JP2013017255A - Antenna - Google Patents

Abstract

An antenna having stable characteristics and capable of efficient power transmission is provided.
An antenna of the present invention is formed on a base 310 and one surface on the base 310, and has two ends, an innermost end 331 and an outermost end 332, to form a coil. And a capacitor 400 fixed to the outermost end.
[Selection] Figure 3

Description

  The present invention relates to an antenna that is used in a magnetic resonance wireless power transmission system and 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.

  A magnetic resonance wireless power transmission system efficiently transmits energy from a power transmission side antenna to a power reception side antenna by making the resonance frequency of the power transmission side antenna and the resonance frequency of the power reception side antenna the same. 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. 2010-74937) discloses a non-contact power receiving device that receives power from a power transmission coil that receives power from a power source and performs power transmission, and uses the power transmitted from the power transmission coil. A power receiving coil that receives power by electromagnetic resonance, a coil case that houses the power receiving coil therein, and an outside of the coil case that is electrically connected to the power receiving coil to adjust a resonance frequency of the power receiving coil. A non-contact power receiving device including a capacitor is disclosed.
Special table 2009-501510 JP 2010-74937 A

  In an antenna used in a conventional power transmission system, an adjustment capacitor that is electrically connected to a power receiving coil has a structure that is disposed outside a coil case that houses the power receiving coil.

  The electrical connection part between the capacitor and the receiving coil has an inductance component. However, if the structure is as described above, the characteristics of the antenna as expected due to variations in the inductance component based on the electrical connection part having an indefinite shape. There is a problem that efficient power transmission cannot be performed. In addition, the electrical connection portion also has a resistance component, and this resistance component deteriorates the characteristics of the entire antenna, and there is also a problem that efficient power transmission cannot be performed.

In order to solve the above problem, the invention according to claim 1 is characterized in that a conductive portion forming a spiral coil having two ends, an innermost end portion and an outermost end portion, is fixed to the outermost end portion. An antenna.
The invention according to claim 2 is a substrate, and a conductive portion formed on one surface of the substrate and having two ends, an innermost end and an outermost end, and forming a coil. And a capacitor fixed to the outermost end portion.
The invention according to claim 3 is the antenna according to claim 1 or 2, characterized in that the dielectric material of the capacitor includes titanium oxide.
According to a fourth aspect of the present invention, in the antenna according to the first or second aspect, the dielectric material of the capacitor includes magnesium titanate.
The invention according to claim 5 is the antenna according to claim 1 or 2, wherein the dielectric material of the capacitor includes a steatite material.
The invention according to claim 6 is the antenna according to any one of claims 1 to 5, wherein both the base material and the capacitor are accommodated in a common case.

  In the antenna according to the present invention, the capacitor is fixed to the outermost end portion of the conductive portion forming the coil. Therefore, according to the antenna according to the present invention having such a configuration, the electric current between the coil and the capacitor is There is no change in the reactance component at the connection portion, and there is substantially no resistance component at the electrical connection portion between the coil and the capacitor, so that the antenna characteristics are stable and efficient power transmission can be performed. Become.

1 is a block diagram of a power transmission system in which an antenna according to an embodiment of the present invention is used. It is a figure which shows the inverter part of an electric power transmission system. 1 is an exploded perspective view of a power receiving antenna 201 according to a first embodiment of the present invention. It is a schematic diagram of the cross section which shows the mode of the electric power transmission by the power receiving antenna 201 which concerns on 1st Embodiment of this invention. It is a figure explaining the attachment structure of the capacitor | condenser 400 in the power receiving antenna 201 which concerns on 1st Embodiment of this invention. It is a figure which shows the frequency dependence example of the power transmission efficiency when the power transmission antenna 105 and the power receiving antenna 201 are made to adjoin. It is a figure which shows typically the mode of the electric current and electric field in a 1st extreme value frequency. It is a figure which shows typically the mode of the electric current and electric field in a 2nd extreme value frequency. It is a disassembled perspective view of the receiving antenna 201 which concerns on 2nd Embodiment of this invention. It is a schematic diagram of the cross section which shows the mode of the electric power transmission by the power receiving antenna 201 which concerns on 2nd Embodiment of this invention. It is a disassembled perspective view of the receiving antenna 201 which concerns on 3rd Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a power transmission system in which an antenna according to an embodiment of the present invention is used. The antenna according to the present invention can be applied to both the power receiving side antenna and the power transmitting side antenna constituting the power transmission system. However, in the following embodiments, the antenna according to the present invention is mainly used as the power receiving side antenna. An example in which is applied will be described.

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 stop space, which is a vehicle charging space, is configured such that the power transmission antenna 105 and the like are buried in the ground. A user of the vehicle stops the vehicle in a stop space where the power transmission system is provided, and makes the power reception antenna 201 mounted on the vehicle and the power transmission antenna 105 face each other to thereby generate power from the power transmission system. Receive power. When the vehicle is stopped in the stop space, the power receiving antenna 201 mounted on the vehicle has a positional relationship with good transmission efficiency with respect to the power transmission antenna 105.

  In the power transmission system, when power is efficiently transmitted from the power transmission antenna 105 on the power transmission system 100 side to the power reception antenna 201 on the power reception side system 200 side, the resonance frequency of the power transmission antenna 105 and the resonance frequency of the power reception antenna 201 are By making the same, energy transmission is efficiently performed from the power transmission side antenna to the power reception side antenna.

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

The inverter unit 103 generates a predetermined AC voltage from the high voltage supplied from the high voltage generation 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 switching of each switching element is about several hundred kHz to several thousand 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 power transmission antenna 105. 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 power transmitting antenna 105 and the power receiving antenna 201 resonate.

  The power transmission antenna 105 is composed of a coil having an inductance component, and resonates with the vehicle-mounted power reception antenna 201 arranged so as to face each other, whereby electric energy output from the power transmission antenna 105 is supplied to the power reception antenna 201. You can send.

  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 for processing. Further, 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 power receiving antenna 201 receives electric energy output from the power transmitting antenna 105 by resonating with the power transmitting antenna 105. Such a power receiving antenna 201 is adapted to be attached to the bottom portion of the vehicle.

  The AC power received by the power receiving antenna 201 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 205 based on a command from the main control unit 210. In addition, the charging control unit 203 is configured to perform the 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 230 is provided in the driver's seat of the vehicle and provides predetermined information to the user (driver) or accepts operation / input from the user. A touch panel, a speaker, and the like. When a predetermined operation by the user is executed, it is sent as operation data from the interface unit 230 to the main control unit 210 and processed. 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 230.

  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 230 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 205 from the charge control unit 203 and calculates the amount of power necessary for charging the battery 205. 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 high voltage generation unit 102, the inverter unit 103, and the matching unit 104 to transmit power to the vehicle side.

  Next, a specific configuration of the antenna used in the power transmission system 100 configured as described above will be described. Hereinafter, although the example which employ | adopted the structure of this invention for the power receiving antenna 201 is demonstrated, the antenna of this invention is applicable also to the power transmission antenna 105. FIG.

  FIG. 3 is an exploded perspective view of the power receiving antenna 201 according to the first embodiment of the present invention. FIG. 4 is a schematic cross-sectional view showing a state of power transmission by the power receiving antenna 201 according to the first embodiment of the present invention. In the following embodiment, a rectangular flat plate is used as an example of the coil body 300, but the antenna of the present invention is not limited to such a coil having such a shape. For example, a circular flat plate or the like can be used as the coil body 300.

  Such a coil body 300 functions as a magnetic resonance antenna unit in the power receiving antenna 201. The magnetic resonance antenna unit includes not only an inductance component of the coil body 300 but also a capacitance component based on the capacitor 400.

  The resin case 260 is used to accommodate the coil body 300 having the inductance component of the power receiving antenna 201. The resin case 260 has a box shape having an opening made of a resin such as polycarbonate.

  Side plate portions 262 are provided from each side of the rectangular bottom plate portion 261 of the resin case 260 so as to extend in a direction perpendicular to the bottom plate portion 261. An upper opening 263 is formed above the resin case 260 so as to be surrounded by the side plate 262. In order to attach the resin case 260 to the vehicle body, any conventionally known method can be used. A flange member or the like may be provided around the upper opening 263 in order to improve attachment to the vehicle main body.

  The coil body 300 includes a rectangular flat plate-like substrate 310 made of glass epoxy and conductive portions formed on the front side and the back side. More specifically, the base material 310 has a first surface 311 as a main surface and a second surface 312 having a front and back relationship with the first surface 311, and among these, the first surface 311 has a spiral shape. By forming the first surface conductive portion 330 as a coil, an inductance component is imparted to the power receiving antenna 201.

  On the first surface 311 on the substrate 310, the innermost end portion 331 of the first surface is formed on the inner peripheral side of the first surface conductive portion 330 forming the spiral coil, and the innermost end of the first surface is formed on the outer peripheral side. Outer end portions 332 are respectively provided.

  In the first surface innermost end portion 331, an innermost end portion through hole 333 penetrating between the first surface 311 and the second surface 312, and in the first surface outermost end portion 332, the first surface Outermost end through holes 334 penetrating between the surface 311 and the second surface 312 are provided.

  The conductive line 241 and the conductive line 242 electrically connect the power receiving antenna 201 and the rectifying unit 202, and among these, the conductive line 241 is electrically connected to the first surface innermost end 331 of the first surface conductive unit 330. Connected. For this purpose, as shown in the drawing, the terminal 243 of the conductive line 241 is arranged on the innermost end 331 of the first surface, and the screw 251 is connected from the first surface 311 side on the substrate 310 to the conductive line 241. The terminal 243 is inserted into the hole and the innermost end through-hole 333 and screwed into the nut 252 on the second surface 312 side on the substrate 310. Thereby, the conductive line 241 is electrically connected to the innermost end 331 of the first surface and is mechanically fixed.

  On the other hand, the first surface outermost end portion 332 is configured such that the capacitor 400 serving as a capacitance component in the power receiving antenna 201 is directly fixed. The fixing structure of the capacitor 400 at the first surface outermost end 332 will be described with reference to FIG. FIG. 5 is a view for explaining the mounting structure of the capacitor 400 in the power receiving antenna 201 according to the first embodiment of the present invention. FIG. 5 schematically shows a mounting cross section of the capacitor 400 at the innermost end 331 of the first surface.

  First, an outline of a capacitor 400 that can be suitably used for the power receiving antenna 201 according to the first embodiment of the present invention will be described.

A metal first connection terminal portion 403 and a first thin-film electrode 407 made of a conductive material are disposed on one side of the dielectric 401 constituting the capacitor 400, and the metal second connection terminal portion 404 is disposed on the other side.
The second thin film electrode 408 made of a conductive material is disposed, and the dielectric 401 is sandwiched between them to secure a capacity. In the power receiving antenna 201 of the present invention, a dielectric material used for the dielectric 401 is preferably a material containing titanium oxide as a main component or a material containing barium titanate as a main component. These materials have a high dielectric constant. Therefore, the capacitor 400 using these materials has a high capacitance despite being compact, and the volume capacity of the power receiving antenna 201 can be reduced.

  In the power receiving antenna 201 of the present invention, it is also preferable to use a material containing magnesium titanate as a main component or a material containing a steatite material as a main component as a dielectric material used for the dielectric 401. It is. This is because such a dielectric material has a high dielectric constant, and thus the capacitor 400 using the dielectric material has a high capacitance despite being compact, and the volume capacity of the power receiving antenna 201 can be reduced.

  A first screw hole 405 is provided in the first connection terminal portion 403 made of metal provided on one side of the capacitor 400. The terminal 244 of the conductive line 242 is disposed on the first screw hole 405, and the screw 253 is inserted into the hole of the terminal 244 of the conductive line 242 and the first screw hole 405 and screwed. Thereby, electrical conduction and mechanical fixation between the conductive line 242 and the first connection terminal portion 403 on one side of the capacitor 400 are achieved.

  A second screw hole 406 is provided in the metal second connection terminal portion 404 provided on the other side of the capacitor 400. The second connection terminal portion 404 of the capacitor 400 is arranged on the first surface outermost end portion 332, and the screw 254 is inserted into the outermost end through hole 334 and the second screw hole 406 from the second surface 312 side. The screw 254 and the second screw hole 406 are screwed through. Accordingly, the second connection terminal portion 404 of the capacitor 400 and the first surface outermost end portion 332 of the first surface conductive portion 330 are electrically connected, and the capacitor 400 and the base material 310 are mechanically fixed. Let

  The first surface innermost end portion 331 on the inner peripheral side and the first surface outermost end portion 332 on the outer peripheral side of the first surface conductive portion 330 having a spiral shape as described above are respectively provided with the conductive line 241 and the conductive line. 242 is electrically connected. As a result, the power received by the power receiving antenna 201 can be guided to the rectifying unit 202. Such a coil body 300 is placed on the rectangular bottom plate portion 261 of the resin case 260 and fixed on the bottom plate portion 261 by an appropriate fixing means.

  In the antenna according to the present invention, the capacitor 400 is fixed to the outermost end portion of the conductive part forming the coil. Therefore, according to the antenna according to the present invention having such a configuration, the capacitor 400 is provided between the coil and the capacitor 400. There is no fluctuation of the reactance component in the electrical connection portion of the antenna, and there is substantially no resistance component in the electrical connection portion between the coil and the capacitor 400, so that the antenna characteristics are stable and efficient power transmission is performed. Is possible.

  The magnetic shield 280 is a flat magnetic member having a hollow portion 285. In order to construct the magnetic shield 280, a magnetic material such as ferrite can be used. The magnetic shield 280 is arranged with a certain amount of space above the coil body 300 by being fixed to the resin case 260 by an appropriate means. With such a layout, the lines of magnetic force generated on the power transmission antenna 105 side have a high rate of transmission through the magnetic shield 280, and the lines of magnetic force generated by metal objects constituting the vehicle main body in power transmission from the power transmission antenna 105 to the power reception antenna 201. The impact on is minor.

In the antenna according to the present invention, the flat magnetic shield 280 disposed above the coil body 300 is preferably provided with a hollow portion 285. By providing the hollow portion 285 in the magnetic shield 280, the loss of the magnetic shield 280 itself is reduced, and the shielding effect of the magnetic shield 280 can be maximized. Further, in the magnetic shield 280 having the hollow portion 285, the member area is small, and the cost of the antenna can be reduced. Note that the width of the hollow portion 285 is preferably limited to such a size that the magnetic shield 280 itself and the conductive portion 272 of the coil body 300 do not overlap each other when viewed from the stacking direction.

  By the way, in the antenna according to the present invention, the capacitor 400 is not fixed to the innermost end portion 331 of the first surface of the first surface conductive portion 330 forming the coil, but the capacitor 400 is connected to the first surface conductive portion 330. The first surface is fixed to the outermost end 332 of the first surface. The reason for this will be described. FIG. 6 is a diagram illustrating a frequency dependence example of power transmission efficiency when the power transmission antenna 105 and the power reception antenna 201 are brought close to each other.

In the magnetic resonance type wireless power transmission system, as shown in FIG. 6, there are two first extreme frequency f _m and second extreme frequency _fe . This is preferably done at frequency.

  FIG. 7 is a diagram schematically showing the state of current and electric field at the first extreme frequency. At the first extreme frequency, the current flowing in the coil of the power transmitting antenna 105 and the current flowing in the coil of the power receiving antenna 201 have substantially the same phase, and the positions where the magnetic field vectors are aligned are the coil of the power transmitting antenna 105 and the power receiving antenna 201. Near the center of the coil. This state is considered as a magnetic wall in which the direction of the magnetic field is perpendicular to the plane of symmetry between the power transmission antenna 105 and the power reception antenna 201.

  FIG. 8 is a diagram schematically showing the state of current and electric field at the second extreme frequency. At the second extreme frequency, the current flowing in the coil of the power transmitting antenna 105 and the current flowing in the coil of the power receiving antenna 201 are almost opposite in phase, and the position where the magnetic field vectors are aligned is the position of the coil of the power transmitting antenna 105 or the power receiving antenna 201. Near the symmetry plane of the coil. This state is considered as an electrical wall in which the direction of the magnetic field is horizontal with respect to the plane of symmetry between the power transmitting antenna 105 and the power receiving antenna 201.

  Regarding the concepts of the electric wall and the magnetic wall as described above, Takehiro Imura and Yoichi Hori “Transmission Technology by Electromagnetic Resonance Coupling”, IEEE Journal, Vol. 129, no. 7, 2009, or Takehiro Imura, Hiroyuki Okabe, Toshiyuki Uchida, Yoichi Hori “Studies on magnetic field coupling and electric field coupling of non-contact power transmission as seen from the equivalent circuit” IEEE Trans. IA, Vol. 130, no. 1, 2010 and the like are applied mutatis mutandis in this specification.

When power transmission is performed at any one of the first extreme value frequency f _m and the second extreme value frequency _fe , the magnetic field lines may concentrate on the inner peripheral side of the coil. When the capacitor 400 is disposed at such a location where the magnetic lines of force concentrate, vortices are not generated in the electrodes (the first connection terminal portion 403, the second connection terminal portion 404, the first thin film electrode 407, and the second thin film electrode 408) constituting the capacitor 400. Current may be generated and heat may be generated. For this reason, in the antenna according to the present invention, the capacitor 400 is not fixed to the innermost end portion 331 of the first surface of the first surface conductive portion 330 forming the coil. The surface conductive portion 330 is fixed to the outermost end portion 332 of the first surface.

Next, another embodiment of the present invention will be described. FIG. 9 is an exploded perspective view of a power receiving antenna 201 according to the second embodiment of the present invention, and FIG. 10 is a schematic cross-sectional view showing a state of power transmission by the power receiving antenna 201 according to the second embodiment of the present invention. . The second embodiment is different from the first embodiment only in the structure of the coil body 300, and the fixing method of the coil body 300 and the capacitor 400 is the same as that of the first embodiment. A specific structure of the coil body 300 will be described.

  FIG. 9 is an exploded perspective view of the power receiving antenna 201 according to the second embodiment of the present invention, and FIG. 9B is an exaggerated representation of the thickness direction of the base material 310 forming the coil body 300. . FIG. 10 is a schematic cross-sectional view showing a state of power transmission by the power receiving antenna 201 according to the second embodiment of the present invention. In the following embodiment, a rectangular flat plate is used as an example of the coil body 300, but the antenna of the present invention is not limited to such a coil having such a shape. For example, a circular flat plate or the like can be used as the coil body 300.

  The coil body 300 includes a rectangular flat plate-like substrate 310 made of glass epoxy and conductive portions formed on the front side and the back side. More specifically, the base material 310 has a first surface 311 as a main surface and a second surface 312 in a front-back relationship with the first surface 311, and the first surface 311 and the second surface. By forming a spiral conductive portion on both sides 312, an inductance component is imparted to the power receiving antenna 201.

  A spiral first surface conductive portion 330 is formed on the first surface 311 on the substrate 310, and the first surface innermost end portion 331 is formed on the inner peripheral side of the first surface conductive portion 330. A first surface outermost end portion 332 is provided on each outer peripheral side.

  Similarly, a spiral second surface conductive portion 350 is formed on the second surface 312 on the substrate 310, and the second surface innermost end 351 is formed on the inner peripheral side of the second surface conductive portion 350. In addition, a second surface outermost end portion 352 is provided on the outer peripheral side.

  Here, the first surface conductive portion 330 and the second surface conductive portion 350 are configured to overlap each other when viewed transparently from the first surface 311 to the second surface 312. With this configuration, the mutual inductance between the inductance component based on the first surface conductive portion 330 on the first surface 311 side and the inductance component based on the second surface conductive portion 350 on the second surface 312 side is adjusted and designed. Easy to do.

  In the base material 310, the first through-hole conducting portion 341 penetrating between the first surface 311 and the second surface 312 has the first surface innermost end portion 331 and the second surface innermost end portion 351. It is designed to conduct. Further, the second through-hole conducting portion 342 penetrating between the first surface 311 and the second surface 312 conducts the first surface outermost end portion 332 and the second surface outermost end portion 352. Yes.

  A conductive line 241 is provided at the innermost first surface innermost portion 331 of the inner peripheral side of the first surface conductive portion 330 having a spiral shape as described above, and a capacitor is provided at the outermost first surface outermost end portion 332. The conductive line 242 is electrically connected via 400. As a result, the power received by the power receiving antenna 201 can be guided to the rectifying unit 202. Such a coil body 300 is placed on the rectangular bottom plate portion 261 of the resin case 260 and fixed on the bottom plate portion 261 by an appropriate fixing means.

  The antenna according to the present invention as described above is based on the first surface conductive portion 330 of the first surface 311, the antenna based on the second surface conductive portion 350 of the second surface 312, and the first as the inductance component. Based on the mutual inductance formed mutually by the surface conductive portion 330 and the second surface conductive portion 350 formed so as to overlap therewith, without significantly reducing the inductance, Since the first surface conductive portion 330 and the second surface conductive portion 350 are connected in parallel, the resistance of the electric circuit in the antenna is reduced. According to the above, since Q (Quality Factor) can be improved, transmission efficiency between antennas is improved.

  According to the second embodiment as described above, the same effect as that of the first embodiment can be obtained, and the Q (Quality Factor) can be reduced by reducing the resistance value without significantly reducing the inductance. The transmission efficiency between antennas can be improved.

  Next, a third embodiment of the present invention will be described. The third embodiment is different from the first embodiment and the second embodiment only in the structure of the coil body 300, and the fixing method of the coil body 300 and the capacitor 400 is the same as that of the first embodiment and the second embodiment. Therefore, hereinafter, the structure of the coil body 300 unique to the third embodiment will be described.

  In the second embodiment, the conductive portion in the coil body 300 is configured to be provided on the front and back of the base material 310. However, in the third embodiment, the conductive portion of the coil body 300 is provided in the intermediate layer of the base material 310. Is different in that it is also provided. Hereinafter, the configuration of the coil body 300 which is the difference will be described.

  FIG. 11 is an exploded perspective view of the power receiving antenna 201 according to the third embodiment of the present invention, and FIG. 11 (B) is an exaggerated representation of the thickness direction of the substrate 310 forming the coil body 300. .

  The coil body 300 is composed of a rectangular flat plate-like base material 310 made of glass epoxy, and conductive portions formed on the front surface side, the back surface side, and the intermediate layer. More specifically, the base material 310 has a first surface 311 as a main surface, a second surface 312 having a front-back relationship with the first surface 311, and an intermediate between the first surface 311 and the second surface 312. A spiral conductive portion is formed in the first surface 311, the second surface 312, and the intermediate layer 313, so that an inductance component is imparted to the power receiving antenna 201.

  A spiral first surface conductive portion 330 is formed on the first surface 311 on the substrate 310, and the first surface innermost end portion 331 is formed on the inner peripheral side of the first surface conductive portion 330. A first surface outermost end portion 332 is provided on each outer peripheral side.

  Similarly, a spiral intermediate layer conductive portion 360 is formed in the intermediate layer 313 on the base material 310, and the intermediate layer innermost end 361 is formed on the inner peripheral side of the intermediate layer conductive portion 360. On the side, an outermost end portion 362 of the intermediate layer is provided.

  Similarly, a spiral second surface conductive portion 350 is formed on the second surface 312 on the substrate 310, and the second surface innermost end 351 is formed on the inner peripheral side of the second surface conductive portion 350. In addition, a second surface outermost end portion 352 is provided on the outer peripheral side.

  Here, the first surface conductive portion 330, the intermediate layer conductive portion 360, and the second surface conductive portion 350 are configured to overlap each other when viewed transparently from the first surface 311 to the second surface 312. With this configuration, the inductance component based on the first surface conductive portion 330 on the first surface 311 side, the inductance component based on the intermediate layer conductive portion 360 of the intermediate layer 313, and the second surface on the second surface 312 side. It becomes easy to adjust and design the mutual inductance with the inductance component based on the conductive portion 350.

  In the substrate 310, the first through-hole conducting portion 341 that penetrates between the first surface 311 and the intermediate layer 313 conducts the first surface innermost end portion 331 and the intermediate layer innermost end portion 361. It is like that. In addition, a second through-hole conduction portion 342 that penetrates between the first surface 311 and the intermediate layer 313 connects the first surface outermost end portion 332 and the intermediate layer outermost end portion 362.

Further, a third through-hole conducting portion 343 penetrating between the intermediate layer 313 and the second surface 312 conducts the intermediate layer innermost end 361 and the second surface innermost end 351. . Further, a fourth through-hole conducting portion 344 penetrating between the intermediate layer 313 and the second surface 312 conducts the intermediate layer outermost end portion 362 and the second surface outermost end portion 352. .

  Even in the third embodiment having the coil body 300 configured as described above, the same effects as those of the previous embodiment can be obtained. In the third embodiment, the conductive portion is formed in three layers of the first surface 311, the intermediate layer 313, and the second surface 312, and the end portions of the respective conductive portions penetrate through the base material. However, it is also possible to provide two or more intermediate layers and four or more layers for providing the conductive portion.

  In this embodiment, an example in which a glass epoxy resin is used for the base material 310 is described. However, a ceramic base material having a higher heat dissipation effect may be used, and an insulating film is applied to a metal base material such as aluminum. You may use the base material which did. Of course, a thing using a flexible printed circuit board etc. may be used.

  According to the third embodiment as described above, the same effect as that of the first embodiment can be obtained, and the Q (Quality Factor) can be reduced by reducing the resistance value without significantly reducing the inductance. The transmission efficiency between antennas can be improved.

DESCRIPTION OF SYMBOLS 100 ... Electric power transmission system 101 ... AC / DC conversion part 102 ... High voltage generation part 103 ... Inverter part 104 ... Matching device 105 ... Power transmission antenna 110 ... Main control part 120 Communication unit 201 Power receiving antenna 202 Rectification unit 203 Charging control unit 204 Battery 210 Main control unit 220 Communication unit 230 Interface unit 241 ..Conductive lines
242: Conductive line,
243 ... terminal,
244 ... Terminal,
251 ... Screw,
252 ... Nuts,
253 ... Screw,
254 ... Screw,
260 ... Resin case 261 ... Bottom plate part 262 ... Side plate part 263 ... Upper opening part 280 ... Magnetic shield 281 ... Shield holding plate 282 ... Magnetic shield divided piece 285 ... Hollow section 300 ... Coil body 310 ... Base material 311 ... First surface 312 ... Second surface 313 ... Intermediate layer 330 ... First surface conductive portion 331 ... First Surface innermost end 332 ... first surface outermost end 333 ... innermost end through-hole,
334 ... Outermost end through hole,
341... First through-hole conducting portion 342... Second through-hole conducting portion 343... Third through-hole conducting portion 344... Fourth through-hole conducting portion 350. 2nd surface innermost end 352 2nd surface outermost end 360 ... intermediate layer conductive portion 361 ... intermediate layer innermost end 362 ... intermediate layer outermost end 400 ... Capacitor 401 ... Dielectric 403 ... First connection terminal portion 404 ... Second connection terminal portion 405 ... First screw hole 406 ... Second screw hole 407 ... First Thin film electrode 408 ... second thin film electrode

Claims (6)

A conductive portion forming a spiral coil having two ends, an innermost end and an outermost end;
A capacitor fixed to the outermost end. A substrate;
A conductive portion that is formed on one surface of the substrate and has two ends, an innermost end and an outermost end, to form a coil;
A capacitor fixed to the outermost end. 3. The antenna according to claim 1, wherein the dielectric material of the capacitor contains titanium oxide. The antenna according to claim 1, wherein the dielectric material of the capacitor includes magnesium titanate. The antenna according to claim 1, wherein the dielectric material of the capacitor includes a steatite-based material. 6. The antenna according to claim 1, wherein both the base material and the capacitor are accommodated in a common case.

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