JP2016165155A - Antenna device and portable electronic apparatus using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna device capable of extending a communication range of an antenna coil even when an opening is not provided in a conductor layer.SOLUTION: An antenna device 1 includes: a first metal member 11a having a first main surface; a second metal member 11b having a second main surface parallel to the first main surface; and an antenna coil 21 having a coil axis perpendicular to the first and second main surfaces. The first metal member 11a constitutes at least a part of a housing of a portable electronic apparatus 10 in which the antenna coil 21 is mounted, and a slit SL1 is formed between the first metal member 11a and the second metal member 11b. An inner diameter part 21a of the antenna coil 21 overlaps the slit SL1 in a plan view, and the slit SL1 has fixed width at least in a region overlapping the antenna coil 21 in a plan view.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an antenna device, and more particularly to an antenna device suitable for NFC (Near Field Communication). The present invention also relates to a portable electronic device in which such an antenna device is mounted.

  In recent years, RFID (Radio Frequency Identification) systems are installed in portable electronic devices such as smartphones, and antennas for short-range wireless communication with readers / writers and the like are installed as communication means. ing.

  On the other hand, in order to protect the built-in circuit from external noise and prevent unnecessary radiation of noise generated in the device, the portable electronic device is provided with a metal shield. Recently, considering the reduction in thickness, weight, durability against impacts such as dropping, and design, the case of portable electronic devices has been changed from resin to metal, and the number of cases that also serve as a metal shield has increased. Yes. However, since a metal shield generally prevents radio waves, when an antenna is provided, it is necessary to provide it at a position that does not overlap with the metal shield. When the metal shield is provided over a wide range, the arrangement of the antenna becomes a problem.

  In order to solve the above problem, for example, the antenna devices disclosed in Patent Documents 1 to 3 form an opening in the conductor layer and a slit connecting the opening and the outer edge, and the inner diameter portion is open. The antenna coil is arranged so as to overlap the part. According to this antenna device, the current flows in the conductor layer so as to block the magnetic field generated by the current flowing in the coil conductor, and passes through the periphery of the slit flowing around the opening of the conductor layer, and the conductor is caused by the edge effect. Current also flows around the layer. Thereby, a magnetic field is also generated from the conductor layer, and the conductor layer largely circulates the magnetic flux, so that the communication distance between the antenna device and the counterpart antenna can be increased. That is, the conductor layer can function as an accelerator that increases the communication distance of the antenna coil.

Japanese Patent No. 4687832 JP 2002-111363 A JP 2013-162195 A

  However, the conventional antenna device described above has a problem in that it is necessary to form an opening and a slit in the conductor layer, which is a limitation in laying out the antenna coil. For example, when the opening cannot be formed at a desired position due to design restrictions, or when the opening can be formed but the slit is not allowed, the antenna device is configured. There is a problem that can not be. The same problem occurs when the opening for exposing the lens of the camera module cannot be used as the opening of the antenna coil.

  Accordingly, an object of the present invention is to provide an antenna device capable of extending the communication distance of an antenna coil even when an opening is not provided in a conductor layer provided in a portable electronic device. It is another object of the present invention to provide a high-performance portable electronic device configured using such an antenna device.

  In order to solve the above problems, an antenna device according to the present invention includes a first metal member having a first main surface, and a second metal member having a second main surface parallel to the first main surface. An antenna coil having a coil axis perpendicular to the first and second main surfaces, and the first metal member constitutes at least a part of a casing of a portable electronic device on which the antenna coil is mounted. And at least one slit is formed between the first metal member and the second metal member, and an inner diameter portion of the antenna coil overlaps the slit in a plan view. The slit has a constant width at least in a region overlapping the antenna coil in plan view.

  A portable electronic device according to the present invention includes a housing, a circuit board provided in the housing, and an antenna device provided in the housing together with the circuit board. A first metal member having a main surface; a second metal member having a second main surface parallel to the first main surface; and a coil axis perpendicular to the first and second main surfaces. An antenna coil, wherein the first metal member constitutes at least a part of the housing, and at least one piece is provided between the first metal member and the second metal member. A slit is formed, and an inner diameter portion of the antenna coil overlaps with the slit in a plan view, and the slit has a constant width at least in a region overlapping with the antenna coil in a plan view. To do.

  In the conventional antenna device, it is necessary to pre-form an opening of approximately the same size as the inner diameter of the antenna coil in the metal layer on the portable electronic device side, and place the antenna coil at the position where the opening is formed. There was a big restriction. However, the antenna device according to the present invention is provided with only an extremely narrow slit compared to the inner diameter portion of the antenna coil without providing an opening, and the antenna coil is provided so that the inner diameter portion overlaps with the slit extending in one direction. Therefore, the antenna coil can be placed at an arbitrary position in the slit extending direction, and the degree of freedom in layout of the antenna coil can be increased.

  In the present invention, it is preferable that an inner diameter portion of the antenna coil has a portion overlapping the first and second metal members in plan view. The area of the inner diameter portion of the antenna coil that does not overlap with the metal member is smaller than that of the conventional antenna device in which the opening is formed in the metal layer, but this does not cause a problem and is equivalent to the conventional antenna device. Antenna characteristics can be obtained.

  In the present invention, it is preferable that a plurality of the slits are provided, and it is particularly preferable that two slits are provided. In this case, in the antenna device according to the present invention, the first metal member and the second metal member are formed such that two slits are formed between the first metal member and the second metal member. It is preferable that a third metal member provided between the antenna coil and the inner diameter portion of the antenna coil overlap the first and second slits in plan view. When two slits are provided between the first and second metal members, the communication distance of the antenna coil can be further increased as compared with the case where one slit is provided.

  The antenna device according to the present invention preferably further includes a magnetic sheet positioned farther from the antenna coil as viewed from the first metal member and fixed to the antenna coil. According to this configuration, the inductance of the antenna coil can be increased, and the communication distance of the antenna coil can be increased.

  In the present invention, it is preferable that the second metal member constitutes a part of the housing together with the first metal member. According to this configuration, the antenna device can be configured using the casing of the portable electronic device, and thereby the communication distance of the antenna coil can be increased.

  The antenna device according to the present invention preferably includes a cover made of an insulating resin, and the first and second metal members are made of a metal film formed on the surface of the cover. According to this configuration, the antenna device can be configured using the metal film that is a part of the casing of the portable electronic device, and thereby the communication distance of the antenna coil can be increased.

  ADVANTAGE OF THE INVENTION According to this invention, even when the opening part is not provided in a conductor layer, the antenna apparatus which can extend the communication distance of an antenna coil can be provided. Further, according to the present invention, a high-performance portable electronic device configured using such an antenna device can be provided.

1A and 1B are diagrams showing a configuration of a portable electronic device including an antenna device according to a first embodiment of the present invention, wherein FIG. 1A is a schematic front sectional view and FIG. 1B is a schematic side sectional view. FIG. 2 is a schematic plan view for explaining the action of the cover 11 on the antenna coil 21. FIG. 3 is a schematic cross-sectional view for explaining the action of the cover 11 on the antenna coil 21. 4A and 4B are schematic plan views showing a layout example of the antenna coil 21. FIG. 5A and 5B are diagrams showing a configuration of an antenna device according to the second embodiment of the present invention, in which FIGS. 5A and 5B are schematic front views, and FIG. 5C is a schematic side sectional view. 6A and 6B are diagrams showing a configuration of an antenna device according to a third embodiment of the present invention, in which FIGS. 6A and 6B are schematic front views, and FIG. 6C is a schematic side sectional view. 7A and 7B are diagrams showing a configuration of a portable electronic device including an antenna device according to a fourth embodiment of the present invention, where FIG. 7A is a schematic front sectional view and FIG. 7B is a schematic side sectional view. FIG. 8 is a diagram showing a configuration of a portable electronic device including an antenna device according to a fifth embodiment of the present invention, in which (a) is a schematic front sectional view and (b) is a schematic side sectional view. FIG. 9 is a schematic side sectional view showing the configuration of the antenna device according to the sixth embodiment of the present invention. FIGS. 10A to 10C are schematic plan views showing the configuration of the antenna device according to the seventh embodiment of the present invention, and are particularly diagrams showing variations in the shape of the slit.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  1A and 1B are diagrams showing a configuration of a portable electronic device including an antenna device according to a first embodiment of the present invention, wherein FIG. 1A is a schematic front sectional view and FIG. 1B is a schematic side sectional view.

  As shown in FIGS. 1A and 1B, the antenna device 1 includes an antenna having a metal cover 11 constituting a casing of a portable electronic device 10 and a coil axis perpendicular to the main surface of the cover 11. And a coil 21. Although not particularly limited, the mobile electronic device 10 may be a smartphone.

  The external shape of the portable electronic device 10 is a thin rectangular parallelepiped, and the main circuit board 30 and the battery pack 31 are built therein. A display 32 is provided on one main surface (front surface) of the portable electronic device 10, and a resin frame 14 is provided on the outer periphery of the display 32. Although not particularly limited, the antenna coil 21 is provided on one end side (upper part) in the longitudinal direction (Y direction) of the portable electronic device 10 together with the main circuit board 30, and the battery pack 31 is provided on the other end side (lower part). ing.

  The cover 11 constitutes the other main surface (back surface) and four side surfaces of the portable electronic device 10. The reason for using a metal for the material of the cover 11 is to reduce the thickness and weight while improving the rigidity and the magnetic shielding property. The cover 11 has an opening AP, and the camera 33 is provided so as to be exposed from the opening AP.

  The cover 11 is formed with one slit SL1 independent of the opening AP, and the slit SL1 is located on one end side in the longitudinal direction of the portable electronic device 10. Insulating resin is provided in the slit SL1, and this insulating resin constitutes a part of the housing together with the cover 11. The slit SL1 extends in the width direction (X direction) of the cover 11 to divide the cover 11, whereby the cover 11 is divided into a first metal member 11a and a second metal member 11b. The first metal member 11a and the second metal member 11b are electrically insulated. The main surface (second main surface) of the second metal member 11 b is flush with the main surface (first main surface) of the first metal member 11 a and forms the back surface of the portable electronic device 10.

  The antenna coil 21 is a planar antenna made of a rectangular spiral conductor, and is formed on the main surface of the flexible substrate 22. The antenna coil 21 is covered with an insulating film 23, and a magnetic sheet 24 is provided on the back surface of the flexible substrate 22. The flexible substrate 22 and the magnetic material sheet 24 are located farther than the antenna coil 21 when viewed from the cover 11. The magnetic sheet 24 constitutes a magnetic path of magnetic flux generated from the antenna coil 21.

  The antenna coil 21 is disposed near the boundary between the first metal member 11a and the second metal member 11b, and the lower half of the antenna coil 21 overlaps the first metal member 11a in plan view. ing. On the other hand, the upper half of the antenna coil 21 does not overlap with the first metal member 11a in plan view, but overlaps with the second metal member 11b. A slit SL1 having a constant width extending in the width direction of the portable electronic device 10 is formed between the first metal member 11a and the second metal member 11b. The central region in the vertical direction of the antenna coil 21 is a region that does not overlap with either the first metal member 11a or the second metal member 11b.

  The method for fixing the antenna coil 21 is not particularly limited, and may be fixed to the main circuit board 30 side or to the cover 11 side. When the battery pack 31 is provided at a position overlapping the antenna coil 21, the antenna coil 21 can be fixed on the battery pack 31. The antenna coil 21 on the flexible substrate 22 faces the outside, but may be provided so as to face the inside.

  Although not shown, both ends of the antenna coil 21 are connected to corresponding connectors on the main circuit board 30. The connection method is not particularly limited. For example, the main circuit board 30 and the antenna coil 21 may be connected via a lead conductor formed on the lead portion of the flexible board 22. Or it is also possible to connect using a feed pin.

  The width W of the slit SL1 is narrower than the width of the inner diameter portion 21a of the antenna coil 21, and the slit SL1 crosses the inner diameter portion of the antenna coil 21. That is, the antenna coil 21 is laid out so that the inner diameter portion thereof overlaps the slit SL1 in plan view. The portion of the antenna coil 21 that is substantially parallel to the slit SL1 preferably overlaps the first metal member 11a and the second metal member 11b.

  The slit SL1 is preferably a straight slit having a constant width from one end to the other end in the width direction (X direction) of the cover 11, but it is not necessarily required to have a constant width over the entire length, and at least the antenna coil 21 mounting region and the plane. It is sufficient that the width is constant in the overlapping region.

  2 and 3 are views for explaining the operation of the cover 11 with respect to the antenna coil 21. FIG. 2 is a schematic plan view, and FIG. 3 is a schematic cross-sectional view.

  As shown in FIGS. 2 and 3, when a counterclockwise current Ia flows through the antenna coil 21, a magnetic flux φ penetrating the inner diameter portion of the antenna coil 21 is generated, and this magnetic flux φ passes through the slit SL1 to cover the antenna coil 21. Interlink with 11 On the other hand, a current generated by the magnetic flux in a direction to cancel the magnetic flux flows through the cover 11, and this current is caused by the edge effect and the eddy current Ib along the periphery of the first and second metal members 11a and 11b. Become. The direction of the eddy current Ib is counterclockwise in the same manner as the current Ia flowing through the antenna coil 21.

  Here, since the magnetic flux φ that has passed through the slit SL1 does not pass through the cover 11, the magnetic flux φ attempts to detour through a path having the slit SL1 of the cover 11 as the inner side and the outer edge of the cover 11 as the outer side. As a result, the magnetic flux φ draws a relatively large loop and is linked to, for example, an antenna coil (not shown) of the reader / writer. That is, the antenna device 1 is magnetically coupled to the communication partner antenna. In particular, since the area of the cover 11 is larger than the area of the antenna coil 21, a large loop magnetic field can be generated. Further, since the magnetic sheet 24 is provided farther from the antenna coil 21 when viewed from the outside of the cover 11, the inductance of the antenna coil 21 can be increased, thereby improving the antenna characteristics. .

  4A and 4B are schematic plan views showing a layout example of the antenna coil 21. FIG.

  As shown in FIG. 4A, the antenna coil 21 is offset at the right end in the width direction, and the opening AP for exposing the camera 33 is located at the center in the width direction. The opening AP and the slit SL1 are independent of each other without being connected. According to this configuration, the antenna coil 21 can be separated from the camera 33 while the camera 33 is arranged in the center, and a margin can be given to the layout of the antenna coil 21. That is, the antenna coil 21 can be freely laid out without being restricted by the position of the opening AP.

  As shown in FIG. 4B, the antenna coil 21 is offset at the right end in the width direction, and the opening AP for exposing the camera 33 is offset at the left end in the width direction. Yes. The opening AP and the slit SL1 are independent of each other without being connected. According to this configuration, the antenna coil 21 can be further separated from the camera 33, and a margin can be given to the layout of the antenna coil 21.

  As described above, in the antenna device 1 according to the present embodiment, since the cover 11 circulates the magnetic flux of the antenna coil 21 greatly, the communication distance from the antenna device to the communication partner antenna can be increased. Further, the antenna coil 21 is provided at a position overlapping the slit SL1 of the cover 11 in plan view, and in particular, since the slit SL1 passes through the inner diameter portion 21a of the antenna coil 21, any position in the extending direction of the slit SL1. It is possible to arrange the antenna coil 21 on the antenna, and the degree of freedom of layout of the antenna coil 21 can be increased.

  5A and 5B are diagrams showing a configuration of an antenna device according to the second embodiment of the present invention, in which FIGS. 5A and 5B are schematic front views, and FIG. 5C is a schematic side sectional view.

  As shown in FIGS. 5A to 5C, the antenna device 2 is characterized in that two slits SL <b> 1 and SL <b> 2 are formed in the cover 11. Other configurations are the same as those of the first embodiment. Although not particularly limited, the widths W1 and W2 of the two slits SL1 and SL2 are preferably the same.

  In order to form the two slits SL1, SL2, a third metal member 11c is provided between the first metal member 11a and the second metal member 11b. The third metal member 11c has an elongated linear shape parallel to the slits SL1 and SL2. The width of the third metal member 11c is preferably wider than the widths of the slits SL1 and SL2. However, if the width is too large, the slits SL1 and SL2 cannot be accommodated in the inner diameter portion of the antenna coil 21. There is a need to. The width W0 from the slit SL1 to the slit SL2 needs to be narrower than the inner diameter portion 21a of the antenna coil 21.

  The slit SL1 extends in the width direction (X direction) of the cover 11 to divide the cover 11, and the cover 11 is divided into a first metal member 11a and a third metal member 11c. Further, the slit SL2 extends in the width direction of the cover 11 to divide the cover 11, and thus the cover 11 is divided into a second metal member 11b and a third metal member 11c. The first to third metal members 11a to 11c are electrically insulated from each other.

  The antenna device 2 according to the present embodiment can achieve an effect equal to or greater than that of the antenna device 1 according to the first embodiment. That is, since the cover 11 circulates the magnetic flux of the antenna coil 21 greatly, the communication distance from the antenna device to the communication partner antenna can be extended. In particular, when two slits are provided, the communication distance of the antenna coil can be further increased as compared with the case where one slit is provided. The antenna coil 21 is provided at a position overlapping the slits SL1 and SL2 of the cover 11 in plan view, and in particular, since the slits SL1 and SL2 pass through the inner diameter portion 21a of the antenna coil 21, the extension of the slits SL1 and SL2 is increased. The antenna coil 21 can be disposed at an arbitrary position in the current direction, and the degree of freedom in layout of the antenna coil 21 can be increased.

  6A and 6B are diagrams showing a configuration of an antenna device according to a third embodiment of the present invention, in which FIGS. 6A and 6B are schematic front views, and FIG. 6C is a schematic side sectional view.

  As shown in FIGS. 6A to 6C, the antenna device 3 is characterized in that the cover 11 has three slits SL1, SL2, and SL3. Other configurations are the same as those of the first embodiment. Although not particularly limited, it is preferable that the widths W1, W2, and W3 of the three slits SL1, SL2, and SL3 are the same.

  In order to form the three slits SL1, SL2 and SL3, third and fourth metal members 11c and 11d are provided between the first metal member 11a and the second metal member 11b. The third and fourth metal members 11c, 11d have an elongated linear shape parallel to the slits SL1, SL2, SL3. The widths of the third and fourth metal members 11c and 11d are preferably wider than the widths of the slits SL1, SL2, and SL3. However, if the width is too wide, both the slits SL1 and SL2 may be accommodated in the inner diameter portion of the antenna coil 21. Since it is not possible, it is necessary to set to an appropriate width. The width W0 from the slit SL1 to the slit SL2 needs to be narrower than the inner diameter portion of the antenna coil 21.

  The slit SL1 extends in the width direction of the cover 11 to divide the cover 11, whereby the cover 11 is divided into a first metal member 11a and a third metal member 11c. Further, the slit SL2 extends in the width direction of the cover 11 to divide the cover 11, whereby the cover 11 is divided into a third metal member 11c and a fourth metal member 11d. Further, the slit SL3 extends in the width direction of the cover 11 to divide the cover 11, so that the cover 11 is divided into a fourth metal member 11d and a second metal member 11b. The first to third metal members 11a to 11c are electrically insulated from each other.

  The antenna device 3 according to the present embodiment can achieve the same effects as the antenna device 1 according to the first embodiment. That is, since the cover 11 circulates the magnetic flux of the antenna coil 21 greatly, the communication distance from the antenna device to the antenna coil on the communication partner side can be extended. Further, the antenna coil 21 is provided at a position overlapping the slits SL1 to SL3 of the cover 11 in plan view, and in particular, since the slits SL1 to SL3 pass through the inner diameter portion 21a of the antenna coil 21, the extension of the slits SL1 to SL3. The antenna coil 21 can be disposed at an arbitrary position in the current direction, and the degree of freedom in layout of the antenna coil 21 can be increased.

  7A and 7B are diagrams showing a configuration of a portable electronic device including an antenna device according to a fourth embodiment of the present invention, where FIG. 7A is a schematic front sectional view and FIG. 7B is a schematic side sectional view.

  As shown in FIGS. 7A and 7B, the antenna device 4 is characterized in that the cover 11 is made of an insulating resin and the metal film 13 is formed on the back surface of the cover 11. The cover 11 includes a main surface (back surface) opposite to the portable electronic device 10 and four side surfaces, and the metal film 13 covers most of the main surface of the cover 11 in a wide range. Such a metal film 13 is substantially a part of the housing.

  An opening AP is formed in the cover 11 and the metal film 13, and the camera 33 is provided so as to be exposed from the opening AP. In addition, one slit SL1 independent of the opening AP is formed in the metal film 13, and the slit SL1 is located on one end side in the longitudinal direction of the portable electronic device 10. The slit SL1 extends in the width direction (X direction) of the metal film 13 to divide the metal film 13, so that the metal film 13 is divided into a first metal member 13a and a second metal member 13b. . The first metal member 13a and the second metal member 13b are electrically insulated. The main surface (second main surface) of the second metal member 13 b is flush with the main surface (first main surface) of the first metal member 11 a and is parallel to the back surface of the portable electronic device 10.

  The antenna device 4 according to the present embodiment can achieve the same effects as the antenna device 1 according to the first embodiment. That is, since the metal film 13 greatly circulates the magnetic flux of the antenna coil 21, the communication distance from the antenna device to the communication partner antenna can be increased. The antenna coil 21 is provided at a position overlapping the slit SL1 of the metal film 13 in plan view. In particular, since the slit SL1 passes through the inner diameter portion 21a of the antenna coil 21, any extension direction of the slit SL1 is provided. The antenna coil 21 can be disposed at a position, and the degree of freedom in layout of the antenna coil 21 can be increased.

  FIG. 8 is a diagram showing a configuration of a portable electronic device including an antenna device according to a fifth embodiment of the present invention, in which (a) is a schematic front sectional view and (b) is a schematic side sectional view.

  As shown in FIGS. 8A and 8B, the antenna device 5 is characterized in that a metal film 13 is formed on the back surface of a cover 11 made of an insulating resin, and is further fixed to an antenna coil 21. Is in the point provided. The slit SL1 is formed by combining the metal film (first metal member) 13 on the cover 11 side and the metal sheet (second metal member) 12 on the antenna coil 21 side. The main surface (second main surface) of the metal sheet 12 is parallel to the main surface (first main surface) of the metal film 13. Other configurations are the same as those of the fourth embodiment.

  The antenna device 5 according to the present embodiment can achieve the same effects as the antenna device 1 according to the first embodiment. That is, since the metal film 13 and the metal sheet 12 circulate the magnetic flux of the antenna coil 21 greatly, the communication distance from the antenna device to the communication partner antenna can be increased. The antenna coil 21 is provided at a position overlapping the slit SL1 between the metal film 13 and the metal sheet 12 in plan view. In particular, since the slit SL1 passes through the inner diameter portion 21a of the antenna coil 21, the slit SL1 is provided. It is possible to arrange the antenna coil 21 at an arbitrary position in the extending direction of the antenna coil 21 and to increase the degree of freedom of the layout of the antenna coil 21. In addition, since it is not necessary to provide the slit SL1 in the housing itself, the degree of freedom in designing the housing can be increased.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. Needless to say, it is included in the range.

  For example, in the above embodiment, a planar coil is used as the antenna coil. However, the present invention is not limited to the planar coil, and for example, a winding type antenna coil 25 as shown in FIG. 9 may be used. Further, in the above embodiment, a perfectly straight straight slit is taken as an example. However, the present invention is not limited to this, and may have a bent pattern as shown in FIG. It may have a comb pattern as shown in FIG. 10B, or may have a waveform pattern as shown in FIG. Further, in the above embodiment, the antenna coil faces the outside as viewed from the flexible substrate, but may be mounted so as to face the inside. Furthermore, it is possible to configure each embodiment in combination.

  In the above embodiment, the main circuit board is provided at a position overlapping the antenna coil in plan view. However, a battery pack may be provided at a position overlapping the antenna coil in plan view.

1 to 5 Antenna device 10 Portable electronic device 11 Cover 11a First metal member 11b Second metal member 11c Third metal member 11d Fourth metal member 12 Metal sheet 13 Metal film 13a First metal member 13b Second Metal member 14 Resin frame 21 Antenna coil 21a Inner diameter portion 22 of antenna coil Flexible substrate 23 Insulating film 24 Magnetic sheet 25 Antenna coil 30 Main circuit board 31 Battery pack 32 Display 33 Camera AP Opening Ia Current Ib Eddy current SL1, SL2 , SL3 slit φ magnetic flux

Claims (6)

A first metal member having a first main surface;
A second metal member having a second main surface parallel to the first main surface and separated from the first metal member by at least one slit;
A substrate having a third major surface parallel to the first and second major surfaces;
An antenna coil made of a spiral conductor provided on the third main surface of the substrate,
The inner diameter portion of the antenna coil overlaps the slit in plan view,
The antenna device according to claim 1, wherein the slit has a constant width at least in a region overlapping with the antenna coil in plan view.   The said board | substrate further has the 4th main surface located in the other side of the said 3rd main surface, The said 4th main surface is provided with the magnetic body, The said 1st feature is characterized by the above-mentioned. The antenna device described.   The antenna device according to claim 1, wherein an insulating film that covers the spiral conductor is provided on the third main surface of the substrate.   The antenna device according to claim 1, wherein an insulating resin is provided in the slit.   5. The device according to claim 1, wherein at least one of the first metal member and the second metal member constitutes a part of a casing of a portable electronic device in which the antenna coil is mounted. The antenna device according to 1.   A portable electronic device comprising: the antenna device according to any one of claims 1 to 5; and a housing that houses the antenna device.

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