JP2013074684A - Antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna capable of suppressing degradation in a power transmission efficiency caused by different resonance frequencies between antennas.SOLUTION: The antenna comprises: a first surface conductive section 330 formed on a first surface 311 of a dielectric substrate 310; a capacitor adjustment region 410 that is formed on the first surface 311 of the dielectric substrate 310 and communicates with the first surface conductive section 330; a second surface conductive section 350 formed on a second surface 312 of the inductive substrate 310; and a capacitor adjustment region corresponding electrode 402 that is formed on the second surface 312 of the inductive substrate 310 and communicates with the second surface conductive section 350.

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

  An antenna used in a conventional magnetic resonance wireless power transmission system has a structure including a coil and an adjustment capacitor connected to the coil. In order to improve the power transmission efficiency in the magnetic resonance type wireless power transmission system, the antenna is required to have a high Q (Quality Factor). However, if the Q of the antenna is to be increased, the capacitor is high during power transmission. A voltage was applied, and it was necessary to use a capacitor having a high withstand voltage. However, since a capacitor having a high withstand voltage is expensive, there is a problem in that this increases the cost of the antenna and thus the wireless power transmission system.

  Therefore, in order to cope with such a problem, the inventors transmit the first coil on one main surface of a flat substrate made of a dielectric material, and transmit the main surface on the other main surface. In view of this, an inexpensive antenna structure including a capacitor function comprising a second coil having a shape overlapping with the first coil has been proposed.

By the way, if the resonant frequency of the power transmitting antenna and the resonant frequency of the power receiving antenna are different, the power transmission efficiency is lowered. In some cases, the position of the second coil may be displaced, which causes the resonance frequency of each antenna to deviate from the assumed value, thereby reducing the power transmission efficiency.

  In order to solve the above problem, an invention according to claim 1 is provided on a first surface conductive portion provided on a first surface of a dielectric substrate, on a second surface of the dielectric substrate, and on the first surface. An antenna comprising: a second surface conductive portion having an area different from the area of the one surface conductive portion.

  According to a second aspect of the present invention, there is provided a first surface conductive portion provided on the first surface of the dielectric base material, a first surface conductive portion provided on the first surface of the dielectric base material, and communicated with the first surface conductive portion. A capacitor adjustment region, a second surface conductive portion provided on the second surface of the dielectric substrate, and a capacitor adjustment provided on the second surface of the dielectric substrate and communicating with the second surface conductive portion. An antenna having a region-corresponding electrode.

  The invention according to claim 3 is the antenna according to claim 1 or 2, characterized in that the conductive portion has a spiral coil shape.

  According to a fourth aspect of the present invention, in the antenna according to the second or third aspect, in the capacitor adjustment region, an area of an electrode constituting the capacitor is increased by attaching a conductive tape. It is characterized by that.

  According to a fifth aspect of the present invention, in the antenna according to the second or third aspect, the capacitor adjustment region is configured by an electrode that can be trimmed.

  According to a sixth aspect of the present invention, in the antenna according to the second or third aspect, the capacitor adjustment region includes a plurality of unit conductive portions, and the first surface conductive portion and the unit conductive are formed by jumper wires. The area of the electrode which comprises a capacitor | condenser is increased by conducting between these parts, It is characterized by the above-mentioned.

  According to a seventh aspect of the present invention, in the antenna according to the second or third aspect, the capacitor adjustment region includes a plurality of unit conductive portions that are connected by trimming adjustment cutting portions. And

  In the antenna according to the present invention, the resonance frequency of each antenna can be made as expected by using the capacitor adjustment region. It is possible to reduce a decrease in power transmission efficiency due to different resonance frequencies.

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. It is a figure explaining the power receiving antenna 201 which concerns on 1st 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 1st Embodiment of this invention. It is a figure explaining the capacitor | condenser adjustment area | region in the 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 figure which shows the characteristic in the extreme value frequency (1st frequency) which a magnetic wall produces among the extreme value frequencies which give two extreme values. It is a figure which shows the characteristic in the extreme value frequency (2nd frequency) which an electric wall produces among the extreme value frequencies which give two extreme values. It is a figure explaining the capacitor | condenser adjustment area | region in the receiving antenna 201 which concerns on 2nd Embodiment of this invention. It is a figure explaining the capacitor | condenser adjustment area | region in the receiving antenna 201 which concerns on 3rd Embodiment of this invention. It is a figure explaining the capacitor | condenser adjustment area | region in the receiving antenna 201 which concerns on 4th Embodiment of this invention. It is a figure explaining the power receiving antenna 201 which concerns on 5th Embodiment of this invention. It is a figure explaining the capacitor | condenser adjustment area | region in the receiving antenna 201 which concerns on 5th Embodiment of this invention. It is a figure explaining the capacitor | condenser adjustment area | region in the receiving antenna 201 which concerns on 6th 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. 3A is an exploded perspective view of the power receiving antenna 201 according to the first embodiment of the present invention, and FIG. 3B exaggeratedly represents the thickness direction of the base material 310 forming the coil body 300. FIG. 3C is a schematic cross-sectional view taken along the line AA ′. 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 a capacitor using the dielectric substrate 310 as a dielectric, and the resonance frequency is determined by the inductance component and the capacitance component. Is done. The inductance component is determined by the width, the number of turns, and the layout of the conductive portion of the coil body 300, and the capacitance component is the dielectric constant and thickness of the dielectric substrate 310, the area of the conductive portion provided on both surfaces of the dielectric substrate 310, And the positional relationship between the conductive parts on both sides. Therefore, a desired magnetic resonance antenna unit can be configured by adjusting those parameters. It should be noted that the dielectric tangent of the dielectric material 310 can be configured as a high-performance antenna with less loss as the resonance frequency is smaller.

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-shaped dielectric substrate 310 made of polycarbonate, and a conductive portion and a capacitor adjustment region formed on the front surface side and the back surface side. More specifically, the dielectric substrate 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, of which the first surface 311 has By forming the spiral-coiled first surface conductive portion 330 and the second surface 312 as a spiral coil-shaped second surface conductive portion 350 as a coil, an inductance component is imparted to the power receiving antenna 201.

  In the present embodiment, the first surface conductive portion 330 and the second surface conductive portion 350 will be described based on an example in which they are formed as spiral coils. However, the necessary inductance component can be ensured. For example, instead of the spiral coil, for example, a linear conductive portion may be used.

  Further, the first surface conductive portion 330 and the second surface conductive portion 350 overlap each other when viewed from the first surface 311 to the second surface 312 in a transparent manner. The dielectric substrate 310 sandwiched between the first surface conductive portion 330 and the second surface conductive portion 350 functions as a capacitor, so that a capacitance component is imparted to the power receiving antenna 201. The

  Furthermore, in the power receiving antenna 201 according to the present embodiment, the capacitor adjustment region 400 that communicates with the first surface conductive portion 330 and the second surface 312 of the dielectric substrate 310 on the first surface 311 of the dielectric substrate 310. 2, the capacitor adjustment region corresponding electrode 402 on the second surface side communicating with the second surface conductive portion 350 functions as a capacitor capable of adjusting the capacitance, whereby a further capacitance component is imparted to the power receiving antenna 201. .

  On the first surface 311 on the dielectric 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 first surface 311 is formed on the outer peripheral side. A surface outermost end 332 is provided.

  In addition, on the second surface 312 on the dielectric substrate 310, the second surface innermost end portion 351 is formed on the inner peripheral side of the second surface conductive portion 350 forming the spiral coil, and on the outer peripheral side. Second surface outermost ends 352 are provided.

  Because of the configuration as described above, in the antenna according to this embodiment, the area of the conductive portion provided on the first surface 311 of the dielectric substrate 310 and the second surface 312 of the dielectric substrate 310 are provided. The area of the conductive part is different.

The conductive line 241 and the conductive line 242 electrically connect the power receiving antenna 201 and the rectifying unit 202, and the conductive line 241 is electrically connected to the first surface outermost end 332 of the first surface conductive unit 330. Connected. Further, the conductive line 242 is electrically connected to the innermost end portion 351 of the second surface of the second surface conductive portion 350. 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 has a resin case 2.
It is placed on 60 rectangular bottom plate portions 261 and fixed on the bottom plate portion 261 by appropriate fixing means.

  In the antenna according to the present invention as described above, the dielectric substrate 310 between the spiral coil-shaped first surface conductive portion 330 and the second surface conductive portion 350 functions as a capacitor. According to the antenna according to the present invention, it is possible to configure the antenna and the wireless power transmission system at low cost. In addition, the dielectric base material 310 becomes a base material for forming a coil, and it is not necessary to provide an independent capacitor as a component. Therefore, the weight of the antenna and the wireless power transmission system can be reduced.

  Next, a method of using the capacitor adjustment region in the antenna according to the present invention will be described with reference to FIG. FIG. 5 is a diagram illustrating a capacitor adjustment region in the power receiving antenna 201 according to the first embodiment of the present invention.

  FIG. 5A shows the first surface side capacitor adjustment region 410 in a state where the capacitance is not adjusted. The first surface side capacitor adjustment region 410 is a relay conductive portion 414 that communicates with the first surface conductive portion 330, and a conductive portion that is disposed perpendicularly to the relay conductive portion 414 with a predetermined distance therebetween. It is composed of a first facing portion 415 and a second facing portion 416.

  FIG. 5B illustrates a method of increasing the capacitance component using the first surface side capacitor adjustment region 410 configured as described above. The conductive tape 418 is, for example, a copper foil and a tape obtained by applying an adhesive component to the copper foil, and the conductivity is ensured even in the adhesive portion, and the entire conductive tape 418 has conductivity.

  Using the conductive tape 418 as described above, the first opposing portion 415 and the second opposing portion 416 are short-circuited as shown in FIG. By increasing the area of the part, the capacitance component can be increased.

  As described above, in the antenna according to the present invention, the capacitance component can be increased by increasing the area of the electrodes constituting the capacitor by attaching the conductive tape 418 in the capacitor adjustment region 400.

  As described above, in the antenna according to the present invention, by using the capacitor adjustment region 400, the resonance frequency of each antenna can be made as expected, so that according to such an antenna according to the present invention, In addition, it is possible to reduce a decrease in power transmission efficiency due to different resonance frequencies between the antennas.

  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. The width of the hollow portion 285 is such that the magnetic shield 280 itself and the conductive portion 272 (the first surface conductive portion 330 and the second surface conductive portion 350) of the coil body 300 do not overlap each other when viewed from the stacking direction. It is preferable to keep it wide.

  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.

  In the present invention, when there are two extreme frequency values, ie, the first extreme value frequency and the second extreme value frequency, the extreme value in which an electric wall is generated on the plane of symmetry between the power transmitting antenna 105 and the power receiving antenna 201 The reason for selecting the frequency will be described.

FIG. 9 is a diagram showing characteristics at an extreme value frequency (first frequency) in which a magnetic wall is generated, among extreme value frequencies giving two extreme values. FIG. 9A is a diagram showing how the voltage (V ₁ ) and current (I ₁ ) on the power transmission side change with the load change fluctuation of the battery 204 (load), and FIG. 9B shows the battery 204 (load). receiving side of the voltage due to load change variation of the load) (V _3), it is a diagram showing a state of variation of the current (I _3). According to the characteristics shown in FIG. 9, it can be seen that there is a characteristic that the voltage increases as the load of the battery 204 (load) increases on the power receiving side.

  At the frequency at which the magnetic wall is generated as described above, the power receiving antenna 201 can be seen as a constant current source when viewed from the battery 204 side. When power transmission is performed at such a frequency that the power receiving antenna 201 operates as a constant current source, if an emergency stop occurs due to a malfunction of the battery 204 on the load side, both ends of the power receiving antenna 201 are The voltage will increase.

On the other hand, FIG. 10 is a diagram showing characteristics at an extreme value frequency (second frequency) at which an electric wall is generated, among extreme value frequencies giving two extreme values. FIG. 10A is a diagram showing how the voltage (V ₁ ) and current (I ₁ ) on the power transmission side vary with the load variation variation of the battery 204 (load), and FIG. receiving side of the voltage due to load change variation of the load) (V _3), it is a diagram showing a state of variation of the current (I _3). According to the characteristics shown in FIG. 10, it can be seen that there is a characteristic that the current decreases as the load of the battery 204 (load) increases on the power receiving side.

  At the frequency at which the electric wall as described above is generated, the power receiving antenna 201 can be seen as a constant voltage source when viewed from the battery 204 side. When power transmission is performed at a frequency at which the power receiving antenna 201 operates like a constant voltage source, even if an emergency stop occurs due to a malfunction of the battery 204 on the load side, both ends of the power receiving antenna 201 The voltage of the part does not increase. Therefore, according to the power transmission system of the present invention, when the load is suddenly reduced, the voltage does not become high voltage, and it is possible to perform power transmission stably.

  In the characteristics of FIG. 9, the charging circuit appears as a current source for the battery 204 (load) on the power receiving side, and the charging circuit is a voltage for the battery 204 (load) on the power receiving side in the characteristics of FIG. It will appear as a source. The characteristic shown in FIG. 10 in which the current decreases as the load increases is preferable for the battery 204 (load). In this embodiment, the first extreme frequency and the second extreme frequency are 2 In the case where there is one, an extreme value frequency at which an electric wall is generated on the plane of symmetry between the power transmitting antenna 105 and the power receiving antenna 201 is selected.

  According to such a power transmission system according to the present invention, even when there are two frequencies that give extreme values of transmission efficiency, the optimum frequency at the time of power transmission can be quickly determined, and the efficiency Power transmission can be performed in a short time.

  In addition, when there are two frequencies that give two extreme values, if an extreme frequency at which an electric wall is generated on the plane of symmetry between the power transmitting antenna 105 and the power receiving antenna 201 is selected, a charging circuit is provided for the battery 204 (load). Therefore, when the output to the battery 204 fluctuates due to charge control, there is an advantage that it is easy to handle because it increases and decreases with the output of the inverter unit 130. Further, even when the charging control unit 203 is urgently stopped, the power supply is automatically minimized, so that no useless device is required.

  In addition, when there are two frequencies that give two extreme values, if an extreme frequency that generates an electric wall on the plane of symmetry between the power transmitting antenna 105 and the power receiving antenna 201 is selected, the rectifier 220 is Since it appears as a voltage source, when the output to the battery 204 fluctuates due to charge control, there is an advantage that it is easy to handle because it increases and decreases with the output of the rectifying booster 120. Further, even when the charging control unit 203 is urgently stopped, the power supply is automatically minimized, so that no useless device is required.

  On the other hand, when there are two frequencies that give two extreme values, the charging control unit 203 outputs the extreme frequency that generates a magnetic wall on the plane of symmetry between the power transmitting antenna 105 and the power receiving antenna 201. Therefore, it is necessary to control the supply voltage as the value is reduced, and a communication means and a detection means for that purpose are required, which increases costs.

  Next, a second embodiment of the present invention will be described. Since the second embodiment is different from the first embodiment only in the structure of the capacitor adjustment region 400 in the coil body 300, the structure of the capacitor adjustment region 400 unique to the second embodiment will be described below.

  FIG. 11 is a diagram illustrating a capacitor adjustment region in the power receiving antenna 201 according to the second embodiment of the present invention.

  FIG. 11A shows the first surface side capacitor adjustment region 410 in a state where the capacitance is not adjusted. The first surface side capacitor adjustment region 410 includes a second surface side capacitor adjustment region corresponding electrode 402 and a trimming electrode portion 419 formed on the first surface 311 with the dielectric substrate 310 interposed therebetween. .

  FIG. 11B illustrates a method of reducing the capacitance component using the first surface side capacitor adjustment region 410 configured as described above. In the present embodiment, the trimming electrode portion 419 as described above is trimmed by scraping as shown in FIG. 11B, and the capacitance component can be reduced by reducing the area of the conductive portion. .

  As described above, in the antenna according to another embodiment, by using the capacitor adjustment region 400, the resonance frequency of each antenna can be made as expected, so that the antenna according to the present invention as described above can be used. According to this, it is possible to reduce a decrease in power transmission efficiency due to a difference in resonance frequency between antennas.

  Next, a third embodiment of the present invention will be described. Since the third embodiment is different from the first embodiment only in the structure of the capacitor adjustment region 400 in the coil body 300, the structure of the capacitor adjustment region 400 unique to the third embodiment will be described below.

  FIG. 12 is a diagram illustrating a capacitor adjustment region in the power receiving antenna 201 according to the third embodiment of the present invention.

  FIG. 12A shows the first surface side capacitor adjustment region 410 in a state where the capacitance is not adjusted. The first surface side capacitor adjustment region 410 includes a plurality of unit conductive portions 420 provided with connection electrodes 421 configured independently of the first surface conductive portion 330.

  FIG. 12B illustrates a method of increasing the capacitance component using the first surface side capacitor adjustment region 410 configured as described above. In the present embodiment, the connecting electrodes 421 in the plurality of unit conductive portions 420 as described above are electrically connected by the first surface conductive portion 330 and the jumper wire 425, or the unit conductive portions 420 are electrically connected by the jumper wire 425. As a result, the area of the conductive portion is increased and the capacitance component is increased.

  As described above, also in the antennas according to other embodiments, by using the capacitor adjustment region 400, the resonance frequencies of the individual antennas can be set to the expected values. According to this, it is possible to reduce a decrease in power transmission efficiency due to a difference in resonance frequency between antennas.

  Next, a fourth embodiment of the present invention will be described. Since the fourth embodiment is different from the first embodiment only in the structure of the capacitor adjustment region 400 in the coil body 300, the structure of the capacitor adjustment region 400 unique to the fourth embodiment will be described below.

  FIG. 13 is a diagram for explaining a capacitor adjustment region in the power receiving antenna 201 according to the fourth embodiment of the present invention.

  FIG. 13A shows the first surface side capacitor adjustment region 410 in a state where the capacitance is not adjusted. The first surface side capacitor adjustment region 410 includes a first surface conductive portion 330 and a plurality of unit conductive portions 430 that are conductively connected by an adjustment cutting portion 431.

  FIG. 13B illustrates a method for reducing the capacitance component by using the first surface side capacitor adjustment region 410 configured as described above. In this embodiment, trimming is performed by scraping the adjustment cutting portion 431 as shown in FIG. 13B to electrically connect a predetermined number of unit conductive portions 430 from the first surface conductive portion 330. The capacitance component can be reduced by reducing the area of the conductive portion as a capacitor.

  As described above, the antennas according to other embodiments can enjoy the same effects as those of the embodiments described above.

  Next, a fifth embodiment of the present invention will be described. Since the fifth embodiment is different from the first embodiment only in the structure of the capacitor adjustment region 400 in the coil body 300, the structure of the capacitor adjustment region 400 unique to the fifth embodiment will be described below.

  FIG. 14 is a diagram illustrating a power receiving antenna 201 according to the fifth embodiment of the present invention, and FIG. 15 is a diagram illustrating a capacitor adjustment region in the power receiving antenna 201 according to the fifth embodiment of the present invention.

  FIG. 15A shows the first surface side capacitor adjustment region 410 in a state where the capacitance is not adjusted. The first surface side capacitor adjustment region 410 includes a first surface conductive portion 330, unit conductive portions 440 connected in series, and an adjustment cutting portion 441 that similarly connects the unit conductive portions 440 in series. Has been. A plurality of unit conductive portions 440 are provided, and the capacitance component of the first surface side capacitor adjustment region 410 can be adjusted step by step. Further, as shown in FIG. 14, the unit conductive portion 440 and the adjustment cutting portion 441 are opposed to the capacitor adjustment region corresponding electrode 402 on the second surface side via the dielectric substrate 310.

  FIG. 15B illustrates a method for reducing the capacitance component using the first surface side capacitor adjustment region 410 configured as described above. In the present embodiment, the adjustment cutting portion 4341 as described above is trimmed by shaving as shown in FIG. 15B, so that a predetermined number of unit conductive portions 440 and first surface conductive portions 330 are electrically connected. By separating, the capacitance component can be reduced by reducing the area of the conductive part as a capacitor.

  As described above, the antennas according to other embodiments can enjoy the same effects as those of the embodiments described above.

  Next, a sixth embodiment of the present invention will be described. Since the sixth embodiment is different from the fifth embodiment only in the structure of the capacitor adjustment region 400 in the coil body 300, the structure of the capacitor adjustment region 400 unique to the sixth embodiment will be described below.

  FIG. 16 is a diagram for explaining a capacitor adjustment region in the power receiving antenna 201 according to the sixth embodiment of the present invention.

  FIG. 16A shows the first surface side capacitor adjustment region 410 in a state where the capacitance is not adjusted. The first surface side capacitor adjustment region 410 includes a plurality of unit conductive portions 450 provided with connection electrodes 451 that are configured independently of the first surface conductive portion 330.

  FIG. 16B illustrates a method of increasing the capacitance component using the first surface side capacitor adjustment region 410 configured as described above. In the present embodiment, the connection electrodes 451 in the plurality of unit conductive portions 450 as described above are electrically connected by the first surface conductive portion 330 and the jumper wire 455, or the unit conductive portions 450 are electrically connected by the jumper wire 455. As a result, the area of the conductive portion is increased and the capacitance component is increased.

  As described above, also in the antenna according to the present invention, by using the capacitor adjustment region 400, the resonance frequency of each antenna can be made as expected, so that according to such an antenna according to the present invention, In addition, it is possible to reduce a decrease in power transmission efficiency due to different resonance frequencies between the antennas.

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,
260 ... Resin case 261 ... Bottom plate part 262 ... Side plate part 263 ... Upper opening part 280 ... Magnetic shield 285 ... Hollow part 300 ... Coil body 310 ... Dielectric property Base material 311 ... 1st surface 312 ... 2nd surface 330 ... 1st surface conductive part 331 ... 1st surface innermost end 332 ... 1st surface outermost end 350 ... Second surface conductive portion 351 ... second surface innermost end portion 352 ... second surface outermost end portion 400 ... capacitor adjustment region 402 ... (second surface side) electrode for capacitor adjustment region 410 ... first surface side capacitor adjustment region 414 ... relay conductive part 415 ... first opposing part 416 ... second opposing part 418 ... conductive tape 419 ... trimming electrode part 420 ... -Unit conductive part 421 ... Connecting electrode 425 ... Jumper wire 430 ... Kuraishirubeden 431 ... adjusting cutting portion 440 ... unit conductive portions 441 ... adjusting cutting portion 450 ... unit conductive portions 451 ... connection electrode 455 ... jumper wire

Claims (7)

A first surface conductive portion provided on the first surface of the dielectric substrate;
An antenna comprising: a second surface conductive portion provided on the second surface of the dielectric substrate and having an area different from the area of the first surface conductive portion. A first surface conductive portion provided on the first surface of the dielectric substrate;
A capacitor adjustment region provided on the first surface of the dielectric substrate and communicating with the first surface conductive portion;
A second surface conductive portion provided on the second surface of the dielectric substrate;
A capacitor adjustment region corresponding electrode provided on the second surface of the dielectric substrate and communicating with the second surface conductive portion;
An antenna comprising: The antenna according to claim 1, wherein the conductive portion has a spiral coil shape. 4. The antenna according to claim 2, wherein in the capacitor adjustment region, an area of an electrode constituting the capacitor is increased by attaching a conductive tape. 5. The antenna according to claim 2 or 3, wherein the capacitor adjustment region is constituted by a trimmable electrode. The capacitor adjustment region is composed of a plurality of unit conductive portions, and the area of the electrodes constituting the capacitor is increased by conducting electrical connection between the first surface conductive portion and the unit conductive portion by jumper wires. The antenna according to claim 2 or 3. 4. The antenna according to claim 2, wherein the capacitor adjustment region includes a plurality of unit conductive portions that are electrically connected by an adjustment cutting portion that can be trimmed. 5.

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