JP6069388B2 - ANTENNA, ELECTRONIC DEVICE, AND MANUFACTURING METHOD USED FOR NEAR RANGE COMMUNICATION - Google Patents

Description

  The present invention relates to an antenna used for near field communication (NFC), and further relates to an antenna suitable for incorporation into an electronic device having a metal casing.

  RFID (Radio Frequency Identification) is known as a wireless communication technique using a non-contact IC card or a non-contact IC tag. NFC (Near Field Communication) is conceptually similar to RFID in that it uses a non-contact IC card. However, some RFIDs can communicate several meters, while NFC connects antennas 2 centimeters apart. Apart from RFID, a standardization organization called the NFC Forum developed technical specifications and defined them as ISO / IEC14443 and ISO / IEC18092.

  In recent years, smartphones and tablet terminals equipped with an NFC module have appeared. NFC includes passive communication in which a reader / writer communicates with a contactless IC card or contactless IC tag that does not have a power supply, and active communication in which two devices equipped with a power supply alternately communicate with an initiator and a target. Is defined. The NFC standard defines three functions: a card emulation function that replaces the role of a contactless IC card, a reader / writer function for reading an NFC tag, and an inter-device communication (P2P) function for communicating between NFC devices. .

  The reader / writer function reads 4 types of contactless IC cards from Topaz (registered trademark), Felica (registered trademark), Mifare UL (registered trademark), Mifare-DESFire (registered trademark), etc. Be able to. In order for the reader / writer to communicate with a non-contact IC card without a power source, the NFC antenna connected to the reader / writer generates as much magnetic flux as possible in the direction of efficiently interlinking with the NFC antenna of the non-contact IC card. It is necessary to let

  Patent Document 1 discloses an RFID antenna formed of a substrate on which a loop coil is formed and a magnetic sheet penetrating through the loop coil. Patent Document 2 discloses an RFID antenna mounted on a wireless terminal. This document describes that a loop antenna is provided so that the coil axis is parallel to a metal body parallel to the main communication surface of the casing of the wireless terminal. Patent Document 3 discloses an RFID antenna mounted on a wireless terminal.

JP 2011-229133 A JP2012-134605A Japanese Patent No. 4978756

  In addition to smartphones and tablet terminals, NFC antennas have been installed so that notebook personal computers (notebook PCs) can function as readers / writers. An NFC antenna mounted on a notebook PC cannot appropriately exchange magnetic flux if there is a metal between a surface (access surface) accessed by a non-contact IC card by a touch operation. In recent notebook PCs, the casing is made of metal, so the location of the NFC antenna is limited. FIG. 4 is a diagram for explaining an example of mounting an NFC antenna on a notebook PC having a metal casing.

  As shown in FIG. 4A, the notebook PC 10 includes a display housing 11 on which an LCD 13 is mounted, a keyboard 17 and a touch pad 19 on the surface, and a system housing that houses a circuit board on which system devices are mounted. The body 15 is connected so that it can be opened and closed. The display housing 11 and the system housing 15 are entirely made of metal, but the region where the keyboard 17 and the touch pad 19 are mounted is partially cut away.

  When the notebook PC 10 is in use, it is difficult to perform a touch operation if an access surface of a non-contact IC card is provided on the opened display housing 11. Therefore, it is desirable to provide an NFC antenna in the system housing 15 for operation. Cutting out a part of the display housing 11 to provide the NFC antenna leads to an increase in cost and is not preferable in terms of design. Therefore, until now, the loop coil NFC antenna 21 has been used as a touch pad. 19 is formed on a circuit board disposed at the lower part of 19. At this time, the surface of the touch pad 19 becomes the access surface of the non-contact IC card.

  FIG. 4B shows a magnetic field formed on the surface of the touch pad 19 by the NFC antenna 21 and a state of magnetic flux when the NFC antenna 51 of the non-contact IC card performs NFC. When a high-frequency current flows through the NFC antenna 21, an alternating magnetic field passing through the antenna opening 22 is formed, and an alternating magnetic flux corresponding to the magnetic permeability flows in the surrounding space and links with the NFC antenna 51. On the contrary, when the alternating magnetic flux of the NFC antenna 51 passes through the coil opening 22 and links with the NFC antenna 21, a high frequency voltage is induced in the NFC antenna 21 and a high frequency current corresponding to the impedance flows. The NFC antenna 21 is a region where the antenna opening 22 on the access surface is projected, and radiates upward or downward magnetic flux. Therefore, the degree of electromagnetic coupling with the NFC antenna 51 is strong, and good NFC is possible.

  However, in order to arrange the NFC antenna 21 below the touch pad 19, various measures are required to prevent malfunction of the touch pad 19. First, the NFC antenna 21 is configured to resonate with a high frequency current of 13.56 MHz as an example. In order to prevent the high frequency component of the magnetic flux from generating noise in the circuit of the touch pad 19, a low-pass filter is used. Need to be inserted. In addition, it is necessary to tune the scanning frequency of the touch pad 19 to a value that is not affected by NFC.

  Furthermore, when the non-contact IC card is left on the touch pad 19 for a long time, the firmware of the touch pad 19 automatically performs calibration, and it is necessary to cope with the problem that the operation becomes unstable. is there. Even when an NFC antenna is provided in a place other than the lower part of the touch pad 19, it is desirable that it is as small as possible. In order to realize good NFC, it is necessary to create a magnetic flux distribution in the vicinity of the access surface so that magnetic flux exchange with the non-contact IC card is efficiently performed. An object of the present invention is to solve such problems related to the NFC antenna.

  Therefore, an object of the present invention is to provide an NFC antenna that can be easily mounted on a small electronic device having a metal casing. A further object of the present invention is to provide an NFC antenna that is small in size and excellent in communication performance. It is a further object of the present invention to provide an NFC antenna that is less affected by magnetic flux on other devices. A further object of the present invention is to provide an NFC antenna that can be mounted without modifying the casing of a portable computer. Furthermore, the objective of this invention is providing the manufacturing method of the electronic device, portable computer, and NFC antenna which mounted such an NFC antenna.

  A first aspect of the present invention provides a portable computer having a metal housing. The portable computer includes a keyboard unit mounted on a housing, an antenna placement section provided in a region where the housing is partially cut, a first coil surface on which a plurality of first coil sides are placed, A plurality of second coil sides disposed on a second coil surface facing the first coil surface at a larger interval than the first coil side so as to form a loop-shaped coil together with one coil side. And an antenna disposed in the antenna placement portion.

  The antenna adjusts the directivity characteristics of the magnetic flux radiated from the first coil side and the magnetic flux radiated from the second coil side according to the interval between the coil sides, so that the communication is good and the influence of noise on the portable computer is reduced. be able to. The first coil side can be arranged at a position closer to the access surface of the non-contact IC card than the second coil side. Since the first coil side has a narrow pitch and a short coil length, it can radiate a magnetic flux that efficiently links with the NFC antenna of the non-contact IC card that exists in the vicinity of the access surface.

  The antenna arrangement portion can be provided on the touch pad. At this time, if the antenna arrangement portion is provided in the non-detection region of the touch pad, the NFC antenna can be prevented from affecting the operation of the touch pad. The antenna arrangement portion provided in the non-detection area can be the back side of the inclined portion existing on the keyboard unit side of the touchpad. In the case where the touch pad includes a movable plate that operates the mechanical switch, it is possible to prevent a design problem from occurring by attaching the antenna from the lower side of the movable plate of the inclined portion. The antenna arrangement part can also be provided under the mouse button or the keyboard unit existing between the touch pad and the keyboard.

  A second aspect of the present invention provides an antenna for short-range wireless communication mounted on an electronic device. The antenna includes a first coil surface, a second coil surface disposed at a position facing the first coil surface, a plurality of first coil sides disposed on the first coil surface, and a first coil. The antenna coil includes a plurality of second coil sides arranged on the second coil surface at a larger interval than the first coil side so as to form a looped coil together with the side.

  When the first coil surface and the second coil surface are defined on the surface of the insulating substrate, the antenna is easily formed by forming the antenna coil on the surface of the insulating substrate and then folding it back so that the back surfaces face each other. be able to. The amount of magnetic flux interlinked can be increased by disposing a magnetic sheet between the back surface facing the first coil surface and the back surface facing the second coil surface. An antenna with such a directional characteristic adjusted is suitable for mounting on an electronic device because it is small in size, has good communication performance, and can reduce the influence of noise.

  When the antenna coil is formed in a rectangular shape and the antenna is folded back by a folding line parallel to the coil side in the longitudinal direction, the antenna can be formed into an elongated shape, which makes it easy to mount on an electronic device. If the cross-sectional area of the portion parallel to the folding line of the second coil side is made larger than the cross-sectional area of the portion parallel to the folding line of the first coil side, power loss can be reduced.

  According to a third aspect of the present invention, there is provided a method for manufacturing an antenna for short-range wireless communication mounted on an electronic device. A first coil surface and a second coil surface are defined on the surface of the insulating substrate with a fold line as a center, and a pitch of at least a part of coil sides of the first coil surface on the surface is a coil in the second coil surface. A loop-like antenna coil pattern is formed so as to be narrower than the pitch of the sides, and is folded back so that the back surface of the insulating substrate is opposed to the folding line. Further, a magnetic sheet can be inserted between the first coil surface and the second coil surface.

  According to the present invention, an NFC antenna that can be easily mounted on a small electronic device having a metal casing can be provided. Furthermore, according to the present invention, a small NFC antenna excellent in communication performance could be provided. Furthermore, according to the present invention, an NFC antenna with less influence of magnetic flux on other devices can be provided. Furthermore, according to the present invention, it is possible to provide an NFC antenna that can be mounted without modifying the casing of the portable computer. Furthermore, according to the present invention, an electronic apparatus, a portable computer, and a method for manufacturing the NFC antenna mounted with such an NFC antenna could be provided.

It is a top view which shows the external shape of the system housing | casing 101 which mounts an NFC antenna. 4 is a diagram for explaining the structure of an NFC antenna 300. FIG. It is a figure for demonstrating the attachment structure of the NFC antenna. It is a figure for demonstrating the conventional attachment method of an NFC antenna.

  FIG. 1 is a plan view of a system housing 101 of the notebook PC according to the present embodiment. A system housing 101 formed almost entirely of metal houses therein system devices such as a processor, system memory, and a hard disk drive, and has a keyboard unit 103, A left button 251, a center button 253, a right button 255, and a touch pad 200 are mounted.

  The keyboard unit 101 includes a pointing stick 105 disposed between the G key, the H key, and the B key. The pointing stick 105 moves a pointer displayed on the display or inputs an object displayed at the position of the pointer.

  A palm rest 101b on which a palm is placed when operating the keyboard is provided on the front side of the keyboard unit 103. The palm rest 101b is formed flat as a whole, but includes an inclined portion 101a that descends toward the keyboard unit 103 on the front side (user side) of the keyboard unit 103. The inclined portion 101a secures a range of thumb movement during key operation so that smooth operation is possible without pressing the thumb when pressing the bottom row of keys arranged on the front side of the keyboard unit 103 with the thumb. Play a role.

  On the front side of the space key, a mechanical left button 251, a center button 253, and a right button 255 used in combination with the pointing stick 105 are arranged. The left button 251, the center button 253, and the right button 255 respectively correspond to the left button, wheel, and right button of an independent mouse operated on the desk. The center button is operated simultaneously with the pointing stick 105 to scroll or enlarge the screen. Hereinafter, the left button 251, the center button 253, and the right button 255 are referred to as mechanical mouse buttons.

  A touch pad 200 is arranged on the near side adjacent to the mechanical mouse button. The touch pad 200 is arranged at the approximate center of the keyboard to prevent the user's hand from touching accidentally while the keyboard is operated with both hands at the home position and unintentional pointer movement is not performed. doing. A palm rest 101b surrounds the touch pad 200.

  The touch pad 200 includes a flat part 201 and an inclined part 203 that can be accessed by the user. The flat part 201 constitutes a detection area where the touch sensor detects the approach or contact of the finger, and the inclined part 203 constitutes a non-detection area where the approach or contact of the finger is not detected. The surface of the flat part 201 exists on substantially the same plane as the flat surface of the palm rest 101b. By setting the inclined portion 203 as a non-detection area, when operating a mechanical mouse button, the user can recognize the boundary with the flat portion 201 with the sense of thumb, so that the detection area is not touched by mistake. It is provided for the purpose.

  As an example, the touch pad 200 may be a click pad (registered trademark) developed by Synaptics of the United States. In Click Pad (registered trademark), one mechanical switch is incorporated inside the touch pad, and an area corresponding to a mechanical mouse button is defined on the surface of the touch pad. Then, the mouse button click operation is emulated by the combination of the coordinates of the pressed position detected by the touch sensor when the user presses any defined area and the operation signal of the mechanical switch. The area defined on the surface of the touch pad in order to emulate the click operation of the mechanical mouse button is hereinafter referred to as a pseudo button.

  The touch pad 200 includes pseudo buttons 205a and 205b intended to be used together with the pointer movement function of the touch pad 200. The pseudo buttons 205a and 205b correspond to a left button and a right button of a mechanical mouse button mounted on a conventional notebook PC, respectively. The touch pad 200 may incorporate a left button 251, a center button 253, and a right button 255 as pseudo buttons so that no mechanical mouse button is used. The present invention can also be applied to a conventional touchpad that does not include a pseudo button. In that case, when the pointing stick 105 is mounted, a mechanical mouse button is also mounted at the same time.

  FIG. 2 is a diagram for explaining the structure of the NFC antenna 300. 2A is a plan view showing an antenna pattern before assembly, and FIG. 2B is an enlarged cross-sectional view showing a state where the antenna pattern of FIG. is there. As shown in FIG. 2A, a first coil surface 301a and a second coil surface 301b are defined on the surface of the insulating substrate 301 with a folding line 307 as a boundary.

  In FIG. 2A, a rectangular antenna coil 303, which is a continuous wire as a whole, is formed as a loop-shaped conductor pattern on the first coil surface 301a and the second coil surface 301b. . An insulating layer is interposed at the portion where the patterns intersect. The antenna coil 303 is composed of four first coil sides 303a existing on the first coil surface 301a and four second coil sides 303b existing on the second coil surface 301b. The number of coil sides need not be particularly limited. A central portion surrounded by the first coil side 303a and the second coil side 303b corresponds to a coil opening 309 through which a magnetic flux interlinking with the antenna coil 303 passes.

The first coil side 303a and the second coil side 303b each include a part parallel to the fold line 307 and a part perpendicular thereto. The portion parallel to the folding line 307 is made longer than the vertical portion so that the elongated NFC antenna 300 is formed when folded. The interval (pitch) between the centers of the coil sides of the first coil side 303a is narrower than that of the second coil side 303b. When the number is constant, the pitch of the second coil sides 303b defines the width W of the NFC antenna 300 in the assembled state as shown in FIG.

  Within the given width W, the width of the portion parallel to the fold line 307 of the second coil side 303b is wider than the width of the portion parallel to the first coil side 303a. When the thickness of the pattern is constant, the second coil side 303b can have a larger cross-sectional area so as to include a portion wider than the first coil side 303a. As a result, the power loss of the second coil side 303b can be reduced. Note that the width and pitch of the vertical portion of the first coil side 303a and the second coil side 303b may be the same as the width and pitch of the parallel portion of the first coil side 303a or the second coil side 303b. .

  For example, the insulating substrate 301 is a flexible substrate such as a polyimide film or a polyester film that can be easily folded back during assembly. The pattern forming method is not particularly limited, and various methods such as etching the copper foil attached to the entire surface of the insulating substrate 301 or copper plating the insulating substrate 301 on which the resist is formed are adopted. Can do.

  FIG. 2B shows a state where the insulating substrate 301 on which the pattern of the antenna coil 303 is formed is folded back by a folding line 307 so that the back surface is opposed. A magnetic sheet 311 formed of a ferromagnetic material such as ferrite powder or metal powder is sandwiched between the back surface of the insulating substrate 301. Both ends of the antenna coil 303 are connected to the resonance circuit 305 mounted on the second coil surface 301b. The resonance circuit 303 includes a resistor, a capacitor, and a reactor, and resonates the antenna coil 303 with a high frequency current of 13.56 MHz as an example.

  Next, the characteristics of the NFC antenna 300 will be described. The NFC antenna 51 of the non-contact IC card is substantially parallel to the access surface when a touch operation is performed. Therefore, the NFC antenna 300 needs to radiate a magnetic flux that is effectively interlinked with the NFC antenna 51 in that state. When a high frequency current is passed through the NFC antenna 300, the antenna coil 303 emits an alternating magnetic flux to generate an induced voltage in the NFC antenna 51 that performs a touch operation.

  The total amount of magnetic flux flowing on the upper side and the lower side of the plane 313 passing through the center of the magnetic sheet 311 and parallel to the surface of the insulating substrate 301 is substantially equal, but the coil length L1 of the first coil side 303a is the second coil side 303b. Shorter than the coil length L2. When the first coil side 303a is arranged at a position close to the access surface, the magnetic flux φ1 radiated by the first coil side 303a flows in and out of the magnetic sheet 311 through a short space and is perpendicular to the access surface. Ingredients become larger.

  Therefore, the distribution of the magnetic flux radiated from the first coil side 303a improves the linkage characteristics with respect to the NFC antenna 51 that performs the touch operation. On the other hand, the magnetic flux φ2 radiated by the second coil side 303b that does not contribute to NFC has a long coil length L2, so that the amount of the component flowing in the vicinity of the second coil surface 301b in the horizontal direction increases. Therefore, it is possible to reduce the influence of the magnetic flux radiated from the second coil side 303b on the device existing on the lower side of the NFC antenna 300.

  That is, when the entire NFC antenna is manufactured with the pitch of the second coil side 303b, the NFC performance is inferior, and when the entire NFC antenna is manufactured with the pitch of the first coil side 303a, it exists in the direction opposite to the access surface. Affects the device. On the other hand, the NFC antenna 300 can achieve both NFC performance maintenance and noise countermeasures by providing a difference in the pitch of the coil side opposite to the access surface side. Regarding the adjustment of the magnetic flux distribution, the width of the portion parallel to the folding line 307 of the second coil side 303b may be the same as the width of the portion parallel to the folding line 307 of the first coil side 303a.

  Since the magnetic sheet 311 has a high magnetic permeability, the magnetic flux density of the magnetic flux flowing inside the predetermined magnetic field is increased. The magnetic flux radiated from the NFC antenna 51 of the non-contact IC card flows so as to pass through the side surface of the magnetic sheet 311 and the coil opening 309 and is linked to the NFC antenna 300. When the alternating magnetic flux radiated from the NFC antenna 51 passes through the coil opening 309 and links with the antenna coil 303, an induced voltage is generated. The magnetic sheet 311 increases the induced voltage by increasing the number of linkages between the magnetic flux radiated by the NFC antenna 51 and the NFC antenna 300.

  FIG. 3 is a diagram for explaining a method of attaching the NFC antenna 300. 3A is a plan view of the touch pad 200, and FIG. 3B is a cross-sectional view of the touch pad 200 with the NFC antenna 300 attached. FIG. 3A shows a planar position of the antenna arrangement portion 211 in the inclined portion 203. 3B, in the touch pad 200, the base plate 229 supports the laminated cover plate 221, capacitive touch sensor 223, movable plate 225, and leaf spring 227.

  The surface of the cover plate 221 constitutes a flat part 201, and the surface of the movable plate 225 constitutes an inclined part 203 in an area where the touch sensor 223 does not exist. The cover plate 221 and the movable plate 225 are made of synthetic resin such as ABS resin. In the inclined portion 203 of the movable plate 225, an antenna placement portion 211 for housing the NFC antenna 300 is formed. The antenna arrangement portion 211 is formed by recessing from below so as not to prevent the movable plate 225 from moving up and down when the pseudo buttons 205a and 205b are pressed when the NFC antenna 300 is attached. The surface of the inclined portion 203 formed of synthetic resin and the vicinity thereof become an access surface of the non-contact IC card. In one example, the NFC antenna 300 can be fixed to the antenna placement portion 211 with double-sided tape so that the first coil side 303a faces the access surface of the inclined portion 203.

  The antenna placement unit 211 is characterized by the fact that it is not necessary to process the system casing 101 in order to attach the NFC antenna 300, that the appearance of the system casing 101 is not changed, and the materials of the components that constitute the system casing And there is no need to change the layout. Further, the antenna placement unit 211 does not overlap with the touch sensor 223 in projection onto a plane parallel to the flat part 201, and thus does not affect the operation of the touch sensor 223. Further, since the magnetic flux flowing under the base plate 229 passes through a shallow place, the influence of noise by the NFC antenna 300 can be reduced.

  The NFC antenna 300 is electrically connected by through holes (via holes) in which the back surfaces of two insulating substrates each having an antenna pattern formed on the front surface are bonded together with a magnetic material sheet sandwiched between them. Can also be created. However, if the pattern is formed on the plane of the insulating substrate 301 and then folded back as in the present embodiment, it is advantageous because the pattern forming process may be performed once and the connection with via holes is unnecessary. is there.

  Further, the NFC antenna 300 can be formed into an elongated shape with the width W (FIG. 2) being halved as compared with a loop-shaped antenna formed on the same plane. For example, the inclined portion 101 a can be formed of a synthetic resin that becomes a part of the keyboard unit 103 and attached below the synthetic resin. Alternatively, it can be mounted under a relatively long space key in the key. It can also be attached under a mechanical mouse button.

  Although the present invention has been described with the specific embodiments shown in the drawings, the present invention is not limited to the embodiments shown in the drawings, and is known so far as long as the effects of the present invention are achieved. It goes without saying that any configuration can be adopted.

100 notebook PC
101 System chassis 101a System chassis sloped part 101b System chassis flat part 103 Keyboard unit 105 Pointing stick 200 Touchpad 201 Touchpad flat part 203 Touchpad sloped part 211 Antenna placement parts 251 to 253 Mouse Button 300 NFC antenna 301 Insulating substrate 301a First coil surface 301b Second coil surface 303 Antenna coil 303a First coil side 303b Second coil side 305 Resonant circuit 307 Folding wire 309 Coil opening 311 Magnetic sheet

Claims (13)

A portable computer comprising a metal housing,
A keyboard unit mounted in the housing;
An antenna placement section provided in a region where the housing is partially cut;
A first coil surface on which a plurality of first coil sides are arranged, and a second coil surface facing the first coil surface so as to form a looped coil together with the first coil sides. A plurality of second coil sides arranged at intervals wider than one coil side, and an antenna for short-range wireless communication arranged in the antenna arrangement unit,
A portable computer in which the first coil side is located closer to the access surface of the non-contact IC card than the second coil side .   The portable computer according to claim 1, wherein the antenna placement unit is provided on a touch pad. The portable computer according to claim 2 , wherein the antenna arrangement unit is provided in a non-detection area of the touch pad. The portable computer according to claim 2 , wherein the antenna arrangement portion is provided on the back side of an inclined portion that exists on the keyboard unit side of the touchpad. The portable computer according to claim 2 , wherein the touch pad includes a movable plate for operating a mechanical switch, and the antenna is attached to a recess formed on a lower side of the movable plate. The portable computer according to claim 2 , wherein the antenna arrangement portion is provided on a back side of a mouse button existing between the touch pad and the keyboard unit.   The portable computer according to claim 1, wherein the antenna placement unit is provided in the keyboard unit. A portable computer comprising a metal housing,
A keyboard unit mounted in the housing;
Touchpad,
An antenna placement section provided in a region where the housing is partially cut;
A first coil surface on which a plurality of first coil sides are arranged, and a second coil surface facing the first coil surface so as to form a looped coil together with the first coil sides. A plurality of second coil sides arranged at intervals wider than one coil side, and an antenna for short-range wireless communication arranged in the antenna arrangement unit,
The portable computer which provided the said antenna arrangement | positioning part in the back side of the inclination part which exists in the said keyboard unit side in the non-detection area | region of the said touchpad . A portable computer comprising a metal housing,
A keyboard unit mounted in the housing;
Touchpad,
An antenna placement section provided in a region where the housing is partially cut;
A first coil surface on which a plurality of first coil sides are arranged, and a second coil surface facing the first coil surface so as to form a looped coil together with the first coil sides. A plurality of second coil sides arranged at intervals wider than one coil side, and an antenna for short-range wireless communication arranged in the antenna arrangement unit,
A portable computer in which the antenna arrangement part is provided on the back side of a mouse button existing between the touchpad and the keyboard unit . An antenna for short-range wireless communication mounted on an electronic device,
A first coil surface;
A second coil surface disposed at a position facing the first coil surface;
A plurality of first coil sides arranged on the first coil surface, and the second coil intervals wider than the plurality of first coil sides so as to form a loop-shaped coil together with the first coil sides. A plurality of second coil sides arranged on the coil surface of the antenna coil,
The antenna which arrange | positions the said 1st coil surface in the position close | similar to the access surface of the non-contact IC card provided in the said electronic device . The antenna according to claim 10 , wherein the antenna coil has a rectangular shape and is folded by a folding line parallel to a coil side in a longitudinal direction. The antenna according to claim 11 , wherein a cross-sectional area of a portion of the second coil side parallel to the folding line is larger than a cross-sectional area of a portion of the first coil side parallel to the folding line. The electronic device which mounts the antenna in any one of Claims 10-12.

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