JP6701948B2 - Antenna device and electronic device - Google Patents

Description

  The present invention relates to an antenna device used in a short-range wireless communication system, a wireless power transmission system, and the like, and an electronic device including the antenna device.

  In an HF band RFID such as NFC (Near Field Communication) mounted on a mobile terminal, a coil antenna that is magnetically coupled to a communication partner antenna is used.

  For example, Patent Document 1 discloses a mobile communication device including an antenna substrate provided with a loop antenna and a capacitor, and a control substrate provided with a transmission/reception circuit and a chip coil.

International Publication No. 2005/017821

  According to the structure of the mobile communication device disclosed in Patent Document 1, since the chip coil and the loop antenna are magnetically coupled to each other, it is not necessary to connect the loop antenna and the transmission/reception circuit with a communication cable.

  However, in the antenna device having the chip coil and the loop antenna coupled to the chip coil as described above, not only the magnetic flux caused by the current flowing through the loop antenna but also the magnetic flux caused by the current flowing through the chip coil. Is also connected to the antenna device of the communication partner. As a result, the coupling state, the resonance state, the magnetic flux pattern, and the like among the loop antenna, the chip coil, and the communication partner antenna become unstable. The inventor of the present application has found out the above-mentioned problems.

  An object of the present invention is to solve the above problems and to provide an antenna device having stable characteristics such as a coupling state with a transmission partner antenna, a magnetic flux pattern, and the like, and an electronic device including the antenna device. ..

(1) The antenna device of the present invention is
A coupling coil having a coupling coil conductor,
A coil antenna having a coil opening and a coil antenna conductor wound around the coil opening and being coupled with the coupling coil conductor via at least a magnetic field;
A planar conductive member that overlaps at least a part of the coil opening in a plan view of the coil opening,
The conductive member represents the shortest distance from the position farthest from the coupling coil to the conductive member in the coil opening by D2, and the conductive distance from the position closest to the coupling coil in the coil opening. When the shortest distance to the member is represented by D1, the relationship is D1<D2.

  With the above configuration, the conductive member suppresses the instability of the characteristics of the antenna device due to the magnetic flux distribution caused by the current flowing through the coil antenna conductor and the magnetic flux distribution caused by the current flowing through the coupling coil being superimposed. It

(2) It is preferable that there is a gap between a position closest to the coupling coil in the coil opening and the conductive member. This facilitates the coupling between the conductive member and the coil antenna conductor via the magnetic flux passing through the gap.

(3) In the above (1) or (2), it is preferable that the coil antenna includes an insulating base material on which the coil antenna conductor is formed, and the conductive member is formed on the insulating base material. .. As a result, it is not necessary to add a special member to provide the conductive member, and the number of parts does not increase.

(4) In the above (3), the insulating base material is composed of a laminated body of a plurality of insulating layers, and the conductive member is more bonded than the insulating layer on which the coil antenna conductor is formed. It is preferably formed in the insulator layer far from the coil. As a result, the gap between the conductive member and the coil antenna conductor increases, so that the degree of coupling between the coupling coil and the coil antenna increases. Moreover, since the gap between the conductive member and the coil antenna conductor also becomes large, the degree of coupling between the coil antenna and the transmission partner antenna increases.

(5) In any one of (1) to (4) above, it is preferable that the coupling coil has a width of the conductive member that is wider than a width of an opening end of the coupling coil in a plan view. As a result, the ratio of the magnetic flux passing through the coupling coil that circulates in the vicinity of the coil antenna conductor increases, and the degree of coupling between the coupling coil and the coil antenna increases.

(6) In any one of (1) to (5) above, the conductive member may have a shape that surrounds the coupling coil in a plurality of directions in a plan view. As a result, the ratio of the magnetic flux passing through the coupling coil that circulates in the vicinity of the coil antenna conductor is effectively increased, and the degree of coupling between the coupling coil and the coil antenna is increased.

(7) In the above (6), it is preferable that the conductive member has an extending portion that extends in a direction closer to the coupling coil in a plan view. As a result, the ratio of the magnetic flux passing through the coupling coil that circulates in the vicinity of the coil antenna conductor is effectively increased, and the degree of coupling between the coupling coil and the coil antenna is increased.

(8) In any one of (1) to (7) above, in the winding axis direction of the coil antenna conductor, the coil antenna conductor is arranged on a side opposite to the coupling coil, and a plane of the coil opening. It is preferable that the first magnetic body is provided so as to overlap a part of the coil antenna conductor located between the conductive member and the coupling coil. This increases the coupling between the coupling coil and the coil antenna due to the action of the first magnetic body as the magnetic path.

(9) In any one of the above (1) to (8), in the winding axis direction of the coil antenna conductor, the coil antenna conductor is arranged on the coupling coil side with respect to the coil antenna conductor, and the coil opening is seen in a plan view. It is preferable to provide a second magnetic body that overlaps at least a part of the coil opening or the coil antenna conductor. This enhances the coupling between the coil antenna and the transmission partner antenna. Further, when the second magnetic body is arranged between the coil antenna conductor and the circuit board, the second magnetic body can also serve as a noise shielding material between the circuit board and the antenna device.

(10) In the above (8), the coil opening or the coil antenna is disposed on the coupling coil side with respect to the coil antenna conductor in a winding axis direction of the coil antenna conductor, and is a plan view of the coil opening. It is preferable to include a second magnetic body that overlaps at least a part of the conductor and is connected to the first magnetic body. This enhances the coupling between the coil antenna and the transmission partner antenna. Further, when the second magnetic body is arranged between the coil antenna conductor and the circuit board, the second magnetic body can also serve as a noise shielding material between the circuit board and the antenna device.

(11) In the above (9) or (10), it is preferable that the second magnetic body has a cutout portion in a region overlapping with the coil antenna conductor located between the conductive member and the coupling coil. This enhances the coupling between the coupling coil and the coil antenna.

(12) In any one of the above (1) to (11), it is preferable that the coil antenna conductor is provided with a capacitor connected in the middle of the current path of the coil antenna conductor. As a result, the current flowing through the coil antenna increases, and the booster function is enhanced.

(13) In the above (12), it is preferable that the conductive member is an electrode forming the capacitor. As a result, the conductive member also serves as a capacitor, so that a capacitor as a separate component becomes unnecessary.

(14) In any one of the above (1) to (13), it is preferable that the coil antenna is coupled to the coil antenna of the coupling partner via an alternating magnetic field in the HF band. This makes it possible to obtain an antenna device having a coil antenna conductor with a relatively small number of turns and which fits within the size of a portable electronic device.

(15) An electronic device of the present invention includes an antenna device and a power feeding circuit connected to the antenna device and using the antenna device for at least one of communication and electric power,
The antenna device is
A coupling coil having a coupling coil conductor,
A coil antenna having a coil opening and a coil antenna conductor wound around the coil opening and being coupled with the coupling coil conductor at least via a magnetic field;
In a plan view of the coil opening, a conductive member overlapping at least a part of the coil opening,
The conductive member represents a shortest distance from the position farthest from the coupling coil in the coil opening to the conductive member as D2, and the conductive distance from the position closest to the coupling coil in the coil opening. When the shortest distance to the member is represented by D1, the relationship is D1<D2.

  With the above configuration, the conductive member suppresses the instability of the characteristics of the antenna device due to the superposition of the magnetic flux distribution caused by the current flowing through the coupling coil on the magnetic flux distribution caused by the current flowing through the coil antenna. ..

  According to the present invention, unnecessary coupling between the coupling coil and the transmission partner antenna is suppressed, the coupling state with the transmission partner antenna, the magnetic flux pattern, etc. are stabilized, and an antenna device having stable characteristics is provided. An electronic device is obtained.

FIG. 1A is a partial cross-sectional view of an electronic device including the antenna device 101 according to the first embodiment, and FIG. 1B is a plan view of a main part of the antenna device 101. FIG. 2 is an exploded perspective view of the coupling coil 1. FIG. 3 is a sectional view of the coupling coil 1. FIG. 4 is a diagram showing a circuit configuration of the antenna device 101. 5A is a partial cross-sectional view of an electronic device including the antenna device 102 according to the second embodiment, and FIG. 5B is a plan view of a main part of the antenna device 102. FIG. 6A is a partial cross-sectional view of an electronic device including the antenna device 103 according to the third embodiment, and FIG. 6B is a plan view of the main part of the antenna device 103. FIG. 7 is a diagram showing a circuit configuration of the antenna device 103. FIG. 8A is a partial cross-sectional view of an electronic device including the antenna device 104 according to the fourth embodiment, and FIG. 8B is a plan view of a main part of the antenna device 104. 9A is a partial cross-sectional view of an electronic device including the antenna device 105 according to the fifth embodiment, and FIG. 9B is a plan view of a main part of the antenna device 105. FIG. 10 is a plan view of the coil antenna 2 applied to the antenna device according to the sixth embodiment. 11A is a diagram showing a conductor pattern formed on the first surface of the base material 22, and FIG. 11B is a diagram showing a conductor pattern formed on the second surface of the base material 22. FIG. 12 is a partial cross-sectional view of the antenna device 106 according to the sixth embodiment having the coil antenna 2 shown in FIG. 10 and an electronic device including the antenna device 106. FIG. 13 is a circuit diagram of the coil antenna 2 according to the sixth embodiment. FIG. 14A is a plan view of the coil antenna 2 included in the antenna device according to the seventh embodiment, and FIG. 14B is a plan view of the coil antenna 2 with the magnetic body 7 removed. 15A is a partial cross-sectional view of an electronic device including the antenna device 107 according to the seventh embodiment, and FIG. 15B is a plan view of a main part of the antenna device 107. 16A is a partial cross-sectional view of an electronic device including the antenna device 108 according to the eighth embodiment, and FIG. 16B is a plan view of a main part of the antenna device 108. 17A is a partial cross-sectional view of an electronic device including the antenna device 109A according to the ninth embodiment, and FIG. 17B is a plan view of the main part of the antenna device 109A. FIG. 17C is an enlarged plan view of the planar conductor 3. FIG. 18A is a partial cross-sectional view of an electronic apparatus including another antenna device 109B according to the ninth embodiment, and FIG. 18B is a plan view of the main part of the antenna device 109B. FIG. 19A is a plan view of a main part of the antenna device 110 according to the tenth embodiment. FIG. 19B is an enlarged plan view of the planar conductor 3. 20A and 20B are plan views of the main parts of the antenna devices 111A and 111B according to the eleventh embodiment. FIG. 21 is a partial cross-sectional view of an electronic device including the antenna device 112 according to the twelfth embodiment. FIG. 22 is a plan view showing the structure inside the housing of the electronic device 201 according to the thirteenth embodiment.

  Hereinafter, a plurality of modes for carrying out the present invention will be shown with some specific examples with reference to the drawings. In the drawings, the same parts are designated by the same reference numerals. Although the embodiments are shown separately for the sake of convenience of explanation or understanding of the main points, partial replacement or combination of the configurations shown in different embodiments is possible. In the second and subsequent embodiments, description of matters common to the first embodiment will be omitted, and only different points will be described. In particular, similar effects obtained by the same configuration will not be sequentially described for each embodiment.

  The “antenna device” shown in each embodiment can be applied to both the transmission (power transmission) side and the reception (power reception) side of a signal (or power). Even when the "antenna device" is described as an antenna that radiates a magnetic flux, the antenna device is not limited to the source of the magnetic flux. Even when the magnetic flux generated by the transmission partner antenna is received (interlinked), that is, even when the transmission/reception relationship is reversed, the same operational effect is achieved.

  The “antenna device” shown in each of the following embodiments is an antenna device used for near-field communication using a magnetic field coupling with a communication partner antenna or a magnetic field coupling with a power transmission partner antenna by an alternating magnetic field. It is an antenna device used for power transmission in the near field. In the case of communication, it is applied to a communication system such as NFC (Near field communication). In the case of power transmission, it is applied to a power transmission system such as an electromagnetic induction system or a magnetic field resonance system.

  The "antenna device" shown in each embodiment uses, for example, the HF band, particularly 13.56 MHz, 6.78 MHz, or a frequency band in the vicinity thereof. The size of the antenna device is sufficiently smaller than the wavelength λ at the frequency used, and the radiation efficiency of electromagnetic waves is low in the frequency band used. The size of the antenna device is λ/10 or less. The wavelength here is an effective wavelength in consideration of the wavelength shortening effect due to the dielectric properties and magnetic permeability of the base material on which the coil antenna conductor is formed.

  In each embodiment, the "electronic device" includes mobile phone terminals such as smartphones and feature phones, wearable terminals such as smart watches and smart glasses, mobile PCs such as notebook PCs and tablet PCs, cameras, game machines, toys, and the like. It refers to various electronic devices such as information devices, IC tags, SD cards, SIM cards, and information media such as IC cards.

<<First Embodiment>>
FIG. 1A is a partial cross-sectional view of an electronic device including the antenna device 101 according to the first embodiment, and FIG. 1B is a plan view of a main part of the antenna device 101. FIG. 1A is a sectional view of a portion AA in FIG.

  The antenna device 101 of this embodiment is configured in an electronic device such as a mobile phone terminal. The antenna device 101 includes a coupling coil 1, a coil antenna 2, and a planar conductor 3. In FIG. 1A, a part of the housing 4 of the electronic device, the circuit board 5 housed in the housing 4, and the like are also illustrated.

  As will be described later, the coupling coil 1 has a coupling coil conductor formed in a rectangular helical shape, and is mounted on the circuit board 5 with its winding axis oriented in the X-axis direction in FIGS. 1A and 1B. Has been done. The coil antenna 2 includes a coil opening AP and a coil antenna conductor 21 wound around the coil opening AP. The coil antenna conductor 21 is formed on an insulating base material 22. The coil antenna conductor 21 is coupled to the coupling coil conductor of the coupling coil 1 via at least a magnetic field.

  The coil antenna conductor 21 is formed in a rectangular spiral shape having a plurality of turns, and both ends thereof are connected to each other. A planar conductor 3 that is a conductor pattern is formed on the base material 22. The planar conductor 3 overlaps the coil opening AP in a plan view of the coil opening AP. The planar conductor 3 is smaller than the area of the coil opening AP in a plan view of the coil opening AP. In the planar conductor 3, the shortest distance from the position farthest from the coupling coil 1 in the coil opening AP to the planar conductor 3 is represented by D2, and the plane from the position closest to the coupling coil 1 in the coil opening AP. When the shortest distance to the conductor 3 is represented by D1, there is a relation of D1<D2. In other words, the planar conductor 3 is deviated to the coupling coil 1 side from the center of the coil opening AP of the coil antenna 2. The planar conductor 3 is an example of the "conductive member" according to the present invention. The distance D1 can also be referred to as "a distance between the planar conductor 3 and a part of the coil antenna conductor 21 located between the planar conductor 3 and the coupling coil 1."

  A portion of the coil opening AP indicated by the shortest distance D1 from the position closest to the coupling coil 1 to the planar conductor 3 is a gap between the coupling coil 1 and the planar conductor 3.

  The coil antenna conductor 21 and the planar conductor 3 are formed by patterning a Cu foil laminated on the base material 22, for example. The planar conductor 3 may be arranged on a surface different from the coil antenna conductor 21. In the present embodiment, the entire planar conductor 3 overlaps the coil opening AP, but if the relationship of D1<D2 is satisfied, a part of the planar conductor 3 overlaps the coil opening AP in plan view. May be

  The base material 22 on which the coil antenna conductor 21 and the planar conductor 3 are formed is adhered or adhered to the lower surface of the housing 4 via the adhesive layer 6. The housing 4 is, for example, a resin housing through which magnetic flux passes. When the housing 4 has conductivity, it has an opening through which a magnetic flux interlinking with at least the coil opening AP of the coil antenna 2 passes, and prevents an eddy current circulating only at the inner edge of the opening. It only has to be configured.

  Most of the magnetic flux passing through the coupling coil 1 passes (links) through the coil opening AP of the coil antenna 2. The magnetic flux φ1 in FIG. 1A represents the magnetic flux that contributes to the coupling between the coupling coil 1 and the coil antenna 2. Thus, the coupling coil conductor of the coupling coil 1 is magnetically coupled to the coil antenna conductor 21 of the coil antenna 2.

  In FIG. 1A, the communication partner antenna 300 is also illustrated. The communication partner antenna 300 includes a communication partner antenna conductor 321 formed in a spiral shape with a predetermined turn, for example. In FIG. 1A, the magnetic flux φ2 is, for example, a magnetic flux due to an alternating magnetic field in the HF band, and passes (links) through the coil opening of the communication partner antenna 300 and the coil opening AP of the coil antenna 2. Therefore, the coil antenna 2 is magnetically coupled to the communication partner antenna 300 via the alternating magnetic field. The communication partner antenna 300 is an example embodiment that corresponds to the “transmitter antenna” according to the present invention. For example, a reader/writer circuit is connected to the communication partner antenna 300. The communication partner antenna 300 is an example embodiment that corresponds to the “combined partner antenna” according to the present invention.

  2 is an exploded perspective view of the coupling coil 1, and FIG. 3 is a sectional view of the coupling coil 1. The coupling coil 1 includes a multilayer substrate 10 in which a plurality of sheets 10a to 10i are laminated, and a coupling coil conductor formed on the multilayer substrate 10. In FIG. 2, the upper and lower non-magnetic material sheets 10a and 10i are not shown. A plurality of first linear portions 11 are formed on the lower surface of the magnetic sheet 10b. A plurality of second linear portions 12 are formed on the upper surface of the magnetic sheet 10h. A plurality of via conductors (interlayer connection conductors) are formed on the magnetic sheets 10b to 10h. The first linear portion 11, the second linear portion 12, and the via conductor are the above-mentioned coupled coil conductor. In this way, the coupling coil 1 including the helical coupling coil conductor along the horizontally placed flat rectangular tube is configured.

  In the present embodiment, the positional relationship between the coil antenna conductor 21 of the coil antenna 2 and the coupling coil conductor of the coupling coil 1 is as follows.

  (A) The coupling coil 1 is located on the opposite side of the coil antenna 2 from the communication partner antenna 300 in the winding axis (Z-axis) direction of the coil antenna conductor 21.

  (B) The winding axis of the coupling coil conductor of the coupling coil 1 faces the X axis direction, and the winding axis of the coil antenna conductor 21 of the coil antenna 2 faces the Z axis direction.

  (C) The coil antenna conductor 21 of the coil antenna 2 is wound substantially parallel to the surface of the housing 4.

  (D) The surface of the circuit board 5 is substantially parallel to the surface of the housing, and the coupling coil 1 is surface-mounted on the circuit board 5.

  (E) In a plan view of the coil antenna 2 (viewed from the Z-axis direction), the coupling coil 1 has a larger area outside the coil antenna 2 than in an area overlapping with the coil antenna 2.

  FIG. 4 is a diagram showing a circuit configuration of the antenna device 101 of this embodiment. In FIG. 4, a circuit on the electronic device side connected to the antenna device 101 and a communication partner antenna are also shown. In FIG. 4, the inductor L1 is an element that represents the inductance of the coupling coil 1 as a lumped constant circuit. The inductors L21A and L21B are elements that represent the coil antenna conductor 21 as a lumped constant circuit. The inductor L321 is an element that represents the communication partner antenna conductor 321 as a lumped constant circuit.

  A series circuit of capacitors C1A and C1B is connected in parallel to the coupling coil 1 to form an LC resonance circuit. The RFIC 110 is a power supply circuit for the coupling coil 1, and supplies a HF band communication signal to the LC resonance circuit via the capacitors C2A and C2B. The coupling between the inductor L1 and the inductor L21A represents the magnetic coupling between the coupling coil 1 and the coil antenna 2. Similarly, the coupling between the inductor L21B and the inductor L321 represents the magnetic coupling between the coil antenna 2 and the communication partner antenna 300. For example, a reader/writer circuit is connected to the communication partner antenna 300.

  In FIGS. 1(A) and 1(B), if the planar conductor 3 is not provided, then of the magnetic flux passing through the coupling coil 1, unnecessary magnetic flux passing through the coil opening of the communication partner antenna 300 increases. In FIG. 1A, the magnetic flux φ12 indicates this unnecessary magnetic flux.

  According to the present embodiment, the planar conductor 3 shields the unnecessary magnetic flux φ12 passing through the coil opening of the communication partner antenna 300 among the magnetic fluxes passing through the coupling coil 1, so that the coupling coil 1 and the communication partner side are shielded. Unnecessary coupling with the antenna 300 is suppressed. Therefore, for example, even if the balance of the currents flowing through the coil antenna 2 and the coupling coil 1 changes, the magnetic flux due to the coupling coil 1 is unlikely to be superimposed on the magnetic flux coupling with the communication partner antenna 300. As a result, the instability of the characteristics of the antenna device 101 is suppressed without depending on the frequency (resonance state) or the coupling state with the communication partner.

  The winding axis of the coupling coil conductor of the coupling coil 1 is not limited to the X-axis direction which is the direction perpendicular to the winding axis of the coil antenna conductor 21 of the coil antenna 2. For example, the direction of the winding axis of the coupling coil conductor of the coupling coil 1 and the direction of the winding axis of the coil antenna conductor 21 may be parallel or may have a relationship having another angle.

  Note that, in FIG. 1A, the communication partner antenna 300 is illustrated as being located above the housing 4 of the electronic device, but in an actual usage mode, a device including the communication partner antenna 300 ( In many cases, the electronic device is placed or held over the reader/writer.

<<Second Embodiment>>
The second embodiment shows an example in which the position of the planar conductor 3 is different from that of the first embodiment.

  5A is a partial cross-sectional view of an electronic device including the antenna device 102 according to the second embodiment, and FIG. 5B is a plan view of a main part of the antenna device 102. FIG. 5A is a sectional view of a portion AA in FIG. The planar conductor 3 is formed in a layer farther from the coupling coil 1 than the layer in which the coil antenna 2 is formed. In the present embodiment, the coil antenna conductor 21 is formed on the first surface of the base material 22, and the planar conductor 3 is formed on the second surface of the base material 22. The other configuration is the same as that of the antenna device 101 shown in the first embodiment.

  According to the present embodiment, as compared with the case where the planar conductor 3 is formed on the same surface as the coil antenna conductor 21, the shortest distance from the position closest to the coupling coil 1 in the coil opening AP to the planar conductor 3. Since D1 becomes large, the substantial width through which the magnetic flux φ1 that contributes to the coupling between the coupling coil 1 and the coil antenna 2 passes is widened, and the coupling between the coupling coil 1 and the coil antenna 2 can be enhanced. Further, since the shortest distance D2 from the position farthest from the coupling coil 1 to the planar conductor 3 in the coil opening AP becomes large, the substantial coil opening of the coil antenna 2 expands, and the coil antenna 2 and the communication partner side. The coupling with the antenna 300 can be enhanced.

  The insulating base material 22 may be composed of a laminated body of insulating layers. In that case, the planar conductor 3 may be formed in an insulator layer farther from the coupling coil 1 than the insulator layer in which the coil antenna conductor 21 is formed. Further, the planar conductor (conductive member) 3 may be formed on a member different from the insulating base material 22 on which the coil antenna conductor 21 is formed. For example, the planar conductor (conductive member) 3 may be formed on the inner surface or the outer surface of the housing 4.

<<Third Embodiment>>
The third embodiment shows an example in which the configuration of the coil antenna is different from that of the first and second embodiments.

  FIG. 6A is a partial cross-sectional view of an electronic device including the antenna device 103 according to the third embodiment, and FIG. 6B is a plan view of the main part of the antenna device 103. FIG. 6A is a sectional view of a portion AA in FIG.

  In the present embodiment, the coil antenna conductor 21a and the planar conductor 3a are formed on the first surface of the base material 22, and the coil antenna conductor 21b and the planar conductor 3b are formed on the second surface of the base material 22. .. The planar conductor 3a and the planar conductor 3b face each other with the base material 22 in between to form a capacitor. That is, the planar conductors 3a and 3b are also electrodes that form a capacitor. As shown in FIG. 6B, the first end of the coil antenna conductor 21a and the first end of the coil antenna conductor 21b are connected via an interlayer connecting conductor. The second end of the coil antenna conductor 21a is connected to the planar conductor 3a, and the second end of the coil antenna conductor 21b is connected to the planar conductor 3b. In this way, the coil antenna conductors 21a and 21b are provided with capacitors formed by the planar conductors 3a and 3b, which are connected to the coil antenna conductors 21a and 21b in the middle of the current path. The other configuration is the same as that of the antenna device 101 shown in the first embodiment.

  FIG. 7 is a diagram showing a circuit configuration of the antenna device 103 of this embodiment. In FIG. 7, a circuit on the electronic device side and a communication partner antenna connected to the antenna device 103 are also shown. In FIG. 7, the inductor L1 corresponds to the coupling coil 1. The inductors L21A and L21B are elements that represent the coil antenna conductor 21 as a lumped constant circuit. The capacitor C3 is an element formed by the planar conductors 3a and 3b. The inductor L321 is an element that represents the communication partner antenna conductor 321 as a lumped constant circuit.

  The coil antenna 2 constitutes an LC resonance circuit including the inductors L21A and L21B and the capacitor C3. The resonance frequency band of this resonance circuit is a frequency band used for communication. For example, in the case of NFC, the frequency is 13.56 MHz or the vicinity thereof.

  According to this embodiment, the current (resonance current) flowing through the coil antenna conductors 21a and 21b is increased, and the function of the coil antenna 2 as a booster is enhanced. Further, since the planar conductors 3a and 3b also serve as a resonance capacitor, it is not necessary to separately provide a capacitor as a component.

<<Fourth Embodiment>>
The fourth embodiment shows an example different from that of the third embodiment in that a magnetic material is provided.

  FIG. 8A is a partial cross-sectional view of an electronic device including the antenna device 104 according to the fourth embodiment, and FIG. 8B is a plan view of a main part of the antenna device 104. FIG. 8A is a sectional view of a portion AA in FIG.

  The antenna device 104 of this embodiment includes the first magnetic body 71. The first magnetic body 71 is on the side opposite to the coupling coil 1 with respect to the coil antenna conductors 21a and 21b in the winding axis direction (Z-axis direction) of the coil antenna conductors 21a and 21b and in a plan view of the coil opening AP. Then, it is arranged between the planar conductors 3 a and 3 b and the coupling coil 1. The first magnetic body 71 overlaps a part of the coil antenna conductors 21 a and 21 b located between the planar conductors 3 a and 3 b and the coupling coil 1 in a plan view of the coil opening AP. The first magnetic body 71 is, for example, a sintered magnetic ferrite sheet or a sheet in which magnetic ferrite powder is kneaded in a resin. The coil antenna conductor 21a, the capacitance forming conductor 21ac and the planar conductor 3a are formed on the first surface of the base material 22, and the coil antenna conductor 21b, the capacitance forming conductor 21bc and the planar shape are formed on the second surface of the base material 22. The conductor 3b is formed. The capacitance forming conductor 21ac and the capacitance forming conductor 21bc face each other with the base material 22 interposed therebetween to form a capacitor. The planar conductor 3a and the planar conductor 3b face each other with the base material 22 in between to form a capacitor. The planar conductors 3a and 3b are examples of the "conductive member" according to the present invention. As described above, the coil antenna 2 includes capacitors formed by the capacitance forming conductors 21ac and 21bc and capacitors formed by the planar conductors 3a and 3b, which are connected in the middle of the current paths of the coil antenna conductors 21a and 21b. Other configurations are similar to those of the third embodiment.

  According to the present embodiment, the first magnetic body 71 constitutes a part of the magnetic path of the magnetic flux φ1 that links the coupling coil 1. As a result, the coupling between the coupling coil 1 and the coil antenna 2 is enhanced.

<<Fifth Embodiment>>
The fifth embodiment shows an example different from that of the fourth embodiment in that the second magnetic body is provided.

  9A is a partial cross-sectional view of an electronic device including the antenna device 105 according to the fifth embodiment, and FIG. 9B is a plan view of a main part of the antenna device 105. FIG. 9A is a sectional view of a portion AA in FIG. 9B.

  The antenna device 105 of this embodiment includes a first magnetic body 71 and a second magnetic body 72. The second magnetic body 72 is arranged on the coupling coil 1 side with respect to the coil antenna conductors 21a and 21b in the winding axis direction (Z-axis direction) of the coil antenna conductors 21a and 21b. The second magnetic body 72 is, for example, a sintered magnetic ferrite sheet or a sheet in which magnetic ferrite powder is kneaded in a resin. The second magnetic body 72 does not overlap (do not extend) with the coil antenna conductors 21a and 21b located between the planar conductors 3a and 3b and the coupling coil 1. That is, the second magnetic body 72 has a cutout portion (a region without a magnetic body) V in a region overlapping with the coil antenna conductors 21a and 21b located between the planar conductors 3a and 3b and the coupling coil 1.

  Further, the second magnetic body 72 has a cutout portion formed in a portion overlapping the planar conductors 3a and 3b. Other configurations are similar to those of the fourth embodiment.

  According to the present embodiment, the second magnetic body 72 constitutes a part of the magnetic path of the magnetic flux φ2 that links the coil antenna 2. As a result, the coupling between the coil antenna 2 and the communication partner antenna 300 is enhanced. Further, the first magnetic body 71 has the magnetic path because the first magnetic body 71 has a cutout portion (a region without a magnetic body) V in a region overlapping the coil antenna conductors 21a and 21b located between the planar conductors 3a and 3b and the coupling coil 1. It effectively acts as a part of the above, and the coupling between the coupling coil 1 and the coil antenna 2 can be enhanced. Further, since the magnetic body is not close to the capacitance forming region formed by the planar conductors 3a and 3b, the magnetic body loss is suppressed. Further, by disposing the second magnetic body 72 between the coil antenna conductors 21 a and 21 b and the circuit board 5, the second magnetic body 72 serves as a noise shielding material between the circuit board 5 and the antenna device 105. Also serve. Therefore, unnecessary coupling between the circuit provided on the circuit board 5 and the antenna device 105 is suppressed. Similarly, when the second magnetic body 72 is arranged between the coil antenna conductors 21a and 21b and the battery pack or the shield member, the second magnetic body 72 is provided between the battery pack or the shield member and the antenna device 105. It acts as a magnetic shield and suppresses the flow of eddy currents in the battery pack and the shield member.

<<Sixth Embodiment>>
The sixth embodiment shows an example in which the configuration of the coil antenna is different from those of the above-described embodiments.

  FIG. 10 is a plan view of the coil antenna 2 applied to the antenna device according to the sixth embodiment. The coil antenna 2 is configured by forming a predetermined conductor pattern on each of the first surface and the second surface of the insulating base material 22. 11A shows a conductor pattern formed on the first surface of the base material 22, and FIG. 11B shows a conductor pattern formed on the second surface of the base material 22. However, FIG. 11A is a diagram transparently viewed from the second surface side of the base material. FIG. 12 is a partial cross-sectional view of the antenna device 106 according to the sixth embodiment having the coil antenna 2 shown in FIG. 10 and an electronic device including the antenna device 106. The alternate long and short dash line AA in FIG. 10 indicates the cross-sectional position in FIG. Note that FIG. 12 also shows the communication partner antenna 300. The configuration other than the coil antenna 2 is the same as that of the above-described embodiments.

  A coil antenna conductor 21a, a capacitance forming conductor 21ac, and a planar conductor 3a are formed on the first surface of the base material 22. A first end of the coil antenna conductor 21a is electrically connected to the planar conductor 3a, and a second end thereof is electrically connected to the capacitance forming conductor 21ac.

  On the second surface of the base material 22, the capacitance forming conductor 21bc and the planar conductors 3b1, 3b2, 3b3 are formed. The planar conductors 3b1, 3b2, 3b3 are electrically connected to the capacitance forming conductor 21bc. The planar conductors 3b1, 3b2, 3b3 are opposed to the planar conductor 3a on the first surface via the base material 22. Further, the capacitance forming conductor 21bc is opposed to the capacitance forming conductor 21ac on the first surface with the base material 22 interposed therebetween.

  FIG. 13 is a circuit diagram of the coil antenna 2 of this embodiment. In FIG. 13, the inductor L2 is an element that represents the inductance of the coil antenna conductor 21a as a lumped constant circuit. The capacitor C21 is an element formed by the capacitance forming conductors 21ac and 21bc. The capacitors C31, C32, C33 are elements formed by the planar conductor 3a and the planar conductors 3b1, 3b2, 3b3.

  The coil antenna 2 constitutes an LC resonance circuit including an inductor L2 and capacitors C21, C31, C32, C33. The resonance frequency band of this resonance circuit is a frequency band used for communication. For example, in the case of NFC, the frequency is 13.56 MHz or the vicinity thereof.

  Trimming points TP1, TP2, TP3 shown in FIG. 10 are trimming points of a conductor pattern that connects the planar conductors 3b1, 3b2, 3b3 and the capacitance forming conductor 21bc. The connection pattern of the capacitors C31, C32, C33 is selected according to the number and position of trimming of the conductor pattern at these trimming points TP1, TP2, TP3. Thereby, the resonance frequency of the coil antenna 2 can be adjusted to a predetermined frequency.

<<Seventh Embodiment>>
The seventh embodiment shows an example in which the shape of the magnetic body is different from that of the fifth embodiment.

  FIG. 14A is a plan view of the coil antenna 2 included in the antenna device according to the seventh embodiment, and FIG. 14B is a plan view of the coil antenna 2 with the magnetic body 7 removed. 15A is a partial cross-sectional view of an electronic device including the antenna device 107 according to the seventh embodiment, and FIG. 15B is a plan view of a main part of the antenna device 107. FIG. 15A is a sectional view of a portion AA in FIG.

  The antenna device 107 of this embodiment includes one magnetic body 7 having a structure in which the first magnetic body 71 and the second magnetic body 72 are continuous. As shown in FIGS. 14A and 14B, a slit SL1 is formed in the base material 22, a part of the magnetic body 7 is inserted into the slit SL1, and the first magnetic body 71 and the second magnetic body 71 are inserted. The body 72 is connected through the slit SL1. Further, the magnetic body 7 is provided with a slit SL2. The conductor pattern formed on the base material 22 is trimmed by irradiating a trimming laser beam through the slit SL2. The conductor pattern formed on the base material 22 is the same as that shown in the sixth embodiment. The configuration other than the coil antenna 2 is the same as that of the fifth embodiment.

  According to the present embodiment, the magnetic body can be arranged at predetermined positions on the first surface and the second surface of the base material 22 while using a single magnetic body, so that the number of parts can be reduced, and the material cost and the manufacturing cost can be reduced. Is reduced. Further, the magnetic flux that contributes to the coupling between the coupling coil 1 and the coil antenna 2 easily passes through the first magnetic body 71, and the degree of coupling between the coupling coil 1 and the coil antenna 2 increases.

<<Eighth Embodiment>>
The eighth embodiment shows an example in which the formation locations of the coil antenna and the planar conductor are different from those of the above-described embodiments.

  16A is a partial cross-sectional view of an electronic device including the antenna device 108 according to the eighth embodiment, and FIG. 16B is a plan view of a main part of the antenna device 108. 16A is a cross-sectional view of a portion AA in FIG. 16B.

  The antenna device 108 of the present embodiment is configured in an electronic device such as a mobile phone terminal. The antenna device 108 includes the coupling coil 1, the coil antenna conductor 21 formed in the housing 4 of the electronic device, and the planar conductor 3. The housing 4 is a cover case made of, for example, ABS resin. The coil antenna conductor 21 and the planar conductor 3 are formed on the housing 4 by LDS (Laser Direct Structuring). Other configurations are the same as those of the antenna device 101 shown in the first embodiment.

  According to the present embodiment, the insulating base material for providing the coil antenna conductor 21 and the planar conductor 3 is unnecessary, the number of parts is reduced, and the cost can be reduced.

<<9th Embodiment>>
The ninth embodiment shows an example in which the shapes of the coil antenna and the planar conductor are different from those of the above-described embodiments.

  17A is a partial cross-sectional view of an electronic device including the antenna device 109A according to the ninth embodiment, and FIG. 17B is a plan view of the main part of the antenna device 109A. FIG. 17C is an enlarged plan view of the planar conductor 3. In the present embodiment, the planar conductor 3 is formed on the surface of the insulating base material 22 on which the coil antenna conductor 21 is formed, which is far from the coupling coil 1. The coil antenna conductors 21a and 21b and the capacitance forming conductors 21ac and 21bc are different in shape from the antenna device shown in the sixth embodiment, but the basic structure is the same.

  As shown in FIG. 17B, in a plan view of the coil opening AP of the coil antenna 2, the coupling coil 1 has two opening ends, and the coupling coil on the side close to the coil opening AP of the coil antenna 2 is shown. The open end 1F of 1 faces the planar conductor 3. The width of the planar conductor 3 facing the opening end 1F in the direction (Y-axis direction) perpendicular to the coil axis direction (X-axis direction) of the coupling coil 1 is wider than the width of the opening end 1F of the coupling coil 1. As a result, as shown by the magnetic flux φ1 in FIG. 17A, the proportion of the magnetic flux passing through the coupling coil 1 and the coil opening AP of the coil antenna 2 passing through the portion indicated by the facing distance D0 is Increase. That is, the ratio of winding around the vicinity of the coil antenna conductor 21 increases, and the degree of coupling between the coupling coil 1 and the coil antenna 2 increases.

  Further, in the present embodiment, the planar conductor 3 faces the facing portion 3C that faces the coupling coil 1 in the coil axis direction (X axis direction) in a plan view of the coil opening AP of the coil antenna 2 (see FIG. 17C). ), a direction (Y-axis direction) extending from the facing portion 3C to the side closer to the coupling coil 1 in the coil axis direction (X-axis direction) of the coupling coil 1 and perpendicular to the coil axis direction (X-axis direction) of the coupling coil 1. ) Facing each other) (see FIG. 17C). The extending portion 3E extends in the coil axis direction (X-axis direction) of the coupling coil 1 by a distance Lc from the position of the opening end 1F of the coupling coil 1. The distance (lateral distance) between the coupling coil 1 and the extension 3E is approximately the same as the facing distance D0. That is, the planar conductor 3 is formed so as to surround the coupling coil 1 in two directions in a plan view of the coil opening AP of the coil antenna 2. With this structure, the ratio of the magnetic flux that passes through the facing distance D0 portion and the lateral spacing portion to the magnetic flux that passes through the coupling coil 1 and the coil opening AP of the coil antenna 2 increases. Therefore, the degree of coupling between the coupling coil 1 and the coil antenna 2 becomes stronger. The facing portion 3C and the extending portion 3E do not have to be connected to each other and may be separated from each other. Further, the planar conductor 3 need not be separated from the coil antenna conductor 21 and may be connected.

  FIG. 18A is a partial cross-sectional view of an electronic apparatus including another antenna device 109B according to the ninth embodiment, and FIG. 18B is a plan view of the main part of the antenna device 109B. The antenna device 109B includes the magnetic body 70 on the lower surface (the surface on the circuit board 5 side) of the coil antenna 2. Other structures are the same as those of the antenna device 109A shown in FIGS. 17A and 17B. The magnetic body 70 is, for example, a sintered magnetic ferrite sheet or a sheet in which magnetic ferrite powder is kneaded in a resin. The magnetic body 70 is arranged in a region that does not cover the facing portion (the portion indicated by the facing distance D0) between the planar conductor 3 and the coupling coil 1. With this structure, the magnetic body 70 is formed on the circuit board 5 without interrupting the coupling between the coupling coil 1 and the coil antenna 2 (the coupling coil 1 and the coil antenna 2 are coupled as indicated by the magnetic flux φ1). Unnecessary coupling between the conductor and the coil antenna 2 is suppressed.

<<10th Embodiment>>
The tenth embodiment shows an example in which the shape of the planar conductor 3 is different from those of the above-described embodiments.

  FIG. 19A is a plan view of a main part of the antenna device 110 according to the tenth embodiment. FIG. 19B is an enlarged plan view of the planar conductor 3. In the present embodiment, the planar conductor 3 has two extending portions 3E1 and 3E2 (see FIG. 19B) in a plan view of the coil opening AP of the coil antenna 2. These extending portions 3E1 and 3E2 extend from the facing portion 3C (see FIG. 19B) toward the side closer to the coupling coil 1 in the coil axis direction (X-axis direction) of the coupling coil 1 and form the coil of the coupling coil 1. They are opposed to each other in the direction (Y-axis direction) perpendicular to the axial direction (X-axis direction). Furthermore, it extends a distance Lc further from the position of the open end 1F of the coupling coil 1 in the coil axis direction (X-axis direction) of the coupling coil 1. In a plan view of the coil opening AP of the coil antenna 2, the extending portions 3E1 and 3E2 face each other with the coupling coil 1 interposed therebetween. The distance (lateral distance) between the coupling coil 1 and the extending portions 3E1 and 3E2 is approximately the same as the facing distance D0. Other configurations are the same as those shown in the ninth embodiment.

  According to this embodiment, of the magnetic flux passing through the coupling coil 1 and the coil opening AP of the coil antenna 2, the ratio of the magnetic flux passing through the facing distance D0 portion and the lateral spacing portion is more effectively increased. .. Therefore, the degree of coupling between the coupling coil 1 and the coil antenna 2 becomes stronger.

<<Eleventh Embodiment>>
The eleventh embodiment shows an example in which the shape of the planar conductor is different from those shown so far.

  FIG. 20A is a plan view of a main part of the antenna device 111A according to the eleventh embodiment. FIG. 20B is a plan view of the main part of the antenna device 111B according to the eleventh embodiment. In the present embodiment, the planar conductor 3 has two extending portions 3E in a plan view of the coil opening AP of the coil antenna 2. The extending portion 3E extends from the facing portion of the planar conductor 3 toward the side closer to the coupling coil 1 in the coil axis direction (X-axis direction) of the coupling coil 1.

  Unlike the antenna device 109A illustrated in FIGS. 17A and 17B, the antenna devices 111A and 111B according to the present embodiment have the extending portion 3E in a direction perpendicular to the coil axis direction (X axis direction) of the coupling coil 1. When viewed in the (Y-axis direction), it does not overlap the coupling coil 1 (it does not reach the open end 1F of the coupling coil 1).

  The antenna device 111B extends so that a part of the extending portion 3E faces the opening end 1F of the coupling coil 1.

  The antenna device having the structure shown in this embodiment also has the effect of increasing the degree of coupling between the coupling coil 1 and the coil antenna 2.

<<Twelfth Embodiment>>
The twelfth embodiment shows an example in which the coil antenna conductor and the planar conductor form a curved surface.

  FIG. 21 is a partial cross-sectional view of an electronic device including the antenna device 112 according to the twelfth embodiment. The coil antenna conductor 21 and the planar conductor 3 of the antenna device 112 of this embodiment are formed in the housing 4 of the electronic device by, for example, the above LDS. Unlike the example shown in the eighth embodiment, the coil antenna conductor 21 and the planar conductor 3 are formed along the curved surface of the housing 4. The portion of the coil opening AP indicated by the shortest distance D1 from the position closest to the coupling coil 1 to the planar conductor 3 is located between the portion of the coil antenna conductor 21 adjacent to the planar conductor 3 and the planar conductor 3. It is a three-dimensional gap. Other configurations are the same as those of the antenna device shown in the first and eighth embodiments.

  According to the present embodiment, the winding axis AX of the coil antenna conductor 21 of the coil antenna 2 can be tilted with respect to the main surface of the housing 4, and communication can be performed by expanding the magnetic flux φ2 at a wide angle. The angle range can be expanded.

<<Thirteenth Embodiment>>
The thirteenth embodiment shows the configuration of the electronic device.

  22 is a plan view showing the internal structure of the housing of the electronic device 201 according to the thirteenth embodiment. The electronic device 201 is, for example, a so-called smartphone, and includes a housing 42 on the display/operation panel side and a housing 41 on the back surface side. Circuit boards 5, 81, a battery pack 83, and the like are housed inside the housing 42. The coupling coil 1 is mounted on the circuit board 5. Further, an RFIC, a resonance capacitor, and the like are also mounted on the circuit board 5.

  A camera module 85, UHF band antennas 86, 87 and the like are also mounted on the circuit board 5. A UHF band antenna 82 and the like are mounted on the substrate 81. The circuit board 5 and the board 81 are connected via a cable 84.

  Inside the circuit board 5, a ground conductor pattern GND that spreads in a plane is formed.

  The housing 41 is a resin housing, and the coil antenna 2 is attached to the inner surface of the housing 41 via an adhesive sheet, for example. The configuration of this coil antenna 2 is the same as that shown in FIG. 14A in the seventh embodiment.

  By combining the housing 42 with the housing 41, the coupling coil 1 comes close to the protruding position of the first magnetic body 71 of the magnetic body 7. As a result, the coupling coil 1 is magnetically coupled to the coil antenna conductor of the coil antenna 2. Since the magnetic body 7 of the coil antenna 2 is interposed between the coil antenna conductor and the ground conductor pattern GND of the circuit board or the battery pack 83, the coil antenna conductor and the ground conductor pattern GND of the circuit board or the battery pack 83 are unnecessary. Binding is suppressed.

  The "electronic device" according to the present invention is not limited to the one having the housing as shown in FIG. For example, a card or the like is provided with a mold resin as a structure.

  In each of the embodiments described above, the winding axis of the coil conductor of the coupling coil 1 is oriented in the X-axis direction, and the winding axis of the coil antenna conductor is oriented in the Z-axis direction, that is, the winding of the coil conductor of the coupling coil 1 is performed. An example has been shown in which the axis and the winding axis of the coil antenna conductor are orthogonal to each other, but the present invention is not limited to this. For example, the winding axis of the coil conductor of the coupling coil 1 may be in the same direction as the winding axis of the coil antenna conductor.

  In each of the embodiments described above, the coil antenna conductor 21 and the planar conductor 3 are formed on the single insulating base material 22, but the coil antenna conductor 21 and the planar conductor 3 are formed on separate base materials. May be done. Further, one or both of the coil antenna conductor 21 and the planar conductor 3 may be formed on the inner layer of the base material.

  In each of the embodiments described above, the planar conductor 3 is given as an example of the “conductive member” according to the present invention, but the “conductive member” is not limited to the planar shape. For example, the shield member or the battery pack may also serve as the “conductive member”.

  In addition, although the antenna device and the electronic device in the communication system mainly using magnetic field coupling such as NFC have been described in the above-described embodiments, the antenna device and the electronic device in the above-described embodiment are non-contact using magnetic field coupling. A power transmission system (electromagnetic induction method, magnetic field resonance method, etc.) can be used in the same manner. For example, the antenna device according to the above-described embodiment can be applied as a power receiving antenna device to a power receiving device of a magnetic field resonance type non-contact power transmission system used in the HF band, particularly at frequencies of 6.78 MHz or 6.78 MHz. Even in this case, the antenna device functions as a power receiving antenna device. In the contactless power transmission system, the “power feeding circuit” described in the above embodiment corresponds to a power receiving circuit or a power transmitting circuit. In the case of a power receiving circuit, the power receiving circuit is connected to a power receiving antenna device and supplies power to a load (for example, a secondary battery). In the case of a power transmission circuit, the power transmission circuit is connected to the power transmission antenna device and supplies power to the power transmission antenna device.

  Finally, the above description of the embodiments is illustrative in all respects and not restrictive. Modifications and changes can be appropriately made by those skilled in the art. The scope of the invention is indicated by the claims rather than the embodiments described above. Further, the scope of the present invention includes modifications from the embodiments within the scope equivalent to the claims.

AP... Coil opening AX... Winding axes C1A, C1B... Capacitors C21, C31, C32, C33... Capacitors C2A, C2B... Capacitor C3... Capacitor GND... Ground conductor patterns L1, L2... Inductors L21A, L21B... Inductors L321A, L321B... Inductors SL1, SL2... Slits TP1, TP2, TP3... Trimming point 1... Coupling coil 1F... Opening end 2... Coil antennas 3, 3a, 3b... Planar conductor (conductive member)
3C... Facing parts 3E, 3E1, 3E2... Extension parts 3b1, 3b2, 3b3... Sheet conductor 4... Housing 5, 81... Circuit board 6... Adhesive layer 7... Magnetic material 10... Multilayer board 10a... Sheet 10b... 10h... Magnetic substance sheet 11... 1st linear part 12... 2nd linear parts 21, 21a, 21b... Coil antenna conductor 21ac, 21bc... Capacitance formation conductor 22... Insulating base material 41, 42... Housing|casing 70... Magnetic body 71... First magnetic body 72... Second magnetic body 81... Substrate 82... UHF band antenna 83... Battery pack 84... Cable 85... Camera modules 86, 87... UHF band antennas 101-109... Antenna device 110... RFIC
201... Electronic device 300... Communication partner antenna (transmitter antenna)
321... Communication partner antenna conductor

Claims (11)

A coupling coil having a coupling coil conductor,
A coil antenna having a coil opening and a coil antenna conductor wound around the coil opening and being coupled with the coupling coil conductor at least via a magnetic field;
A planar conductive member that overlaps at least a part of the coil opening in a plan view of the coil opening,
The conductive member represents a shortest distance from the position farthest from the coupling coil in the coil opening to the conductive member as D2, and the conductive distance from the position closest to the coupling coil in the coil opening. when representing the shortest distance to the member at D1, Ri near relationship D1 <D2,
A second coil element disposed on the coupling coil side with respect to the coil antenna conductor in a winding axis direction of the coil antenna conductor and overlapping at least a part of the coil opening or the coil antenna conductor in a plan view of the coil opening; Equipped with magnetic material,
Antenna device. A coupling coil having a coupling coil conductor,
A coil antenna having a coil opening and a coil antenna conductor wound around the coil opening and being coupled to the coupling coil conductor via at least a magnetic field;
A planar conductive member that overlaps at least a part of the coil opening in a plan view of the coil opening,
The conductive member represents a shortest distance from the position farthest from the coupling coil in the coil opening to the conductive member as D2, and the conductive distance from the position closest to the coupling coil in the coil opening. when representing the shortest distance to the member at D1, Ri near relationship D1 <D2,
The coil antenna includes an insulating base material on which the coil antenna conductor is formed,
The conductive member is formed on the insulating substrate,
The insulating substrate is composed of a laminate of a plurality of insulator layers,
The conductive member is formed on the insulator layer farther from the coupling coil than the insulator layer on which the coil antenna conductor is formed,
Antenna device. A coupling coil having a coupling coil conductor,
A coil antenna having a coil opening and a coil antenna conductor wound around the coil opening and being coupled to the coupling coil conductor via at least a magnetic field;
A planar conductive member that overlaps at least a part of the coil opening in a plan view of the coil opening,
The conductive member represents a shortest distance from the position farthest from the coupling coil in the coil opening to the conductive member as D2, and the conductive distance from the position closest to the coupling coil in the coil opening. when representing the shortest distance to the member at D1, Ri near relationship D1 <D2,
The conductive member surrounds the coupling coil from a plurality of directions in a plan view,
Antenna device. The antenna device according to claim 3 , wherein the conductive member has an extending portion that extends in a direction closer to the coupling coil in a plan view. A coupling coil having a coupling coil conductor,
A coil antenna having a coil opening and a coil antenna conductor wound around the coil opening and being coupled with the coupling coil conductor at least via a magnetic field;
A planar conductive member that overlaps at least a part of the coil opening in a plan view of the coil opening,
The conductive member represents a shortest distance from the position farthest from the coupling coil in the coil opening to the conductive member as D2, and the conductive distance from the position closest to the coupling coil in the coil opening. when representing the shortest distance to the member at D1, Ri near relationship D1 <D2,
In the winding axis direction of the coil antenna conductor, the coil antenna conductor is arranged on the opposite side to the coupling coil, and is located between the conductive member and the coupling coil in a plan view of the coil opening. A first magnetic body overlapping a part of the coil antenna conductor,
Antenna device. In the winding axis direction of the coil antenna conductor, the coil antenna conductor is arranged on the coupling coil side with respect to the coil antenna conductor, and overlaps at least a part of the coil opening or the coil antenna conductor in a plan view of the coil opening, The antenna device according to claim 5 , further comprising a second magnetic body connected to the first magnetic body. It said second magnetic body has a cut-out portion in a region which overlaps with the coil antenna conductor located between the coupling coil and the conductive member, the antenna device according to claim 1 or 6. The antenna device according to any one of claims 1 to 7 , wherein the coil antenna conductor is provided with a capacitor connected in the middle of a current path of the coil antenna conductor. The antenna device according to claim 8 , wherein the conductive member is an electrode forming the capacitor. The antenna device according to any one of claims 1 to 9 , wherein the coil antenna is coupled to a coil antenna of a coupling partner via an HF band alternating magnetic field. In an electronic device comprising an antenna device and a power supply circuit connected to the antenna device and used for at least one of communication and power transmission of the antenna device,
The antenna device is
A coupling coil having a coupling coil conductor,
A coil antenna having a coil opening and a coil antenna conductor wound around the coil opening and being coupled to the coupling coil conductor via at least a magnetic field;
A planar conductive member that overlaps at least a part of the coil opening in a plan view of the coil opening,
The conductive member represents a shortest distance from the position farthest from the coupling coil in the coil opening to the conductive member as D2, and the conductive distance from the position closest to the coupling coil in the coil opening. when representing the shortest distance to the member at D1, Ri near relationship D1 <D2,
A second coil element disposed on the coupling coil side with respect to the coil antenna conductor in a winding axis direction of the coil antenna conductor and overlapping at least a part of the coil opening or the coil antenna conductor in a plan view of the coil opening; Equipped with magnetic material,
An electronic device characterized in that

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