JP2014197757A - Antenna coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna coil of good manufacturability.SOLUTION: An antenna consists of a first coil 510 having a first inductance value, and a second coil 520 having a second inductance value, which is connected in series with the first coil 510 and generating second magnetic flux cancelling a first magnetic flux, when the first coil 510 generates the first magnetic flux. The second inductance value is set smaller than the first inductance value.

Description

  The present invention relates to an antenna coil used in a magnetic resonance type wireless power transmission system and used in an antenna that receives power or transmits power.

  In recent years, development of technology for transmitting electric power (electric energy) wirelessly without using a power cord or the like has become active. Among wireless transmission methods, there is a technique called magnetic resonance as a technology that has attracted particular attention. This magnetic resonance method was proposed by a research group of Massachusetts Institute of Technology in 2007, and a technology related to this is disclosed in, for example, Japanese Patent Application Laid-Open No. 2009-501510.

  The magnetic resonance type wireless power transmission system uses an antenna having the same resonance frequency of the power transmission side antenna as that of the power reception side antenna and a high Q value (100 or more), so that the power transmission side antenna is changed to the power reception side antenna. On the other hand, energy transmission is performed efficiently, and one of the major features is that the power transmission distance can be several tens of centimeters to several meters.

Some proposals have been made on the specific configuration of the antenna used in the above-described magnetic resonance type wireless power transmission system. For example, Patent Document 2 (Japanese Patent Application Laid-Open No. 2010-73976) discloses a structure of a communication coil provided in each of the power feeding circuit and the power receiving circuit of a wireless power transmission apparatus that wirelessly transmits power from the power feeding circuit to the power receiving circuit. A printed circuit board made of a material having a relative dielectric constant greater than 1, a primary coil provided on the first layer of the printed circuit board and formed of a conductive pattern forming at least one loop, and a second layer of the printed circuit board And a resonance coil formed of a conductive pattern having a spiral shape. The communication coil structure of the wireless power transmission device is disclosed.
Special table 2009-501510 JP 2010-73976 A

  When the magnetic resonance type power transmission system as described above is used for power supply to a vehicle such as an electric vehicle (EV) or a hybrid electric vehicle (HEV), a coil for power transmission is embedded in the ground, It is assumed that the coil for use is laid out on the bottom of the vehicle.

  However, in the coil having the structure described in Patent Document 2, the electromagnetic field leaked from the coil during power transmission enters the metal part of the vehicle and heats it, or leaks from between the bottom surface of the vehicle and the ground. There is also a problem that it is not preferable because it may affect the human body.

  Therefore, the inventors have given directivity to the coil used for the antenna so that the electromagnetic field in the space between the power receiving antenna and the power transmitting antenna is increased, and conversely, it is possible in other spaces. As long as it is proposed to suppress the leakage of electromagnetic field.

The outline of the manufacturing process of the antenna coil which the inventors have proposed is shown in FIG. The conventional antenna coil is manufactured by winding the conductor wire 400 around the base material 300 used for shaping the coil.

  The base material 300 is a substrate-like member having a first surface 301 and a second surface 302 having a front and back relationship with the first surface 301, and a material having a small dielectric loss tangent, such as polycarbonate or polypropylene, is used.

  The base material 300 includes a base portion 310 that forms a substantially circular flat plate portion, and a plurality of projecting pieces that extend radially from the base portion 310. There are two types of protrusions: a main coil forming protrusion 320 and a sub coil forming protrusion 330.

  In FIG. 8, the arrow shown by the conductor wire 400 has shown the order at the time of winding. For example, assuming that the conductor wire 400 starts to be wound around the base material 300 from (a) in the figure, first, from (a) to (b), on the first surface 301 side of the main coil shaping protrusion 320, The conductor wire 400 is locked.

  Subsequently, in the section from (b) to (c), the conductor wire 400 is connected to the second surface of the sub-coil shaping projection piece 330 → the first surface of the sub-coil shaping projection piece 330 → the first of the sub-coil shaping projection piece 330. As in the case of the two surfaces, it is wound over the circumference of the sub-coil shaping projection piece 330 over approximately one and a half times.

  The coil wound as described above in the sub-coil shaping projection piece 330 forms a magnetic field as the sub-coil SC as a whole, and the conductor wire 400 wound on the second surface side of the sub-coil shaping projection piece 330. This also forms a magnetic field as the main coil MC.

  By the winding pattern as described above, winding is sequentially performed in the order of (c) → (d) → (e) →. When all the projecting pieces of the base material 300 are wound in the winding pattern as described above for one circumference around the base material 300, and when returning to (a) again, the projecting pieces extend from the base portion 310. Shift in the direction you want to go and proceed with the winding.

  As described above, the conventional antenna coil is manufactured so that the conductor wire 400 is wound around the entire base material 300 while the sub-coil forming projection piece 330 is wound over approximately one and a half halves. However, since such a manufacturing method requires a very complicated winding operation of the conductor wire 400, the manufacturability is very poor, and therefore it is difficult to adopt automation of antenna coil production. There was a problem that there was.

In order to solve the above problem, an antenna according to the present invention includes a first coil having a first inductance value,
A second coil having a second inductance value, which is connected in series with the first coil and generates a second magnetic flux that cancels the first magnetic flux when the first coil generates the first magnetic flux;
The antenna coil, wherein the second inductance value is set smaller than the first inductance value.

  In the antenna according to the present invention, the first coil is wound in a first winding direction, and the second coil is wound in a second winding direction opposite to the first winding direction. Features.

  Further, the antenna according to the present invention is fed from the end where the first coil is not connected in series with the second coil and the end where the second coil is not connected in series with the first coil. It is characterized by that.

  The antenna according to the present invention is characterized in that a magnetic material is disposed between the first coil and the second coil.

  According to the antenna coil according to the present invention, it is not necessary to use a coil having a complicated winding operation for the conductor wire as the first coil and the second coil, and the manufacturability is better than the conventional antenna coil. It is possible to deal with automation of antenna coil production.

1 is a block diagram of a power transmission system 100 in which an antenna coil according to an embodiment of the present invention is used. 2 is a diagram illustrating an inverter unit of the power transmission system 100. FIG. 1 is a diagram illustrating an equivalent circuit of a power transmission system 100. FIG. It is a schematic diagram of the antenna coil 500 which concerns on embodiment of this invention. It is a figure explaining the spider coil suitable for the 1st coil 510 of the antenna coil 500. FIG. It is a figure explaining the shielding performance of the antenna coil. It is a schematic diagram of the antenna coil 500 which concerns on other embodiment of this invention. It is a figure explaining an example of the manufacturing process of the conventional antenna coil.

  Embodiments of the present invention will be described below with reference to the drawings. 1 is a block diagram of a power transmission system in which an antenna coil according to an embodiment of the present invention is used. In the present embodiment, an example will be described in which the primary resonator 150 is used as a power transmission-side antenna and a secondary resonator 250 is used as a power-receiving antenna. Therefore, in this embodiment, the primary resonator coil 160 included in the primary resonator 150 is an antenna coil on the power transmission side, and the primary resonator coil 260 included in the secondary resonator 250 is the power receiving side. Antenna coil.

  As a power transmission system using the antenna of the present invention, for example, a system for charging a vehicle such as an electric vehicle (EV) or a hybrid electric vehicle (HEV) is assumed. Since the electric power transmission system transmits electric power to the vehicle as described above in a non-contact manner, the electric power transmission system is provided in a stop space where the vehicle can be stopped. The user of the vehicle stops the vehicle in a stop space where the power transmission system is provided, and makes the secondary resonator 250 mounted on the vehicle and the primary resonator 150 face each other, thereby causing the power transmission system. Receives power from.

  In the power transmission system, when power is efficiently transmitted from the primary resonator 150 on the power transmission system 100 side to the secondary resonator 250 on the power receiving system 200 side, the resonance frequency of the primary resonator 150, 2 By making the resonance frequency of the next resonator 250 the same, energy is efficiently transferred from the power transmission side antenna to the power reception side antenna.

  The AC / DC conversion unit 101 in the power transmission system 100 is a converter that converts an input commercial power source into a constant direct current. The output from the AC / DC converter 101 is boosted to a predetermined voltage by the voltage controller 102. Setting of the voltage generated by the voltage control unit 102 can be controlled from the main control unit 110.

The inverter unit 103 generates a predetermined AC voltage from the voltage supplied from the voltage control unit 102 and inputs it to the matching unit 104. FIG. 2 is a diagram illustrating an inverter unit of the power transmission system. For example, as shown in FIG. 2, the inverter unit 103 includes four field effect transistors (FETs) composed of Q _{A to} Q _D connected in a full bridge system.

In the present embodiment, between the connection portion T1 between the switching elements Q _A and Q _B connected in series and the connection portion T2 between the switching elements Q _C and Q _D connected in series. The matching device 104 is connected to the switching element Q _A.
When the switching element Q _D is on, the switching element Q _B and the switching element Q _C are off. When the switching element Q _B and the switching element Q _C are on, the switching element Q _A and the switching element Q _D are off. As a result, a rectangular wave AC voltage is generated between the connection portion T1 and the connection portion T2. In the present embodiment, the range of the frequency of the rectangular wave generated by the switching of each switching element is about 20 kHz to several 1000 kHz.

Drive signals for the switching elements Q _{A to} Q _D constituting the inverter unit 103 as described above are input from the main control unit 110. The frequency for driving the inverter unit 103 can be controlled from the main control unit 110.

  The matching unit 104 is composed of a passive element having a predetermined circuit constant, and receives an output from the inverter unit 103. The output from the matching unit 104 is supplied to the primary resonator 150. The circuit constants of the passive elements constituting the matching unit 104 can be adjusted based on a command from the main control unit 110. The main control unit 110 instructs the matching unit 104 so that the primary resonator 150 and the secondary resonator 250 resonate. The matching unit 104 is not an essential configuration.

  The primary resonator 150 includes a primary resonator coil 160 having an inductive reactance component and a primary resonator capacitor 170 having a capacitive reactance component, and is mounted on the vehicle so as to face each other. By resonating with the secondary resonator 250, the electrical energy output from the primary resonator 150 can be sent to the secondary resonator 250. The primary resonator 150 and the secondary resonator 250 function as a magnetic resonance antenna unit in the power transmission system 100.

  The main control unit 110 of the power transmission system 100 is a general-purpose information processing unit that includes a CPU, a ROM that holds a program that runs on the CPU, and a RAM that is a work area of the CPU. The main control unit 110 operates in cooperation with the components connected to the main control unit 110 shown in the figure.

  The communication unit 120 is configured to perform wireless communication with the vehicle-side communication unit 220 so that data can be transmitted to and received from the vehicle. Data received by the communication unit 120 is transferred to the main control unit 110, and the main control unit 110 can transmit predetermined information to the vehicle side via the communication unit 120.

  Next, a configuration provided on the vehicle side will be described. In the system on the power receiving side of the vehicle, the secondary resonator 250 receives electric energy output from the primary resonator 150 by resonating with the primary resonator 150. Such a secondary resonator 250 is attached to the bottom surface of the vehicle.

  The secondary resonator 250 includes a secondary resonator coil 260 having an inductive reactance component and a secondary resonator capacitor 270 having a capacitive reactance component.

  The AC power received by the secondary resonator 250 is rectified by the rectification unit 202, and the rectified power is stored in the battery 204 through the charge control unit 203. The charging control unit 203 controls the storage of the battery 204 based on a command from the main control unit 210. More specifically, the output from the rectifying unit 202 is stepped up or down to a predetermined voltage value in the charge control unit 203 and stored in the battery 204. In addition, the charging control unit 203 is configured to be able to perform remaining amount management of the battery 204 and the like.

  The main control unit 210 is a general-purpose information processing unit that includes a CPU, a ROM that holds programs that run on the CPU, and a RAM that is a work area of the CPU. The main controller 210 operates in cooperation with the components connected to the main controller 210 shown in the figure.

  The interface unit 215 is provided in the driver's seat of the vehicle and provides predetermined information to the user (driver) or accepts an operation / input from the user. A touch panel, a speaker, and the like. When a predetermined operation by the user is executed, the interface unit 215 sends the operation data to the main control unit 210 for processing. Further, when providing predetermined information to the user, display instruction data for displaying the predetermined information is transmitted from the main control unit 210 to the interface unit 215.

  Further, the vehicle-side communication unit 220 is configured to perform wireless communication with the power transmission-side communication unit 120 and to transmit and receive data to and from the power transmission-side system. Data received by the communication unit 220 is transferred to the main control unit 210, and the main control unit 210 can transmit predetermined information to the power transmission system side via the communication unit 220.

  In the power transmission system, a user who wants to receive power inputs the information indicating that charging is performed from the interface unit 215 by stopping the vehicle in the stop space where the power transmission side system as described above is provided. Receiving this, the main control unit 210 obtains the remaining amount of the battery 204 from the charge control unit 203 and calculates the amount of power necessary for charging the battery 204. The calculated amount of power and information to request power transmission are transmitted from the vehicle side communication unit 220 to the communication unit 120 of the power transmission side system. The main control unit 110 of the power transmission side system that has received the information controls the voltage control unit 102, the inverter unit 103, and the matching unit 104 to transmit power to the vehicle side.

  Next, circuit constants (inductance component and capacitance component) of the primary resonator 150 and the secondary resonator 250 configured as described above will be described. FIG. 3 is a diagram showing an equivalent circuit of the power transmission system 100 according to the embodiment of the present invention.

  In the power transmission system 100 according to the present invention, the circuit constants (inductance component, capacitance component) of the primary resonator 150 and the circuit constants of the secondary resonator 250 are intentionally different from each other, so that the transmission efficiency can be improved. To improve.

In the equivalent circuit shown in FIG. 3, the inductance component of the primary resonator 150 is L ₁ , the capacitance component is C ₁ , the resistance component is Rt ₁ , the inductance component of the secondary resonator 250 is L ₂ , and the capacitance component is C ₂ , the resistance component is Rt ₂ , and the mutual inductance between the primary resonator 150 and the secondary resonator 250 is M. The resistance component Rt ₁ and the resistance component Rt ₂ are internal resistances such as conductive wires, and are not intentionally provided. R represents the internal resistance of the battery 204. The coupling coefficient between the primary resonator 150 and the secondary resonator 250 is indicated by K.

In the present embodiment, the primary resonator 150 is a series resonator having an inductance component L ₁ and a capacitance component C ₁ , and the secondary resonator 250 is an inductance component L ₂ and a capacitance component C ₂ . Consider a series resonator.

  First, in the magnetic resonance type power transmission, when power is efficiently transmitted from the primary resonator 150 on the power transmission system 100 side to the secondary resonator 250 on the power receiving side system 200 side, By making the resonance frequency and the resonance frequency of the secondary resonator 250 the same, energy is efficiently transferred from the power transmission side antenna (primary resonator 150) to the power reception side antenna (secondary resonator 250). Like to do. The condition for this can be expressed by the following formula (1).

This can be summarized by the following equation (2) when the inductance component is L ₁ , the capacitance component is C ₁ , the inductance component is L ₂ , and the capacitance component is C ₂ only.

  Further, the impedance of the primary resonator 150 can be expressed by the following equation (3), and the impedance of the secondary resonator 250 can be expressed by the following equation (4). In the present specification, values defined by the following expressions (3) and (4) are defined as impedances of the respective resonators.

In the power receiving side system of the magnetic resonance type power transmission system 100, when the battery 204 shifts to the constant voltage charging mode, the voltage of the battery 204 is constant, so the input impedance changes depending on the charging power. If the charging power to the battery 204 is large, the input impedance is low, and if the charging power is small, the input impedance is high. Secondary resonator 25 on the power receiving side
0 is preferably set to an impedance close to the input impedance corresponding to the charging power of the battery 204 in terms of efficiency.

  On the other hand, the input impedance to the primary resonator 150 viewed from the power source on the power transmission side is better as it is higher in terms of efficiency. This is because a loss occurs in proportion to the square of the current due to the internal resistance of the power supply.

  From the above, the relationship of the following equation (5) is satisfied between the impedance of the primary resonator 150 expressed by the equation (3) and the impedance of the secondary resonator 250 expressed by the equation (4). It is desirable that

This can be summarized by the following equation (6) when the inductance component is L ₁ , the capacitance component is C ₁ , the inductance component is L ₂ , and the capacitance component is C ₂ only.

  In the power transmission system 100 according to the present invention, the circuit constant of the primary resonator 150 and the circuit constant of the secondary resonator 250 satisfy the above formulas (2) and (6). In addition, when the battery 204 is charged by the power receiving side system, efficient power transmission can be performed.

  Further, the relationship with the internal impedance of the battery 204 will also be mentioned. In the power receiving side system, as a condition for efficiently charging the battery 204, the impedance of the secondary resonator 250 and the impedance of the battery 204 can be matched.

  That is, in the present embodiment, in addition to the conditions of the expressions (2) and (6), the impedance between the secondary resonator 250 of the expression (4) and the impedance R of the battery 204 is

Thus, when the battery 204 is charged in the power receiving side system, efficient power transmission can be performed as the entire system.

  Next, the primary resonator coil 160 in the power transmission system 100 configured as described above will be described in more detail.

  Next, a specific configuration of the antenna coil used in the power transmission system 100 configured as described above will be described. The antenna coil of the present invention can be applied to both the primary resonator 150 and the secondary resonator 250. Further, the antenna coil of the present invention is employed for the primary resonator coil 160 on the power transmission side, and is employed for the secondary resonator coil 260 on the power reception side.

  The outline of the antenna coil of the present invention will be described below. FIG. 4 is a schematic diagram of an antenna coil 500 according to an embodiment of the present invention.

  The antenna coil 500 according to the embodiment of the present invention includes a first coil 510 having a first inductance value and a second coil 520 having a second inductance value.

  In addition, the first coil 510 has a first inductance value, the second coil 520 has a second inductance value smaller than the first inductance value, and the first coil 510 generates a first magnetic flux. The second coil 520 generates a second magnetic flux that cancels the first magnetic flux.

  Therefore, in the antenna coil 500 according to the embodiment of the present invention, the antenna coil 500 has directivity by partially canceling the first magnetic flux generated by the first coil 510 and the second magnetic flux generated by the second coil 520. Will be granted.

  For example, the first coil 510 of the antenna coil 500 is wound from P to Q in the first circumferential direction (counterclockwise), while the second coil 520 is in the first circumferential direction (counterclockwise). It is constituted by being wound in the second circumferential direction (clockwise) from Q ′ to P ′, which is opposite to the above.

  In addition, the first coil 510 and the second coil 520 are electrically connected by a series connection conductor 530, and the first feeding end 540 in which the first coil 510 is not connected in series with the second coil 520, The second coil 520 is fed from a second feeding end 550 that is not connected in series with the first coil 510. That is, in the present embodiment, power is supplied from the end of the first coil 510 and the end of the second coil 520.

  From the above, for example, when a current flows in the first coil 510 in the first circulation direction (counterclockwise), a current flows in the second coil 520 in the second rotation direction (clockwise). This means that the phase of the current flow in the first coil 510 is 180 ° out of phase with the current flow in the second coil 520.

  Any type of coil can be used as the first coil 510 and the second coil 520 as long as the above conditions are satisfied. For example, it may be a solenoid coil wound around a bobbin, or a spiral coil made of a conductor printed on a polycarbonate substrate.

According to the antenna coil 500 according to the present invention as described above, the first coil 510 and the second coil 520 do not need to use a coil with complicated winding work of the conductor wire, and are manufactured as compared with the conventional antenna coil. Because of its good characteristics, it is possible to cope with automation of antenna coil production.

  Here, the coil used for the first coil 510 is required to have a high inductance value. Therefore, it is preferable that the first coil 510 has a high winding density of the conductor wire. As such a coil, there is a so-called spider coil. Hereinafter, a spider coil suitable for use as the first coil 510 will be described.

  FIG. 5 is a view for explaining a spider coil suitable for the first coil 510 of the antenna coil 500, and FIG. 5A is a view showing a base material 600 used for forming the spider coil. (B) is a figure which shows an example of the pattern at the time of winding the conductor wire 400 around the base material 600, FIG.5 (C) is a figure which shows a spider coil.

  In the diagram shown in FIG. 5A, the base material 600 is described as an example of a substantially circular shape, but is not limited to this.

  The base material 600 is a substrate-like member having a first surface 601 and a second surface 602 that has a front and back relationship with the first surface 601, and may be configured using a material having a small dielectric loss tangent, such as polycarbonate or polypropylene. preferable.

  The base material 600 includes a base portion 610 that forms a substantially circular flat plate portion, and a plurality of coil shaping protrusions 620 that extend radially from the base portion 610.

  The coil shaping projecting piece 620 is used for engaging the conductor wire 400 with the conductor wire 400 passing through either the first surface 601 or the second surface 602. Thereby, the shape of the spider coil is maintained by the conductor wire 400.

  Next, an example of the winding pattern of the conductor wire 400 when modeling with the base material 600 as described above will be described with reference to FIG. As the conductor wire 400, it is preferable to use a stranded wire in which a plurality of conductor wires are assembled.

  In FIG. 5 (B), the arrow has shown the order at the time of winding a coil. For example, assuming that the conductor wire 400 starts to be wound by locking the conductor wire 400 to the coil shaping protrusion 620 shown in FIG. 5A, first, the two coil shaping protrusions shown in FIG. To 620, the conductor wire 400 is locked on the first surface 601 side of the coil shaping protrusion 620.

  Subsequently, the conductor wire 400 is locked on the second surface 602 side of the coil shaping projection piece 620 over the two coil shaping projection pieces 620 shown in FIG.

  On the other hand, the conductor wire 400 is locked on the first surface 601 side of the coil shaping projection piece 620 over the two coil shaping projection pieces 620 shown in FIG.

  As described above, for each of the two coil shaping projection pieces 620, the winding pattern in which the surface on which the conductor wire 400 is locked is alternately changed from the first surface 601 side and the second surface 602 side to (c) → (D) → (e) →. By using such a winding pattern, an antenna coil having a large inductance component can be formed.

  On the other hand, when forming an antenna coil with a small inductance component, the surface on which the conductor wire 400 is locked for each of the coil shaping projection pieces 620 is the first surface 601 side and the second surface 602 side. A winding pattern that alternates with is preferable. A coil made in this manner is suitable as the second coil 520.

  Next, the shielding performance of the antenna coil 500 according to the present invention as described above will be described. FIG. 6 is a diagram for explaining the shielding performance of the antenna coil 500. The round plot in FIG. 6 shows the relationship between the positional deviation between the coils and the transmission efficiency in the power transmission system using the antenna coil 500 according to the present invention as the primary resonator coil 160 and the secondary resonator coil 260. Show.

  The square plots in FIG. 6 show the positional deviation between the coils and the transmission efficiency in the power transmission system using the antenna coil shielded by the shielding material as the primary resonator coil 160 and the secondary resonator coil 260. Shows the relationship.

  Referring to FIG. 6, the reduction in transmission efficiency due to the positional deviation between the coils is suppressed when the antenna coil 500 according to the present invention is used, compared to the antenna coil using the shield material. In the antenna coil 500 according to the present invention, the first coil 510 has a comparatively simple configuration in which a second coil 520 having a reverse winding direction is connected in series, and is comparable to an antenna coil using a shield material. Performance can be obtained.

  Next, another embodiment of the present invention will be described. FIG. 7 is a schematic diagram of an antenna coil 500 according to another embodiment of the present invention.

  In FIG. 7, the configurations denoted by the same reference numerals as those in FIG. 4 are the same as those in the previous embodiment, and the description thereof will be omitted. The present embodiment is different from the previous embodiment in that a magnetic material 560 is disposed between the first coil 510 and the second coil 520.

  Such a magnetic material 560 is made of a ferromagnetic material such as a ferrite material having a high magnetic permeability and specific resistance. By disposing such a magnetic material 560 between the first coil 510 and the second coil 520, the first magnetic flux by the first coil 510 and the second magnetic flux by the second coil 520 are more efficient. Therefore, strong directivity is imparted by the antenna coil 500.

  As described above, according to the antenna coil according to the present invention, it is not necessary to use a coil having a complicated winding operation for the conductor wire as the first coil and the second coil, and the manufacturability is better than the conventional antenna coil. Therefore, it is possible to cope with automation of antenna coil production.

DESCRIPTION OF SYMBOLS 100 ... Electric power transmission system 101 ... AC / DC conversion part 102 ... Voltage control part 103 ... Inverter part 104 ... Matching device 110 ... Main control part 120 ... Communication part 150- ..Primary resonator 160 ... primary resonator coil (power transmission side antenna coil)
170 ... primary resonator capacitor 201 ... secondary resonator 202 ... rectifier 203 ... charge control unit 204 ... battery 210 ... main control unit 215 ... interface unit 220- ..Communication unit 250 ... secondary resonator 260 ... secondary resonator coil (power receiving side antenna coil)
300 ... Base material 301 ... First surface 302 ... Second surface 310 ... Base 320 ... Main coil shaping protrusion 330 ... Subcoil shaping protrusion 400 ... Conductor wire 500 ... Antenna coil 510 ... First coil 520 ... Second coil 530 ... Series connection conductor 540 ... First feeding end 550 ... Second feeding end 560 ... Magnetic material 600 ... Base material 601 ... First surface 602 ... Second surface 610 ... Base 620 ... Projection piece for coil shaping

Claims (4)

A first coil having a first inductance value;
A second coil having a second inductance value, which is connected in series with the first coil and generates a second magnetic flux that cancels the first magnetic flux when the first coil generates the first magnetic flux;
The antenna coil, wherein the second inductance value is set smaller than the first inductance value. The first coil is wound in a first circumferential direction;
The antenna coil according to claim 1, wherein the second coil is wound in a second circumferential direction opposite to the first circumferential direction. The antenna coil according to claim 1 or 2, wherein power is supplied from an end portion of the first coil and an end portion of the second coil. The antenna coil according to any one of claims 1 to 3, wherein a magnetic material is disposed between the first coil and the second coil.

Images