JP2011101293A - Composite antenna and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite antenna including an antenna for near-field communication and an antenna for far-field communication, increasing density of mounting in an electronic apparatus while suppressing performance deterioration of the antennas; and the electronic apparatus equipped with the same. <P>SOLUTION: Coil conductors 31-1, 31-2 which are spiral respectively are formed on a flexible substrate 21, and the two coil conductors 31-1, 31-2 are connected in series. The antenna 41 for far-field communication is disposed at a center part of an arrangement region of the two coil conductors 31-1, 31-2. The antenna 41 for far-field communication is composed of a patterned conductor formed on the flexible substrate 21. On a lower surface of the flexible substrate 21, magnetic cores 51-1, 51-2 formed of ferrite plates are disposed below the two coil conductors 31-1, 31-2. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a composite antenna of a coil antenna and a radio communication antenna used in an RFID (Radio Frequency Identification) system or the like that communicates with an electromagnetic field signal, and an electronic device including the same.

  Patent Document 1 discloses a mobile phone mounting antenna in which an RFID antenna configured by one loop and a mobile phone communication antenna are formed on one flexible substrate.

  FIG. 1 is a plan view showing a configuration of a flexible printed circuit board mounted on a mobile phone as disclosed in Patent Document 1. As shown in FIG. A flexible printed circuit board 1 mounted on a mobile phone includes an antenna (RFID antenna) 11 for communicating with an external RFID reader or reader / writer, and an antenna (mobile phone communication antenna) for communicating with a base station. And 12) are printed with a copper foil or the like at a predetermined interval. Although the RFID antenna 11 is a multi-turn coil antenna, only the formation region is shown in FIG.

  The RFID antenna 11 is a coiled antenna that is driven by receiving electric power from an electromagnetic wave transmitted from an RFID reader or reader / writer. The cellular phone communication antenna 12 serves as an antenna element for allowing the copper foil portion printed on the flexible printed circuit board 1 to communicate with the cellular phone.

JP 2007-306287 A

  The RFID antenna 11 disclosed in Patent Document 1 is a coil antenna, and the mobile phone communication antenna 12 is a monopole antenna. Each antenna is originally composed of two substrates on a single substrate. For this reason, the area occupied by the antenna cannot be reduced, and interaction with each other's antenna may occur, leading to deterioration of communication characteristics.

  The present invention relates to a composite antenna including an antenna for near-field (near-field electromagnetic) communication and an antenna for far-field communication, and the present invention increases the mounting density inside an electronic device and suppresses performance degradation of the antenna. It is an object of the present invention to provide a composite antenna and an electronic device including the same.

  The composite antenna of the present invention is a composite antenna of a near-field communication antenna and a far-field communication antenna, arranged separately on the left and right, and connected so that the voltage induced by the passing magnetic flux is not canceled out. The far-field communication antenna is arranged at the center of the arrangement area of the two coil conductors (for example, the position where the symmetry axis of the symmetrical magnetic flux passes). Is.

  The two coil conductors are, for example, spiral conductors each having a winding center portion as a conductor opening formed in a flexible substrate, and the flexible substrate has a through hole formed in the conductor opening. Thus, a magnetic core is inserted into the through hole.

  The two coil conductors are, for example, spiral conductors formed on a flexible substrate, and a magnetic core is disposed close to the coil conductor forming region of the flexible substrate.

  The two coil conductors are, for example, spiral conductors formed on a flexible substrate, respectively, and the formation area of the coil conductor of the flexible substrate is wound around three surfaces of the end of the magnetic core. A magnetic core is disposed.

  The far-field communication antenna is a patterned conductor formed on the flexible substrate, and a dielectric may be disposed close to the patterned conductor.

  The far-field communication antenna is, for example, a dielectric antenna in which a patterned conductor is formed on a dielectric substrate, and the dielectric antenna is mounted on the flexible substrate.

  The electronic device according to the present invention is an electronic device in which the composite antenna having any one of the above-described configurations is housed in a housing, and a width of a circuit board in the housing is substantially equal to a width in the left-right direction of the composite antenna. The composite antenna is disposed (mounted) on the circuit board from one end to the other end in the width direction of the substrate.

  According to the present invention, since the magnetic flux generated by the two coil conductors is weak at the center of the arrangement area of the two coil conductors, the eddy current generated in the conductor of the far-field communication antenna is small. Therefore, unnecessary loss during near-field communication such as RFID can be reduced.

  In addition, during communication using the far-field communication antenna, inflow of signals due to near-field communication such as RFID is reduced, and communication is stabilized.

  As described above, the electrical characteristics can be improved and, at the same time, the near-field communication antenna and the far-field communication antenna can be configured in the same region, so that the area occupied by the antenna can be reduced. As a result, the electronic device can be downsized.

FIG. 11 is a plan view showing a configuration of a flexible printed board mounted on a mobile phone according to Patent Document 1. 2 is a plan view of the composite antenna 61 according to the first embodiment in a state where the composite antenna 61 is disposed on a circuit board 71. FIG. FIG. 3A is a cross-sectional view of the composite antenna 61. FIG. 3B is a cross-sectional view in a state where the composite antenna 61 is disposed on the circuit board 71. FIG. 3C is a cross-sectional view of an electronic device provided with the composite antenna 61. 7 is a plan view of a state in which a composite antenna 62 according to a second embodiment is arranged on a circuit board 71. FIG. FIG. 5 is a developed perspective view of the composite antenna 62 shown in FIG. 4. FIG. 6A is a plan view of the composite antenna 63 according to the third embodiment. FIG. 6B is a front view in a state where the composite antenna 63 is disposed on the circuit board 71. It is a top view of the composite antenna 64 which concerns on 4th Embodiment. FIG. 8A is a plan view of the composite antenna 65 according to the fifth embodiment. FIG. 8B is a front view of the composite antenna 65 arranged on the circuit board 71. FIG. 9A is a plan view of the composite antenna 66 according to the sixth embodiment. FIG. 9B is a front view in a state where the composite antenna 66 is disposed on the circuit board 71. FIG. 10A is a plan view of a composite antenna 67 according to the seventh embodiment. FIG. 10B is a front view of the composite antenna 67 placed on the circuit board 71. FIG. 11A is a development view of the flexible substrate 24 used in the composite antenna 68 according to the eighth embodiment. FIG. 11B is a front view of the composite antenna 68. FIG. 11C is a top view of the composite antenna 68.

<< First Embodiment >>
The composite antenna according to the first embodiment will be described with reference to FIGS.
FIG. 2 is a plan view of the composite antenna 61 according to the first embodiment arranged on the circuit board 71.

  As shown in FIG. 2, spiral flexible coil conductors 31-1 and 31-2 are separately formed on the flexible substrate 21 on the left and right sides, and the two coil conductors 31-1 and 31 are formed. -2 are connected in series so that the voltage induced by the magnetic flux passing through them is not canceled. One end of the coil conductor 31-1 is electrically connected to the connecting portion 31-1A. Similarly, one end of the coil conductor 31-2 is electrically connected to the connection 31-2A. As will be described later, the coil conductors 31-1 and 31-2 are part of a near-field communication antenna.

  A far-field communication antenna 41 is arranged at the center of the arrangement area of the two coil conductors 31-1, 31-2. The far-field communication antenna 41 is composed of a patterned conductor formed on the flexible substrate 21. The end of the far-field communication antenna 41 (patterned conductor) is electrically connected to the connecting portion 41A.

  On the lower surface of the flexible substrate 21, magnetic cores 51-1 and 51-2 made of ferrite plates are disposed below the two coil conductors 31-1 and 31-2.

  The circuit board 71 is provided with a capacitor connected in parallel to the series circuit of the coil conductors 31-1 and 31-2. Due to the parallel resonance of the inductances of the coil conductors 31-1 and 31-2 and the capacitance of the capacitor, it acts as an antenna that resonates at a frequency of near field communication (for example, 13.56 MHz). That is, the coil conductors 31-1, 31-2, the capacitor, and the magnetic cores 51-1, 51-2 constitute a near-field communication antenna.

On the other hand, the far-field communication antenna 41 is used, for example, to communicate with a mobile phone base station.
The composite antenna 61 having the configuration described above is disposed on the upper surface of the circuit board 71.

  FIG. 3A is a cross-sectional view of the composite antenna 61. FIG. 3B is a cross-sectional view in a state where the composite antenna 61 is disposed on the circuit board 71. FIG. 3C is a cross-sectional view of an electronic device such as a mobile phone terminal provided with the composite antenna 61.

  The width of the circuit board 71 is substantially equal to the width in the left-right direction of the composite antenna 61. The composite antenna 61 is disposed (mounted) on the circuit board 71 from one end to the other end in the width direction of the circuit board 71. Yes. 2 are connected to the electrodes on the circuit board 71. The connection portions 31-1A, 31-2A, and 41A shown in FIG.

  As shown in FIG. 3C, an electronic device such as a mobile phone terminal is housed with a composite antenna 61 and a circuit board 71 inside housings 81 and 82.

In FIG. 3B, a broken-line arrow representatively represents a magnetic flux path in a state of near-field communication in a coupled state with an RFID reader / writer side antenna.
As shown in FIG. 2, the two coil conductors 31-1 and 31-2 are connected in series. As shown in FIG. 3B, this series connection is such that when the symmetrical magnetic flux passes, the voltages induced in the two coil conductors 31-1 and 31-2 are added. Has been made.

  Thus, the magnetic flux passing through the coil conductors 31-1 and 31-2 is weak at the center of the arrangement area of the coil conductors 31-1 and 31-2. Also, the magnetic flux generated by the RFID reader / writer is weak at the center of the arrangement area of the coil conductors 31-1 and 31-2. Therefore, there is little eddy current generated in the conductor of the far-field communication antenna 41 by the magnetic field during communication for RFID. Therefore, unnecessary loss during communication for RFID can be reduced.

In addition, the inflow of signals due to near-field communication such as RFID is reduced in the far-field communication antenna 41, and communication using the far-field communication antenna is stabilized.
Furthermore, the electrical characteristics can be improved, and at the same time, the near-field communication antenna and the far-field communication antenna can be configured in the same region as a composite antenna. Occupied area can be reduced. As a result, the electronic device 101 can be downsized.

<< Second Embodiment >>
A composite antenna according to the second embodiment will be described with reference to FIGS.
FIG. 4 is a plan view of the composite antenna 62 according to the second embodiment arranged on the circuit board 71.

  As shown in FIG. 4, helical coil conductors 32-1 and 32-2 are respectively formed on the flexible substrate 22, and the two coil conductors 32-1 and 32-2 are connected in series. It is connected. One end of the coil conductor 32-1 is electrically connected to the connection portion 32-1A. Similarly, one end portion of the coil conductor 32-2 is electrically connected to the connection portion 32-2A.

  A far-field communication antenna 41 is arranged at the center of the arrangement area of the two coil conductors 32-1 and 32-2. The far-field communication antenna 41 is composed of a patterned conductor formed on the flexible substrate 22. The far-field communication antenna 41 is formed on the flexible substrate 22 in an insulated state from the coil conductors 32-1 and 32-2. The end of the far-field communication antenna 41 (patterned conductor) is electrically connected to the connecting portion 41A.

  Magnetic body cores 52-1 and 52-2 made of ferrite plates are arranged inside the coil conductors 32-1 and 32-2 wound in a helical shape. In other words, the coil conductors 32-1 and 32-2 are helically wound around the magnetic cores 52-1 and 52-2.

  FIG. 5 is an exploded perspective view of the composite antenna 62 shown in FIG. The flexible substrate 22 is formed with patterned conductors in which the coil conductors 32-1 and 32-2 are developed. The flexible substrate 22 is bent so that the patterned conductor surrounds the periphery of the magnetic cores 52-2 and 52-1. And the helical coil conductor shown in FIG. 4 is comprised by electrically connecting the predetermined ends of the patterned conductor.

  In the flexible substrate 22, a far-field communication antenna 41 is formed of a patterned conductor at a position where the bending is not performed.

<< Third Embodiment >>
FIG. 6A is a plan view of the composite antenna 63 according to the third embodiment. FIG. 6B is a front view in a state where the composite antenna 63 is disposed on the circuit board 71. The difference from the composite antenna 61 according to the first embodiment shown in FIGS. 2 and 3 is the relationship between the coil conductor on the flexible substrate and the magnetic core.

  As shown in FIGS. 6 (A) and 6 (B), the two coil conductors 33-1 and 33-2 are spiral conductors having respective winding centers as conductor openings, It is formed on the flexible substrate 23. A through hole is formed in the conductor opening of the flexible substrate 23, and the magnetic cores 53-1 and 53-2 are inserted into the through hole.

Other configurations are the same as those shown in the first embodiment.
Thus, a composite antenna of a type in which a magnetic core is inserted into a spiral coil conductor can also be configured.

<< Fourth Embodiment >>
FIG. 7 is a plan view of the composite antenna 64 according to the fourth embodiment. What is different from the composite antenna 61 according to the first embodiment shown in FIG. 2 is the shape of the magnetic cores 54-1 and 54-2.

  As shown in FIG. 7, the two coil conductors 31-1 and 31-2 are spiral conductors having respective winding centers as conductor openings, and are formed on the flexible substrate 21. The outer widths of the magnetic cores 54-1 and 54-2 are larger than the inner width. The inner widths of the magnetic cores 54-1 and 54-2 are substantially equal to the conductor openings of the coil conductors 31-1 and 31-2. Other configurations are the same as those shown in the first embodiment.

  In this way, by widening the outside of the magnetic cores 54-1 and 54-2, the magnetic resistance of the near-field communication antenna is reduced without increasing the size of the entire composite antenna 64, and near-field communication is achieved. The antenna gain of the antenna can be improved.

<< Fifth Embodiment >>
FIG. 8A is a plan view of the composite antenna 65 according to the fifth embodiment. FIG. 8B is a front view of the composite antenna 65 arranged on the circuit board 71. What is different from the composite antenna 61 according to the first embodiment shown in FIGS. 2 and 3 is the positional relationship between the coil conductor on the flexible substrate and the magnetic core.

  As shown in FIG. 8 (A) and FIG. 8 (B), the two coil conductors 31-1 and 31-2 are spiral conductors having respective winding centers as conductor openings, It is formed on the flexible substrate 21.

On the lower surface of the flexible substrate 21, magnetic cores 55-1 and 55-2 made of ferrite plates are disposed below the two coil conductors 31-1 and 31-2. In this example, one corner of the magnetic cores 55-1 and 55-2 coincides with the corner of the flexible substrate 21, and the corner at a diagonal position with respect to the magnetic core 55-1, 55-2 does not protrude from the conductor opening. Body cores 55-1 and 55-2 are arranged.
Other configurations are the same as those shown in the first embodiment.

  Thus, by arranging the magnetic cores 55-1 and 55-2 at positions shifted outward from the positions where the coil conductors 31-1 and 31-2 are formed, the coil conductors 31-1 and 31-2 are disposed. The magnetic flux that passes effectively increases, and the antenna gain of the near-field communication antenna can be improved.

<< Sixth Embodiment >>
FIG. 9A is a plan view of the composite antenna 66 according to the sixth embodiment. FIG. 9B is a front view in a state where the composite antenna 66 is disposed on the circuit board 71. What is different from the composite antenna 63 according to the third embodiment shown in FIGS. 6 (A) and 6 (B) is the configuration of the part related to the far-field communication antenna 41.

  The far-field communication antenna 41 is a patterned conductor formed on the flexible substrate 23, and a dielectric plate 91 is disposed in proximity to the patterned conductor. Therefore, the patterned conductor of the far-field communication antenna 41 receives the wavelength shortening effect of the dielectric. Therefore, the area occupied by the far-field communication antenna 41 can be reduced. Further, a high-gain far-field communication antenna can be configured within a limited area.

<< Seventh Embodiment >>
FIG. 10A is a plan view of a composite antenna 67 according to the seventh embodiment. FIG. 10B is a front view of the composite antenna 67 placed on the circuit board 71. What is different from the composite antenna 63 according to the third embodiment shown in FIGS. 6 (A) and 6 (B) is the configuration of the far-field communication antenna 42.

  The far-field communication antenna 42 is a dielectric antenna in which a patterned conductor is formed on a rectangular parallelepiped dielectric base, and the far-field communication antenna 42 is mounted on the flexible substrate 23. Further, the flexible substrate 23 is configured with a conductor line that conducts between the terminal electrode (land) to which the terminal electrode of the far-field communication antenna 42 is connected and the connecting portion 42A.

<< Eighth Embodiment >>
FIG. 11A is a development view of the flexible substrate 24 used in the composite antenna 68 according to the eighth embodiment. FIG. 11B is a front view of the composite antenna 68. FIG. 11C is a top view of the composite antenna 68.

  Each of the two coil conductors 34-1 and 34-2 is formed by forming a spiral conductor on the flexible substrate 24, and the formation area of the coil conductors 34-1 and 34-2 on the flexible substrate 24 is a magnetic core. Magnetic cores 56-1 and 56-2 are arranged so as to be wound around the three surfaces of the end portions of 56-1 and 56-2.

  In this manner, a composite antenna of a type in which a spiral coil conductor is formed in the formation region and the flexible substrate is wound around three surfaces of the magnetic core can be configured.

  In each of the embodiments described above, the two coil conductors are connected in series. However, the two coil conductors may be connected in parallel so that the voltages induced in the two coil conductors do not cancel each other. .

  In each of the embodiments described above, a conductor surface such as a circuit board is disposed in proximity to two coil conductors for near-field communication arranged separately on the left and right, but this conductor surface is not essential. . Even in the type having no conductor surface, the magnetic flux passing through the two coil conductors becomes zero or substantially zero at the position of the far-field communication antenna, and the same effect is obtained.

21-24 ... Flexible substrates 31-1, 31-2 ... Coil conductors 32-1, 32-2 ... Coil conductors 33-1, 33-2 ... Coil conductors 34-1 and 34-2 ... Coil conductors 31-1A, 31-2A ... Connections 32-1A, 32-2A ... Connections 33-1A, 33-2A ... Connections 34-1A, 34-2A ... Connections 41, 42 ... Far-field communication antennas 41A, 42A ... Connections Units 51-1, 51-2 ... magnetic cores 52-1, 52-2 ... magnetic cores 53-1, 53-2 ... magnetic cores 54-1 and 54-2 ... magnetic cores 55-1, 55 -2 ... Magnetic cores 56-1, 56-2 ... Magnetic cores 61-68 ... Composite antenna 71 ... Circuit boards 81, 82 ... Housing 91 ... Dielectric plate 101 ... Electronic equipment

Claims (7)

Provided with two coil conductors for near-field communication, arranged separately on the left and right, connected in a relationship that does not cancel the voltage induced by the passing magnetic flux,
A composite antenna in which a far-field communication antenna is arranged at the center of the arrangement area of the two coil conductors.   The two coil conductors are each formed by forming a spiral conductor having a winding opening as a conductor opening in a flexible substrate, and the flexible substrate has a through hole formed in the conductor opening, The composite antenna according to claim 1, wherein a magnetic core is inserted into the through hole.   2. The composite according to claim 1, wherein each of the two coil conductors has a spiral conductor formed on a flexible substrate, and a magnetic core is disposed close to a region where the coil conductor is formed on the flexible substrate. antenna.   Each of the two coil conductors is formed by forming a spiral conductor on a flexible substrate, and the magnetic body is formed such that the formation area of the coil conductor of the flexible substrate is wound around three end surfaces of the magnetic core. The composite antenna according to claim 1, wherein a core is disposed.   5. The composite antenna according to claim 2, wherein the far-field communication antenna is a patterned conductor formed on the flexible substrate, and a dielectric is disposed in proximity to the patterned conductor.   5. The composite antenna according to claim 2, 3, or 4, wherein the far-field communication antenna is a dielectric antenna in which a patterned conductor is formed on a dielectric substrate, and the dielectric antenna is mounted on the flexible substrate. . An electronic device in which the composite antenna according to any one of claims 1 to 6 is housed in a housing,
The width of the circuit board in the housing is substantially equal to the width in the left-right direction of the composite antenna,
An electronic apparatus in which the composite antenna is disposed on the circuit board from one end to the other end in the width direction of the circuit board.

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