil 105 are disposed at the same corner, so that the wiring for feeding efficiently can be done with

7 shows the distribution of current and magnetic field in each transmitting coil constituting the antenna for wireless power transmission according to the second embodiment of the present invention.

Referring to FIG. 7 , the magnetic field is formed in one direction (⊙) in the rectangular coil 101, while in the -45 degree coil 104, the other direction (lower left → upper right) in the first direction (lower left → upper right) in one direction (⊙) ⓧ), and in the +45 degree coil 105, a magnetic field is formed in the other direction (ⓧ) from one direction (⊙) to the second direction (bottom right → top left).

As such, since the magnetic field passes in the first direction and the second direction in the -45 degree coil 104 and the +45 degree coil 105, respectively, wireless power transmission is performed even if the receiving coil of the mobile device is disposed in a vertical direction with different directions This becomes possible.

8 shows the structure of the antenna according to the third embodiment of the present invention, FIG. 9 shows the structure of the antenna according to the fourth embodiment of the present invention, and FIG. 10 shows the antenna structure according to the fifth embodiment of the present invention. structure is shown.

The antenna shown in Fig. 8 is similar to the antenna of the first embodiment except that the basic coil 106 is circular, and accordingly, the second coil 107 and the third coil 108 are also configured in a circular shape.

The antenna shown in FIG. 9 uses the basic coil 101 of the first embodiment, but the second coil 109 and the third coil 110 disposed in the basic coil 101 are different. That is, the power supply ports of the second coil 109 and the third coil 110 are formed in the center of the coil.

In addition, the antenna is configured in a structure in which the second coil 109 is disposed in the basic coil 101 and the third coil 110 is disposed in the second coil 109 .

Also, the antenna shown in FIG. 10 is similar to the antenna of the fourth embodiment, except that both sides of the second coil 109 ′ and the third coil 110 ′ are folded to form a three-dimensional structure. Accordingly, when the second coil 109 ′ and the third coil 110 ′ are disposed in the basic coil 101 , the antenna has a three-dimensional structure.

In this way, by combining the coil of the two-dimensional structure with the wireless charging plate, wireless power transmission is possible regardless of the various three-dimensional arrangement of the receiving coil.

In the antenna according to the present invention, wireless power transmission is possible no matter where the receiving coils of mobile devices placed parallel to the wireless charging plate are located using the basic coil in the antenna according to the present invention. It enables wireless power transmission.

The other two coils have a figure-eight structure, so the upper and lower or left and right coils have a differential phase, and the magnetic field passes from top to bottom or from left to right, so the receiving coil is positioned perpendicular to the transmitting coil. Since wireless power transmission is possible, wireless charging can be performed on receiving coils of various three-dimensional arrangements.

Simulation results

12 to 14 are graphs illustrating simulation analysis and measurement results for an antenna for wireless power transmission according to the present invention.

12 illustrates power transmission efficiency when the receiving coil of the mobile device is positioned on the xy plane. 12 , it can be seen that power transmission (S21 < -30 dB) is not performed in the conventional basic coil (single loop antenna), but 50% power transmission (S21 ≒ -3 dB) is achieved in the antenna according to the present invention.

Also, FIG. 13 shows power transmission efficiency when the receiving coil of the mobile device is positioned on the xz plane. Referring to FIG. 13, power transmission (S21 < -30 dB) is not performed in the conventional basic coil (single loop antenna), but 50% power transmission (S21 ≒ -3 dB) is performed in the antenna according to the present invention.

Also, FIG. 14 shows power transmission efficiency when the receiving coil of the mobile device is positioned on the yz plane. Referring to FIG. 14, power transmission (S21 < -30 dB) is not performed in the conventional basic coil (single loop antenna), but 50% power transmission (S21 ≒ -3 dB) is performed in the antenna according to the present invention.

The above description is merely illustrative of the present invention, and various modifications may be made by those of ordinary skill in the art to which the present invention pertains without departing from the technical spirit of the present invention.

Accordingly, the embodiments disclosed in the specification of the present invention are not intended to limit the present invention. The scope of the present invention should be construed by the following claims, and all technologies within the scope equivalent thereto should be construed as being included in the scope of the present invention.

It can be widely used for charging various household items, including wireless charging pads.

Claims

a first coil which is a basic coil; and

a second coil disposed within the first coil;

An antenna for wireless power transmission including a third coil superimposed on the second coil;
According to claim 1,

The first coil is an antenna for wireless power transmission, characterized in that the rectangular or circular loop antenna.
3. The method of claim 2,

For wireless power transmission, characterized in that in the second coil, an intersection region for passing a current flowing in the first side in the opposite direction to the second side is formed so that a magnetic field is formed from left to right or from right to left antenna.
3. The method of claim 2,

Antenna for wireless power transmission, characterized in that in the third coil, an intersecting region for transmitting a current flowing in the first side in the opposite direction to the second side is formed so that a magnetic field is formed from top to bottom or from bottom to top.
A first coil, which is a basic coil in which a magnetic field is formed in one direction, and

a second coil disposed in the first coil and having a magnetic field formed in the first direction in the other direction along the first direction;

An antenna for wireless power transmission including a third coil disposed together with the second coil in the first coil and having a magnetic field formed in the other direction along a second direction different from the first direction in the one direction;
6. The method of claim 5,

Antenna for wireless power transmission, characterized in that in the second coil or the third coil, an intersecting area for transferring a current flowing to the first side in the opposite direction to the second side is formed.
7. The method of claim 6,

The antenna for wireless power transmission, characterized in that the crossing area is formed perpendicularly or parallel to the first coil in the second coil or the third coil.
7. The method of claim 6,

The antenna for wireless power transmission, characterized in that the crossing area is formed to be inclined with respect to the first coil in the second coil or the third coil.
6. The method of claim 5,

When the second coil and the third coil are disposed in the first coil, the feeding port of the first coil, the feeding port of the second coil, and the feeding port of the third coil are disposed at the same corner Antenna for wireless power transmission.
A first coil that is a basic coil in which a magnetic field is formed in one direction;

An antenna for wireless power transmission comprising a second coil disposed together with the first coil to form a magnetic field in the other direction opposite to the one direction along a specific direction in the one direction.