WO2018030363A1 - Antenna device and electronic instrument - Google Patents

Abstract

An antenna device (101) comprises a first planar conductor (21) having a main surface, and a coil antenna. The coil antenna is wound multiple times to form a coil opening, and includes a first coil conductor (31) and a second coil conductor (32) having different positions in the vertical direction (Z-axis direction) with respect to the main surface of the first planar conductor (21). The first coil conductor (31) is connected to the first planar conductor (21). In a plan view (Z-axis directional view) of the first planar conductor (21), the first coil conductor (31) and second coil conductor (32) are positioned facing each other, across the coil opening (CP), in a first direction (X-axis direction). The area of the first planar conductor (21) is greater than the area of the coil opening (CP) as viewed in the Z-axis direction.

Description

ANTENNA DEVICE AND ELECTRONIC DEVICE

The present invention relates to an antenna device, and more particularly to an antenna device including a coil antenna and a planar conductor, and an electronic device including the antenna device.

Conventionally, an antenna device having a structure capable of obtaining a predetermined communication distance even when a planar conductor (planar conductor) and a coil antenna are close to each other has been devised.

For example, Patent Document 1 describes an antenna device in which a coil conductor is wound around a magnetic body having one surface and the other surface close to the planar conductor. The antenna device is configured such that the coil conductor disposed in proximity to one surface of the magnetic body does not overlap the coil conductor disposed in proximity to the other surface of the magnetic body as viewed from the normal direction of the one surface or the other surface. An apparatus is disclosed. In the above antenna device, the winding axis of the coil antenna constituted by the coil conductor is inclined with respect to the main surface of the planar conductor, and an antenna device that secures a communicable distance in a predetermined direction is realized. Yes.

JP 2010-245776 A

However, when a planar conductor is close to the coil antenna, the inductance of the coil antenna is reduced, and the frequency characteristics of the coil antenna are fluctuated. As a result, the communication characteristics of the antenna device may be reduced.

An object of the present invention is to provide an antenna device that suppresses fluctuations in the frequency characteristics of a coil antenna and has good communication characteristics in a configuration including a coil antenna and a planar conductor. Another object is to provide an electronic device including the antenna device.

(1) The antenna device of the present invention
A first planar conductor having a main surface;
A coil antenna including at least a first coil conductor and a second coil conductor, and being wound a plurality of times to form a coil opening;
With
The first coil conductor is continuous with the first planar conductor;
The first coil conductor and the second coil conductor are different from each other in the position in the direction perpendicular to the main surface of the first planar conductor,
The first coil conductor and the second coil conductor are arranged to face each other with the coil opening sandwiched in a first direction in a plan view of the first planar conductor,
The area of the first planar conductor is larger than the area of the coil opening when the first planar conductor is viewed in plan.

With this configuration, the variation in frequency characteristics due to the proximity of the coil antenna to the planar conductor is suppressed, and an antenna device having good communication characteristics can be realized. Also, with the above configuration, the substantial antenna area that functions as an antenna is increased, and magnetic flux is radiated and collected efficiently, so that it is easy to couple with the coil antenna on the communication partner side, and the antenna characteristics are improved.

(2) In the above (1), the first planar conductor is opposite to the second coil conductor in the first direction with respect to the first coil conductor in a plan view of the first planar conductor. It is preferable to arrange | position. With this configuration, the magnetic flux that attempts to pass through the first planar conductor in the direction perpendicular to the main surface of the first planar conductor is likely to be linked to the coil opening of the coil antenna along the first planar conductor.

(3) In the above (1) or (2), the first planar conductor has a length in the second direction orthogonal to the first direction in the plan view of the first planar conductor. It is preferably longer than the antenna. With this configuration, the magnetic flux collection effect by the first planar conductor is increased, and the substantial antenna area that functions as an antenna is further increased, so that the antenna characteristics are further improved.

(4) In any one of the above (1) to (3), the coil antenna includes a third coil conductor that is different from the first planar conductor in a position in a direction perpendicular to the main surface of the first planar conductor. The first planar conductor does not overlap the entire coil opening in a plan view of the first planar conductor, and at least a part of the third coil conductor in the first direction is included in the first planar conductor. You may overlap with the part arrange | positioned between a 1st coil conductor and the said coil opening. With this configuration, the generation of magnetic flux that attempts to pass through the gap between the third coil conductors in the direction perpendicular to the main surface of the first planar conductor is suppressed, and the coil opening is linked along the first planar conductor. The density of magnetic flux is relatively increased. Therefore, the antenna characteristics of the antenna device are further enhanced.

(5) In any one of the above (1) to (4), a second planar conductor is provided, and the area of the second planar conductor is larger than the coil opening in plan view of the second planar conductor. On the other hand, it may be arranged on the opposite side to the first coil conductor, and the second coil conductor may be continuous with the second planar conductor. With this configuration, the magnetic flux that attempts to pass through the second planar conductor in the direction perpendicular to the main surface of the first planar conductor is likely to be linked to the coil opening along the second planar conductor. Therefore, both the radiation efficiency of the magnetic flux and the magnetic flux collection effect are enhanced, and it becomes easy to couple with the coil antenna on the communication partner side.

(6) In the above (5), the length of the second planar conductor in the second direction orthogonal to the first direction is longer than that of the coil antenna in plan view of the second planar conductor. It is preferable. With this configuration, the magnetic flux collection effect by the second planar conductor is increased, and the substantial antenna area that functions as an antenna is further increased.

(7) In the above (5) or (6), the coil antenna includes a fourth coil conductor whose position in a direction perpendicular to the main surface of the first planar conductor is different from that of the second planar conductor, The second planar conductor does not overlap the entire coil opening in a plan view of the second planar conductor, and at least part of the second coil in the first direction is the fourth coil conductor. You may overlap with the part arrange | positioned between a conductor and the said coil opening. With this configuration, generation of a magnetic flux that attempts to pass through the gap between the fourth coil conductors in the direction perpendicular to the main surface of the second planar conductor is suppressed, and the coil opening is linked along the second planar conductor. The density of magnetic flux is relatively increased. Therefore, the antenna characteristics of the antenna device are further enhanced.

(8) In the above (7), it is preferable that the second planar conductor overlaps the entire fourth coil conductor in a plan view of the second planar conductor. With this configuration, the generation of magnetic flux that attempts to pass through the gap between the fourth coil conductors in the direction perpendicular to the main surface of the second planar conductor is further suppressed, and the coil opening is linked to the coil opening along the second planar conductor. The density of magnetic flux is relatively increased. Therefore, the antenna characteristics of the antenna device are further enhanced as compared with the case where the second planar conductor overlaps only part of the fourth coil conductor in plan view of the second planar conductor.

(9) In any one of the above (5) to (8), the second planar conductor may be bent or curved. With this configuration, an antenna device having desired directivity can be realized.

(10) In any one of the above (1) to (9), it is preferable that the first planar conductor is a conductor pattern formed on a circuit board provided in an electronic device to be assembled. With this configuration, it is not necessary to separately form the first planar conductor, so that the manufacture is easy and the cost can be reduced.

(11) In any one of the above (1) to (10), the second planar conductor is a conductor formed on a part of a housing provided in an electronic device to be assembled or on the inner surface of the housing. Preferably there is. With this configuration, it is not necessary to separately form the second planar conductor, so that the manufacturing is easy and the cost can be reduced.

(12) In any one of the above (1) to (11), it is preferable that the magnetic body 4 is disposed in the coil opening of the coil antenna. With this configuration, a predetermined inductance value can be obtained without increasing the size of the coil antenna. Also, with this configuration, a coil antenna having a predetermined inductance can be realized with a small number of turns.

(13) The electronic device of the present invention
An antenna device;
A feeding circuit;
With
The antenna device is
A first planar conductor having a main surface;
A coil antenna including at least a first coil conductor and a second coil conductor, and being wound a plurality of times to form a coil opening;
Have
The first coil conductor is continuous with the first planar conductor;
The first coil conductor and the second coil conductor are different from each other in the position in the direction perpendicular to the main surface of the first planar conductor,
The first coil conductor and the second coil conductor are disposed opposite to each other with the coil opening sandwiched with respect to a first direction in a plan view of the first planar conductor,
The first planar conductor is larger than the area of the coil opening when the first planar conductor is viewed in plan,
The feeding circuit is connected to the coil antenna.

With this configuration, fluctuations in frequency characteristics due to the proximity of the coil antenna to the planar conductor are suppressed, and an electronic device including an antenna device having good communication characteristics can be realized.

According to the present invention, in the configuration including the coil antenna and the planar conductor, it is possible to suppress the fluctuation of the frequency characteristics of the coil antenna and realize an antenna device having good communication characteristics. In addition, an electronic device including the antenna device can be realized.

FIG. 1A is a plan view of the antenna device 101 according to the first embodiment, and FIG. 1B is a cross-sectional view taken along the line AA in FIG. FIG. 2 is a plan view showing the structure of the coil antenna included in the antenna device 101. FIG. 3A is a plan view showing the main part of the electronic apparatus 202 according to the second embodiment, and FIG. 3B is a cross-sectional view taken along the line BB in FIG. FIG. 4 is a plan view of the circuit board 10 included in the electronic device 202. FIG. 5 is a plan view of the main antenna unit 61 included in the electronic device 202. FIG. 6 is a circuit diagram of the electronic device 202 according to the second embodiment. FIG. 7A is a plan view showing a main part of an electronic apparatus 203A according to the third embodiment, and FIG. 7B is a cross-sectional view taken along the line CC in FIG. 7A. FIG. 8 is a plan view showing a main part of another electronic device 203B according to the third embodiment. 9 is a cross-sectional view taken along the line DD in FIG. FIG. 10A is a plan view showing the main part of an electronic apparatus 204 according to the fourth embodiment, and FIG. 10B is a cross-sectional view taken along line EE in FIG. FIG. 11A is a plan view showing a main part of an electronic apparatus 205 according to the fifth embodiment, and FIG. 11B is a cross-sectional view taken along line FF in FIG. 11A. FIG. 12A is a plan view showing the main part of an electronic device 206 according to the sixth embodiment, and FIG. 12B is a cross-sectional view taken along the line GG in FIG. FIG. 13A is a plan view showing the main part of an electronic device 207 according to the seventh embodiment, and FIG. 13B is a cross-sectional view taken along line HH in FIG. FIG. 14 is a plan view of the circuit board 10 included in the electronic device 207 according to the seventh embodiment. FIG. 15A is a plan view showing a main part of an electronic apparatus 208 according to the eighth embodiment, and FIG. 15B is a cross-sectional view taken along the line II in FIG. FIG. 16A is a plan view showing the main part of an electronic apparatus 209 according to the ninth embodiment, and FIG. 16B is a JJ cross-sectional view in FIG. FIG. 17A is a plan view showing the main part of the electronic apparatus 210 according to the tenth embodiment, and FIG. 17B is a cross-sectional view taken along the line KK in FIG. FIG. 18A is a plan view showing the main part of an electronic apparatus 211 according to the eleventh embodiment, and FIG. 18B is a cross-sectional view taken along line LL in FIG. FIG. 19A is a plan view showing the main part of an electronic apparatus 212 according to the twelfth embodiment, and FIG. 19B is a cross-sectional view taken along line MM in FIG. 19A. FIG. 20A is a plan view showing the main part of an electronic device 213 according to the thirteenth embodiment, and FIG. 20B is a cross-sectional view taken along line NN in FIG. FIG. 21 is a plan view of the circuit board 10 included in the electronic device 213 according to the thirteenth embodiment.

Hereinafter, several specific examples will be given with reference to the drawings to show a plurality of modes for carrying out the present invention. In each figure, the same reference numerals are assigned to the same portions. In consideration of ease of explanation or understanding of the main points, the embodiments are shown separately for convenience, but the components shown in different embodiments can be partially replaced or combined. In the second and subsequent embodiments, description of matters common to the first embodiment is omitted, and only different points will be described. In particular, the same operation effect by the same configuration will not be sequentially described for each embodiment.

In the embodiments described below, the “coil antenna” is a kind of minute loop antenna and is an antenna that radiates magnetic flux. The coil antenna is an antenna used for communication (near field communication) by magnetic field coupling with an antenna on the communication partner side, and is used for communication such as NFC (Near Field Communication), for example.

<< First Embodiment >>
FIG. 1A is a plan view of the antenna device 101 according to the first embodiment, and FIG. 1B is a cross-sectional view taken along the line AA in FIG. FIG. 2 is a plan view showing the structure of the coil antenna included in the antenna device 101. In FIG. 2, the magnetic body 4 is not shown. In FIG. 2, the first coil conductor 31 is indicated by hatching, and the second coil conductor 32 is indicated by a dot pattern. The same applies to the plan views shown below.

The antenna device 101 includes a base material 1, a routing conductor 41, a first planar conductor 21 having a main surface, a first coil conductor 31, a second coil conductor 32, other coil conductors 30A, 30B and 30C, a protective film 2, A magnetic body 4 is provided.

The substrate 1 is a resin sheet having flexibility and having a rectangular planar shape whose longitudinal direction matches the X-axis direction. The substrate 1 has a first surface S1 and a second surface S2. The substrate 1 is, for example, a thermoplastic resin sheet whose main material is a liquid crystal polymer.

The lead conductor 41 is formed on the first surface S1 of the base 1. A first coil conductor 31, a second coil conductor 32, and other coil conductors 30A, 30B, and 30C are formed on the second surface S2 of the substrate 1. The lead conductor 41 connects the other coil conductor 30 </ b> B and the other coil conductor 30 </ b> C via the interlayer connection conductor 7 formed on the base material 1. The lead conductor 41, the first coil conductor 31, the second coil conductor 32, and the coil conductors 30A, 30B, and 30C are conductor patterns made of, for example, Cu foil.

The first planar conductor 21 is a conductor that is formed on the second surface S2 of the substrate 1 and has a rectangular planar shape whose longitudinal direction coincides with the X-axis direction. As shown in FIG. 2, the first coil conductor 31 is continuous with the first planar conductor 21. The first planar conductor 21 is a conductor pattern made of Cu foil, for example.

As shown in FIG. 1B, the first coil conductor 31 and the second coil conductor 32 have a first direction (X-axis direction) in a plan view of the first planar conductor 21 (viewed from the Z-axis direction). Are opposed to each other with the coil opening interposed therebetween.

These first coil conductor 31, second coil conductor 32, other coil conductors 30 </ b> A, 30 </ b> B, 30 </ b> C, the routing conductor 41 and the interlayer connection conductor 7 constitute a coil antenna. The coil antenna is a rectangular spiral conductor wound about 3 turns and having a coil opening, and has a first end E1 and a second end E2. The first end E1 and the second end E2 are connected to a power supply circuit (not shown).

In the present invention, “the first coil conductor is continuous with the first planar conductor” means that the first coil conductor 31 and the first planar conductor 21 are structurally connected (integrated). Say that. The first coil conductor “continuous to the first planar conductor” refers to the shortest electrical path that functions as a part of the coil antenna. In the present embodiment, the electrical path connecting the one end E0 of the other coil conductor 30A to the first end E1 of the coil antenna in the shortest is the first coil conductor that is “continuous with the first planar conductor”. (Refer to the first coil conductor 31 shown by hatching in FIG. 2).

Note that the first coil conductor 31 according to the present embodiment is located in the −X direction most among the portions opposed to each other across the coil opening in the first direction (X axis direction) when viewed from the Z axis direction. Part. In addition, the second coil conductor 32 according to this embodiment is a portion that is located in the + X direction most among the portions that are opposed to each other across the coil opening in the first direction (X-axis direction) when viewed from the Z-axis direction. It is.

The protective film 2 is formed on the entire second surface S2 of the substrate 1, and covers the first planar conductor 21 and the formation surface of the coil antenna. The protective film 2 is a resin film provided for the purpose of preventing oxidation of the conductor pattern formed on the surface of the base material 1, improving heat resistance, and preventing a short circuit between conductors due to metallic foreign matter, and is a coverlay film, for example. However, it may be a solder resist film or the like.

The magnetic body 4 is a resinous sheet having flexibility and having a rectangular planar shape whose longitudinal direction coincides with the X-axis direction. As shown in FIG. 2, a through hole 5 is formed in the base material 1 and the protective film 2 in a portion inside the coil opening CP of the coil antenna, and the magnetic body 4 is inserted into the through hole 5. The magnetic body 4 is, for example, a resin sheet containing ferrite powder in which magnetic ferrite powder is dispersed in a resin.

As shown in FIG. 1B, the first coil conductor 31 and the second coil conductor 32 are different in position (height) in the vertical direction (Z-axis direction) with respect to the main surface of the first planar conductor 21. Yes.

Further, the area of the first planar conductor 21 is larger than the area of the coil opening CP when the first planar conductor 21 is viewed in plan (when viewed from the Z-axis direction), as shown in FIG. large. Further, as shown in FIG. 2, the first planar conductor 21 has a length in the first direction (X-axis direction) longer than the coil opening CP when viewed from the Z-axis direction (LA1 <LA2). The first planar conductor 21 is disposed on the opposite side of the first coil conductor 31 from the second coil conductor 32 (the −X direction side of the first coil conductor 31) when viewed from the Z-axis direction.

The antenna device 101 according to the present embodiment has the following effects.

(A) The antenna device 101 includes the first planar conductor 21 larger than the area of the coil opening CP of the coil antenna when viewed from the Z-axis direction, and a part of the coil antenna (first coil conductor 31) is the first. It is continuous with the one-plane conductor 21. In other words, the first coil conductor 31 is a portion that is electrically continuous with the first planar conductor 21. With this configuration, variation in frequency characteristics due to the proximity of the coil antenna to the planar conductor is suppressed, and an antenna device having good communication characteristics can be realized. Also, with the above configuration, the substantial antenna area that functions as an antenna is increased, and magnetic flux is radiated and collected efficiently, so that it is easy to couple with the coil antenna on the communication partner side, and the antenna characteristics are improved.

(B) In the present embodiment, the first planar conductor 21 is disposed on the opposite side of the first coil conductor 31 from the second coil conductor 32 in the X-axis direction when viewed from the Z-axis direction. The coil conductor 31 and the second coil conductor 32 have different positions (heights) in the Z-axis direction. Therefore, the magnetic flux that attempts to pass through the first planar conductor 21 in the Z-axis direction is likely to be linked to the coil opening of the coil antenna along the first planar conductor 21 (magnetic flux φ2 in FIG. 1B). reference).

(C) In this embodiment, the magnetic body 4 is arrange | positioned in the coil opening of a coil antenna. With this configuration, a predetermined inductance value can be obtained without increasing the size of the coil antenna. Also, with this configuration, a coil antenna having a predetermined inductance can be realized with a small number of turns.

<< Second Embodiment >>
In the second embodiment, an example of an electronic apparatus including the antenna device of the present invention is shown.

The “electronic device” in the present invention is a device including an antenna device, a power feeding circuit, and the like. , Game machines, toys and the like.

FIG. 3A is a plan view showing the main part of the electronic apparatus 202 according to the second embodiment, and FIG. 3B is a cross-sectional view taken along line BB in FIG. 3A. FIG. 4 is a plan view of the circuit board 10 included in the electronic device 202. FIG. 5 is a plan view of the main antenna unit 61 included in the electronic device 202. In FIG. 4, the first coil conductor 31 is indicated by hatching, and in FIG. 5, the second coil conductor 32 is indicated by a dot pattern. Further, in FIG. 5, illustration of the magnetic body 4 is omitted.

The electronic device 202 includes the circuit board 10, the RFIC 51, the reactance element 52, the main antenna unit 61, and the like.

The circuit board 10 is an insulative flat plate having a rectangular planar shape whose longitudinal direction coincides with the X-axis direction, and has a first main surface VS1 and a second main surface VS2. Conductor patterns 42 and 43 are formed on the first main surface VS1 of the circuit board 10. The RFIC 51 is mounted on the first main surface VS1 of the circuit board 10 and connected to one end of the conductor patterns 42 and 43, respectively. The reactance element 52 is mounted on the first main surface VS1 of the circuit board 10 and connected to the conductor patterns 42 and 43, respectively. The circuit board 10 is, for example, a printed wiring board. The RFIC 51 is an RFIC element for RFID of 13.56 MHz, for example, and is an example of the “feed circuit” in the present invention. The reactance element 52 is, for example, a chip capacitor.

Also, the first planar conductor 21 and the first coil conductor 31 are formed inside the circuit board 10. The first planar conductor 21 is a conductor pattern having a rectangular planar shape whose longitudinal direction coincides with the X-axis direction. The first coil conductor 31 is continuous with the first planar conductor 21. In other words, the first coil conductor 31 is a portion that is electrically continuous with the first planar conductor 21. The first planar conductor 21 is a ground conductor formed inside the circuit board, for example.

In the present embodiment, an electrical path that connects the connection point of the interlayer connection conductor (not shown) connected to the connection pin 6 to the connection point of the interlayer connection conductor 8 connected to the conductor pattern 43 in the shortest is “first”. The first coil conductor is continuous with the single planar conductor (see the first coil conductor 31 indicated by hatching in FIG. 4).

The main antenna unit 61 includes a base material 1A, a second coil conductor 32, a plurality of third coil conductors 33A, 33B, 33C, 33D, a protective film 2A, a routing conductor 41, an interlayer connection conductor 7, and a magnetic body 4. The main antenna unit 61 is attached to the inner surface of a housing (not shown) included in the electronic device 202, for example.

The base material 1A is a resin sheet having flexibility and having a rectangular planar shape whose longitudinal direction matches the Y-axis direction. The base material 1A has a first surface S1 and a second surface S2. A lead conductor 41 is formed on the first surface S1 of the base 1A. Further, the second coil conductor 32 and a plurality of third coil conductors 33A, 33B, 33C, and 33D are formed on the second surface S2 of the base 1A. The routing conductor 41 connects the third coil conductor 33 </ b> C and the third coil conductor 33 </ b> D via the interlayer connection conductor 7.

The protective film 2A is formed on the entire second surface S2 of the substrate 1A and covers the formation surfaces of the second coil conductor 32 and the third coil conductors 33B and 33C. The protective film 2A has openings corresponding to the positions of the third coil conductors 33A and 33D. Therefore, the third coil conductors 33A and 33D are exposed on the second surface S2 of the base 1A.

The third coil conductor 33 </ b> A is connected to one end of the first coil conductor 31 (see FIG. 4) formed inside the circuit board 10 through the connection pin 6. The third coil conductor 33 </ b> D is connected to the other end of the conductor pattern 42 formed on the first main surface VS <b> 1 of the circuit board 10 via the connection pin 6. The other end of the conductor pattern 43 formed on the first main surface VS1 of the circuit board 10 is connected to the first coil conductor 31 formed inside the circuit board 10 via the interlayer connection conductor 8 formed on the circuit board 10. It is connected to the other end (see FIG. 4). The connection pin 6 is, for example, a movable probe pin.

The first coil conductor 31, the second coil conductor 32, the plurality of third coil conductors 33A, 33B, 33C, and 33D, the routing conductor 41, the interlayer connection conductor 7, and the connection pin 6 constitute a coil antenna. The coil antenna according to the present embodiment is a rectangular spiral conductor wound about three turns and having a coil opening, and has a first end (the other end of the first coil conductor 31) and a second end (the third end). A coil conductor 33D). The first end and the second end of the coil antenna are connected to the RFIC 51 via conductor patterns 42, 43 and the like.

Further, the antenna device according to the present embodiment includes the first planar conductor 21, the first coil conductor 31, the second coil conductor 32, the third coil conductors 33A, 33B, 33C, and 33D, the connection pin 6, and the interlayer connection conductor 7. , 8 etc.

The magnetic body 4 is a resinous sheet having flexibility and having a rectangular planar shape whose longitudinal direction coincides with the X-axis direction. As shown in FIG. 5, the base 1 </ b> A and the protective film 2 </ b> A are formed with through holes 5 in portions inside the coil openings formed by the second coil conductor 32 and the third coil conductors 33 </ b> A, 33 </ b> B, 33 </ b> C. The magnetic body 4 is inserted into the through hole 5.

As shown in FIG. 3B, the first coil conductor 31 and the second coil conductor 32 have different positions (heights) in the Z-axis direction. In addition, as shown in FIG. 3A, the first planar conductor 21 according to the present embodiment has a second direction (Y that is orthogonal to the first direction (X-axis direction) when viewed from the Z-axis direction. The length in the axial direction is longer than that of the coil antenna (LB1 <LB2).

FIG. 6 is a circuit diagram of the electronic device 202 according to the second embodiment. In FIG. 6, the coil antenna is represented by L3, and the reactance element 52 is represented by C.

The coil antenna L3 is connected to the RFIC 51, and the reactance element C is connected in parallel to the coil antenna L3. An LC resonance circuit is configured by the coil antenna L3, the reactance element C, and the capacitive component of the RFIC 51 itself. The capacitance of the reactance element C is selected so that the resonance frequency of the LC resonance circuit is substantially equal to the communication frequency of the RFID system (for example, 13.56 MHz). There may be a plurality of reactance elements (52).

The electronic device 202 according to the present embodiment has the following effects in addition to the effects described in the first embodiment.

(D) Since the first planar conductor 21 is a conductor pattern formed on the circuit board 10 provided in the electronic device, it is not necessary to form the first planar conductor 21 separately, and the manufacturing is easy and the cost is reduced. Can be planned.

(E) When the first planar conductor 21 is viewed from the Z-axis direction, the length in the second direction (Y-axis direction) orthogonal to the first direction (X-axis direction) is longer than that of the coil antenna. The magnetic flux collecting effect by the first planar conductor 21 is increased, and the substantial antenna area that functions as an antenna is further increased.

In the present embodiment, a configuration example in which the first planar conductor 21 is formed inside the circuit board 10 has been described. However, the first planar conductor 21 is formed on the first main surface VS1 of the circuit board 10. Alternatively, it may be formed on the second main surface VS2.

<< Third Embodiment >>
The third embodiment shows an example in which the shape of the first planar conductor is different from that of the second embodiment.

FIG. 7A is a plan view showing the main part of an electronic apparatus 203A according to the third embodiment, and FIG. 7B is a cross-sectional view taken along the line CC in FIG. 7A. In FIG. 7A, illustration of the magnetic body 4 is omitted.

The electronic device 203A is different from the electronic device 202 according to the second embodiment in the configuration of the first planar conductor. Other configurations are substantially the same as those of the electronic device 202.

The electronic device 203A includes the circuit board 10, the RFIC 51, the reactance element 52, the main antenna unit 61, and the like. Inside the circuit board 10, a first planar conductor 21A and a first coil conductor 31 are formed.

The first planar conductor 21A according to the present embodiment is longer in the first direction (X-axis direction) than the first planar conductor 21 shown in the second embodiment. As shown in FIGS. 7A and 7B, the third coil conductors 33A, 33B, 33C, 33D are different from the first planar conductor 21 in the position (height) in the Z-axis direction. . Further, the first planar conductor 21A has a first coil conductor 31 and a coil opening CP in the first direction (X-axis direction) among the third coil conductors 33A, 33B, 33C, and 33D as viewed from the Z-axis direction. It overlaps with a portion (a part of the third coil conductor 33C) disposed between the two. On the other hand, the first planar conductor 21A does not overlap the entire coil opening CP as viewed from the Z-axis direction.

The electronic device 203A according to the present embodiment has the following effects in addition to the effects described in the second embodiment.

(F) In the present embodiment, the first planar conductor 21A does not overlap the entire coil opening CP as viewed from the Z-axis direction, and at least a part of the third coil conductors 33A, 33B, 33C, 33D In the first direction (X-axis direction), it overlaps with a portion (a part of the third coil conductor 33C) disposed between the first coil conductor 31 and the coil opening CP. With this configuration, the magnetic flux that attempts to pass through the first planar conductor 21A from the −Z direction to the + Z direction is likely to interlink with the coil opening along the first planar conductor 21A (in FIG. 7B). (Refer to magnetic flux φ3). Therefore, an antenna device having directivity in a direction different from that of the antenna device described above can be realized.

Further, with the above configuration, a magnetic flux (passing through the gap between the third coil conductors 33C disposed between the first coil conductor 31 and the coil opening CP in the first direction (X-axis direction) in the Z-axis direction ( The generation of the magnetic flux φ4 in FIG. 7B is suppressed, and the density of the magnetic flux interlinking with the coil opening along the first planar conductor 21A (the magnetic flux φ3 in FIG. 7B) is relatively increased. Therefore, the antenna characteristics of the antenna device are further enhanced.

Next, another electronic device according to this embodiment will be described with reference to the drawings. FIG. 8 is a plan view showing a main part of another electronic device 203B according to the third embodiment. 9 is a cross-sectional view taken along the line DD in FIG. In FIG. 8, illustration of the magnetic body 4 is omitted.

The electronic device 203B is different from the electronic device 202 according to the second embodiment in the configuration of the circuit board and the first planar conductor. Other configurations are substantially the same as those of the electronic device 202.

The electronic device 203B includes a circuit board 10A, an RFIC 51, a reactance element 52, a main antenna unit 61, and the like. A first planar conductor 21B and a first coil conductor 31 are formed inside the circuit board 10A.

The first planar conductor 21B according to the present embodiment is an L-shaped conductor pattern. The first planar conductor 21B is disposed adjacent to both the first direction (−X direction of the coil antenna) and the second direction (+ Y direction of the coil antenna) of the coil antenna as viewed from the Z-axis direction. . With this configuration, the magnetic flux collection effect by the first planar conductor 21B is further increased, and the substantial antenna area that functions as an antenna is further increased. Therefore, the antenna characteristics of the antenna device are further enhanced.

<< Fourth Embodiment >>
In the fourth embodiment, an example of an electronic device that does not include a magnetic body is shown.

FIG. 10A is a plan view showing the main part of an electronic apparatus 204 according to the fourth embodiment, and FIG. 10B is a cross-sectional view taken along line EE in FIG.

The electronic device 204 is different from the electronic device 203A according to the third embodiment in that the main antenna unit 61 does not include the through hole 5 and the magnetic body 4. Other configurations are substantially the same as those of the electronic device 203A.

Even with such a configuration, the same operations and effects as in the third embodiment are achieved.

<< Fifth Embodiment >>
In 5th Embodiment, the 2nd coil conductor shows the structural example which is a conductor pattern formed in the inner surface of a housing | casing.

FIG. 11A is a plan view showing a main part of an electronic apparatus 205 according to the fifth embodiment, and FIG. 11B is a cross-sectional view taken along line FF in FIG. 11A. In FIG. 11, the resin casing 71 is not shown.

The electronic device 205 includes a resin casing 71, a circuit board 10, an RFIC 51, a reactance element 52, and the like. The circuit board 10, the RFIC 51, the reactance element 52, and the like are accommodated in the resin casing 71.

The circuit board 10 is an insulative flat plate having a rectangular planar shape whose longitudinal direction coincides with the X-axis direction, and has a first main surface VS1 and a second main surface VS2. Conductor patterns 42 and 43 are formed on the first main surface VS1 of the circuit board 10. The RFIC 51 is mounted on the first main surface VS1 of the circuit board 10 and connected to one end of the conductor patterns 42 and 43, respectively. The reactance element 52 is mounted on the first main surface VS1 of the circuit board 10 and connected to the conductor patterns 42 and 43, respectively.

Also, the first planar conductor 21, the first coil conductor 31, and the fourth coil conductors 34A, 34B, 34C, 33 are formed inside the circuit board 10. The first planar conductor 21 is a conductor pattern having a rectangular planar shape whose longitudinal direction coincides with the X-axis direction. As shown in FIG. 11A, the first coil conductor 31 is continuous with the first planar conductor 21.

In the present embodiment, the electrical path connecting the shortest distance from one end E0 of the other coil conductor 30A to the connection point of the interlayer connection conductor 8 connected to the conductor pattern 43 is “continuous with the first planar conductor”. The first coil conductor (see the first coil conductor 31 shown by hatching in FIG. 11A).

On the other hand, the other coil conductor 33 and the second coil conductor 32 are formed on the inner surface of the resin casing 71. The other coil conductor 33 and the second coil conductor 32 are conductor patterns extending in the second direction (Y-axis direction). One end of the other coil conductor 33 and one end of the second coil conductor 32 are connected to the other ends of the fourth coil conductors 34 </ b> A and 34 </ b> B formed inside the circuit board 10 via the connection pins 6. The other end of the other coil conductor 33 and the other end of the second coil conductor 32 are connected to one end of fourth coil conductors 34 </ b> B and 34 </ b> C formed inside the circuit board 10 via the connection pin 6. The other end of the other coil conductor 30 </ b> C is connected to the other end of the conductor pattern 42 via an interlayer connection conductor 8 formed on the circuit board 10. The other end of the first coil conductor 31 is connected to the other end of the conductor pattern 43 formed on the first main surface VS1 of the circuit board 10 via the interlayer connection conductor 8 formed on the circuit board 10.

The first coil conductor 31, the second coil conductor 32, the fourth coil conductors 34A, 34B, 34C, 33, the routing conductor 41, and the interlayer connection conductor 7 constitute a coil antenna. The coil antenna according to the present embodiment is a rectangular spiral conductor that is wound about three turns and has a coil opening, and has a first end (the other end of the first coil conductor 31) and a second end (the fourth end). The other end of the coil conductor 34C). The first end and the second end of the coil antenna are connected to the RFIC 51 via conductor patterns 42, 43 and the like.

The antenna device according to the present embodiment includes the first planar conductor 21, the first coil conductor 31, the second coil conductor 32, the fourth coil conductors 34 </ b> A, 34 </ b> B, 34 </ b> C, 33, and the connection pins 6.

As shown in FIG. 11A, the first coil conductor 31 and the second coil conductor 32 are opposed to each other across the coil opening in the first direction (X-axis direction) when viewed from the Z-axis direction. Further, as shown in FIG. 11B, the first coil conductor 31 and the second coil conductor 32 are different from each other in position (height) in the Z-axis direction.

Even in such a configuration, the basic configuration of the antenna device according to the present embodiment is the same as that of the antenna device 101 according to the first embodiment, and the same operations and effects as the antenna device 101 are achieved.

<< Sixth Embodiment >>
In the sixth embodiment, an example of an antenna device including a second planar conductor is shown.

FIG. 12A is a plan view showing the main part of the electronic device 206 according to the sixth embodiment, and FIG. 12B is a cross-sectional view taken along the line GG in FIG. In FIG. 12A, the resin casing 71 is not shown.

The electronic device 206 is different from the electronic device 205 according to the fifth embodiment in that the electronic device 206 includes the second planar conductor 22 having a main surface. Other configurations are substantially the same as those of the electronic device 205.

The electronic device 206 includes a resin casing 71, a second planar conductor 22, a circuit board 10, an RFIC 51, a reactance element 52, and the like. The second planar conductor 22 according to the present embodiment is a part of a housing included in the electronic device 206.

The second planar conductor 22 is a conductor having a rectangular planar shape whose longitudinal direction coincides with the Y-axis direction. As shown in FIG. 12A, the second coil conductor 32 is continuous with the second planar conductor 22. In other words, the second coil conductor 32 is a portion that is electrically continuous with the second planar conductor 22.

In the present invention, “the second coil conductor is continuous with the second planar conductor” means that the second coil conductor 32 and the second planar conductor 22 are structurally connected (integrated). Say that. The second coil conductor “continuous to the second planar conductor” refers to the shortest electrical path that functions as a part of the coil antenna. In the present embodiment, the electrical path connecting the two connection points of the second planar conductor 22 and the connection pin 6 in the shortest is the second coil conductor that is “continuous with the second planar conductor”. (See the second coil conductor 32 shown by the dot pattern in FIG. 12A).

The second planar conductor 22 is disposed on the opposite side of the second coil conductor 32 from the first coil conductor 31 (the + X direction side of the second coil conductor 32) when viewed from the Z-axis direction. As shown in FIG. 12A, the area of the second planar conductor 22 is larger than the area of the coil opening CP of the coil antenna when viewed from the Z-axis direction. Furthermore, the length of the second planar conductor 22 in the first direction (X-axis direction) is longer than the coil opening CP when viewed from the Z-axis direction (LC1 <LC2).

As shown in FIG. 12A, the second planar conductor 22 has a length in a second direction (Y-axis direction) orthogonal to the first direction (X-axis direction) when viewed from the Z-axis direction. Is longer than the coil antenna (LD1 <LD2).

The electronic device 206 according to the present embodiment has the following effects.

(G) In the present embodiment, the second planar conductor 22 having a larger area than the coil opening CP of the coil antenna when viewed from the Z-axis direction is provided, and a part of the coil antenna (second coil conductor 32) is the first. It is continuous with the two-plane conductor 22. In other words, the second coil conductor 32 is a portion that is electrically continuous with the second planar conductor 22. With this configuration, the magnetic flux that attempts to pass through the second planar conductor 22 in the Z-axis direction is likely to be linked to the coil opening along the second planar conductor 22 (magnetic flux φ5 in FIG. 12B). (See φ6). Therefore, both the radiation efficiency of the magnetic flux and the magnetic flux collection effect are enhanced, and it becomes easy to couple with the coil antenna on the communication partner side.

(H) Further, since the second planar conductor 22 is a part of the housing of the electronic device, it is not necessary to form the second planar conductor 22 separately, and manufacturing is easy and cost reduction can be achieved.

(I) Since the second planar conductor 22 has a length in the second direction (Y-axis direction) orthogonal to the first direction (X-axis direction) as viewed from the Z-axis direction, it is longer than the coil antenna. The magnetic flux collection effect by the second planar conductor 22 is increased, and the substantial antenna area that functions as an antenna is further increased.

In the present embodiment, an example in which the second planar conductor 22 is a part of the casing has been described. However, the second planar conductor 22 may be a conductor formed on the inner surface or the surface of the casing. Good.

<< Seventh Embodiment >>
In the seventh embodiment, an example of an antenna device including one second coil conductor is shown.

FIG. 13A is a plan view showing a main part of an electronic device 207 according to the seventh embodiment, and FIG. 13B is a cross-sectional view taken along line HH in FIG. FIG. 14 is a plan view of the circuit board 10 included in the electronic device 207 according to the seventh embodiment. In FIG. 13A, the resin casing 71 is not shown.

The electronic device 207 is different from the electronic device 206 according to the sixth embodiment in that there is one second coil conductor 32. Other configurations are substantially the same as those of the electronic device 206.

The electronic device 207 includes a resin casing 71, a second planar conductor 22, a circuit board 10, an RFIC 51, a reactance element 52, and the like. Inside the circuit board 10, a first planar conductor 21, a first coil conductor 31, and a plurality of fourth coil conductors 34A and 34B are formed.

The second planar conductor 22 is the same as the second planar conductor shown in the sixth embodiment. As shown in FIG. 13A, the second coil conductor 32 is continuous with the second planar conductor 22. In other words, the second coil conductor 32 is a portion that is electrically continuous with the second planar conductor 22.

One end of the second coil conductor 32 is connected to the other end of the fourth coil conductor 34 </ b> A formed inside the circuit board 10 through the connection pin 6. The other end of the second coil conductor 32 is connected to one end of a fourth coil conductor 34 </ b> B formed inside the circuit board 10 via the connection pin 6. The other end of the fourth coil conductor 34 </ b> B is connected to the other end of the conductor pattern 42 via an interlayer connection conductor 8 formed on the circuit board 10. The other end of the first coil conductor 31 is connected to the other end of the conductor pattern 43 via an interlayer connection conductor 8 formed on the circuit board 10.

The first coil conductor 31, the second coil conductor 32, the plurality of fourth coil conductors 34A and 34B, the interlayer connection conductor 8, and the connection pin 6 constitute a coil antenna. The coil antenna according to the present embodiment is a rectangular spiral conductor that is wound about three turns and has a coil opening, and has a first end (the other end of the first coil conductor 31) and a second end (the fourth end). The other end of the coil conductor 34B). The first end and the second end of the coil antenna are connected to the RFIC 51 via conductor patterns 42, 43 and the like.

In addition, the antenna device according to this embodiment includes the first planar conductor 21, the first coil conductor 31, the second coil conductor 32, the second planar conductor 22, the plurality of fourth coil conductors 34 </ b> A and 34 </ b> B, and the connection pins 6. Etc.

In the antenna device according to this embodiment, there is one second coil conductor 32. In this configuration, even when the magnetic flux that attempts to pass in the X-axis direction along the first planar conductor 21 does not interlink with the coil opening CP viewed from the Z-axis direction, a part of the coil antenna ( Since it is interlinked with the second coil conductor 32), the coupling with the coil antenna on the communication partner side can be ensured (see magnetic flux φ7 in FIG. 13B).

<< Eighth Embodiment >>
The eighth embodiment shows an example in which the shape of the second planar conductor is different from that of the seventh embodiment.

FIG. 15A is a plan view showing the main part of the electronic apparatus 208 according to the eighth embodiment, and FIG. 15B is a cross-sectional view taken along the line II in FIG. 15A. In FIG. 15A, the resin casing 71 is not shown.

The electronic device 208 is different from the electronic device 207 according to the seventh embodiment in the configuration of the second planar conductor. Other configurations are substantially the same as those of the electronic device 207.

The electronic device 208 includes a resin casing 71, the second planar conductor 22A, the circuit board 10, the RFIC 51, the reactance element 52, and the like.

The second planar conductor 22A according to this embodiment is longer in the first direction (X-axis direction) than the second planar conductor 22 shown in the seventh embodiment. As shown in FIGS. 15A and 15B, the second planar conductor 22A is different from the fourth coil conductors 34A, 34B in the position (height) in the Z-axis direction.

Further, as shown in FIG. 15A, the second planar conductor 22A is the first of the fourth coil conductors 34A and 34B in a plan view of the second planar conductor 22A (viewed from the Z-axis direction). It overlaps with a portion (a part of the fourth coil conductor 34B) disposed between the second coil conductor 32 and the coil opening CP in one direction (X-axis direction). On the other hand, the second planar conductor 22A does not overlap the entire coil opening CP viewed from the Z-axis direction.

The electronic device 208 according to the present embodiment has the following effects in addition to the effects described in the seventh embodiment.

(J) In the present embodiment, the second planar conductor 22A does not overlap the entire coil opening CP as viewed from the Z-axis direction, and at least a part of the fourth coil conductors 34A and 34B is in the first direction. It overlaps with a portion (a part of the fourth coil conductor 34B) disposed between the second coil conductor 32 and the coil opening CP in the (X-axis direction). With this configuration, the gap between the fourth coil conductors 34B disposed between the second coil conductor 32 and the coil opening CP in the first direction (X-axis direction) is perpendicular to the main surface of the second planar conductor 22A. Generation of magnetic flux (see magnetic flux φ9 in FIG. 15B) that attempts to pass in the direction (Z-axis direction) is suppressed, and magnetic flux that interlinks with the coil opening along the second planar conductor 22A (FIG. 15B ) In the magnetic flux φ8) is relatively increased. Therefore, the antenna characteristics of the antenna device are further enhanced.

<< Ninth embodiment >>
The ninth embodiment shows an example in which the shape of the second planar conductor is different from that of the eighth embodiment.

FIG. 16A is a plan view showing the main part of an electronic device 209 according to the ninth embodiment, and FIG. 16B is a JJ cross-sectional view in FIG. In FIG. 16A, the resin casing 71 is not shown.

The electronic device 209 is different from the electronic device 208 according to the eighth embodiment in the shape of the second planar conductor. Other configurations are the same as those of the electronic device 208.

The electronic device 209 includes a resin casing 71, a second planar conductor 22B, a circuit board 10, an RFIC 51, a reactance element 52, and the like.

The second planar conductor 22B according to the present embodiment has a configuration in which a portion extending in the XY plane and a portion extending in the YZ plane are connected to each other by bending or bending. The second planar conductor 22B is disposed between the second coil conductor 32 and the coil opening CP in the first direction (X-axis direction) of the fourth coil conductors 34A and 34B when viewed from the Z-axis direction. It overlaps with the part (a part of the fourth coil conductor 34B). The second planar conductor 22B does not overlap the entire coil opening CP as viewed from the Z-axis direction.

As shown in this embodiment, an antenna device having desired directivity can be realized by bending or bending the second planar conductor.

<< Tenth Embodiment >>
The tenth embodiment shows an example in which the shape of the second planar conductor is different from that of the ninth embodiment.

FIG. 17A is a plan view showing the main part of the electronic apparatus 210 according to the tenth embodiment, and FIG. 17B is a cross-sectional view taken along the line KK in FIG. In FIG. 17A, the resin casing 71 is not shown.

The electronic device 210 is different from the electronic device 209 according to the ninth embodiment in the shape of the second planar conductor. Other configurations are the same as those of the electronic device 209.

The electronic device 210 includes a resin casing 71, a second planar conductor 22C, a circuit board 10, an RFIC 51, a reactance element 52, and the like.

The second planar conductor 22C according to the present embodiment is a C-shaped (U-shaped) conductor as viewed from the Z-axis direction. Further, the second planar conductor 22C is bent or curved, and has a configuration in which a portion extending in the XY plane and a portion extending in the YZ plane are connected. Further, the second planar conductor 22C overlaps the fourth coil conductors 34A and 34B as viewed from the Z-axis direction. On the other hand, the second planar conductor 22C does not overlap the entire coil opening CP as viewed from the Z-axis direction.

The electronic device 210 according to the present embodiment has the following effects.

(K) In the present embodiment, the second planar conductor 22C overlaps the entire fourth coil conductors 34A and 34B when viewed from the Z-axis direction. With this configuration, generation of magnetic flux that attempts to pass through the gap between the fourth coil conductor 34A and the fourth coil conductor 34B or the gap between the fourth coil conductors 34B is further suppressed, and along the second planar conductor 22C. The density of magnetic flux interlinking with the coil opening is relatively increased. Therefore, when viewed from the Z-axis direction, the antenna characteristics of the antenna device are further enhanced as compared with the case where the second planar conductor overlaps only part of the fourth coil conductor.

<< Eleventh Embodiment >>
In the eleventh embodiment, an electronic apparatus further including an auxiliary coil antenna will be described.

FIG. 18A is a plan view showing the main part of the electronic apparatus 211 according to the eleventh embodiment, and FIG. 18B is a cross-sectional view taken along the line LL in FIG. In FIG. 18A, the resin casing 71 is not shown.

The electronic device 211 is different from the electronic device 208 according to the eighth embodiment in that it includes the auxiliary coil antenna 81. Other configurations are substantially the same as those of the electronic device 208.

The electronic device 211 includes a resin casing 71, the second planar conductor 22A, the circuit board 10, the RFIC 51, the reactance element 52, the auxiliary coil antenna 81, and the like. The auxiliary coil antenna 81 is, for example, a multilayer chip antenna.

The antenna device according to this embodiment includes a first planar conductor 21, a first coil conductor 31, a second coil conductor 32, a second planar conductor 22A, a plurality of fourth coil conductors 34A and 34B, a connection pin 6, and an auxiliary device. The coil antenna 81 is used.

Conductor patterns 42A, 42B, and 43 are formed on the first main surface VS1 of the circuit board 10. The RFIC 51 is mounted on the first main surface VS1 of the circuit board 10 and connected to one ends of the conductor patterns 42A and 43, respectively. The reactance element 52 is mounted on the first main surface VS1 of the circuit board 10 and connected to the conductor patterns 42A and 43, respectively.

The auxiliary coil antenna 81 is mounted on the first main surface VS1 of the circuit board 10 so that the winding axis coincides with the X-axis direction, and is connected to the other end of the conductor pattern 42A and one end of the conductor pattern 42B. The other end of the conductor pattern 42B is connected to the second end (the other end of the fourth coil conductor 34C) of the coil antenna according to this embodiment. That is, the auxiliary coil antenna 81 is connected in series between the RFIC 51 and the coil antenna.

In this embodiment, since the auxiliary coil antenna 81 is provided, an antenna device having desired directivity can be easily realized. Note that the arrangement of the auxiliary coil antenna 81 and the direction of the winding axis can be appropriately changed within the scope of the effects and advantages of the present invention. Further, the number of auxiliary coil antennas is not limited to one and may be plural.

<< Twelfth Embodiment >>
In the twelfth embodiment, an electronic apparatus further including a feeding coil will be described.

FIG. 19A is a plan view showing the main part of an electronic device 212 according to the twelfth embodiment, and FIG. 19B is a cross-sectional view taken along line MM in FIG. 19A. In FIG. 19A, the resin casing 71 is not shown.

The electronic device 212 is different from the electronic device 209 according to the ninth embodiment in that it includes a power supply coil 82. Other configurations are substantially the same as those of the electronic device 209.

The electronic device 212 includes a resin casing 71, a second planar conductor 22A, a circuit board 10, an RFIC 51, a reactance element 52, a feeding coil 82, and the like. The power supply coil 82 is, for example, a multilayer chip coil.

The antenna device according to the present embodiment includes a first planar conductor 21, a first coil conductor 31, a second coil conductor 32, a second planar conductor 22A, a plurality of fourth coil conductors 34A and 34B, and a connection pin 6. Is done.

Conductor patterns 44, 45, and 46 are formed on the first main surface VS1 of the circuit board 10. The reactance element 53 is mounted on the first main surface VS1 of the circuit board 10. As shown in FIG. 19A, the first end (the other end of the first coil conductor 31) and the second end (the other end of the fourth coil conductor 34B) of the coil antenna according to the present embodiment are arranged on the conductor pattern 44. And are connected to each other through the reactance element 53 and the like. In the present embodiment, an LC resonance circuit is configured by the coil antenna and the capacitive component of the reactance element 53.

The RFIC 51 is mounted on the first main surface VS1 of the circuit board 10 and connected to one end of the conductor patterns 45 and 46, respectively. The reactance element 52 is mounted on the first main surface VS1 of the circuit board 10 and connected to the conductor patterns 45 and 46, respectively. The feeding coil 82 is mounted on the first main surface VS1 of the circuit board 10 and connected to the other ends of the conductor patterns 45 and 46, respectively. In this embodiment, it arrange | positions so that the winding axis | shaft of the feeding coil 82 may face the coil opening of a coil antenna. Therefore, the feeding coil 82 is connected to the coil antenna according to the present embodiment by magnetic field coupling (see the magnetic flux φ10 in FIG. 19B).

This configuration makes it possible to connect the coil antenna and the feeding circuit (RFIC 51) regardless of the balance / unbalance.

In the present embodiment, the configuration in which the feeding coil 82 is magnetically coupled to the coil antenna according to the present embodiment has been described. However, the present invention is not limited to this configuration. The power supply coil 82 may not only be magnetically coupled to the coil antenna, but may also be configured to contribute to coupling with the coil antenna on the communication partner side, like the auxiliary coil antenna 81 shown in the eleventh embodiment. That is, the antenna device may be configured including the power supply coil 82 according to the present embodiment.

On the contrary, when the feeding coil 82 does not contribute to the coupling with the coil antenna on the communication partner side, that is, when the feeding coil 82 is coupled only with the coil antenna like a transformer, design such as impedance matching is easy. Become. Impedance conversion can be performed by adjusting the winding ratio and effective magnetic permeability of the coupling portion between the feeding coil 82 and the coil antenna, thereby achieving impedance matching. Further, by suppressing the winding ratio and effective permeability so as to reduce the inductance of the coupling portion between the feeding coil 82 and the coil antenna, the reduction in the coupling coefficient between the coil antenna and the coil antenna on the communication partner side is suppressed. You can also.

<< Thirteenth embodiment >>
In the thirteenth embodiment, an electronic apparatus having a feeding coil with a coupling conductor provided therein will be described.

FIG. 20A is a plan view showing the main part of an electronic device 213 according to the thirteenth embodiment, and FIG. 20B is an NN cross-sectional view in FIG. FIG. 21 is a plan view of the circuit board 10 included in the electronic device 213 according to the thirteenth embodiment. In FIG. 20A, the resin casing 71 is not shown.

The electronic device 213 is different from the electronic device 212 according to the twelfth embodiment in that it includes a feeding coil 83. Other configurations are substantially the same as those of the electronic device 212.

The electronic device 213 includes a resin casing 71, a second planar conductor 22A, a circuit board 10, an RFIC 51, a reactance element 52, a feeding coil 83, and the like.

Conductor patterns 47A and 47B are further formed on the first main surface VS1 of the circuit board 10, and a first coil conductor 31 and fourth coil conductors 34A, 34B and 34C are formed inside the circuit board 10. . The conductor pattern 47A is connected to one end of the fourth coil conductor 34B, and the conductor pattern 47B is connected to one end of the fourth coil conductor 34C.

The power supply coil 83 according to the present embodiment has a coupling conductor 48. The coupling conductor 48 is a conductor disposed near the mounting surface inside the power supply coil 83. By mounting the power feeding coil 83 on the first main surface VS1 of the circuit board 10, the coupling conductor 48 is connected to the conductor patterns 47A and 47B, respectively.

The first coil conductor 31, the second coil conductor 32, the plurality of fourth coil conductors 34A, 34B, 34C, the coupling conductor 48, the connection pin 6, and the like constitute a coil antenna. That is, in this embodiment, a part of the coil antenna (coupling conductor 48) is formed inside the feeding coil 83.

The antenna device according to this embodiment includes a first planar conductor 21, a first coil conductor 31, a second coil conductor 32, a second planar conductor 22A, a plurality of fourth coil conductors 34A, 34B, and 34C, and a feeding coil 83. (Including the coupling conductor 48) and the connection pin 6.

In this configuration, since the distance between the coil conductor 49 of the feeding coil 83 and a part of the coil antenna (coupling conductor 48) is short, the coil conductor 49 of the feeding coil 83 and the coupling conductor 48 generate an electric field and a magnetic field. To join through. Therefore, the coupling between the coil conductor of the feeding coil 83 and the coil antenna can be strengthened.

<< Other Embodiments >>
In each of the embodiments described above, the example in which the planar shapes of the first planar conductor and the second planar conductor are rectangular has been described, but the present invention is not limited to this configuration. The planar shapes of the first planar conductor and the second planar conductor can be changed as appropriate within the scope of the operations and effects of the present invention. The first planar conductor and the second planar conductor may have a three-dimensional structure.

Moreover, in each embodiment shown above, although the example of the antenna apparatus provided with one 1st coil conductor 31 and one 2nd coil conductor 32 was shown, it is not limited to this structure. The number of the first coil conductors 31 and the second coil conductors 32 may be plural.

In each of the embodiments described above, an example in which the coil antenna has a rectangular helical shape of about 3 turns has been described. However, the present invention is not limited to this configuration. The outer shape of the coil antenna can be changed as appropriate within the range where the functions and effects of the present invention are exhibited. For example, the outer shape of the coil antenna may be circular, elliptical, polygonal or the like. The number of turns of the coil antenna can be changed as appropriate.

Finally, the description of the above embodiment is illustrative in all respects and not restrictive. Modifications and changes can be made as appropriate by those skilled in the art. The scope of the present invention is shown not by the above embodiments but by the claims. Furthermore, the scope of the present invention includes modifications from the embodiments within the scope equivalent to the claims.

CP: Coil opening E1 in plan view of the first planar conductor E1 First end E2 of coil antenna Second end S1 of coil antenna First surface S2 Second surface VS1 First main surface VS2 First 2 main surface 1, 1A ... base material 2 ... protective film 2A ... protective layer 2A ... protective film 4 ... magnetic body 5 ... through hole 6 ... connection pins 7, 8 ... interlayer connection conductors 10, 10A ... circuit boards 21, 21A, 21B ... 1st planar conductor 22, 22A, 22B, 22C ... 2nd planar conductor 30A, 30B, 30C, 30D, 30E ... Other coil conductors 31, 31A, 31B ... 1st coil conductor 32 ... 2nd coil conductor 33A, 33B, 33C, 33D ... third coil conductors 34A, 34B, 34C, 34D ... fourth coil conductor 41 ... routing conductors 42A, 42B, 43, 44, 45, 46, 47A, 47B ... conductor pattern 48 ... for coupling Conductor 49 ... Coil conductor 51 ... RFIC electrodeposition coil (feed circuit)
52, 53 ... Reactance element 61 ... Main antenna 71 ... Resin casing 81 ... Auxiliary coil antenna 82, 83 ... Feed coil 101 ... Antenna devices 202, 203A, 203B, 204, 205, 206, 207, 208, 209, 210 , 211, 212, 213... Electronic equipment

Claims (13)

1. A first planar conductor having a main surface;
   A coil antenna including at least a first coil conductor and a second coil conductor, and being wound a plurality of times to form a coil opening;
   With
   The first coil conductor is continuous with the first planar conductor,
   The first coil conductor and the second coil conductor are different from each other in the position in the direction perpendicular to the main surface of the first planar conductor,
   The first coil conductor and the second coil conductor are arranged to face each other with the coil opening sandwiched in a first direction in a plan view of the first planar conductor,
   The antenna device, wherein an area of the first planar conductor is larger than an area of the coil opening when the first planar conductor is viewed in plan.
2. The said 1st planar conductor is arrange | positioned on the opposite side to the said 2nd coil conductor with respect to the said 1st coil conductor in the said 1st direction by planar view of the said 1st planar conductor. The antenna device described.
3. 3. The first planar conductor according to claim 1, wherein a length of the first planar conductor in a second direction orthogonal to the first direction is longer than that of the coil antenna in a plan view of the first planar conductor. Antenna device.
4. The coil antenna includes a third coil conductor whose position in a direction perpendicular to the main surface of the first planar conductor is different from that of the first planar conductor;
   The first planar conductor does not overlap the entire coil opening in a plan view of the first planar conductor, and at least a part of the first coil conductor in the first direction is the third coil conductor. The antenna device according to claim 1, wherein the antenna device overlaps a portion disposed between a coil conductor and the coil opening.
5. A second planar conductor;
   The second planar conductor has a larger area than the coil opening in a plan view of the second planar conductor, and is disposed on the opposite side to the first coil conductor with respect to the second coil conductor.
   The antenna device according to any one of claims 1 to 4, wherein the second coil conductor is continuous with the second planar conductor.
6. The antenna device according to claim 5, wherein the second planar conductor has a length in a second direction orthogonal to the first direction longer than that of the coil antenna in a plan view of the second planar conductor. .
7. The coil antenna includes a fourth coil conductor that is different from the second planar conductor in a position in a direction perpendicular to the main surface of the first planar conductor,
   The second planar conductor does not overlap the entire coil opening in a plan view of the second planar conductor, and at least a part of the second coil conductor in the first direction is the fourth coil conductor. The antenna device according to claim 5, wherein the antenna device overlaps a portion disposed between a coil conductor and the coil opening.
8. The antenna device according to claim 7, wherein the second planar conductor overlaps the entire fourth coil conductor in a plan view of the second planar conductor.
9. The antenna device according to any one of claims 5 to 8, wherein the second planar conductor is bent or curved.
10. The antenna device according to any one of claims 1 to 9, wherein the first planar conductor is a conductor pattern formed on a circuit board provided in an electronic device to be assembled.
11. The antenna device according to any one of claims 1 to 10, wherein the second planar conductor is a conductor formed on a part of a housing provided in an electronic device to be assembled or an inner surface of the housing.
12. The antenna device according to any one of claims 1 to 11, wherein a magnetic body is disposed in the coil opening of the coil antenna.
13. An antenna device;
    A feeding circuit;
    With
    The antenna device is
    A first planar conductor having a main surface;
    A coil antenna including at least a first coil conductor and a second coil conductor, and being wound a plurality of times to form a coil opening;
    Have
    The first coil conductor is continuous with the first planar conductor;
    The first coil conductor and the second coil conductor are different from each other in the position in the direction perpendicular to the main surface of the first planar conductor,
    The first coil conductor and the second coil conductor are disposed opposite to each other with the coil opening sandwiched with respect to a first direction in a plan view of the first planar conductor,
    The first planar conductor is larger than the area of the coil opening when the first planar conductor is viewed in plan,
    The electronic device, wherein the power feeding circuit is connected to the coil antenna.

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