JP2013081072A - Antenna device and communication terminal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an antenna device having excellent transmission efficiency of RF radio signals with a high coupling degree between a power supply coil and an antenna coil, and to enable easy application of the antenna device to a communication terminal device.SOLUTION: An antenna device 301 includes a power supply coil 101 and an antenna coil 201. The power supply coil 101 includes a tabular magnetic substance core 13 and a power supply coil 12 wound around the periphery thereof. Both ends of the power supply coil 12 are connected to a power supply circuit including an RFIC. The antenna coil 201 includes an antenna coil conductor 22 formed on a flexible base material 21 and a magnetic substance core 25. A magnetic flux MF1 passes through the magnetic substance core 13 of the power supply coil 101 and the magnetic substance core 25 of the antenna coil 201, and circulates through a path passing through an inner edge portion of the antenna coil conductor 22, to interlink with an antenna of an opposite communication party.

Description

  The present invention relates to an antenna device and a communication terminal device used in an RFID (Radio Frequency Identification) system or a short-range wireless communication (NFC) system that communicates with a counterpart device via an electromagnetic field signal.

  For example, Patent Document 1 discloses an RFID tag using a booster coil. FIG. 12 is a plan view showing the arrangement of booster coils and IC elements provided in the RFID tag. The RFID tag includes an RFIC (Radio Frequency Integrated Circuit) chip 2 in which an antenna coil is integrally formed, an insulating member 6 in which a booster coil 3 and conductive films 4a and 4b for capacitance connection are formed, and these. And a base body for casing. A rectangular spiral antenna coil is integrally formed on the RFIC 2, and the antenna coil is attached toward the booster coil forming surface side of the insulating member 6.

  On the back surface of the insulating member 6, a conductive film for capacitance connection is formed opposite to the conductive films 4 a and 4 b on the front surface. The capacitance connecting conductor film formed on the back surface side of the insulating member 6 is electrically connected via a conducting wire.

  The antenna coil and the booster coil 3 of the RFIC chip 2 are electromagnetically coupled, and a signal is transmitted between the RFIC chip 2 and the booster coil 3.

JP 2002-042083 A

  In the RFID tag as shown in FIG. 12, the antenna coil has a size approximate to the size of the RFIC chip, and the booster coil has a larger size, for example, a card size. Therefore, it is difficult to increase the degree of coupling between the antenna coil and the booster coil.

  Further, the structure in which the RFIC chip integrally formed with the antenna coil as shown in FIG. 12 is stacked on the booster coil cannot be applied to a device provided with an RFIC in addition to the antenna device provided with the booster coil. Therefore, there is a problem that the degree of freedom in design is low for application to a communication terminal device used in an RFID system or a short-range wireless communication (NFC) system.

  In view of the above-described circumstances, the present invention has an antenna device that has a high degree of coupling between a feeding coil and an antenna coil, is excellent in RF signal transmission efficiency, and can be easily applied to a communication terminal device, and the antenna device An object of the present invention is to provide a communication terminal device.

(1) The antenna device of the present invention
An antenna device comprising a feeding coil and an antenna coil coupled to the feeding coil via a magnetic field,
The coil conductor of the antenna coil is formed in a spiral shape having an inner edge and an outer edge,
A first magnetic layer is provided on the opposite side of the surface of the antenna coil from the surface close to the feeding coil so as to cover a part of the coil conductor of the antenna coil.

(2) It is preferable that the first magnetic layer is disposed from the inner edge to the outer edge of the coil conductor of the antenna coil.

(3) The winding axis of the coil conductor of the feeding coil is substantially orthogonal to the winding axis of the coil conductor of the antenna coil,
The first magnetic layer and the feeding coil are arranged at a position where the feeding coil and the first magnetic layer overlap in a plan view from the winding axis direction of the coil conductor of the antenna coil. Is preferred.

(4) From the inner edge portion to the outer edge portion of the coil conductor of the antenna coil, on the surface side of the antenna coil close to the feeding coil, at a position different from the position where the first magnetic layer overlaps. The second magnetic layer is preferably disposed so as to cover a part of the coil conductor of the antenna coil.

(5) The coil conductor of the antenna coil is composed of a spiral conductor pattern wound around the opening formed in the flexible base material,
The first magnetic layer and the second magnetic layer are preferably integrated sheet-like magnetic layers and are inserted through the openings of the flexible base material.

(6) The communication terminal device of the present invention
Provided on the inner surface or surface of the terminal housing with an antenna coil to which a feeding coil is coupled via a magnetic field,
The coil conductor of the antenna coil is formed in a spiral shape having an inner edge and an outer edge,
A first magnetic layer is provided on the side of the antenna coil opposite to the side close to the feeding coil so as to cover a part of the coil conductor of the antenna coil,
The power feeding coil and a power feeding circuit connected to the power feeding coil are arranged in the casing.

(7) In (6), from the inner edge of the coil conductor of the antenna coil to a position different from the position where the first magnetic layer overlaps on the surface side of the antenna coil close to the feeding coil. A second magnetic layer is disposed over the outer edge so as to cover a part of the coil conductor of the antenna coil,
It is preferable that a metal article is disposed at a position close to the second magnetic layer on the surface side where the power feeding coil is close.

(8) In (7), the coil conductor of the antenna coil is composed of a spiral conductor pattern wound around the opening formed in the flexible base material,
The first magnetic layer and the second magnetic layer are preferably integrated sheet-like magnetic layers, and are preferably inserted through the openings of the flexible base material.

  ADVANTAGE OF THE INVENTION According to this invention, the coupling | bonding degree of a feeding coil and an antenna coil is high, the antenna apparatus excellent in the transmission efficiency of RF signal can be comprised, Furthermore, it can apply easily to a communication terminal device.

FIG. 1 is an exploded perspective view of an antenna device 301 according to the first embodiment. FIG. 2A is a diagram showing a flexible substrate of the antenna coil 201 and a conductor pattern formed thereon. FIG. 2B is a plan view of the antenna coil 201, and FIG. 2C is a front view of the antenna coil 201. FIG. 3 is a diagram illustrating coupling between the feeding coil 101 and the antenna coil 201 and coupling between the antenna coil 201 and the antenna of the communication partner. FIG. 4 is a cross-sectional view of a communication terminal device including the antenna device 301. FIGS. 5A to 5D are diagrams illustrating a configuration of an antenna coil included in the antenna device of the second embodiment. FIG. 5A is a plan view of the antenna coil in which the magnetic core is not shown, FIG. 5B is a diagram showing a pattern of the antenna coil conductor 22 formed on the upper surface of the flexible substrate 21, and FIG. ) Is a diagram showing a pattern of the antenna coil conductor 23 formed on the lower surface of the flexible base 21. FIG. 5D is an equivalent circuit diagram of the antenna coil. FIG. 6 is a diagram illustrating a configuration of the antenna coil 203 provided in the antenna device of the third embodiment. FIG. 7 is a diagram illustrating the coupling between the feeding coil 101 and the antenna coil 203 and the coupling between the antenna coil 203 and the antenna of the communication partner. FIG. 8 is a diagram illustrating a configuration of the antenna coil 204 provided in the antenna device of the fourth embodiment. FIG. 9 is a diagram illustrating coupling between the feeding coil 101 and the antenna coil 204 and coupling between the antenna coil 204 and the antenna of the communication partner. FIG. 10 is a diagram illustrating the coupling between the feeding coil 102 and the antenna coil 202 and the coupling between the antenna coil 202 and the communication partner antenna in the antenna device 305 according to the fifth embodiment. FIG. 11 is a cross-sectional view of a communication terminal apparatus according to the sixth embodiment. FIG. 12 is a plan view showing the arrangement of booster coils and IC elements provided in the RFID tag of Patent Document 1. FIG.

<< First Embodiment >>
FIG. 1 is an exploded perspective view of an antenna device 301 according to the first embodiment. An antenna device 301 shown in FIG. 1 includes a feeding coil 101 and an antenna coil 201.

  The power supply coil 101 includes a plate-like magnetic core 13 and a power supply coil conductor 12 that is wound around the magnetic core 13. Both ends of the feeding coil conductor 12 are connected to an input / output terminal 14 to which a feeding circuit including an RFIC is connected. The feeding coil conductor 12 and the input / output terminal 14 are conductor patterns formed on a flexible substrate. However, illustration of a flexible base material is abbreviate | omitted in FIG.

  FIG. 2A is a diagram showing a flexible substrate of the antenna coil 201 and a conductor pattern formed thereon. FIG. 2B is a plan view of the antenna coil 201, and FIG. 2C is a front view of the antenna coil 201.

  The antenna coil 201 includes an antenna coil conductor 22 and a magnetic core 25 formed on the flexible base material 21. The flexible substrate 21 is a polyimide film or a PET film, and the antenna coil conductor 22 is a conductor pattern such as a copper foil formed on the first main surface of the flexible substrate 21.

  The antenna coil conductor 22 is formed in a spiral shape having an inner edge portion which is the innermost conductor portion and an outer edge portion which is the outermost conductor portion. A magnetic core 25 is provided on the antenna coil conductor 22 so as to cover a part of the antenna coil conductor 22 on the side opposite to the surface close to the feeding coil 101. However, in the first embodiment, the magnetic core 25 is extended so that the antenna coil conductor 22 is wound around the magnetic core 25. This magnetic core 25 corresponds to the “magnetic layer” of the present invention.

  As shown in FIG. 2A, the antenna coil conductor 22 is formed of a spiral conductor pattern wound around an opening 24 formed in the flexible base material 21. However, illustration of a flexible base material is abbreviate | omitted in FIG. The inner peripheral end and the outer peripheral end of the spiral conductor pattern are electrically connected. The magnetic core 25 is a sheet-like magnetic body such as a ferrite sheet that is inserted through the opening of the flexible base material.

  FIG. 3 is a diagram illustrating coupling between the feeding coil 101 and the antenna coil 201 and coupling between the antenna coil 201 and the antenna of the communication partner.

  The feeding coil 101 is mounted on the printed wiring board 32, and the antenna coil 201 is affixed to the inner surface of the casing 31 of the communication terminal device via a double-sided adhesive sheet or the like.

  The magnetic flux MF1 passing through the magnetic core 13 of the power supply coil 101 passes through the magnetic core 25 of the antenna coil 201. The magnetic flux MF1 passing through the magnetic core 25 circulates along a path that passes through the inner edge of the antenna coil conductor 22. As a result, the feeding coil 101 and the antenna coil 201 are magnetically coupled.

  The magnetic flux MF2 passing through the magnetic core 25 of the antenna coil 201 circulates along a path that passes through the inner edge of the antenna coil conductor 22 of the antenna coil 201. This magnetic flux MF2 is coupled to a communication partner antenna (for example, a loop antenna). As a result, the antenna coil 201 and the communication partner antenna are magnetically coupled.

  FIG. 4 is a cross-sectional view of a communication terminal device including the antenna device 301. In addition to the power supply coil 101, a battery pack 33 and other mounting components 34 are mounted on the printed wiring board 32 in the housing 31 of the communication terminal device. An antenna coil 201 is affixed to the inner surface of the housing 31.

  The magnetic core 25 of the antenna coil 201 is disposed on the side farther from the power supply coil 101 with the antenna coil conductor 22 in between the portion where the power supply coil 101 is close (the right half of the magnetic core 25 in FIG. 4). . Also, the magnetic core 25 is such that the portion of the magnetic core 25 that is adjacent to the battery pack 33 (the left half of the magnetic core 25 in FIG. 4) is interposed between the antenna coil conductor 22 and the battery pack 33. 25 is arranged. Thus, if the magnetic core 25 is interposed between the antenna coil conductor 22 and the battery pack 33, the magnetic flux passing through the antenna coil conductor 22 passes through the battery pack 33 due to the magnetic shielding action of the magnetic core 25. Can be prevented. Therefore, eddy current does not occur in the metal material of the battery pack 33, and loss can be reduced. In addition, since the antenna coil 201 can be arranged at a position close to the battery pack, the degree of integration can be increased and the overall size can be reduced.

  As described above, by disposing the magnetic core 25 between the antenna coil conductor 22 and the battery pack 33 in a portion where a metal article such as the battery pack 33 is close, the loss of the antenna can be reduced and the degree of integration can be reduced. A small communication terminal device with a high value can be obtained.

Metal products are not limited to battery packs, and eddy currents such as antennas, memory cards, liquid crystal displays, metal cases, and semiconductor chips of other communication systems that may cancel the magnetic field of the antenna due to the presence of metal may occur. The same effect is obtained when all the articles are included and such metal articles are close to each other.

  In the example shown in FIG. 4, since the antenna device 301 is arranged on the lower surface CS1 side of the casing 31 of the communication terminal device, the lower surface of the communication terminal device is held over a communication partner antenna such as a reader / writer. Communication becomes possible. Further, the magnetic core 25 is arranged such that the antenna device 301 is disposed near the rear end CS3 of the casing 31 and the magnetic core 25 is hidden behind the antenna coil conductor 22 when viewed from the lower surface of the casing 31. Is arranged, the directivity of the antenna coil 201 is directed in the direction of arrow D. Therefore, a high gain can be obtained in a state where the center portion of the lower surface CS1 of the casing 31 of the communication terminal device is held parallel to the center portion of the communication partner antenna.

<< Second Embodiment >>
FIGS. 5A to 5D are diagrams illustrating a configuration of an antenna coil included in the antenna device of the second embodiment. FIG. 5A is a plan view of the antenna coil. However, the illustration of the magnetic core is omitted. FIG. 5B shows a pattern of the antenna coil conductor 22 formed on the upper surface of the flexible base material 21, and FIG. 5C shows a pattern of the antenna coil conductor 23 formed on the lower surface of the flexible base material 21. . Thus, the antenna coil conductors 22 and 23 are spiral conductor patterns wound around the opening 24 of the flexible base material 21. The antenna coil conductor 22 and the antenna coil conductor 23 are electrically connected by stray capacitance generated between the conductors or by direct connection via via holes (not shown) provided in the flexible base material 21.

  FIG. 5D is an equivalent circuit diagram of the antenna coil. Here, the inductor L22 is an inductor corresponding to the inductance of the antenna coil conductor 22, and the inductor L23 is an inductor corresponding to the inductance of the antenna coil conductor 23. Capacitors C1 and C2 are capacitors that represent the capacitance generated between the antenna coil conductors 22 and 23 in a lumped constant circuit.

  In this way, an LC resonance circuit is constituted by the antenna coil conductors 22 and 23. The resonance frequency of this resonance circuit is made to coincide with the frequency of the communication signal. As a result, it can be matched with the feeding coil and matched with the antenna of the communication partner.

  As shown in FIG. 5A, if the conductor patterns of the antenna coil conductor 22 on the upper surface and the antenna coil conductor 23 on the lower surface are arranged so as to interpolate with each other in plan view, the flexible substrate 21 can be passed through. Therefore, the magnetic flux effectively passes through the magnetic core inserted through the opening 24. Therefore, the degree of coupling with the power feeding coil and the degree of coupling with the communication partner antenna can be increased.

<< Third Embodiment >>
FIG. 6 is a diagram illustrating a configuration of the antenna coil 203 provided in the antenna device of the third embodiment. A spiral antenna coil conductor 22 is formed on the upper surface of the flexible substrate 21, and a spiral antenna coil conductor 23 is formed on the lower surface. The outer peripheral end of the antenna coil conductor 22 is electrically connected to the outer peripheral end of the antenna coil conductor 23, and the inner peripheral end of the antenna coil conductor 22 is electrically connected to the inner peripheral end of the antenna coil conductor 23.

  FIG. 7 is a diagram illustrating the coupling between the feeding coil 101 and the antenna coil 203 and the coupling between the antenna coil 203 and the antenna of the communication partner.

  A magnetic material is provided so as to cover the antenna coil conductors 22, 23 along a part of the antenna coil conductors 22, 23 on the side opposite to the surface close to the power supply coil 101 (that is, the surface on which the antenna coil conductor 22 is formed). A core 26 is disposed. The magnetic core 26 is disposed from the inner edge to the outer edge of the antenna coil conductors 22 and 23.

  The configuration of the power supply coil 101 is the same as that of the power supply coil 101 shown in the first embodiment. The feeding coil 101 and the antenna coil 203 constitute an antenna device 303.

  The feeding coil 101 is mounted on the printed wiring board 32, and the antenna coil 203 is attached to the inner surface of the casing 31 of the communication terminal device.

  The magnetic flux MF1 passing through the magnetic core 13 of the feeding coil 101 passes through the magnetic core 26 of the antenna coil 203. The magnetic flux MF1 passing through the magnetic core 26 circulates along a path passing through the inner edge portions of the antenna coil conductors 22 and 23. As a result, the feeding coil 101 and the antenna coil 203 are magnetically coupled.

  Further, the magnetic flux MF2 passing through the magnetic core 26 of the antenna coil 203 circulates along a path that passes through the inner edge portions of the antenna coil conductors 22 and 23 of the antenna coil 203. This magnetic flux MF2 is coupled to a communication partner antenna (for example, a loop antenna). As a result, the antenna coil 203 and the communication partner antenna are magnetically coupled.

  The antenna coil conductor is not limited to the one formed by a pair of coil conductors formed on both surfaces of the flexible base material 21, and the antenna coil conductor can be similarly applied to one formed only on one surface of the flexible base material.

<< Fourth Embodiment >>
FIG. 8 is a diagram illustrating a configuration of the antenna coil 204 provided in the antenna device of the fourth embodiment. A spiral antenna coil conductor 22 is formed on the upper surface of the flexible substrate 21, and a spiral antenna coil conductor 23 is formed on the lower surface. The outer peripheral end of the antenna coil conductor 22 is electrically connected to the outer peripheral end of the antenna coil conductor 23, and the inner peripheral end of the antenna coil conductor 22 is electrically connected to the inner peripheral end of the antenna coil conductor 23.

  FIG. 9 is a diagram illustrating coupling between the feeding coil 101 and the antenna coil 204 and coupling between the antenna coil 204 and the antenna of the communication partner.

  A magnetic material is provided so as to cover the antenna coil conductors 22, 23 along a part of the antenna coil conductors 22, 23 on the side opposite to the surface close to the power supply coil 101 (that is, the surface on which the antenna coil conductor 22 is formed). A core 26 is disposed. In addition, the magnetic core 27 is disposed on the surface side of the antenna coil conductors 22 and 23 where the feeding coil 101 is close (that is, on the surface on which the antenna coil conductor 23 is formed). The magnetic cores 26 and 27 are disposed from the inner edge to the outer edge of the antenna coil conductors 22 and 23, respectively.

  The configuration of the power supply coil 101 is the same as that of the power supply coil 101 shown in the first embodiment. The feeding coil 101 and the antenna coil 204 constitute an antenna device 304.

  The feeding coil 101 is mounted on the printed wiring board 32, and the antenna coil 204 is attached to the inner surface of the casing 31 of the communication terminal device.

  The magnetic flux MF1 passing through the magnetic core 13 of the power feeding coil 101 passes through the magnetic core 26 of the antenna coil 204. The magnetic flux MF1 passing through the magnetic core 26 circulates along a path passing through the inner edge portions of the antenna coil conductors 22 and 23. As a result, the feeding coil 101 and the antenna coil 204 are magnetically coupled.

  On the other hand, the magnetic flux MF2 passing through the magnetic cores 26 and 27 of the antenna coil 204 circulates along a path passing through the inner edge portions of the antenna coil conductors 22 and 23 of the antenna coil 204. This magnetic flux MF2 is coupled to a communication partner antenna (for example, a loop antenna). As a result, the antenna coil 204 and the communication partner antenna are magnetically coupled.

  The antenna coil conductor is not limited to the one formed by a pair of coil conductors formed on both surfaces of the flexible base material 21, and the antenna coil conductor can be similarly applied to one formed only on one surface of the flexible base material.

<< Fifth Embodiment >>
FIG. 10 is a diagram illustrating the coupling between the feeding coil 102 and the antenna coil 202 and the coupling between the antenna coil 202 and the communication partner antenna in the antenna device 305 according to the fifth embodiment.

  The feeding coil 102 is mounted on the printed wiring board 32, and the antenna coil 201 is attached to the inner surface of the casing 31 of the communication terminal device.

  A magnetic core that covers the antenna coil conductors 22 and 23 along a part of the antenna coil conductors 22 and 23 on the side opposite to the surface where the feeding coil 102 is close (the surface on which the antenna coil conductor 22 is formed). 26 is arranged. The magnetic core 26 is disposed from the inner edge to the outer edge of the antenna coil conductors 22 and 23.

  The power supply coil 102 has the power supply coil 12 wound around four side surfaces of a rectangular parallelepiped magnetic core 13 made of ferrite. That is, the coil winding axis is perpendicular to the plane formed by the antenna coil conductors 22 and 23. The feeding coil 102 is disposed at a position surrounded by the inner edge portions of the antenna coil conductors 22 and 23 in plan view. Therefore, the magnetic flux MF1 passing through the magnetic core 13 of the power feeding coil 102 passes through the magnetic core 26 of the antenna coil 202. The magnetic flux MF1 passing through the magnetic core 26 circulates along a path passing through the inner edge portions of the antenna coil conductors 22 and 23. As a result, the feeding coil 102 and the antenna coil 202 are magnetically coupled.

  The magnetic flux MF2 passing through the magnetic core 26 of the antenna coil 202 circulates along a path that passes through the inner edge portions of the antenna coil conductors 22 and 23 of the antenna coil 202. This magnetic flux MF2 is coupled to the communication partner antenna. As a result, the antenna coil 202 and the communication partner antenna are magnetically coupled.

  The antenna coil conductor is not limited to the one formed by a pair of coil conductors formed on both surfaces of the flexible base material 21, and the antenna coil conductor can be similarly applied to one formed only on one surface of the flexible base material.

  Thus, the winding axis of the feeding coil 12 may be perpendicular to the plane formed by the antenna coil conductor.

<< Sixth Embodiment >>
FIG. 11 is a cross-sectional view of a communication terminal apparatus according to the sixth embodiment. In addition to the feeding coil 101, a battery pack 33, which is a metal article, and other mounting parts are mounted on the printed wiring board 32 in the housing 31 of the communication terminal device. An antenna coil 201 is affixed to the inner surface of the housing 31. An antenna device 301 including the feeding coil 101 and the antenna coil 201 is the same as that shown in the first embodiment.

  In the example shown in FIG. 11, the antenna device 301 is disposed on the lower surface CS1 side of the housing 31 of the communication terminal device. Is possible. In addition, the magnetic core 25 is arranged so that the antenna device 301 is disposed at a position near the tip CS4 of the casing 31 and the magnetic core 25 is hidden behind the antenna coil conductor 22 when viewed from the lower surface of the casing 31. Since the antenna coil 201 is arranged, the directivity of the antenna coil 201 is directed in the arrow D direction. Therefore, a high gain can be obtained by holding a ridge formed by the tip CS4 and the lower surface CS1 of the casing 31 of the communication terminal device over the central portion of the antenna of the communication partner.

<< Other embodiments >>
In each of the embodiments described above, an example in which the antenna coil is attached to the inner surface of the housing has been described. However, the antenna coil may be provided on the surface (outer surface) of the housing, and the feeding coil may be disposed in the housing. .

CS1 ... lower surface CS3 of the casing ... rear end CS4 of the casing ... tips MF1 and MF2 of the casing ... magnetic flux 12 ... feeding coil 13 ... magnetic body core 14 ... input / output terminals 21 ... flexible base materials 22 and 23 ... antenna coil conductor 24 ... Openings 25, 26, 27 ... Magnetic core 31 ... Housing 32 ... Printed wiring board 33 ... Battery pack 34 ... Mounted parts 101, 102 ... Feed coils 201-204 ... Antenna coils 301, 303-305 ... Antenna device

Claims (8)

An antenna device comprising a feeding coil and an antenna coil coupled to the feeding coil via a magnetic field,
The coil conductor of the antenna coil is formed in a spiral shape having an inner edge and an outer edge,
An antenna device, wherein a first magnetic layer is provided on a surface of the antenna coil opposite to a surface where the feeding coil is close so as to cover a part of the coil conductor of the antenna coil. .   The antenna device according to claim 1, wherein the first magnetic layer is disposed from an inner edge portion to an outer edge portion of a coil conductor of the antenna coil. The winding axis of the coil conductor of the feeding coil is substantially orthogonal to the winding axis of the coil conductor of the antenna coil,
The first magnetic layer and the feeding coil are arranged at a position where the feeding coil and the first magnetic layer overlap in a plan view from the winding axis direction of the coil conductor of the antenna coil. The antenna device according to claim 1 or 2.   The antenna coil extends from the inner edge portion to the outer edge portion of the coil conductor of the antenna coil at a position different from the position where the first magnetic layer overlaps on the surface side of the antenna coil close to the feeding coil. The antenna device according to claim 1, wherein the second magnetic layer is disposed so as to cover a part of the coil conductor of the coil. The coil conductor of the antenna coil is composed of a spiral conductor pattern wound around the opening formed in the flexible base material,
The antenna device according to claim 4, wherein the first magnetic layer and the second magnetic layer are an integrated sheet-like magnetic layer, and are inserted through the opening of the flexible base material. . A communication terminal device including an antenna coil to which a feeding coil is coupled to an inner surface or a surface of a housing via a magnetic field,
The coil conductor of the antenna coil is formed in a spiral shape having an inner edge and an outer edge,
A first magnetic layer is provided on the side of the antenna coil opposite to the side close to the feeding coil so as to cover a part of the coil conductor of the antenna coil,
A communication terminal apparatus, wherein the power supply coil and a power supply circuit connected to the power supply coil are disposed in the casing. The antenna coil extends from the inner edge portion to the outer edge portion of the coil conductor of the antenna coil at a position different from the position where the first magnetic layer overlaps on the surface side of the antenna coil close to the feeding coil. A second magnetic layer is disposed so as to cover a part of the coil conductor of the coil;
The communication terminal device according to claim 6, wherein a metal article is disposed at a position close to the second magnetic layer on a surface side where the power feeding coil is close. The coil conductor of the antenna coil is composed of a spiral conductor pattern wound around the opening formed in the flexible base material,
The communication terminal according to claim 7, wherein the first magnetic body layer and the second magnetic body layer are an integrated sheet-like magnetic body layer, and are inserted into the opening of the flexible base material. apparatus.

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