JP2013162195A - Antenna device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna device that can increase a communication possible angular range and distance.SOLUTION: An RFID antenna 1 comprises: a booster antenna 3; and a power supply coil 2 formed by winding a coil conductor 21. The booster antenna 3 includes: an opening part 312 larger than the power supply coil 2 viewed from its thickness direction and passing through in the thickness direction; a slit 311 extending from a front end H to the opening part 312; and a slit 313 connected to the opening part 312. About the power supply coil 2, at least part of the coil opening part of the coil conductor 21 overlaps with the opening part 312 viewed from the thickness direction of the booster antenna 3.

Description

  The present invention relates to an antenna device used in an RFID system or a short-range wireless communication system that communicates with a counterpart device via an electromagnetic field signal.

  In recent years, in NFC (Near Field Communication) systems, which have been increasingly used, in order to communicate between portable electronic devices such as mobile phones or between portable electronic devices and reader / writers, a communication coil is provided for each device. Some have an antenna. On the other hand, since portable electronic devices are being miniaturized and enhanced in function, there is not enough space in the enclosure to install an antenna. Therefore, for example, as disclosed in Patent Document 1, a small coil conductor is connected to an RFID IC chip, and a radio signal is transmitted from a large-area conductor layer disposed adjacent to the coil conductor. May be.

  FIG. 12 is a plan view of the antenna device described in Patent Document 1. FIG. The antenna device 100 described in Patent Document 1 includes a conductor layer 101 and a coil conductor 102. The conductor layer 101 includes an opening 101A and a slit 101B that connects the opening 101A and the outer edge. The coil conductor 102 is disposed such that the coil opening 102A overlaps the opening 101A of the conductor layer 101 in plan view. In this configuration, since the magnetic flux generated by the current I flowing through the coil conductor 102 passes through the opening 101B of the conductor layer 101, the current I ′ flows in the opening 101B in the direction opposite to the current I, and due to the edge effect. A current I ′ flows along the edge of the conductor layer 101 through the slit 101A. Thereby, the conductor layer 101 functions as a radiating element (booster antenna) that strengthens the magnetic field of the coil conductor 102. According to this configuration, since the conductor layer 101 may be a thin metal film, for example, the conductor layer can be provided in a slight gap between the printed wiring board and the terminal casing.

International Publication No. 2010/122585 Pamphlet

  FIG. 13 is a cross-sectional view taken along the line AA in FIG. 12 and schematically shows a magnetic field radiated from the antenna device 100. In the antenna device 100 shown in FIGS. 12 and 13, current concentrates on the periphery of the opening 101A formed in the conductor layer 101 and the edge of the slit 101B. Therefore, the current intensity distribution in the region Z1 shown in FIG. 12 is high. A current flows through the edge of the conductor layer 101, but the current density decreases as the distance from the slit 101B increases. Therefore, the current density in the region Z2 shown in FIG. 12 is relatively low. Therefore, the current may circulate without being along all the edges of the conductor layer 101 like the current I ′ shown in FIG. Thereby, the strength of the magnetic field generated in the region where the opening 101A and the slit 101B are formed is high, and the communication sensitivity in the region surrounded by the broken line shown in FIG. 13 is high. In addition, the directivity is directed in the direction in which the opening 101A and the slit 101B are formed, as indicated by arrows in FIG.

  However, communication is performed in a region other than the region where the opening 101A and the slit 101B of the conductor layer 101 are formed, and communication is performed in a direction opposite to the region where the opening 101A and the slit 101B are formed (that is, the region Z2 side). It may also be necessary. In the antenna device 100 shown in FIGS. 12 and 13, it is necessary to point the portable electronic device toward the communication partner in consideration of the high gain range and direction of the antenna, and the portable electronic device is indiscriminately used as a reader / writer. Communication may not be possible even if you hold it over.

  Therefore, an object of the present invention is to provide an antenna device that can improve the communicable angle range and distance.

  An antenna device according to the present invention includes a plate-shaped metal member, and a loop-shaped or spiral coil antenna in which a coil conductor is wound so that a coil opening is formed inside, and the metal member is a flat surface. And having at least one second slit connected to the opening and a first slit that communicates the opening, the first outer edge, and the opening, which is larger than the coil antenna in view. The coil antenna is characterized in that at least a part of a coil opening of the coil conductor overlaps with the opening in a plan view.

  In this configuration, the magnetic field of the coil conductor can be efficiently radiated by the metal member. Further, when the coil conductor and the metal member are magnetically coupled, a current flows along the periphery of the opening of the metal member, the current flows along the first slit and the second slit, and further along the periphery of the metal member. Will begin to flow. The current flowing along the periphery of the metal member is in the same direction as the current flowing in the coil conductor, and the metal member generates a magnetic field in the same direction as the magnetic field from the coil conductor. In this way, the opening is provided with the first slit and the second slit, and at least a part of the coil opening of the coil conductor overlaps the opening in a plan view, so that the metal member amplifies the magnetic field of the coil conductor. It functions as a so-called booster antenna. Furthermore, since the current intensity distribution in the opening, the first slit and the second slit forming region is relatively large, the magnetic field strength in the slit forming direction can be increased, and the communicable angle range and distance can be improved. be able to.

  The second slit includes one extending to a second outer edge different from the first outer edge of the metal member, and the opening is formed in the second outer edge via the second slit. The structure which is connected may be sufficient.

  At least one of the second slits may not reach any end of the metal member.

  In this configuration, it is possible to expand the directivity in the direction of forming the second slit while ensuring the directivity in the direction of formation of the first slit without excessively widening the current intensity distribution to the formation region of the second slit. it can. Moreover, it is not necessary to prepare a plurality of metal members.

The second slit includes a slit having a width different from that of the first slit.
In this configuration, the current intensity distribution in the first slit formation region and the current intensity distribution in the second slit formation region can be set as appropriate, and the degree of freedom in designing directivity increases.

  The antenna device may include a substrate on which a ground conductor pattern is formed and on which the coil antenna is mounted, and the metal member may be all or part of the ground conductor pattern.

  In this configuration, since it is not necessary to provide an independent metal member, an increase in the number of components provided in the antenna device can be suppressed, and space saving and downsizing of the antenna device can be achieved.

  The coil antenna may be housed, and a case may be provided in which all or a part is a metal part, and the metal member may be a metal part of the case.

  In this configuration, since the housing is also used as a metal member, an increase in the number of parts provided in the antenna device can be suppressed, and the space and size of the antenna device can be reduced.

  ADVANTAGE OF THE INVENTION According to this invention, the metal member in which the opening part, the 1st slit, and the 2nd slit were formed can be functioned as a booster antenna, and the magnetic field by a coil conductor can be radiated | emitted efficiently. In addition, since the current intensity distribution in the formation region of the opening, the first slit, and the second slit is relatively large, the communicable angle range and distance can be improved.

Side surface sectional drawing of the communication terminal device provided with the antenna for RFID which concerns on embodiment. (A) is a top view of a feed coil, (B) is a front view of a feed coil. 1 is a perspective view of an RFID antenna according to Embodiment 1. FIG. Sectional drawing in the IV-IV line of FIG. Sectional drawing in the VV line | wire of FIG. The figure which shows the example of the path | route of the electric current which flows into the coil conductor of a feed coil, and a booster antenna. (A) is a figure which shows typically a communication range at the time of forming one slit in a booster antenna, (B) is forming two slits in a booster antenna. The schematic diagram which shows the modification of a booster antenna. The schematic diagram which shows the modification of a booster antenna. The schematic diagram which shows the modification of a booster antenna. The schematic diagram for demonstrating the antenna for RFID which utilizes the ground electrode pattern of a board | substrate as a booster antenna. The top view of the antenna apparatus of patent document 1. FIG. It is sectional drawing of the AA line of FIG. 12, and is a figure which shows typically the magnetic field radiated | emitted from an antenna apparatus.

  In the embodiments described below, an antenna device according to the present invention is described as an RFID antenna, and an electronic device according to the present invention is described as a communication terminal device including an RFID antenna. Examples of the communication terminal device include a mobile phone.

  FIG. 1 is a side cross-sectional view of a communication terminal device including an RFID antenna according to an embodiment. In FIG. 1, the left side of the paper is the front end portion (one end portion of the present invention) H of the communication terminal device 10, the right side of the paper is the other end B where the user holds the communication terminal device 10, and the front end H and the other end B The direction is referred to as the longitudinal direction of the communication terminal device 10. Further, the lower side of the sheet of FIG. 1 is the front side of the communication terminal apparatus 10 provided with the input unit and the display unit, and the upper side of the sheet is the rear side of the communication terminal apparatus 10. The normal direction of the back surface is the 0 ° direction, and the longitudinal direction parallel to the back surface is the 90 ° direction. Therefore, the other end B side from the 0 ° direction is the minus direction.

  The communication terminal device 10 includes a housing 11 made of an insulating resin or the like. A substrate (printed substrate) 12, a battery pack 13, and the like are incorporated in the housing 11. A ground conductor pattern 12G is formed on the inner layer of the substrate 12, and a large number of mounting parts such as a power feeding circuit 121 and a mobile phone antenna 122 are mounted on the front and back surfaces. In the present embodiment, the substrate 12 is mainly composed of two substrates: a substrate on which the cellular phone antenna 122 is mounted and a substrate on which an IC chip constituting the power feeding circuit 121 is mounted. They are electrically connected by a coaxial cable or a strip line cable. The cellular phone antenna 122 is a chip antenna in which a radiation electrode is formed on the outer surface of a dielectric block, and is disposed near the other end B of the housing 11. The mobile phone antenna 122 performs communication using, for example, a 700 MHz band to a 2.7 GHz band. Since metal parts (other electronic devices such as the battery pack 13) are interposed between the cellular phone antenna 122 and the RFID antenna 1 described later, both antennas hardly interfere with each other. The antenna characteristics are ensured.

  An RFID antenna (antenna device of the present invention) 1 is disposed inside the housing 11 on the back side of the communication terminal device 10. The RFID antenna 1 is an antenna for an RFID system using an HF band such as 13.56 MHz. The RFID antenna 1 according to this embodiment is configured to improve the gain in the 0 ° direction, 90 ° direction, 45 ° direction, and −45 ° direction.

  The RFID antenna 1 includes a feeding coil (coil antenna of the present invention) 2 and a booster antenna 3 made of a metal member. The feeding coil 2 is disposed on the distal end H side of the communication terminal device 10 and is connected to a feeding circuit 121 mounted on the substrate 12 by a feeding pin 12A. The booster antenna 3 is disposed between the back surface of the communication terminal device 10 and the power feeding coil 2 and is electromagnetically coupled (mainly magnetic field coupling) to the power feeding coil 2. The feeding coil 2 may be attached to the booster antenna 3 with an adhesive or the like, or may be provided in the vicinity of the booster antenna 3 with a gap.

  FIG. 2A is a bottom view of the feeding coil 2, and FIG. 2B is a front view of the feeding coil 2. The feeding coil 2 includes a rectangular plate-like flexible substrate 23 and a rectangular plate-like magnetic sheet 24. 2A is a bottom view of the feeding coil 2 from which the magnetic sheet 24 is removed. The flexible substrate 23 is formed with a spiral coil conductor 21 having a coil opening portion CW at the winding center and a connection portion 22 used for connection with the power supply circuit 121. The magnetic sheet 24 is, for example, ferrite formed into a sheet shape. The number of turns (number of turns) of the coil conductor 21 is determined by the required inductance. If it is one turn, it will simply be a looped coil conductor.

  FIG. 3 is a perspective view of the RFID antenna 1 according to the first embodiment. 4 is a cross-sectional view taken along line IV-IV in FIG. 5 is a cross-sectional view taken along line VV in FIG. In this embodiment, the booster antenna 3 has a rectangular outer shape that is long in one direction. The booster antenna 3 is larger than the feeding coil 2 when viewed from the thickness direction of the booster antenna 3. As shown in FIG. 1, the booster antenna 3 is arranged such that the longitudinal direction is the longitudinal direction of the communication terminal device 10. The booster antenna 3 includes a linear slit (first slit of the present invention) 311 and a slit (second slit of the present invention) 313 penetrating in the thickness direction, and a rectangular opening 312 penetrating in the thickness direction. Is formed.

  The slit 311 is formed from the distal end portion H of the communication terminal device 10 along the longitudinal direction. The opening 312 communicates with the outside (first outer edge portion of the present invention) on the front end portion H side of the booster antenna 3 through the slit 311. The slit 313 is formed along the longitudinal direction from the other end B of the communication terminal device 10 to the opening 312, and the outer side of the opening 312 and the other end B of the booster antenna 3 (second outer edge of the present invention). Is communicated. The length of the slits 311 and 313 and the size of the opening 312 are not particularly limited. Note that the width of the slit 311 may be the same as the width of the opening 312. The width of the slit 313 is preferably smaller than the width of the opening 312.

  The booster antenna 3 is structurally divided into two by slits 311 and 313 and an opening 312. Hereinafter, one is referred to as a first member 31 and the other is referred to as a second member 32. The slit 313 reaches the other end B and is open at the end, but may not reach the other end B. In this case, the booster antenna 3 has a configuration in which the first member 31 and the second member 32 are connected on the other end B side. In this configuration, the directivity can be expanded in the formation direction of the slit 313 while ensuring the directivity in the formation direction of the slit 311 without excessively widening the current intensity distribution to the formation region of the slit 313.

  The feeding coil 2 is disposed at a position where a part or all of the coil opening CW overlaps the opening 312 in a plan view. When the coil opening CW and the opening 312 have substantially the same size, the coil conductor 21 is disposed substantially coincident with the periphery of the opening 312 in the thickness direction of the booster antenna 3, and is generated from the coil conductor 22. The magnetic field can be passed through the opening 312 efficiently. Therefore, a large current flows through the booster antenna 3, and the booster antenna 3 can efficiently radiate the magnetic field generated by the feeding coil 2.

  The feeding coil 2 is arranged such that the flexible substrate 23 is on the booster antenna 3 side. A substrate 12 is disposed at a position facing the booster antenna 3 with the feeding coil 2 interposed therebetween. The substrate 12 is simplified compared to FIG. Since the feeding coil 2 includes the magnetic sheet 24 on the substrate 12 side, the magnetic field generated from the feeding coil 2 does not affect other electronic components mounted on the substrate 12. The magnetic sheet 24 is not necessary depending on the installation location of the RFID antenna 1 and the positional relationship with other electronic components.

  Further, a capacitor (not shown) connected in parallel to the connection portion 22 of the power supply coil 2 is provided on the power supply coil 2 or the substrate connected to the power supply coil 2. The resonance frequency of the feeding coil 2 alone is determined by the inductance determined by the coil conductor 21 and the magnetic sheet 24 of the feeding coil 2 and the capacitance of the capacitor. The resonance frequency between the feeding coil 2 and the booster antenna 3 is set to a predetermined resonance frequency. For example, when the HF band having a center frequency of 13.56 MHz is used, the resonance frequency is set to 13.56 MHz.

  FIG. 6 is a diagram illustrating an example of a path of a current flowing through the coil conductor 21 of the feeding coil 2 and the booster antenna 3. The broken-line arrows in FIG. 6 indicate the direction of the current flowing through the coil conductor 21, and the coil conductor 21 is simplified in FIG.

  When the feeding coil 2 and the booster antenna 3 are viewed in plan, the coil opening CW and the opening 312 are coaxial and substantially overlap over the entire circumference. With such a configuration, when the feeding coil 2 is viewed in plan, the entire feeding coil 2 can be overlaid on the booster antenna 3. As a result, all the magnetic flux generated from the feeding coil 2 tries to interlink with the booster antenna 3, so that the direction of the current flowing through the feeding coil 2 is opposite to the booster antenna 3 so as to block the magnetic flux (broken arrow in the figure). A high-density current flows in the direction (solid arrow in the figure).

  The current flowing along the periphery of the opening 312 flows along the edges of the slits 311 and 313, and flows along the outer edge of each of the first member 31 and the second member 32. Thereby, a strong magnetic field is generated from the booster antenna 3, and the communication distance can be further increased. In addition, a loop of magnetic flux that passes through the opening 312 and the coil opening CW and goes around each of the first member 31 and the second member 32 is more effectively spread.

  In the present embodiment, since the two slits 311 and 313 are formed, the region where the edge effect occurs is expanded as compared with the case where only one slit 311 (or slit 313) is formed, and the booster antenna is formed. 3 can be expanded. Thereby, the communication range (angle and distance) by the RFID antenna 1 can be expanded. Further, for example, like the communication terminal device 10 shown in FIG. 1, the booster antenna 3 must be arranged near the end of the housing 11 for reasons such as arrangement space restrictions and avoiding interference with other components. Even in this case, directivity can be secured in the direction in which the slit 313 is formed. Therefore, it is possible to provide a communicable region near the center of the housing 11 while arranging the booster antenna 3 closer to the end.

  In addition, by arranging a plurality of slits in the booster antenna 3, the current path around the booster antenna 3 becomes relatively long. Therefore, the inductance value of the booster antenna 3 is increased. As a result, the resonance frequency of the booster antenna 3 is shifted low so as to approach the use frequency (for example, 13.56 MHz). As a result, the degree of magnetic field coupling with the communication partner antenna increases, so that the effect of extending the communicable distance can also be obtained.

  In addition, since the current density is high in the region where the slit is formed, the radiation of the magnetic field becomes strong. Therefore, the directivity (communication sensitivity) in the direction in which the slit 313 is formed in addition to the slit 311 can be enhanced. FIG. 7 is a diagram schematically showing a communication range of the RFID antenna 1 according to the present embodiment. FIG. 7 corresponds to the cross-sectional view shown in FIG. Hereinafter, a comparison with the case where the slit 313 is not formed will be described with reference to FIG. In the case of the antenna device 100 shown in FIG. 13, since the slit corresponding to the slit 313 according to this embodiment is not formed on the opposite side of the slit 101A corresponding to the slit 311, the communication sensitivity is formed with the slit 101A. Only the side (tip H side) is improved. As shown in FIG. 7, in the case of the present embodiment in which the slit 313 is formed, the communication sensitivity is improved on both sides of the distal end portion H and the other end portion B where the slits 311 and 313 are formed. As described above, the communication terminal device 10 according to the present embodiment includes the RFID antenna 1, so that the magnetic field strength in the 0 ° direction, 45 ° direction, 90 ° direction, and −45 ° direction can be increased, and the communication range (angle And distance).

  By extending the communication range (angle and distance), for example, when the communication terminal device 10 is held over a reader / writer device, the degree of freedom in the angle when the communication terminal device 10 is held over the reader / writer device is improved. For this reason, since the communication is performed by holding the communication terminal device 10 over the reader / writer device without considering the angle direction of the communication terminal device 10, the user changes the communication terminal device 10 when holding the user. Can be saved.

  The slit formed in the booster antenna 3 can be changed as appropriate. Hereinafter, modifications of the booster antenna 3 of the RFID antenna 1 will be described. 8, 9 and 10 are schematic views showing modifications of the booster antenna. FIG. 8 also shows the current flowing through the booster antenna. 9 and 10, the flowing current is omitted, but the way of flowing the current is the same as in FIG.

  In the booster antenna 3A shown in FIG. 8A, slits 314 and 315 are formed in a direction orthogonal to the longitudinal direction (hereinafter referred to as a short direction). The opening 312 communicates with the outside of the booster antenna 3A through slits 314 and 315. In the case of this configuration, communication can be performed at a wider angle along the short direction.

  In the booster antenna 3B shown in FIG. 8B, slits 311 and 313 are formed in the longitudinal direction, and 314 and 315 are formed in the lateral direction, respectively. In the case of this configuration, communication at a wider angle along each of the longitudinal direction and the lateral direction can be performed.

  In the booster antenna 3C shown in FIG. 8C, slits 311 and 313 are formed in the longitudinal direction, and a slit 315 is formed in the lateral direction. In the case of this configuration, communication at a wider angle along one direction in the longitudinal direction and the short direction can be performed.

  In the booster antenna 3D shown in FIG. 8D, a slit 311 is formed along the longitudinal direction, and a slit 315 is formed in the lateral direction. The opening 312 is connected to the outside of the booster antenna 3D through slits 311 and 315. In this case, directivity in the direction in which the slits 311 and 315 are formed can be enhanced.

  A booster antenna 3E shown in FIG. 9A has a configuration in which a rectangular opening 317 is further formed, and the opening 317 communicates with the opening 312 by a slit 316. In this case, the current flowing in the short direction of the booster antenna 3E increases, and the radiation efficiency can be further increased. The booster antenna 3F shown in FIG. 9B includes slits 318 and 319 connected to the opening 312 in addition to the slits 311 and 316 formed along the longitudinal direction. In this case, in addition to the slits 311 and 316, directivity can be enhanced in the direction in which the slits 318.319 are formed. The slit 311 of the booster antenna 3G shown in FIG. 9C is formed to be inclined with respect to the longitudinal direction. In this case, the booster antenna 3G is inclined so as to avoid other metal members, electronic components, circuits, or the like in the vicinity of the slit 311 so that the slits 311 are other metal members, electronic components, circuits, or the like. Can not be close to. Accordingly, electromagnetic interference with them can be prevented and a role as a shield can be achieved.

  The shape of the booster antenna is not limited to a rectangular shape. A booster antenna 3H shown in FIG. 10A has a trapezoidal shape. The booster antenna 3I shown in FIG. 10B and the booster antenna 3J shown in FIG. 10C have a shape in which a part of a rectangular shape is missing. In these cases, other mounting parts of the communication terminal device 10 can be avoided and arranged. The width of the slit 313 of the booster antenna 3K shown in FIG. With such a slit shape, the slit 313 can be prevented from overlapping other metal members, electronic components, circuits, or the like.

  The specific configuration and the like of the communication terminal device 10 described above can be appropriately changed in design, and the actions and effects described in the above-described embodiment are merely a list of the most preferable actions and effects resulting from the present invention. The operations and effects of the present invention are not limited to those described in the above embodiment.

  For example, in the above-described embodiment, the RFID antenna 1 including the feeding coil 2 and the booster antenna 3 has been described. However, the RFID antenna may be formed of another member, for example, a ground electrode pattern on a substrate on which the feeding coil 2 is mounted. It may be configured to be used as FIG. 11 is a schematic diagram for explaining an RFID antenna that uses the ground electrode pattern of the substrate as a booster antenna.

  The feeding coil 2 is mounted on the front surface of the resin substrate 50, and the ground electrode pattern 51 is formed on the inner layer (or back surface). In FIG. 11, the substrate 50 is indicated by a broken line, and the ground electrode pattern 51 of the inner layer is indicated by a solid line. In addition to the feeding coil 2, a mobile phone antenna 53 and other electronic components 54 such as a capacitor or a camera module are mounted on the surface of the substrate 50.

  The ground electrode pattern 51 is formed with notches 511 and 513 in part. The feeding coil 2 is mounted on the surface of the substrate 50 so that the opening 512 and the coil opening at least partially overlap each other when viewed from the stacking direction. The ground electrode pattern 51 corresponds to the booster antenna according to the above-described embodiment, the notches 511 and 513 correspond to the slits 311 and 313, and the opening 512 corresponds to the opening 312. In this case, by using an existing component (ground electrode pattern), it is not necessary to separately provide a metal member that functions as a booster antenna, and an increase in the number of components can be suppressed. In the present embodiment, the power feeding coil 2 is mounted on the surface of the substrate 50, but it may not be mounted, and may be disposed close to the ground electrode pattern 51 so as to be magnetically coupled.

  Moreover, although the housing | casing 11 is made from insulating resin, when a part or all of the housing | casing 11 is comprised with the metal, the slit 311 and the opening part 312 etc. are formed in the metal part, and it serves as a booster antenna. It is good also as a structure which serves as the above-mentioned function. Moreover, the material of the booster antenna 3 is not particularly limited. For example, a magnesium alloy may be used. In this case, the strength of the casing 11 can be increased. Further, although the RFID antenna 1 is disposed on the front end portion H side of the communication terminal device 10, it may be disposed on the other end portion B side or may be disposed on the front side of the communication terminal device 10. Good. For example, when other antennas are arranged at each of the front end portion H and the other end portion B, interference with these antennas can be prevented. The booster antenna 3 may further have an opening or a notch for exposing a camera lens or the like, for example.

1-RFID antenna (antenna device)
2-feed coil (coil antenna)
10-communication terminal device (electronic equipment)
11-housing 12-board 21-coil conductor 22-magnetic core 23-flexible board 24-magnetic sheet 3-booster antenna 31-first member 32-second member 121-feed circuit 122-cell phone antenna 311 -Slit (first slit)
312-opening 313-slit (second slit)
H-tip B-other end

Claims (6)

A plate-shaped metal member and a loop or spiral coil antenna in which a coil conductor is wound so that a coil opening is formed inside;
The metal member is larger than the coil antenna in a plan view, and has an opening, a first slit that communicates the first outer edge with the opening, and at least one first member connected to the opening. Has 2 slits,
In the coil antenna, at least a part of a coil opening of the coil conductor overlaps the opening in a plan view.
Antenna device. The second slit includes a portion extending to a second outer edge portion different from the first outer edge portion of the metal member,
The antenna device according to claim 1, wherein the opening communicates with the second outer edge through the second slit.   The antenna device according to claim 1, wherein at least one of the second slits does not reach any end of the metal member.   The antenna device according to claim 1, wherein the second slit includes a slit having a width different from that of the first slit. A ground conductor pattern is formed, and includes a substrate on which the coil antenna is disposed in proximity.
The metal member is all or part of the ground conductor pattern;
The antenna device according to claim 1. The coil antenna is accommodated, and a housing in which all or a part is a metal part is provided,
The antenna device according to claim 1, wherein the metal member is a metal portion of the housing.

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