JP2018148452A - Antenna device and communication terminal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ring-type antenna device that has a simple configuration and an excellent communication characteristic, and a communication terminal device comprising the antenna device.SOLUTION: An antenna device comprises a power supply coil 5 and a ring-shaped conductor 1 that is arranged around an axis A and has a first edge face 11 and second edge face 12 in the axis A direction. The power supply coil 5 includes a power supply wire wound when viewed from the radial direction of the ring-shaped conductor 1. The ring-shaped conductor 1 has an aperture 3 at a position apart from the first edge face 11 and second edge face 12, the aperture extending around the axis A and opening outwards. When viewed from the radial direction, at least part of the aperture 3 overlaps with a coil aperture of the power supply coil 5.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an antenna device and a communication terminal device.

  In recent years, various ring-shaped communication terminal devices such as rings, bracelets, and wristwatches that can be directly worn and carried have been devised. Such a communication terminal device is referred to as a so-called wearable terminal, and is an information terminal that is worn on the body and used instead of being carried like a smartphone or a notebook computer.

  For example, Patent Document 1 describes a communication terminal device including an integrated circuit, a wireless tag side antenna, and a reader / writer side antenna on a base portion of a ring. Patent Document 2 describes a bracelet-type communication terminal device that is connected to a control circuit in a main body and performs non-contact data communication by using two sheet-like coils embedded in a belt. Patent Document 3 describes a ring-type communication terminal device in which a linear conductor continuous in the circumferential direction is built in an arm and functions as an antenna.

JP 2008-187653 A Japanese Patent Laid-Open No. 3-202997 JP 2003-93368 A

  However, the communication terminal devices of Patent Documents 1 to 3 still have a problem that communication characteristics are low.

  An object of the present invention is to provide a ring-type antenna device having good communication characteristics and a communication terminal device including the antenna device.

  The antenna device of the present invention includes a feeding coil and a ring-shaped conductor that is arranged around the axis and has a first end face and a second end face in the axial direction, and the feeding coil extends from the radial direction of the ring-shaped conductor. The ring-shaped conductor has an opening that extends around the axis and opens outward at a position spaced from the first end surface and the second end surface. The portion is characterized in that at least a portion thereof overlaps with a coil opening of the power feeding coil as viewed from the radial direction.

  The antenna device of the present invention includes a feeding coil, a ring-shaped conductor disposed around the axis and having a first end surface and a second end surface in the axial direction, and an inner ring-shaped member inserted into the ring-shaped conductor. The power supply coil is configured by winding a power supply wire around the outer surface of the inner ring-shaped member, and the ring-shaped conductor is located at a position spaced apart from the first end surface and the second end surface. It has an opening that extends around the axis and opens outward, and a part of the feeding coil is located in the opening as viewed from the radial direction of the ring-shaped conductor.

  A communication terminal device according to the present invention includes the antenna device described above and a power feeding circuit that is connected to the power feeding coil or that performs electric field coupling, magnetic field coupling, or electromagnetic field coupling.

  According to the present invention, it is possible to realize a ring-type antenna device with good communication characteristics and a communication terminal device including the antenna device.

The antenna apparatus which concerns on 1st Embodiment is shown, (a) is a top view, (b) is sectional drawing along the 1b-1b line of (a), (c) is 1c-1c of (a). It is sectional drawing along a line. The modification of the antenna device which concerns on 1st Embodiment is shown, (a) is a top view, (b) is sectional drawing along the 2b-2b line of (a), (c) is (a). Sectional drawing along the 2c-2c line, (d) is a top view which shows the state which only the side surface of the both sides around the axis | shaft in an opening part has spread outside. The other modification of the antenna device which concerns on 1st Embodiment is shown, (a) is sectional drawing which shows the state which the side surface of the both sides around the axis | shaft in an opening part has spread outside, (b) is (a) (C) is a cross-sectional view showing a state in which one side surface around the axis of the opening is spread outward, and (d) is a plan view of (c). The antenna apparatus which concerns on 2nd Embodiment is shown, (a) is a top view, (b) is sectional drawing along the 4b-4b line of (a), (c) is 4c-4c of (a). It is sectional drawing along a line. The antenna apparatus which concerns on 3rd Embodiment is shown, (a) is a top view, (b) is sectional drawing along the 5b-5b line of (a), (c) is 5c-5c of (a). It is sectional drawing along a line. The modification of the antenna device which concerns on 3rd Embodiment is shown, (a) is a top view, (b) is sectional drawing along the 6b-6b line | wire of (a). The other modification of the antenna device which concerns on 3rd Embodiment is shown, (a) is a top view, (b) is sectional drawing along the 7b-7b line of (a), (c) is (a) ) Is a cross-sectional view taken along line 7c-7c. The antenna apparatus which concerns on 4th Embodiment is shown, (a) is a top view, (b) is sectional drawing along the 8b-8b line | wire of (a). It is explanatory drawing which shows the simulation model of the antenna apparatus of FIG. It is explanatory drawing which shows the simulation model of the antenna apparatus of FIG.

  Hereinafter, several specific examples will be given with reference to the drawings to show a plurality of modes for carrying out the present invention. In each figure, the same reference numerals are assigned to the same portions. Each embodiment is an exemplification, and a partial replacement or combination of the configurations shown in different embodiments is possible.

  In each embodiment described below, an “antenna device” is an antenna that radiates magnetic flux. The antenna device is an antenna used for near-field communication using magnetic field coupling with an antenna on the communication partner side, and is used for communication such as NFC (Near Field Communication). The antenna device is used in, for example, the HF band as a communication frequency band, and particularly used at a frequency near 13.56 MHz.

  FIG. 1 shows an antenna device according to the first embodiment, and the antenna device includes a ring-shaped conductor 1 and a feeding coil 5.

The ring-shaped conductor 1 is a ring-shaped conductor disposed around the axis A, and has a first end surface 11 and a second end surface 12 that are perpendicular to the direction of the axis A (the vertical direction in FIG. 1A). The ring-shaped conductor 1 has an opening 3 that extends around the axis A and opens outward at a portion that is a predetermined distance away from the first end surface 11 and the second end surface 12. A side surface around the axis A of the opening 3 is formed by a through hole having a side surface along the radial direction (shown by an arrow) of the ring-shaped conductor 1.

  In other words, the first end surface 11 and the second end surface 12 of the ring-shaped conductor 1 are continuous in the circumferential direction, and the opening 3 is not connected to the first end surface 11 and the second end surface 12.

  The opening 3 has a rectangular shape in plan view (as viewed from the radial direction), and the feeding coil 5 is accommodated in the opening 3. The feeding coil 5 is a spiral conductor pattern in which a feeding line is wound when viewed from the radial direction of the ring-shaped conductor 1, and both ends thereof are connected to a feeding circuit (not shown). The power feeding coil 5 in the present embodiment is, for example, a Cu foil, and is formed on the main surface of a resin sheet such as polyimide (PI) or liquid crystal polymer (LCP).

  Since the feeding coil 5 is accommodated in the opening 3, the entire coil opening of the feeding coil 5 overlaps the opening 3 when viewed from the radial direction of the ring-shaped conductor 1.

  The opening 3 is filled with a dielectric material 7 such as resin or glass, and the feeding coil 5 is embedded in the dielectric material 7. As shown in FIG. 1C, the feeding coil 5 is disposed at the central portion of the dielectric material 7 in the radial direction, in other words, at the central portion in the thickness direction. Such an antenna device can be produced, for example, by fitting a dielectric material 7 in which the feeding coil 5 is built into the opening 3 of the ring-shaped conductor 1.

  In the present embodiment, the ring-shaped conductor 1 is curved around the axis A, and this is an example of the ring-shaped conductor “arranged around the axis” in the present invention. The magnetic field is shown by broken lines in FIGS.

  In such an antenna device, by eliminating the upper and lower conductors of the feeding coil 5, the reverse current is eliminated and the antenna characteristics are improved. In this embodiment, a magnetic material is not necessary and the cost can be reduced. By disposing the entire feeding coil 5 in the opening 3, the spread of the magnetic field can be increased and the antenna can function as an antenna.

  In such an antenna device, it is preferable that the ring-shaped conductor 1 is provided in a mounting portion through which a part of the human body (for example, a finger) is inserted. With this configuration, as a so-called wearable terminal, it is possible to realize a communication terminal device including an antenna device used in a communication system in the HF band or the UHF band.

  In the above-described example, the operation in the case where the antenna device is the transmitting antenna has been described. However, even if transmission / reception is reversed by the antenna reversibility theorem (reciprocity theorem). That is, the same operation is performed when the antenna device is a receiving antenna.

  In the antenna device according to the present embodiment, the example in which the shape of the feeding coil is a rectangular spiral conductor pattern when viewed from the radial direction is shown, but the configuration is not limited thereto. The shape of the power feeding coil can be changed as appropriate from a radial direction such as a circle, an ellipse, or a polygon. Moreover, as described above, the opening 3 is preferably sealed with a low-loss dielectric material 7 such as resin or glass. At this time, a part of the dielectric material 7 may have a decoration made of a dielectric such as sapphire or ruby.

  The communication terminal device includes, for example, the antenna device, RFIC elements connected to both ends of the feeding coil 5, and a capacitor connected in parallel to the feeding coil 5.

FIG. 2 shows a modification of the antenna device according to the first embodiment of FIG. 1 described above. In this antenna device, the entire side surface of the opening 3 of the ring-shaped conductor 1 spreads outward. ing.

  That is, as shown in FIG. 2 (c), the opening 3 is composed of an annular inner side surface 31 along the radial direction and an annular outer side surface 32 extending outward from the inner side surface 31. The feeding coil 5 is located at the outer side surface 32 portion. The outer side surface 32 is formed on the entire circumference of the opening 3. The outer side surface 32 is a portion indicated by an alternate long and short dash line in FIG. 2C so that the outer side surface 32 formed on the entire circumference of the opening 3 is flush with the outer surface of the ring-shaped conductor 1 of FIG. It can be formed by removing by polishing or the like.

  In such an antenna device, the magnetic field spreads from the feeding coil 5 in the direction around the axis A and in the direction of the axis A, and the magnetic field spreads more outward than the antenna device of FIG. Thus, an antenna device with good communication characteristics can be provided. It is desirable that at least a part of the feeding coil 5 is at the upper side than the plane of the outer side surface 32. If even a part of the feeding coil 5 is above the plane of the outer side surface 32, an effect of improving antenna characteristics can be obtained. This is because the magnetic field can spread in the plane direction from the feeding coil 5 by eliminating the conductor on the side surface of the feeding coil 5 even if only a part is present.

  In FIG. 2, the outer side surface 32 forming the opening 3 is polished so as to be on the same plane. However, the outer side surface 32 only needs to spread outward, and a part thereof is inclined at a different angle. You may have a face.

  Further, as shown in FIG. 2D, the ring-shaped conductor 1 is polished in the direction around the axis A of the ring-shaped conductor 1 without polishing the outer surface in the vicinity of the first end face 11 side and the second end face 12 side. Also good. In this case, the outer side surface 32 is formed only on both sides of the opening 3 in the direction around the axis A.

  Even in such an antenna device, since the magnetic field spreads outward in the direction around the axis A as compared with the antenna device of FIG. 1, it is easier to couple with the antenna coil on the communication partner side, and an antenna device with good communication characteristics can be provided.

  FIG. 3 shows another form of the antenna device in which the side surface of the opening 3 is expanded. In FIG. 2, a part of the side surface (outer portion) of the opening 3 is expanded outward. 3A and 3B, the entire side surfaces 33 on both sides in the direction around the axis A of the ring-shaped conductor 1 are spread outward. That is, in this antenna device, the side surfaces on the first end surface 11 side and the second end surface 12 side in the opening 3 are side surfaces along the radial direction, but the side surfaces 33 on both sides in the direction around the axis A of the ring-shaped conductor 1. However, it inclines outside rather than the side surface of radial direction.

  In such an antenna device, since the magnetic field spreads outward in the direction around the axis A, the antenna device can be easily coupled to the antenna coil on the communication partner side, and an antenna device with good communication characteristics can be provided.

  3C and 3D, one side surface of the opening 3 around the axis A is widened outward to form a side surface 34, and the other side surface is a side surface 35 along the radial direction. Even in such an antenna device, since the magnetic field spreads outward, it is easy to couple with the antenna coil on the communication partner side. Note that the magnetic field can be expanded outward as the distance between the side surface of the opening 3 and the feeding coil 5 increases. In FIG. 3C, the distance between the side surface 35 along the radial direction and the feeding coil 5 is larger than the distance between the side surface 34 spreading outward and the feeding coil 5.

FIG. 4 shows an antenna device in which the opening 3 of the ring-shaped conductor 1 is formed by a recess that opens outward, and the bottom surface of the opening 3 that is formed of the recess is the ring-shaped conductor 1. Although not shown, a magnetic layer is disposed between the coil 5 and the bottom surface of the opening 3.

  Even with such an antenna device, the same effect as that of the antenna device of FIG. 1 can be obtained. Also in this form of antenna device, the side surface around the axis constituting the opening 3 of the ring-shaped conductor 1 as shown in FIG. 2 can be expanded outward.

  FIG. 5 shows an antenna device according to the second embodiment, and the antenna device includes a ring-shaped conductor 1 and a feeding coil 5.

  In this antenna device, an inner ring-shaped member 15 made of, for example, an insulating material such as a resin is disposed inside the ring-shaped conductor 1, and the bottom of the opening 3 is closed by the inner ring-shaped member 15, so that power is fed. A part of the coil 5 is disposed between the ring-shaped conductor 1 and the inner ring-shaped member 15.

  The side surface of the opening 3 is configured by a side surface along the radial direction of the ring-shaped conductor 1. As in the first embodiment, the opening 3 is filled with a dielectric material 7 such as resin or glass, and when viewed from the radial direction of the ring-shaped conductor 1, the opening 3 5 overlaps part of the coil opening. Although not shown, a magnetic layer is disposed between the feeding coil 5 and the ring-shaped conductor 1.

  Such an antenna device can be manufactured by inserting the inner ring-shaped member 15 in which the feeding coil 5 is disposed in the ring-shaped conductor 1 in which the opening 3 is formed.

  Even with such an antenna device, the same effect as that of the antenna device of FIG. 1 can be obtained.

  FIG. 6 shows a modification of the antenna device of FIG. 5 according to the second embodiment. In this antenna device, the openings 3 are arranged on both sides around the axis A in the feeding coil 5. That is, two openings 3 are formed at intervals around the axis A of the ring-shaped conductor 1, and coil openings at both ends around the axis A of the feeding coil 5 overlap each other. .

  In such an antenna device, the magnetic field can be spread outward from the two openings 3, and it becomes easier to couple with the antenna coil on the communication partner side, and an antenna device with good communication characteristics can be provided.

  FIG. 7 shows a modification of the antenna device according to the second embodiment. In this antenna device, the side surface constituting the opening 3 of the ring-shaped conductor 1 spreads outward. In such an antenna device, as shown in FIG. 7C, the opening 3 has an inner side surface (not shown) extending in the radial direction and an outer side surface extending outward from the inner side surface. 36, and the power feeding coil 5 is located outside the outer side surface 36. The outer side surface 36 is formed on the entire circumference of the opening 3. The outer side surface 36 can be formed by polishing the outer surface of the ring-shaped conductor 1 so that the outer side surface 36 formed on the entire circumference of the opening 3 becomes the same plane (FIG. 2 and specification). (See the relevant part of the book).

  In such an antenna device, for example, the inner ring-shaped member 15 in which the feeding coil 5 is disposed is inserted into the ring-shaped conductor 1 in which the opening 3 is formed, and the insulating material 7 is disposed in the opening 3. Can be produced.

  In such an antenna device, the magnetic field spreads from the feeding coil 5 in the direction around the axis A and in the direction of the axis A. In other words, the magnetic field spreads from the feeding coil 5 in all directions and becomes more easily coupled to the antenna coil on the communication partner side. An antenna device with good communication characteristics can be provided.

  5-7, the inner ring-shaped member 15 made of an insulating material such as resin is used, but a conductive inner ring-shaped member can also be used. When using a conductive inner ring-shaped member, it is necessary to dispose a magnetic layer between the feeding coil 5 and the inner ring-shaped member.

  In FIG. 7, the outer side surface 36 formed on the entire circumference of the opening is polished so as to be in the same plane. However, the outer side surface 36 only needs to spread outward, and a part thereof is at a different angle. It may have an inclined surface.

  Further, the ring-shaped conductor 1 may be polished in the direction around the axis A of the ring-shaped conductor 1 without polishing the outer surfaces on the first end face 11 side and the second end face 12 side. In this case, the outer side surface 32 is formed only on both sides of the opening 3 in the direction around the axis A (see FIG. 2D).

  FIG. 8 shows an antenna device according to the third embodiment. In this antenna device, an inner ring-shaped member 15 is inserted in the ring-shaped conductor 1, and the feeding coil 5 is formed by the inner ring-shaped member 15. The power supply line is wound around the outer surface of the.

  The feeding coil 5 is configured by winding a feeding line around the outer surface of the inner ring-shaped member 15, and a part of the feeding coil 5 is located in the opening 3 when viewed from the radial direction of the ring-shaped conductor 1. ing.

  Even such an antenna device can be easily coupled to the antenna coil on the communication partner side, and an antenna device with good communication characteristics can be provided.

  In the antenna device of FIG. 8 as well, it is easy to couple with the antenna coil on the communication partner side by widening the side surface constituting the opening toward the outside, and an antenna device with good communication characteristics can be provided.

  The antenna device of the present invention can be used for, for example, a ring, a bracelet, a wristband, a wristwatch, a bracelet, earrings, earrings, and the like. When considered as jewelry, the conductor may be a precious metal such as gold, silver or platinum, or a cemented carbide such as cermet. Since it is desirable that the size can be adjusted as a function when used as a ring, a member whose dimensions can be easily changed is preferable in the inner ring-shaped member as shown in FIG. For example, a metal such as silver may be extended or may be cut by polishing.

  In the above embodiment, when the ring-shaped conductor 1 has the opening 3 extending around the axis A at a position separated from the first end surface 11 and the second end surface 12, the opening 3 of the ring-shaped conductor 1 is formed. Although the case where the side surface around the axis A constituting the side surface is expanded outward has been described, the structure in which the opening extends to the first end surface and / or the second end surface, in other words, the first end surface and / or Even when the slit extending inward of the ring-shaped conductor from the second end face is connected to the opening 3, the magnetic field is expanded in the direction around the axis A by spreading the side face around the axis A outward. Communication characteristics can be improved.

  The transmission characteristics of the antenna device of the embodiment shown in FIG. 5 were calculated by simulation. An analysis model is shown in FIG. In the simulation, the magnetic material and the conductor were assumed to be lossless in order to investigate the influence of communication interference due to the opening. The ring-shaped conductor has a width of 12 mm, an inner diameter of 8.5 mm, an outer diameter of 14 mm, and is a conductor including the side surface except for the opening.

The structure of the ring is from the inside to the inside conductor, inside magnetic body, air, coil, air, outside magnetic body,
The outer conductors have thicknesses of 0.5mm, 1mm, 1mm, and 0.01mm, respectively.
1 mm, 1 mm, and 1 mm. However, the coil is not included in the total thickness because it is in an internal relationship with the air layer. The opening is opened as an arc with respect to the outer magnetic body and the outer conductor with a length of 13 mm and a width of 3 mm.

  The coil is configured with a width of 0.1 mm, an interval of 0.1 mm, and 13 turns, and is curved along the ring to set the port 1. If the start of 13 turns is outside, the outside dimensions of the coil are 20.1 mm in length and 10.1 mm in width. If the end of 13 turns is inside, the inside dimensions are 15.3 mm in length and 5. It is 1 mm.

  Further, a coil different from the coil of the ring is prepared and the port 2 is set. The coil of port 2 has a planar structure with a width of 0.1 mm, an interval of 0.1 mm, and 13 turns. The outside dimensions of the coil are 80.1 mm in length and 40.1 mm in width when the start of 13 turns is outside, and the inside dimensions are 75.1 mm in length and 35. 3 mm. In the antenna device of FIG. 5, the attenuation between the coils at the analysis frequency of 13.56 MHz was −9.4 dB, which was an allowable range.

  On the other hand, in the antenna device of FIG. 5, the both sides on the axis side constituting the opening portion are widened outward, and the attenuation is −0.2 dB, which can be drastically improved. It was. The analysis model at this time is shown in FIG.

  From these simulations, it can be seen that the antenna device of the present invention can be easily coupled to the antenna coil on the communication partner side and can provide an antenna device with good communication characteristics.

A ... shaft 1 ... ring-shaped conductor 3 ... opening 5 ... feeding coil 11 ... first end surface 12 ... second end surface 15 ... inner ring-shaped members 31, 35, ..Inner side surfaces 32, 33, 34, 36 ... Outer side surfaces

Claims (9)

A feeding coil;
A ring-shaped conductor disposed around the axis and having a first end surface and a second end surface in the axial direction;
With
The feed coil is wound with a feed line as seen from the radial direction of the ring-shaped conductor,
The ring-shaped conductor has an opening extending around the axis and opening outward at a position spaced apart from the first end surface and the second end surface.
The antenna device according to claim 1, wherein at least a part of the opening overlaps with the coil opening of the feeding coil when viewed from the radial direction.   The antenna device according to claim 1, wherein the openings are arranged on both sides of the feeding coil around the axis.   The antenna device according to claim 1, wherein the opening is configured by a through hole or a recess formed in the ring-shaped conductor.   An inner ring-shaped member is inserted inside the ring-shaped conductor, a bottom of the opening is closed with the inner ring-shaped member, and at least a part of the feeding coil includes the ring-shaped conductor and the ring-shaped conductor. The antenna device according to any one of claims 1 to 3, wherein the antenna device is disposed between the inner ring-shaped member. A feeding coil;
A ring-shaped conductor disposed around the axis and having a first end surface and a second end surface in the axial direction;
An inner ring-shaped member inserted into the ring-shaped conductor;
With
The feeding coil is configured by winding a feeding line around the outer surface of the inner ring-shaped member,
The ring-shaped conductor has an opening extending around the axis and opening outward at a position spaced apart from the first end surface and the second end surface.
A part of the feeding coil is located in the opening as viewed from the radial direction of the ring-shaped conductor.   The antenna device according to any one of claims 1 to 5, wherein a side surface around the axis that forms the opening of the ring-shaped conductor extends outward.   The antenna device according to claim 1, wherein resin or glass is disposed in the opening. An antenna device according to any one of claims 1 to 7,
A communication terminal device comprising: a power feeding circuit connected to the power feeding coil or coupled to an electric field, a magnetic field, or an electromagnetic field.   The communication terminal device according to claim 8, wherein the ring-shaped conductor is provided in a mounting portion through which a part of a human body is inserted.