JP6881447B2 - Antenna device and IC tag using it - Google Patents

Description

The present invention relates to an antenna device and an IC tag using the same, and more particularly to an antenna device having improved communication characteristics by providing a booster antenna composed of a plurality of antennas and an IC tag using the same.

Conventionally, an IC chip and an antenna electrically connected to the IC chip are provided in an insulating substrate, and power reception from the reader / writer and transmission / reception of signals with the reader / writer are not performed by using electromagnetic waves. IC tags performed by contact are known. In recent years, IC tags have been used not only for production process management in factories and goods management in warehouses, but also as IC cards incorporating IC tags in transportation tickets. The antenna provided on the IC tag is generally manufactured by winding a conducting wire around a base material to form a coil, or by printing a coil pattern on the surface of the base material.

In the IC tag, in order to increase the communication distance between the reader / writer and the antenna and to expand the communicable direction for the purpose of improving the communication characteristics, a booster is added to the IC tag separately from the above antenna. An antenna is provided (see, for example, Patent Document 1). The booster antenna can be electromagnetically coupled to the antenna provided in the reader / writer, and can be electromagnetically coupled to the antenna provided in the IC tag.

Therefore, by providing such a booster antenna on the IC tag, it is possible to supplement the distance and range that cannot be communicated only by the antenna of the IC tag. In addition to the configuration disclosed in Patent Document 1, for example, a booster antenna composed of a large planar loop coil may be provided in the vicinity of a plurality of coil antennas having different winding axes provided on the IC tag, or on the surface of the base material. It is considered to provide a booster antenna composed of the formed planar loop coil (see, for example, Patent Documents 2 and 3).

International release WO2012 / 005278 International release WO2012 / 144482 Japanese Unexamined Patent Publication No. 2008-129850

However, as in Patent Documents 1 to 3, even if a booster antenna configured by a planar loop antenna is combined with the antenna, they may interfere with each other depending on the arrangement and configuration, and the range in which the antenna can communicate is limited. There is a risk of shrinking or some parts of the communicable area that cannot be communicated locally. Further, even if the communicable direction can be supplemented, there is a possibility that other communication characteristics such as a reduction in the communication distance may be deteriorated.

The present invention has been made in view of the above problems, and an object of the present invention is to use an antenna device having improved communication characteristics by expanding the communicable range by providing booster antennas in a preferable arrangement. It is to get the IC tag that was there.

In order to achieve the above object, in the present invention, in the antenna device, for example, a main antenna in which a coil is formed on a magnetic material and a surface of a non-magnetic material arranged on the surface of the antenna are connected in parallel with each other. It was provided in combination with a booster antenna composed of a plurality of loop antennas.

Specifically, the antenna device according to the present invention has a main antenna in which an antenna portion made of a conductor is formed on a magnetic material and a plurality of loop antenna portions on the same surface of a non-magnetic material arranged on the surface of the magnetic material. A plurality of loop antenna portions are arranged so as to partially overlap with the antenna portion of the main antenna, and the plurality of loop antenna portions constituting the booster antenna are parallel to each other. It is characterized in that it is connected and wound in the same direction.

According to the antenna device according to the present invention, the communicable range of the antenna can be expanded. In particular, in the antenna device according to the present invention, since a plurality of loop antenna portions are arranged so as to partially overlap the antenna portion of the main antenna provided on the magnetic material, the main antenna and the loop antenna portion are arranged. It can be strongly coupled with the configured booster antenna, and the communication range of the antenna device can be expanded. Further, in the antenna device according to the present invention, a plurality of loop antenna portions constituting the booster antenna are connected in parallel to each other on the same surface of the non-magnetic material, and the self-inductance of each loop antenna portion can be increased. As a result, the coupling coefficient with the antenna on the reader / writer side can be increased. As a result, the communication characteristics can be improved, and the communication distance can be extended in the direction in which the communication distance usually drops. Further, in the antenna device according to the present invention, in the booster antenna, since a plurality of loop antenna portions are wound in the same direction, each loop antenna portion may independently perform electromagnetic coupling with the antenna. It is possible to communicate with each other by strengthening the effect of expanding the communicable range between the loop antennas in the area where the connectable areas of the loop antennas overlap each other, instead of interfering with each other. The range can be expanded. Further, since the loop antenna is adopted as the booster antenna in the present invention, the communicable area of the antenna device can be expanded while minimizing the increase in the production process and the size of the antenna device.

In the antenna device according to the present invention, the antenna portion of the main antenna has a solenoid coil shape in which a conductor is wound around a magnetic material, and the non-magnetic material is a magnetic material parallel to the winding axis direction of the conductor. It may be arranged on the surface.

In this way, the booster antenna enables communication in a direction that cannot be communicated only by the solenoid coil-shaped main antenna, so that the communicable range of the antenna device can be expanded. Specifically, only the solenoid coil-shaped main antenna can communicate well in the winding axis direction and in a direction inclined to some extent from the winding axis direction, but the direction perpendicular to the winding axis, particularly the solenoid coil-shaped main antenna. Good communication is not possible from the central region of the main antenna to the direction perpendicular to the winding axis. However, the antenna device of the present invention provides excellent communication performance in a direction perpendicular to the winding axis of the solenoid coil-shaped main antenna, particularly in a direction perpendicular to the winding axis from the central region of the solenoid coil-shaped main antenna. As shown, a plurality of loop antenna portions connected in parallel to each other as booster antennas are arranged on the same surface of the non-magnetic material arranged on the surface of the magnetic material. More specifically, the non-magnetic material is arranged on the surface of the magnetic material parallel to the winding axis direction of the solenoid coil-shaped main antenna, that is, the solenoid coil-shaped main antenna cannot communicate well. It is arranged so that the opening surfaces of the plurality of loop antenna portions formed of the non-magnetic material face in the direction perpendicular to the winding axis. These loop antenna portions are capable of satisfactorily electromagnetically coupling with an antenna existing in a direction perpendicular to the winding axis of the solenoid coil-shaped main antenna. In particular, in the antenna device according to the present invention, since each of the plurality of loop antenna portions is arranged so as to partially overlap the wound portion of the conductor in the magnetic material, the solenoid coil-shaped main antenna Communication from the central region of the antenna to the direction perpendicular to the winding axis can be improved.

When the antenna is a solenoid coil-shaped main antenna, the non-magnetic material is preferably arranged on a plurality of surfaces of the magnetic material. In this case, the booster antennas arranged on different surfaces may or may not be connected in parallel to each other.

In this way, the communicable area can be expanded not only in one direction perpendicular to the winding axis of the solenoid coil-shaped main antenna but also in all directions facing the surface on which the booster antenna is provided. For example, in a rectangular antenna device having a solenoid coil-shaped main antenna, if booster antennas are provided on four surfaces excluding the surfaces where the winding axes of the solenoid coil-shaped main antenna intersect, the antenna device can communicate in all directions. The area can be expanded.

When the main antenna has a solenoid coil shape, a gap may be provided between the plurality of loop antenna portions of the booster antenna, and the interval may be half or less of the coil length of the solenoid coil antenna. preferable.

In this way, the booster antenna can better compensate for the communication performance in the direction perpendicular to the winding axis from the central region of the solenoid coil-shaped main antenna, and the communication region of the antenna device can be expanded.

In another antenna device according to the present invention, the main antenna is a main antenna in which a loop antenna portion is formed on the surface of the magnetic material as the antenna portion, and the opening direction of the booster antenna is the antenna portion of the main antenna. It may be the same as the opening direction of.

As described above, even if the main antenna is not a solenoid coil-shaped antenna but a loop antenna-shaped antenna, the communicable range can be improved by the booster antenna as well.

When the main antenna has a loop antenna shape, a gap may be provided between the plurality of loop antenna portions of the booster antenna, and the distance is preferably equal to or less than the radius of the main antenna.

In this way, the booster antenna can better supplement the communication performance in the direction perpendicular to the winding axis from the central region of the main antenna, and the communication region of the antenna device can be expanded.

In the antenna device according to the present invention, it is preferable that the booster antenna is arranged so as to partially overlap with the main antenna.

In this way, the main antenna and the booster antenna can be strongly coupled, and the communication area of the antenna device can be expanded.

In the antenna device according to the present invention, two loop antenna portions constituting the booster antenna are formed, and the two loop antenna portions are arranged symmetrically with respect to the center of the surface of the non-magnetic material. Is preferable.

By using two loop antenna portions constituting the booster antenna, it is possible to expand the communicable area of the antenna device while minimizing the increase in the production process and the size of the antenna device. Further, for example, the solenoid coil-shaped main antenna cannot communicate well in the direction perpendicular to the coil winding axis, particularly in the direction perpendicular to the winding axis from the central region of the solenoid coil-shaped main antenna. However, by arranging the two loop antenna parts symmetrically with respect to the center of the surface of the non-magnetic material, communication in the direction perpendicular to the winding axis is particularly good from the central region of the solenoid coil-shaped main antenna. Can be supplemented.

Another object of the present invention is an IC tag including any of the above antenna devices.

Since such an IC tag includes the above-mentioned antenna device according to the present invention, the communicable region can be expanded and excellent communication performance can be exhibited.

According to the antenna device according to the present invention and the IC tag using the antenna device, the communicable area can be expanded and the communication performance can be improved.

FIG. 1 is a circuit diagram showing a configuration of an IC tag according to an embodiment of the present invention. FIG. 2 is an exploded perspective view showing a configuration of an antenna device according to an embodiment of the present invention. FIG. 3-1 is a diagram for explaining the relationship between the arrangement of the loop antenna portion constituting the booster antenna of the antenna device and the communicable region of the antenna device. FIG. 3-2 is a diagram for explaining the relationship between the arrangement of the loop antenna portion constituting the booster antenna of the antenna device and the communicable region of the antenna device. FIG. 3-3 is a diagram for explaining the relationship between the arrangement of the loop antenna portion constituting the booster antenna of the antenna device and the communicable region of the antenna device. FIG. 4 is a perspective view showing the configuration of the antenna device according to the first modification of the embodiment of the present invention. 5 (a) and 5 (b) are perspective views showing the configuration of the antenna device according to the second modification of the embodiment of the present invention. FIG. 6 is an exploded perspective view showing the configuration of the antenna device according to the third modification of the embodiment of the present invention. FIG. 7 is an exploded perspective view showing the configuration of the antenna device according to the fourth modification of the embodiment of the present invention. FIG. 8 is an exploded perspective view showing the configuration of the antenna device according to another embodiment of the present invention.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The following description of preferred embodiments is merely exemplary and is not intended to limit the invention, its application methods or its uses.

First, the IC tag according to the embodiment of the present invention will be described with reference to FIG. As shown in FIG. 1, the IC tag 1 according to the present embodiment is composed of an IC chip 10 and an antenna device 20. The antenna device 20 includes a solenoid coil-shaped main antenna 30 that is electrically connected to the IC chip 10 and a booster antenna 40 for improving the communication characteristics of the solenoid coil-shaped main antenna 30. The main antenna 30 includes a solenoid coil-shaped antenna portion 31 and a capacitor 32, and the booster antenna 40 includes a first loop antenna portion 41a and a second loop antenna portion 41b connected in parallel to each other, and a capacitor 42. ing. The solenoid coil-shaped main antenna 30 and the booster antenna 40 can be electromagnetically coupled to each other. As described above, the IC tag 1 according to the present embodiment can exhibit excellent communication performance by including the antenna device 20 in which the solenoid coil-shaped main antenna 30 and the booster antenna 40 are combined.

The configuration of the antenna device 20 according to the present embodiment will be described in more detail below. In FIG. 2, for simplification of the figure, the capacitor 32 in the solenoid coil-shaped main antenna 30 and the capacitor 42 in the booster antenna 40 are omitted, and the connection between the two loop antenna portions 41a and 41b is also omitted. doing. However, in reality, as shown in FIG. 1, the capacitor 32 in the solenoid coil-shaped main antenna 30 is connected to the antenna portion 31, and the capacitor 42 in the booster antenna 40 is the first loop antenna portion 41a and the second loop antenna portion 41b. Are connected to each so that they are connected in parallel.

As shown in FIG. 2, in the antenna device 20, the main antenna 30 is composed of a solenoid coil-shaped antenna portion 31 in which a conducting wire is wound around a rectangular parallelepiped magnetic body 33. Although not shown in FIG. 2, the magnetic body 33 is provided with an IC chip connecting terminal extending from the solenoid coil-shaped antenna portion 31, which is used when connecting to the IC chip 10. The magnetic material 33 may be any material containing a magnetic material, and the magnetic material used for the magnetic material 33 is not particularly limited, and for example, a Ni—Zn ferrite magnetic material or the like can be used. Further, the material of the conducting wire used for the solenoid coil-shaped antenna portion 31 is not particularly limited, and for example, metal conductors such as silver, gold and copper are used.

On the other hand, in the booster antenna 40, a first loop antenna portion (first booster antenna portion) 41a and a second loop antenna portion (second booster antenna portion) 41b are formed on the surface of the non-magnetic material 43. Become. In the present invention, the loop antenna is not an antenna in which a conductor is wound around a magnetic core like a solenoid coil, but an antenna in which a conductor is formed in a spiral shape on the surface of a substrate. The non-magnetic material 43 is not particularly limited as long as it is made of a non-magnetic material, and for example, glass-based ceramics, non-magnetic ferrite, or the like can be used. The first loop antenna portion 41a and the second loop antenna portion 41b can be formed by winding a conducting wire on the surface of the non-magnetic material 43. For example, the surface of the non-magnetic material 43 can be formed by using a printing technique or the like. As the material thereof, a metal conductor or the like can be used as in the solenoid coil-shaped antenna portion 31. The first loop antenna portion 41a and the second loop antenna portion 41b are configured to be electromagnetically coupled to the solenoid coil-shaped main antenna 30.

Further, the first loop antenna portion 41a and the second loop antenna portion 41b are connected in parallel as described above, and by doing so, the respective loop antenna portions are independently connected to the main antenna or the main antenna. Since electromagnetic field coupling with the antenna on the reader / writer side is possible, it is possible to extend the communication distance in the direction in which the communication distance usually drops. Further, the first loop antenna portion 41a and the second loop antenna portion 41b are wound in the same direction, and by doing so, in the region where the communicable regions of the respective loop antenna portions overlap. The effect of expanding the communicable range between the loop antennas is strengthened, and the communicable range can be further expanded.

In the antenna device 20, as shown in FIG. 2, a non-magnetic body 43 provided with the plurality of loop antenna portions is laminated on the magnetic body 33 of the main antenna 30, but specifically, the non-magnetic body 43 provided with the plurality of loop antenna portions is laminated. The non-magnetic material 43 is laminated in a direction (upward direction in FIG. 2) perpendicular to the winding axis direction (left-right direction in FIG. 2) of the antenna portion 31 in the magnetic material 33. As a result, the opening surface of the antenna portion 31 of the main antenna 30 and the opening surfaces of the first loop antenna portion 41a and the second loop antenna portion 41b are arranged so as to be perpendicular to each other.

As described above, the main antenna 30 can communicate mainly in the winding axis direction of the antenna portion 31 and in a direction inclined to some extent from the winding axis direction, and is perpendicular to the winding axis, particularly the main antenna 30. Good communication is not possible in the direction perpendicular to the winding axis from the central region of. However, in the present embodiment, the booster antenna 40 is provided on the main antenna 30, and the booster antenna 40 is a non-magnetic material 43 in which the first loop antenna portion 41a and the second loop antenna portion 41b are formed. Good communication is possible in the direction perpendicular to the surface, that is, in the direction perpendicular to the winding axis of the antenna portion 31. Therefore, the booster antenna 40 can supplement the region where the solenoid coil-shaped main antenna 30 cannot communicate well, and as a result, the antenna device 20 of the present embodiment expands the communicable range.

Further, in the present embodiment, in order to further expand the communicable range of the antenna device 20, the first loop antenna portion 41a and the second loop antenna portion 41b are partially composed of conductors in the magnetic material 33. It is arranged directly above the wound portion (antenna portion 31). That is, the first loop antenna portion 41a and the second loop antenna portion 41b partially overlap with the solenoid coil-shaped antenna portion 31. In particular, the first loop antenna portion 41a and the second loop antenna portion 41b are preferably arranged symmetrically at the center on the surface of the non-magnetic material 43, and further, the first loop antenna portion 41a and the second loop antenna portion 41a and the second loop antenna portion 41a. It is preferable that the gap between the loop antenna portion 41b and the loop antenna portion 41b is short. Further, it is preferable that the first loop antenna portion 41a and the second loop antenna portion 41b overlap each other with the end portion of the solenoid coil-shaped antenna portion 31. Here, the end portion of the solenoid coil-shaped antenna portion 31 means the outermost coil portion in the winding axis direction (left-right direction in FIG. 2) of the antenna portion. By doing so, the overlap of the connectable regions of each loop antenna portion becomes large, and in particular, communication from the central region of the solenoid coil-shaped main antenna 30 to the direction perpendicular to the winding axis is good. can do. On the other hand, when the first loop antenna portion 41a and the second loop antenna portion 41b do not overlap with the solenoid coil-shaped antenna portion 31 at all and there is a large gap between them, the above-mentioned solenoid coil-shaped The first loop antenna portion 41a and the second loop antenna portion 41b cannot supplement the communication in the region where the main antenna 30 cannot communicate well, and the communicable range of the antenna device 20 cannot be satisfactorily expanded.

Hereinafter, the relationship between the arrangement of the first loop antenna portion 41a and the second loop antenna portion 41b and the communicable range of the antenna device 20 will be described with reference to FIGS. 3-1 to 3-3. The area surrounded by the broken line in FIGS. 3-1 to 3-3 indicates the communicable area of the antenna device 20. Further, in FIGS. 3-1 to 3-3, for the sake of simplification of the drawings, the illustration of the capacitor is omitted, and the connection between the two loop antenna portions is also omitted. In addition, in FIGS. 4 to 8 described later, the illustration of the capacitor is omitted as in FIGS. 3-1 to 3-3, and the connection between the two loop antenna portions is also omitted.

First, as shown in FIG. 3-1 (a), in the case of only the solenoid coil-shaped main antenna 30 without providing the booster antenna 40, as described above, the winding axis direction of the antenna portion 31 and the winding axis. Communication is possible in a direction inclined to some extent from the direction, but communication is not possible above the central portion of the solenoid coil-shaped main antenna 30.

Next, when the two loop antenna portions 41a and 41b are provided on the solenoid coil-shaped main antenna 30, first, as shown in FIG. 3-1 (b), the two loop antenna portions 41a and 41b are provided. If it is not provided directly above the solenoid coil-shaped antenna portion 31, that is, if it is provided so as not to overlap with the antenna portion 31, the communication distance in the vicinity of the region where the two loop antenna portions 41a and 41b are provided is large. However, as in the case where the two loop antenna portions 41a and 41b shown in FIG. 3-1 (a) are not provided, communication cannot be performed above the central portion of the solenoid coil-shaped main antenna 30.

On the other hand, as shown in FIG. 3-1 (c), only a part of the two loop antenna portions 41a and 41b is on the solenoid coil-shaped antenna portion 31, that is, the two loop antenna portions 41a, When 41b partially overlaps with the antenna portion 31, and particularly overlaps with the end portion of the antenna portion 31, the communication distance in the vicinity of the region where the two loop antenna portions 41a and 41b are provided becomes large. Communication is also possible above the central portion of the solenoid coil-shaped main antenna 30.

Further, as shown in FIG. 3-2 (d), when the two loop antenna portions 41a and 41b are arranged closer to each other than in the case shown in FIG. 3-1 (c), particularly two loop antenna portions. When the gap length l of the gaps 41a and 41b is less than half of the coil length L of the solenoid coil-shaped antenna portion 31, these loop antenna portions 41a and 41b are the central portion of the solenoid coil-shaped main antenna 30. Increase the communication distance above. Therefore, as the antenna device 20, the communication above the central portion of the solenoid coil-shaped main antenna 30 becomes better. As a result, good communication is possible in a direction of 180 ° or more. However, it is preferable that the loop antenna portions 41a and 41b partially overlap with the antenna portion 31 as in FIG. 3-1 (c). In other words, it is preferable that a part of the loop antenna portions 41a and 41b protrudes to a position outside the antenna portion 31. In this way, the antenna portion 31 and the loop antenna portions 41a and 41b can be more strongly coupled to each other, and the communication range of the antenna device can be further expanded.

Further, in FIGS. 3-1 (c) and 3-2 (d), the magnetic body 33 and the non-magnetic body 43 are overlapped so as to coincide with each other, but the two loop antenna portions 41a and 41b are As long as it is arranged so as to partially overlap the solenoid coil-shaped antenna portion 31, the non-magnetic body 43 may protrude from the magnetic body 33 as shown in FIG. 3-2 (e). Absent. Even with such a configuration, the same effect as in the case of FIG. 3-2 (d) can be obtained. At this time, the arrangement of the solenoid coil-shaped antenna portion 31 and the loop antenna portions 41a and 41b is maintained as it is, and the periphery of the magnetic body 33 is supplemented with the non-magnetic material, that is, the non-magnetic material 43 portion protruding from the magnetic body 33. A rectangular antenna device 20 may be provided by supplementing a non-magnetic material directly underneath. As shown in FIGS. 3-1 (c) to 3-2 (e), the two loop antenna portions 41a and 41b partially overlap the solenoid coil-shaped antenna portion 31 and are made of a non-magnetic material 43. It is particularly preferable that the antennas are arranged symmetrically with respect to the center of the surface of the antenna, but if the range that cannot be communicated can be supplemented by the solenoid coil-shaped main antenna 30, for example, two as shown in FIG. 3-3 (f). As long as each of the loop antenna portions 41a and 41b partially overlaps with the solenoid coil 31, the gap between the two loop antennas may be slightly deviated from the central portion. Further, as shown in FIG. 3-3 (f), the sizes of the loop antenna portions 41a and 41b do not have to be the same. By doing so, the directivity in a specific direction (leftward in FIG. 3-3 (f)) can be improved while compensating for the non-communication range of the solenoid coil-shaped main antenna 30.

According to the present embodiment described above, the communicable area can be expanded as compared with the case where only the solenoid coil-shaped main antenna 30 is used.

Hereinafter, various modifications of the present embodiment will be described. Regarding the following description, the description of the same configuration as that of the present embodiment will be omitted, and only the different parts will be described.

In the present embodiment, the non-magnetic material 43 is provided with two loop antenna portions, but the number may be three or more. For example, as a first modification of the present embodiment, as shown in FIG. 4, the non-magnetic material 43 may be provided with four loop antenna portions. In this case, it is preferable that each of the four loop antenna portions 41a to 41d is arranged so as to partially overlap the solenoid coil-shaped antenna portion 31. Therefore, as shown in FIG. 4, it is preferable that the four loop antenna portions 41a to 41d are arranged close to the four corners of the surface of the non-magnetic material 43, respectively.

Further, when three or more loop antenna portions are provided, as a second modification of the present embodiment, as shown in FIGS. 5A and 5B, the non-magnetic material 43 protrudes from the magnetic material 33. It may be. By doing so, the area of the surface of the non-magnetic material 43 is increased so that each of the plurality of loop antenna portions is partially located directly above the solenoid coil-shaped antenna portion 31, that is, the antenna portion 31. It is easy to arrange so that it partially overlaps with the antenna.

Further, in the present embodiment, the booster antenna 40 is provided on the surface of the solenoid coil-shaped main antenna 30 in one direction, but as a third modification of the present embodiment, the booster antennas may be provided on a plurality of surfaces. As shown in FIG. 6, for example, two booster antennas 40 and 50 may be provided on the opposing surfaces of the solenoid coil-shaped main antenna 30 so as to sandwich the antenna portion 31.

Specifically, in the present modification, as in the above embodiment shown in FIG. 2, a plurality of loop antenna portions 41a and 41b are provided on the magnetic body 33 of the solenoid coil-shaped main antenna 30. The magnetic material 43 is laminated. Specifically, the first non-magnetic material 43 is laminated in a direction (upward direction in FIG. 6) perpendicular to the winding axis direction (horizontal direction in FIG. 6) of the solenoid coil-shaped antenna portion 31 in the magnetic material 33. Will be done. Further, as shown in FIG. 6, a plurality of loop antenna portions 51a and 51b are provided on the side of the magnetic body 33 opposite to the side where the first non-magnetic body 43 is provided (lower side of FIG. 6). 2 Non-magnetic material 53 is laminated. As a result, the solenoid coil-shaped main antenna 30 is sandwiched between the two booster antennas, the first booster antenna 40 and the second booster antenna 50, in a direction perpendicular to the winding axis direction (vertical direction in FIG. 6). It becomes.

In this way, the communication region of the antenna device 20 can be expanded not only in one of the directions perpendicular to the winding axis direction but also in the opposite direction. In FIG. 6, the two booster antennas 40 and 50 are arranged so as to sandwich the solenoid coil-shaped main antenna 30 in a direction perpendicular to the winding axis direction, but the arrangement is not limited to this. The booster antennas 40 and 50 can be arranged on any two of the four surfaces of the magnetic body 33 parallel to the winding axis direction of the coiled main antenna 30, respectively. For example, if the booster antennas 40 and 50 are arranged on two adjacent surfaces of the magnetic body 33, respectively, the directivity as an antenna device can be improved on the arranged side. Further, the number of booster antennas arranged on the magnetic body 33 is not limited to two, but may be three, and further, four surfaces of the magnetic body 33 excluding the two surfaces intersecting the winding axis of the solenoid coil-shaped main antenna 30. It may be provided in all of. In this way, good communication is possible in the 360 ° direction. In this modification, it is preferable that the winding directions of the loop antenna portions 41a, 41b, 51a, 51b in the booster antennas 40 and 50 are the same. Further, the booster antennas arranged on different surfaces may or may not be connected in parallel to each other.

Further, as a fourth modification of the present embodiment, as shown in FIG. 7, another booster antenna 60 may be laminated on the booster antenna 40. In the other booster antenna 60, for example, one loop antenna portion 61 is formed in the center of the surface of the non-magnetic material 63. With such a configuration, communication above the central portion of the solenoid coil-shaped main antenna 30 can be improved.

In the above, an embodiment in which a solenoid coil-shaped main antenna is used as an antenna for reinforcing the booster antenna and a modification thereof have been described, but a plane loop coil-shaped antenna portion is used instead of the solenoid coil-shaped antenna portion. , The booster antenna of each configuration described above may be combined with the loop antenna portion. For example, in the antenna device according to another embodiment of the present invention, as shown in FIG. 8, the one surface of the loop coil-shaped main antenna 70 in which the loop coil-shaped antenna portion 71 is formed on one surface of the magnetic body 73. The booster antenna 40 is stacked on top of it. With such a configuration, it is possible to improve the directivity toward the side where the loop antenna portion 71 is arranged and the booster antenna 40 is provided.

As described above, according to the antenna device according to each embodiment and each modification of the present invention, the communicable area can be expanded, and according to the IC tag including the antenna device, the communication performance of the IC tag is improved. can do.

Hereinafter, examples for explaining the antenna device according to the present invention in detail will be shown. This example illustrates the present invention and does not limit the scope of the invention.

First, the configuration of the antenna device of this embodiment will be described. The main antenna in the antenna device of this embodiment is composed entirely of a solenoid coil-shaped antenna portion, and a ferrite magnetic material having a length of 10 mm, a width of 3 mm, and a thickness of 1.0 mm is used as a magnetic core. A conductor having a width of 0.2 mm formed of sintered silver was wound around a magnetic core made of a magnetic material at intervals of 0.25 mm for 20 turns to form a coil, thereby producing a main antenna.

The booster antenna is made by printing a pattern in which two loop antennas are wound in the same direction for two turns on non-magnetic ferrite with silver paste so as to form conductors with a width of 0.2 mm at intervals of 0.2 mm. did. Then, the main antenna and the booster antenna were superposed to produce an antenna device.

The arrangement of the two loop antenna portions in the booster antenna was changed for each embodiment. In the antenna devices of Examples 1 to 4, the arrangement of the two loop antenna portions is the arrangement shown in FIGS. 3-1 (c) to 3-3 (f), respectively.

Specifically, as shown in FIG. 3-1 (c), the antenna device of the first embodiment has a configuration in which two loop antenna portions are arranged so as to overlap both ends of the solenoid coil-shaped antenna portion. In particular, the distance between the two loop antenna portions was set to half the coil length of the solenoid coil-shaped antenna portion.

Similar to the antenna device of the first embodiment, the antenna device of the second embodiment has a configuration in which two loop antenna portions are arranged so as to overlap both ends of the solenoid coil-shaped antenna portion. As shown in FIG. 3-2 (d), the distance between the two loop antenna portions was made smaller than that of the antenna device of the first embodiment so that they were brought closer to each other.

Similar to the antenna device of the first embodiment, the antenna device of the third embodiment has a configuration in which two loop antenna portions are arranged so as to overlap both ends of the solenoid coil-shaped antenna portion. As shown in FIG. 3-2 (e), the booster antenna is 1.5 times as large as that of the first embodiment, and has a configuration protruding from the main antenna.

Similar to the antenna device of the second embodiment, the antenna device of the fourth embodiment has a configuration in which two loop antenna portions are arranged so as to overlap and approach both ends of the antenna coil-shaped antenna portion. However, in particular, as shown in FIG. 3-3 (f), one loop antenna portion is configured to be larger than the other loop antenna portion.

For these examples, the following antenna devices of each comparative example were also produced.

As an antenna device of Comparative Example 1, as shown in FIG. 3-1 (a), an antenna device was manufactured from only the main antenna without providing a booster antenna.

As the antenna device of Comparative Example 2, an antenna device was manufactured by superimposing a booster antenna having only one loop antenna portion in the center on the main antenna.

Similar to the antenna device of the second embodiment, the antenna device of Comparative Example 3 has a configuration in which two loop antenna portions are arranged so as to overlap and approach both ends of the solenoid coil-shaped antenna portion. The two loop antenna units are connected in series.

Similar to the antenna device of the second embodiment, the antenna device of Comparative Example 4 has a configuration in which two loop antenna portions are arranged so as to overlap and approach both ends of the solenoid coil-shaped antenna portion. The two loop antenna portions are wound in opposite directions.

As shown in FIG. 3-1 (b), the antenna device of Comparative Example 5 has a configuration in which the two loop antenna portions are largely separated from each other so as not to overlap with the solenoid coil-shaped antenna portions.

The communication distances of the antenna devices of Examples 1 to 4 and Comparative Examples 1 to 5 described above were evaluated by a reader / writer TR3-C2-01 manufactured by Takaya. The communication distances of A (5 mm from the center), the opposite end B (5 mm from the center), and the center of the antenna device were compared and evaluated in the direction orthogonal to the opening of the solenoid coil, which is the main antenna. .. In Example 4, the end portion on the side where the larger of the two loop antenna portions was arranged was designated as A. The results are shown in Table 1.

As shown in Table 1, the antenna devices of Examples 1 to 4 in which two loop antenna portions are arranged so as to overlap both ends of the solenoid coil-shaped antenna portion do not include a booster antenna. Compared with Comparative Example 1, the communication distance was longer at all of the end portion A, the central portion, and the end portion B. The communication distance was longer in Example 2 in which the two loop antenna portions were brought closer to each other than in Example 1, and the communication distance was further longer in Example 3 in which the booster antenna was enlarged. Further, in the fourth embodiment in which only one loop antenna portion is enlarged, it can be seen that the communication distance on the side where the loop antenna portion is enlarged is long.

On the other hand, in Comparative Example, although the communication distance could be slightly increased in Comparative Example 5, no remarkable effect was observed.

From the above, it can be seen that the antenna device according to the present invention can improve the communication performance.

The antenna device according to the present invention and the IC tag using the antenna device have an expanded communicable range, and are useful for application to production process management, article management in warehouses, and the like.

1 IC tag 10 IC chip 20 Antenna device 30 Main antenna 31 (solar coil shape) Antenna part 32 Condenser 33 Magnetic material 40 (1st) booster antenna 41a to 41d Loop antenna part 42 Condenser 43 (1st) non-magnetic material 50 Second booster antenna 51a, b Loop antenna part 53 Second non-magnetic material 60 Other booster antenna 61 Loop antenna part 63 Non-magnetic material 70 Main antenna 71 (loop coil shape) Antenna part 73 Magnetic material

Claims (7)

A main antenna having an antenna portion made of a conductor formed on a magnetic material and a booster antenna having a plurality of loop antenna portions formed on the same surface of a non-magnetic material arranged on the surface of the magnetic material are provided.
The plurality of loop antenna portions are arranged so as to partially overlap the antenna portion of the main antenna, and the plurality of loop antenna portions constituting the booster antenna are connected in parallel to each other and wound in the same direction. An antenna device characterized by being rotated. The antenna portion of the main antenna has a solenoid coil shape in which a conductor is wound around the magnetic material as a magnetic core, and the non-magnetic material is placed on the surface of the magnetic material parallel to the winding axis direction of the conductor. The antenna according to claim 1, wherein the antenna is arranged. The antenna device according to claim 2, wherein the non-magnetic material is arranged on a plurality of surfaces of the magnetic material. The main antenna is a main antenna in which a loop antenna portion is formed on the surface of the magnetic material as the antenna portion, and the opening direction of the booster antenna is the same as the opening direction of the antenna portion of the main antenna. The antenna device according to claim 1, wherein the antenna device is characterized by the above. The antenna device according to any one of claims 1 to 4, wherein the loop antenna portion constituting the booster antenna is arranged so as to partially overlap the antenna portion of the main antenna. Two loop antenna portions constituting the booster antenna are formed on the surface of the non-magnetic material, and the two loop antenna portions are arranged symmetrically with respect to the center of the surface of the non-magnetic material. The antenna device according to any one of claims 1 to 5, characterized in that. An IC tag including the antenna device according to any one of claims 1 to 6.

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