JP5655503B2 - Cross dipole antenna and non-contact communication medium having the same - Google Patents

Description

  The present invention relates to an antenna design of an RFID tag having, for example, a low directivity and a large number of directions that can be read, and more particularly, to a cross dipole antenna applied to an IC chip having a plurality of pairs of ports independent of each other. The present invention relates to a non-contact communication medium provided with the cross dipole antenna.

Conventionally, there is an RFID (Radio Frequency IDentification) system as a system for performing communication of information between a reader / writer and a tag (non-contact communication medium) using a radio frequency signal.
As such an RFID system, for example, as described in Patent Document 1, there is one having a pair of dipole antennas.

A pair of dipole antennas described in Patent Document 1 has a line extending from a feeding point that crosses each other in a cross shape, and a line that spreads in a triangular shape at the point where the line is bent. The total length of each of the pair of dipole antennas is longer than λ / 2 of the operating wavelength λ.
An RFID tag formed using such a pair of dipole antennas is almost omnidirectional regardless of the direction of the RFID tag, even if the reader / writer side is configured using a linearly polarized antenna. Has reading performance.

  The RFID system described in Patent Document 1 has a conductive bar connected to a line extending from a feeding point of a pair of dipole antennas, and the conductive bar is connected to a line extending from the feeding point. The impedance is adjusted by adjusting the position to be adjusted. Here, the line extending in the above-described triangular shape may be formed by a conductor existing in a contour portion of a peripheral portion that is hollowed out at the center portion.

JP 2007-324709 A

However, the RFID system described in Patent Document 1 has a problem that it is difficult to independently adjust the real part impedance and the imaginary part impedance for a pair of dipole antennas, for example, when matching impedances. is there.
The present invention has been made paying attention to the above-mentioned problems, and includes a cross dipole antenna that can easily perform independent adjustment of real part impedance and imaginary part impedance, and the cross dipole antenna. Another object is to provide a non-contact communication medium.

In order to solve the above-mentioned problems, among the present inventions, the invention described in claim 1 is a cross dipole having a plurality of dipole antennas intersecting each other at the center point in plan view and having at least two pairs of terminals. An antenna,
Each of the dipole antennas includes a pair of radiating elements whose one end is connected to the IC chip at the center point,
A loop line connecting all the radiating elements surrounding the center point in an endless shape in plan view,
The loop line is formed with a line width and a path length according to a preset imaginary part impedance ,
Imaginary part impedance the preset is characterized in imaginary part impedance der Rukoto at one pair of said two pairs of terminals.

Next, of the present invention, the invention described in claim 2 is the invention described in claim 1, wherein the loop line includes an inner loop line surrounding the center point in an endless shape, and the inner loop line. An outer loop line surrounding the outer peripheral side of the outer end in an endless shape,
Each of the inner loop line and the outer loop line is connected to all the radiating elements.

Next, of the present invention, the invention described in claim 3 is the invention described in claim 2, wherein the radiating element is closer to the center point than the inner loop line, and An outer radiating element portion farther from the center point than the outer loop line, and
The inner loop line connects all the inner radiating element portions,
The outer loop line connects all the outer radiating element portions,
Between the inner loop line and the outer loop line, a gap surrounding the center point in an endless shape is formed,
The gaps are formed at intervals according to preset real part impedance.

Next, of the present invention, the invention described in claim 4 is the invention described in claim 3, wherein the loop line includes a part of the inner loop line and a part of the outer loop line. Equipped with an even number of loop connections to connect to a common line,
The inner loop line or the outer loop line is divided by the loop connection portion in plan view,
At least one of the inner radiating element portions is connected to a portion divided by two adjacent loop connection portions of the inner loop line,
At least one of the outer radiating element portions is connected to a portion of the outer loop line divided by two adjacent loop connection portions.

Next, among the present inventions, the invention described in claim 5 is the invention described in claim 3 or claim 4, wherein the pair of outer radiating element portions facing each other with the center point interposed therebetween is the shortest distance. The straight line connected by the lines overlaps with a line that bisects two adjacent inner radiating element portions in plan view.
Next, of the present invention, the invention described in claim 6 is the invention described in any one of claims 3 to 5, wherein the cross dipole antenna includes the plurality of dipole antennas. Formed with a plurality of layers stacked in a direction perpendicular to the arranged plane,
The inner radiating element portion and the outer radiating element portion are formed in different layers among the plurality of layers.
Next, of the present invention, the invention described in claim 7 is the invention described in any one of claims 1 to 6, wherein all the radiating elements have the same shape in plan view. It is characterized by being formed.

Next, of the present invention, the invention described in claim 8 is the invention described in any one of claims 1 to 7, wherein the loop line has the center point in plan view. It is formed in the same shape in each region obtained by equally dividing the cross dipole antenna with a plurality of straight lines passing through,
In each region, only one of the pair of radiating elements is arranged.
Next, among the present inventions, the invention described in claim 9 includes the cross dipole antenna described in any one of claims 1 to 8 and the IC chip. It is a non-contact communication medium.

According to the present invention, by adjusting the line width and path length of the loop line, the imaginary part impedance of the crossed dipole antenna is controlled in advance while minimizing the influence on the real part impedance. It becomes possible to adjust the impedance. That is, it is possible to preferentially adjust the imaginary part impedance to a preset value while minimizing the change in the real part impedance value.
As a result, it is possible to provide a cross-dipole antenna capable of easily performing independent adjustment of the real part impedance and the imaginary part impedance, and a non-contact communication medium including the cross-dipole antenna.

It is a top view which shows schematic structure of the non-contact communication medium of 1st embodiment of this invention. It is the enlarged view of the range enclosed with the circle | round | yen II in FIG. 1, and its periphery. FIG. 3 is an enlarged view of a range surrounded by a circle III in FIG. 2, and is a diagram illustrating a detailed configuration of an IC chip. It is a correlation diagram which shows the relationship between the line | wire width and path length of a loop line, and the real part impedance and imaginary part impedance of a cross dipole antenna. It is a figure which shows the modification of 1st embodiment of this invention. It is a top view which shows schematic structure of the non-contact communication medium of 2nd embodiment of this invention. FIG. 7 is an enlarged view of a range surrounded by a rectangle VII in FIG. 6 and its surroundings. It is a correlation diagram which shows the relationship between the clearance gap formed between the inner loop line and the outer loop line, and the real part impedance and imaginary part impedance of a cross dipole antenna. It is a figure which shows the modification of 2nd embodiment of this invention. It is a top view which shows schematic structure of the non-contact communication medium of 3rd embodiment of this invention. It is a top view which shows schematic structure of the non-contact communication medium of 4th embodiment of this invention. FIG. 12 is an enlarged view of a range surrounded by a rectangle XII in FIG. 11 and its surroundings. It is a correlation diagram which respectively shows the real part impedance and imaginary part impedance of a cross dipole antenna with respect to two types of cross dipole antennas from which the structure of a loop connection part differs. It is a figure which shows schematic structure of the non-contact communication medium of 5th embodiment of this invention, FIG. 14 (a) is a top view which shows schematic structure of a non-contact communication medium, FIG.14 (b) is FIG. It is BB sectional drawing of a). It is a figure which shows the modification of 5th embodiment of this invention. It is a figure which shows the modification of 5th embodiment of this invention.

(First embodiment)
Hereinafter, a first embodiment of the present invention (hereinafter referred to as “the present embodiment”) will be described with reference to the drawings.
(Constitution)
(Configuration of non-contact communication media)
First, the structure of the non-contact communication medium 1 of this embodiment is demonstrated using FIG.1 and FIG.2.
FIG. 1 is a plan view showing a schematic configuration of a non-contact communication medium 1 of the present embodiment. FIG. 2 is an enlarged view of the area surrounded by a circle II in FIG. 1 and its surroundings.
As shown in FIGS. 1 and 2, the non-contact communication medium 1 (inlet) includes an IC chip 2 and a cross dipole antenna 4.

Here, the above inlet indicates a state in which the IC chip 2 is mounted on a metal coil constituting the cross dipole antenna 4, and is the most basic product form. In the inlet, the metal coil (cross dipole antenna 4) and the IC chip 2 are exposed.
The IC chip 2 is formed so as to be able to store, for example, information relating to an attachment target of the non-contact communication medium 1. The attachment target of the non-contact communication medium 1 is, for example, a DVD (Digital Versatile Disc). Here, when the attachment target of the non-contact communication medium 1 is a DVD, the information related to the attachment target of the non-contact communication medium 1 is the product name, price, etc. of the DVD.

Here, in this embodiment, as an example, the case where the configuration of the non-contact communication medium 1 is a configuration in which the cross dipole antenna 4 and the IC chip 2 are formed on the substrate 6 will be described.
The substrate 6 is made of, for example, PET (polyethylene terephthalate) and an adhesive layer.

(Configuration of cross dipole antenna 4)
Hereinafter, the configuration of the cross dipole antenna 4 will be described with reference to FIGS. 1 and 2 and FIGS. 3 and 4. FIG.
The cross dipole antenna 4 includes a plurality of dipole antennas 8 and a loop line 10.
Here, in this embodiment, a case where the number of dipole antennas 8 is two will be described as an example.
Each dipole antenna 8 is made of a conductive material such as a metal (Cu, Ag, Al, etc.) foil, and is electrically connected to the IC chip 2. In the present embodiment, as an example, a case where each dipole antenna 8 is formed of a metal foil will be described.

The dipole antennas 8 cross each other at the center point in plan view.
Here, in the present embodiment, a case will be described in which the two dipole antennas 8 are orthogonal at the center point of each other, that is, intersect at an angle of 90 [°].
Each dipole antenna 8 includes a pair of radiating elements 12a and 12b.
Each radiating element 12 has one end connected to the IC chip 2 at a center point where the two dipole antennas 8 are orthogonal to each other.

Here, all the radiating elements 12 included in the cross dipole antenna 4, that is, the four radiating elements 12, as shown in FIG. 3, are independent individual among a plurality of ports 14 included in the IC chip 2. Connected to port 14.
3 is an enlarged view of a range surrounded by a circle III in FIG. 2, and shows a detailed configuration of the IC chip 2. FIG. In FIG. 3, the radiation element 12 is not shown for the sake of explanation. In FIG. 3, the port 14 for connecting the radiating elements 12 a and 12 b included in one of the two dipole antennas 8 is denoted as “port 14 a”, and the radiating element 12 a and the other included in the other of the two dipole antennas 8. The port 14 to which 12b is connected is indicated as “port 14b”.

Further, each radiating element 12 has a meander-shaped continuous portion between both end portions.
Further, all the radiating elements 12 included in the cross dipole antenna 4, that is, the four radiating elements 12 are formed in the same shape when viewed from the direction orthogonal to the plane on which the two dipole antennas 8 are arranged.
The loop line 10 surrounds an endless shape at a center point where the two dipole antennas 8 are orthogonal when viewed in a plan view, that is, from a direction orthogonal to the plane where the two dipole antennas 8 are arranged.

The loop line 10 connects all the radiating elements 12 included in the cross dipole antenna 4, that is, four radiating elements 12.
Here, in the present embodiment, as an example, the case where the shape of the loop line 10 is an annular shape that surrounds the center point where the two dipole antennas 8 are orthogonal to each other at an equal distance from the entire circumference will be described.

Further, the loop line 10 is formed in the same shape in each of the regions 16a to 16d obtained by dividing the cross dipole antenna 4 into four equal parts by two straight lines Lcp passing through a center point where the two dipole antennas 8 are orthogonal to each other in plan view. Has been.
Here, each of the regions 16a to 16d obtained by equally dividing the cross dipole antenna 4 by two straight lines Lcp is a region where only one of the pair of radiating elements 12a and 12b is disposed. In addition, an angle formed by two straight lines Lcp passing through the center point where the two dipole antennas 8 are orthogonal to each other and a straight line connecting both ends of the radiating element 12 is 45 [°].

The line width and path length of the loop line 10 are set to values corresponding to the imaginary part impedance (imaginary part input impedance) of the cross dipole antenna 4 set in advance.
Here, when the configuration of the cross dipole antenna 4 includes a pair (two) of dipole antennas 8 as in the present embodiment, the cross dipole antenna 4 has four terminals (two pairs of terminals). It will have.

  In this case, the “imaginary part impedance of the cross dipole antenna 4” described above is a value (imaginary part impedance) in one of the two pairs of terminals. Here, when the shape of the pair (two) of dipole antennas 8, that is, the intersecting dipole antennas 8 is the same, the values (imaginary part impedance) at the two pairs of terminals are the same value. The same applies to “real part impedance” described later. The same applies even if the number (pair) of terminals is two or more.

Here, the “line width” of the loop line 10 is the width of the loop line 10 as seen from the direction orthogonal to the plane on which the two dipole antennas 8 are arranged. In FIG. ing. In FIG. 1, the magnitude relationship between the loop line 10 and other configurations, such as the width W of the loop line 10 and the width of the dipole antenna 8, for example, may be different from the actual magnitude relationship. The same applies to the following drawings.
The “path length” of the loop line 10 is the circumference of the loop line 10 formed in an annular shape.

Hereinafter, the line width and path length of the loop line 10 will be described with reference to FIGS. 1 to 3 and FIG. 4.
FIG. 4 is a correlation diagram showing the relationship between the line width and path length of the loop line 10 and the real part impedance and imaginary part impedance of the cross dipole antenna 4. FIG. 4B is a correlation diagram showing the relationship between the path length and the real part impedance of the cross dipole antenna 4, and FIG. 4B is a correlation diagram showing the relation between the imaginary part impedance of the cross dipole antenna 4.

In FIG. 4A, the horizontal axis indicates the path length of the loop line 10 (loop line path length), and the vertical axis indicates the real part impedance of the cross dipole antenna 4. Similarly, in FIG. 4B, the horizontal axis indicates the path length of the loop line 10 (the path length of the loop line), and the vertical axis indicates the imaginary part impedance of the cross dipole antenna 4.
As shown in FIG. 4A, for example, when the line width W of the loop line 10 is 0.3 [mm], the length of the loop line 10 is 10 [mm]. The real part impedance is about 19 [Ω].

In this case, as shown in FIG. 4B, the imaginary part impedance of the cross dipole antenna 4 is about 104 [Ω].
Here, as shown in FIG. 4A, for example, when the path length of the loop line 10 is 15 [mm], the real part impedance of the cross dipole antenna 4 is about 21 [Ω]. That is, when the path length of the loop line 10 is changed from 10 [mm] to 15 [mm], the amount of change in the real part impedance is about 2 [Ω].

In this case, as shown in FIG. 4B, the imaginary part impedance of the cross dipole antenna 4 is about 155 [Ω]. That is, when the path length of the loop line 10 is changed from 10 [mm] to 15 [mm], the amount of change in the imaginary part impedance is about 51 [Ω].
Therefore, in the cross dipole antenna 4 of the present embodiment, the amount of change in the real part impedance value due to the change in the path length of the loop line 10 is the amount of change in the imaginary part impedance value due to the change in the path length of the loop line 10. Smaller than For this reason, when changing the path length of the loop line 10, it is possible to preferentially adjust the imaginary part impedance to a preset value while minimizing the change in the real part impedance value. .

As described above, when forming the cross dipole antenna 4 of the present embodiment, for example, when it is desired to obtain an imaginary part impedance of about 104 [Ω], the line width W of the loop line 10 is set to 0.3 [mm]. And the length of the loop line 10 is set to 10 [mm] to form the loop line 10.
Therefore, in the present embodiment, the values of the line width and the path length of the loop line 10 are set according to the desired imaginary part impedance set in advance.

  In addition, in FIG. 4, the point which shows the imaginary part impedance of the cross dipole antenna 4 according to the change of the path length of the loop line 10 when the line width W of the loop line 10 is 0.3 [mm]. , Indicated by a symbol “◯”. Similarly, in FIG. 4, the imaginary part impedance of the cross dipole antenna 4 corresponding to the change in the path length of the loop line 10 when the line width W of the loop line 10 is 0.4 [mm]. Is indicated by a symbol “□”. In addition, in FIG. 4, a point indicating the imaginary part impedance of the cross dipole antenna 4 according to the change in the path length of the loop line 10 when the line width W of the loop line 10 is 0.5 [mm]. , Indicated by the symbol “Δ”.

(Effects of the first embodiment)
The effects of this embodiment are listed below.
(1) In the cross dipole antenna 4 of this embodiment, the loop line 10 that surrounds the center point where the two dipole antennas 8 are orthogonal to each other in a plan view in an endless shape and connects all the radiating elements 12 is set in advance. It is formed with a line width W and a path length corresponding to the imaginary part impedance.
For this reason, by adjusting the line width W and the path length of the loop line 10 to form the cross dipole antenna 4, the imaginary part impedance of the cross dipole antenna 4 is minimized while affecting the real part impedance. It becomes possible to adjust to the imaginary part impedance set in advance.

As a result, it is possible to provide the cross dipole antenna 4 capable of easily adjusting the real part impedance and the imaginary part impedance independently.
Further, when changing the path length of the loop line 10, it is possible to preferentially adjust the imaginary part impedance to a preset value while minimizing the change in the real part impedance value.
Thereby, independent adjustment of the real part impedance and the imaginary part impedance can be easily performed, so that the design efficiency of the cross dipole antenna 4 can be improved.

(2) In the cross dipole antenna 4 of the present embodiment, the two dipole antennas 8 intersecting with each other at the center point in a plan view include a pair of radiating elements 12a and 12b whose one end is connected to the IC chip 2. It has.
For this reason, the directivity with respect to the null point existing in the single dipole antenna 8, that is, the direction in which the radio wave does not radiate and corresponding to the axial direction of the single dipole antenna 8, It can be supplemented by the dipole antenna 8.
As a result, data can be read from any direction with respect to the non-contact communication medium 1 having the cross dipole antenna 4 of the present embodiment, and the operation efficiency of the non-contact communication medium 1 can be improved.

(3) In the cross dipole antenna 4 of this embodiment, all the radiating elements 12 are formed in the same shape in plan view.
For this reason, the directivity of each dipole antenna 8 is all symmetric with respect to the four directions from the center point where the two dipole antennas 8 are orthogonal to the other end of the radiating element 12 (end on the outer peripheral side). Sexual distortion can be reduced.
As a result, the non-contact communication medium 1 having the cross dipole antenna 4 of the present embodiment can perform communication over a highly stable communication distance from any direction.

(4) In the cross dipole antenna 4 of the present embodiment, the loop line 10 is divided into four equal parts by two straight lines Lcp passing through the center point where the two dipole antennas 8 are orthogonal in a plan view. The regions 16a to 16d are formed in the same shape. In addition, only one of the pair of radiating elements 12a and 12b is disposed in each of the regions 16a to 16d.
For this reason, it is possible to predict the characteristics of the entire cross dipole antenna 4 by performing analysis and calculation on the loop line 10 and the radiating element 12 for only one of the quartered regions 16a to 16d. .
As a result, it is possible to predict the characteristics of the entire cross dipole antenna 4 without performing analysis and calculation on the entire cross dipole antenna 4, so that the design efficiency of the cross dipole antenna 4 can be improved.

(5) In the non-contact communication medium 1 of the present embodiment, the IC chip 2 and the loop line 10 connecting all the radiating elements 12 are formed with a line width W and a path length corresponding to a preset imaginary part impedance. A non-contact communication medium 1 is formed with a cross dipole antenna 4.
For this reason, it becomes possible to form the non-contact communication medium 1 using the cross dipole antenna 4 which can perform the independent adjustment of a real part impedance and an imaginary part impedance easily.
As a result, it is possible to provide the non-contact communication medium 1 that can improve the design efficiency.

(Modification)
Hereinafter, modifications of the present embodiment will be listed.
(1) In the cross dipole antenna 4 of the present embodiment, all the radiating elements 12 are formed in the same shape in plan view, but the present invention is not limited to this, and at least one of all the radiating elements 12 is You may form in the shape which is not the same as the other radiation | emission element 12 by planar view.
(2) In the cross dipole antenna 4 of the present embodiment, the loop line 10 is formed in the same shape in each of the regions 16a to 16d in plan view, but is not limited thereto. That is, the loop line 10 may be formed in a shape that is not the same in each of the regions 16a to 16d in plan view.

(3) Although the number of dipole antennas 8 is two in the cross dipole antenna 4 of the present embodiment, the number is not limited to this, and the number of dipole antennas 8 may be three or more. In short, the number of dipole antennas 8 may be plural.
Here, for example, when the number of dipole antennas 8 is three, it is preferable that the angle at which these three dipole antennas 8 intersect at the center point of each other is 60 [°].

  For example, when the number of dipole antennas 8 is three, the number of radiating elements 12 is six, and three dipole antennas 8 are arranged in an area equally divided when the loop line 10 is formed in the same shape. When viewed from the direction orthogonal to the plane, six regions 16 are obtained by dividing the cross dipole antenna 4 into six equal parts by three straight lines passing through the center point where the three dipole antennas 8 intersect. In this case, it is preferable that the angle formed by the three straight lines passing through the center point where the three dipole antennas 8 intersect and the straight line connecting the both end portions of the radiating element 12 is 30 [°].

(4) In the cross dipole antenna 4 of the present embodiment, the shape of the loop line 10 is an annular shape, but the shape of the loop line 10 is not limited to this, for example, a triangle, a quadrilateral, a pentagon or more A polygonal shape or a gear shape having a large number of irregularities may be used. In short, the shape of the loop line 10 may be any shape that surrounds the center point where the plurality of dipole antennas 8 intersect in an endless shape in plan view and connects all the radiating elements 12.
(5) In the cross dipole antenna 4 of the present embodiment, the radiating element 12 is configured to have a meander-shaped continuous portion between both ends, but the configuration of the radiating element 12 is not limited to this. For example, as shown in FIG. 5, it is good also as a structure which is linear between both ends and is a straight line as a whole. FIG. 5 is a diagram showing a modification of the present embodiment.
In addition to the linear shape shown in FIG. 5, the configuration of the radiating element 12 is a configuration having, for example, a portion continuous in a sawtooth shape between both end portions, that is, a portion continuous in a shape other than the meander shape. May be.

(Second embodiment)
Hereinafter, a second embodiment of the present invention (hereinafter referred to as “the present embodiment”) will be described with reference to the drawings.
(Constitution)
First, the configuration of the non-contact communication medium 1 according to the present embodiment will be described with reference to FIGS. 1 to 5 and FIGS. 6 to 8.
FIG. 6 is a plan view showing a schematic configuration of the non-contact communication medium 1 of the present embodiment. FIG. 7 is an enlarged view of the area surrounded by the rectangle VII in FIG. 6 and its surroundings.
As shown in FIGS. 6 and 7, the non-contact communication medium 1 of the present embodiment has the above-described first configuration except for the configuration of the cross dipole antenna 4, specifically, the configuration of the radiating element 12 and the loop line 10. Since the configuration is the same as that of the embodiment, the following description will focus on the radiating element 12 and the loop line 10.

The radiating element 12 includes an inner radiating element portion 12in and an outer radiating element portion 12out.
The inner radiating element portion 12in forms a portion of the radiating element 12 that is closer to the center point where the two dipole antennas 8 are orthogonal to each other than an inner loop line 10in described later. In FIG. 6, the inner radiating element portion 12in included in the radiating element 12a is indicated as “inner radiating element portion 12ain”, and the inner radiating element portion 12in included in the radiating element 12b is indicated as “inner radiating element portion 12bin”. ing.

  The outer radiating element portion 12out forms a portion of the radiating element 12 farther from the center point where the two dipole antennas 8 are orthogonal to each other than an outer loop line 10out described later. In FIG. 6, the outer radiating element portion 12out included in the radiating element 12a is indicated as “outer radiating element portion 12aout”, and the outer radiating element portion 12out included in the radiating element 12b is indicated as “outer radiating element portion 12bout”. ing.

Here, in this embodiment, a straight line connecting a pair of outer radiating element portions 12out (for example, a pair of outer radiating element portions 12aout) facing each other across a center point where the two dipole antennas 8 are orthogonal is a plane. When viewed, a pair of inner radiating element portions 12in facing each other across a center point where two dipole antennas 8 are orthogonal to each other overlap (for example, a pair of inner radiating element portions 12ain).
The loop line 10 includes an inner loop line 10in and an outer loop line 10out.
The internal loop line 10in is formed in an annular shape, and surrounds the center point where the two dipole antennas 8 are orthogonal to each other in an endless shape.

Further, the inner loop line 10in connects all the inner radiating element portions 12in.
The outer loop line 10out is formed in an annular shape having a larger diameter than the inner loop line 10in, and surrounds the outer peripheral side of the inner loop line 10in in an endless shape. Specifically, the outer loop line 10out is formed such that its inner diameter is larger than the outer diameter of the inner loop line 10in.

The outer loop line 10out connects all the outer radiating element portions 12out.
Further, the inner loop line 10in and the outer loop line 10out are disposed so as to be concentric with each other with a center point where the two dipole antennas 8 are orthogonal to each other as a reference.
Therefore, the inner loop line 10in and the outer loop line 10out are separated by an equal distance along the entire circumferential direction, and two dipole antennas 8 are orthogonal between the inner loop line 10in and the outer loop line 10out. A gap 18 surrounding the center point is formed in an endless shape.
A gap 18 formed between the inner loop line 10in and the outer loop line 10out and surrounding the center point where the two dipole antennas 8 are orthogonal to each other in an endless shape is formed at an interval corresponding to a preset real part impedance. Yes.

Hereinafter, the gap 18 formed between the inner loop line 10in and the outer loop line 10out will be described with reference to FIGS. 1 to 7 and FIG.
FIG. 8 is a correlation diagram showing the relationship between the gap 18 formed between the inner loop line 10in and the outer loop line 10out, and the real part impedance and the imaginary part impedance of the cross dipole antenna 4. In FIG. 8, the horizontal axis indicates the gap 18 (gap) formed between the inner loop line 10in and the outer loop line 10out, and the left vertical axis indicates the real part impedance of the cross dipole antenna 4. The right vertical axis indicates the imaginary part impedance of the cross dipole antenna 4.

Here, in FIG. 8, when the line width W of the loop line 10 is 0.4 [mm] and the path length of the loop line 10 is 15 [mm], the inner loop line 10in and the outer loop line 10out. The relationship between the gap 18 formed between and the real part impedance and the imaginary part impedance of the cross dipole antenna 4 is shown.
As shown in FIG. 8, when the gap 18 formed between the inner loop line 10in and the outer loop line 10out is increased, the real impedance of the cross dipole antenna 4 is lowered, and the imaginary of the cross dipole antenna 4 is reduced. The impedance increases.

  In FIG. 8, a point indicating the real part impedance of the crossed dipole antenna 4 in accordance with a change in the gap 18 formed between the inner loop line 10in and the outer loop line 10out is indicated by a symbol “◯”. Show. Similarly, in FIG. 8, the point indicating the imaginary part impedance of the crossed dipole antenna 4 in accordance with the change of the gap 18 formed between the inner loop line 10 in and the outer loop line 10 out is indicated by a symbol “□”. It shows by.

Here, as shown in FIG. 8, when the gap 18 formed between the inner loop line 10in and the outer loop line 10out is increased by, for example, about 0.4 [μm], the cross dipole antenna 4 The real part impedance decreases by about 15 [Ω], and the imaginary part impedance of the cross dipole antenna 4 increases by about 6 [Ω].
That is, when the cross dipole antenna 4 of the present embodiment is formed, the cross dipole antenna 4 is formed between the inner loop line 10in and the outer loop line 10out in a state where the fluctuation of the imaginary part impedance is small with respect to the fluctuation of the real part impedance. It is possible to set the interval of the gap 18.
Therefore, in the present embodiment, the interval of the gap 18 formed between the inner loop line 10in and the outer loop line 10out is set according to a desired real part impedance set in advance.
Other configurations are the same as those of the first embodiment described above.

(Effect of the second embodiment)
Hereinafter, effects of the present embodiment will be described.
In the cross dipole antenna 4 of the present embodiment, a gap 18 formed between the inner loop line 10in and the outer loop line 10out and surrounding the center point where the two dipole antennas 8 are orthogonal to each other in an endless shape is set in advance. It is formed at intervals according to the real part impedance.
For this reason, it is possible to set the interval of the gap 18 formed between the inner loop line 10in and the outer loop line 10out in a state where the fluctuation of the imaginary part impedance with respect to the fluctuation of the real part impedance is small.

As a result, it is possible to provide the cross dipole antenna 4 capable of easily adjusting the real part impedance and the imaginary part impedance independently.
In addition, since independent adjustment of the real part impedance and the imaginary part impedance can be easily performed, the design efficiency of the cross dipole antenna 4 can be improved.

(Modification)
Hereinafter, modifications of the present embodiment will be described.
In the crossed dipole antenna 4 of the present embodiment, the radiating element 12 is configured to include an inner radiating element portion 12in and an outer radiating element portion 12out, and between the inner loop line 10in and the outer loop line 10out, Although the gap 18 surrounding the center point where the two dipole antennas 8 are orthogonal to each other is formed in an endless shape, the present invention is not limited thereto. That is, for example, as shown in FIG. 9, the configuration of the radiating element 12 is the same as that of the above-described first embodiment, and the inner loop line 10 in and the outer loop line 10 out each include all the radiating elements 12. It may be configured to be connected. FIG. 9 is a diagram illustrating a modification of the present embodiment.

(Third embodiment)
Hereinafter, a third embodiment of the present invention (hereinafter referred to as “the present embodiment”) will be described with reference to the drawings.
(Constitution)
First, the configuration of the non-contact communication medium 1 according to the present embodiment will be described with reference to FIGS. 1 to 9 and FIG.
FIG. 10 is a plan view showing a schematic configuration of the non-contact communication medium 1 of the present embodiment.
As shown in FIG. 10, the non-contact communication medium 1 of this embodiment is the same as that of the second embodiment described above except for the configuration of the cross dipole antenna 4, specifically, the configuration of the radiating element 12 and the loop line 10. Since the configuration is the same, the following description will focus on the radiating element 12 and the loop line 10.

As in the second embodiment described above, the radiating element 12 includes an inner radiating element portion 12in and an outer radiating element portion 12out. 10, the inner radiating element portion 12in and the outer radiating element portion 12out included in the radiating element 12a, and the inner radiating element portion 12in and the outer radiating element portion 12out included in the radiating element 12b are illustrated in the same manner as in FIG. Yes.
The loop line 10 includes an inner loop line 10in and an outer loop line 10out, as in the second embodiment described above.

Here, in this embodiment, unlike the second embodiment described above, a pair of outer radiating element portions 12out (for example, a pair of outer radiating element portions 12aout) facing each other across a center point where two dipole antennas 8 are orthogonal to each other. Is overlapped with a line Ldiv that bisects the two adjacent inner radiating element portions 12ain and 12bin in plan view.
That is, the angle θ1 formed by the straight line Lmin connecting the pair of outer radiating element portions 12out with the shortest distance and the inner radiating element portion 12ain, and the angle θ2 formed by the straight line Lmin and the inner radiating element portion 12bin have a relationship of θ1 = θ2. Is pleased.
Other configurations are the same as those of the first embodiment described above.

(Effect of the third embodiment)
Hereinafter, effects of the present embodiment will be described.
In the cross dipole antenna 4 of the present embodiment, a straight line Lmin that connects the pair of outer radiating element portions 12out at the shortest distance is a line Ldiv that bisects the two adjacent inner radiating element portions 12ain and 12bin in plan view. overlapping.
Therefore, the symmetry of the two dipole antennas 8 can be maintained even when the configuration of the cross dipole antenna 4, specifically, the positional relationship between the inner radiating element portion 12 in and the outer radiating element portion 12 out is changed. It becomes.
As a result, even if the configuration of the cross dipole antenna 4 is changed, the non-contact communication medium 1 including the cross dipole antenna 4 of the present embodiment can perform communication over a stable communication distance from any direction. In addition, the degree of freedom in designing the cross dipole antenna 4 can be improved.

(Fourth embodiment)
Hereinafter, a fourth embodiment of the present invention (hereinafter referred to as “the present embodiment”) will be described with reference to the drawings.
(Constitution)
First, the configuration of the non-contact communication medium 1 according to the present embodiment will be described with reference to FIGS. 1 to 10 and FIGS. 11 and 12.
FIG. 11 is a plan view showing a schematic configuration of the non-contact communication medium 1 of the present embodiment. FIG. 12 is an enlarged view of the area surrounded by the rectangle XII in FIG. 11 and its surroundings.
As shown in FIGS. 11 and 12, the non-contact communication medium 1 of the present embodiment is the same as the above-described second embodiment except for the configuration of the cross dipole antenna 4, specifically, the configuration of the loop line 10. In the following description, the loop line 10 will be mainly described.

The loop line 10 includes an even number of loop connection parts 20, an internal loop line 10in, and an outer loop line 10out.
Here, in this embodiment, the case where the loop line 10 is provided with the eight loop connection parts 20 is demonstrated as an example.
Each loop connection part 20 is formed from, for example, a plate-shaped metal foil. In addition, each loop connection part 20 may combine what was shape | molded separately with respect to the inner loop line 10in and the outer side loop line 10out, and may be shape | molded integrally.
Here, in this embodiment, the case where each loop connection part 20 is shape | molded integrally with the outer side loop track | line 10out as an example is demonstrated.

  In addition, each loop connection portion 20 is mutually connected between the inner loop line 10in and the outer loop line 10out that are spaced apart at equal distances along the entire circumferential direction of the loop line 10 (the length direction of the path length). The internal loop line 10in and the outer loop line 10out are connected to each other, and a part of the inner loop line 10in and a part of the outer loop line 10out are connected to form a shared line.

The configuration of the internal loop line 10in is the same as that of the second embodiment described above.
The outer loop line 10out is divided by the loop connection portions 20 in plan view.
Specifically, the outer loop line 10out is divided into four in plan view by a set of two loop connections 20 out of the eight loop connections 20.
In addition, one outer radiating element portion 12out is connected to a portion of the outer loop line 10out divided by the two adjacent loop connection portions 20.
Other configurations are the same as those of the second embodiment described above.

(Effect of the fourth embodiment)
Hereinafter, effects of the present embodiment will be described.
In the cross dipole antenna 4 of the present embodiment, each loop connection portion 20 included in the loop line 10 connects a part of the inner loop line 10in and a part of the outer loop line 10out to form a shared line. In addition, each loop connection portion 20 divides the outer loop line 10out in a plan view, and a portion of the outer loop line 10out divided by two adjacent loop connection portions 20 has one outer radiation. The element part 12out is connected.

For this reason, each loop connection portion 20 enables a part of the outer loop line 10out to be integrated with the inner loop line 10in. For example, as shown in FIG. The value can be greatly increased.
Here, FIG. 13 is a correlation diagram showing the real part impedance and the imaginary part impedance of the cross dipole antenna 4 with respect to two types of cross dipole antennas 4 having different configurations of the loop connection part 20.

  In FIG. 13, two types of cross dipole antennas 4 having different configurations of the loop connection portion 20 are shown on the horizontal axis. Specifically, on the left side of the horizontal axis, the cross dipole antenna 4 of the above-described second embodiment, that is, the cross dipole antenna 4 having a configuration in which the loop connection portion 20 does not include the loop connection portion 20 ( No loop connection). Similarly, on the right side of the horizontal axis, the cross dipole antenna 4 of the present embodiment, that is, the configuration of the loop connection unit 20 includes the above-described loop connection unit 20 (with a loop connection unit). Is shown.

In FIG. 13, the left vertical axis represents the real part impedance of the cross dipole antenna 4, and the right vertical axis represents the imaginary part impedance of the cross dipole antenna 4.
Here, in FIG. 13, the line width W of the loop line 10 is 0.4 [mm], the path length of the loop line 10 is 15 [mm], and between the inner loop line 10in and the outer loop line 10out. When the gap 18 formed in the cross section is 0.3 [mm], the real part impedance and the imaginary part impedance of the cross dipole antenna 4 with respect to two types of cross dipole antennas 4 having different configurations of the loop connection part 20 Showing the relationship.
In FIG. 13, a point indicating the real part impedance of the cross dipole antenna 4 is indicated by a symbol “◯”, and a point indicating the imaginary part impedance of the cross dipole antenna 4 is indicated by a symbol “□”.

As shown in FIG. 13, the cross dipole antenna 4 of the present embodiment is substantially more specific than the cross dipole antenna 4 of the second embodiment described above. Specifically, it can be increased by about 80 [Ω]. On the other hand, the value of the imaginary part impedance of the cross dipole antenna 4 can be suppressed to a decrease of about 20 [Ω].
As a result, with the cross dipole antenna 4 of the present embodiment, the real impedance value of the cross dipole antenna 4 can be significantly increased, and the imaginary impedance value of the cross dipole antenna 4 can be reduced. It becomes possible to suppress.

(Modification)
Hereinafter, modifications of the present embodiment will be described.
In the crossed dipole antenna 4 of the present embodiment, the outer loop line 10out is divided by the loop connection parts 20 in plan view, but the present invention is not limited to this, and the inner loop line 10 is changed by the loop connection parts 20. It may be divided in a plan view.
In this case, one inner radiation element portion 12in is connected to a portion of the inner loop line 10in that is divided by two adjacent loop connection portions 20. In this case, the configuration of the external loop line 10 is the same as that of the second embodiment described above.

(Fifth embodiment)
Hereinafter, a fifth embodiment of the present invention (hereinafter referred to as “the present embodiment”) will be described with reference to the drawings.
(Constitution)
First, the configuration of the non-contact communication medium 1 according to the present embodiment will be described with reference to FIGS. 1 to 13 and FIG.
FIG. 14 is a diagram showing a schematic configuration of the non-contact communication medium 1 of the present embodiment, FIG. 14A is a plan view showing the schematic configuration of the non-contact communication medium 1, and FIG. It is BB sectional view taken on the line of 14 (a).
As shown in FIG. 14, the non-contact communication medium 1 of the present embodiment has the same configuration as that of the second embodiment described above except for the configuration of the cross dipole antenna 4. 4 is mainly described.

The cross dipole antenna 4 is formed of a plurality of layers stacked in a direction orthogonal to the plane on which the two dipole antennas 8 are arranged.
Here, in the cross dipole antenna 4 of the present embodiment, as shown in FIG. 14B, the inner radiating element portion 12in and the outer radiating element portion 12out are formed in different layers among the plurality of layers.
Specifically, the cross dipole antenna 4 is formed in a three-layer structure that is laminated in a direction orthogonal to the plane on which the two dipole antennas 8 are arranged.

And the inner side radiation | emission element part 12in is formed in one surface (the lower surface of the base material 6 in FIG.14 (b)) of the base material 6, and is formed in the lowest layer among three layers.
The outer radiating element portion 12out is formed on the other surface of the substrate 6 (the upper surface of the substrate 6 in FIG. 14B), and is formed on the uppermost layer of the three layers.
Therefore, the base material 6 forms an intermediate layer among the three layers.
Here, in the present embodiment, the inner radiating element portion 12in and the outer radiating element portion 12out are not overlapped in a plan view and a side view (a viewpoint from a direction orthogonal to the paper surface in FIG. 14B). To do.
Other configurations are the same as those of the second embodiment described above.

(Effect of the fifth embodiment)
Hereinafter, effects of the present embodiment will be described.
In the cross dipole antenna 4 of the present embodiment, the cross dipole antenna 4 is formed of a plurality of layers stacked in a direction orthogonal to the plane on which the two dipole antennas 8 are arranged, and the inner radiating element portion 12in and the outer radiating element portion 12out. Are formed in different layers among the plurality of layers.
For this reason, the distance between the inner loop line 10in and the outer loop line 10out can be reduced over the entire circumferential direction of the loop line 10 (the length direction of the path length), and the inner loop line 10in and the outer loop line 10out can be reduced. It is possible to prevent the loop line 10out from contacting.

As a result, when the cross dipole antenna 4 is designed, the adjustment width of the input impedance can be increased and the input impedance can be easily adjusted.
In addition, it is possible to increase the real impedance of the cross dipole antenna 4 and to suppress a decrease in the stability of the input impedance.

(Modification)
Hereinafter, modifications of the present embodiment will be listed.
(1) In the cross dipole antenna 4 of the present embodiment, the inner radiating element portion 12in and the outer radiating element portion 12out are configured not to overlap each other in plan view and side view, but the present invention is not limited to this.
That is, for example, as shown in FIG. 15, the inner radiating element portion 12in and the outer radiating element portion 12out may be overlapped in plan view and side view. FIG. 15 is a diagram illustrating a modification of the present embodiment.

(2) In the cross dipole antenna 4 of the present embodiment, the cross dipole antenna 4 is formed in a three-layer structure laminated in a direction perpendicular to the plane on which the two dipole antennas 8 are arranged. However, the present invention is not limited to this. .
That is, for example, as shown in FIG. 16, the cross dipole antenna 4 may be formed in a five-layer structure in which the cross dipole antenna 4 is stacked in a direction orthogonal to the plane on which the two dipole antennas 8 are arranged. FIG. 16 is a diagram illustrating a modification of the present embodiment.

In this case, the cross dipole antenna 4 includes an inner base 6in in which the inner radiating element portion 12in is formed on one surface (the lower surface in FIG. 16), the inner radiating element portion 12in, and the outer radiating element portion 12out. Is formed between the outer base 6out formed on one surface (the upper surface in FIG. 16), the outer radiating element portion 12out, the inner radiating element portion 12in, and the outer radiating element portion 12out. It is set as the structure provided with the adhesion layer 22 which adhere | attaches the radiation element part 12in and the outer side radiation element part 12out.
The pressure-sensitive adhesive layer 22 is formed using, for example, a polyester polyurethane adhesive or the like as a material.

1 Non-contact communication medium (inlet)
2 IC chip 4 Cross dipole antenna 6 Base material 8 Dipole antenna 10 Loop line 10in Internal loop line 10out Outer loop line 12 Radiation element 12in Inner radiation element part 12out Outer radiation element part 14 Port 16 Cross dipole antenna 4 is equally divided by straight line Lcp 18 The gap formed between the inner loop line 10in and the outer loop line 10out 20 Loop connection part 22 Adhesive layer Lcp Straight line passing through the center point where the two dipole antennas 8 are orthogonal W Line width of the loop line 10 Lmin A straight line connecting a pair of outer radiating element portions 12out facing each other across a center point where two dipole antennas 8 are orthogonal to each other at the shortest distance Ldiv A line θ1 straight line that bisects two adjacent inner radiating element portions 12ain and 12bin Lmi The angle between the angle θ2 linear Lmin and the inner radiation element portion 12bin the inner radiation element portion 12ain

Claims (9)

A cross-dipole antenna comprising a plurality of dipole antennas intersecting each other at a center point in plan view and having at least two pairs of terminals ,
Each of the dipole antennas includes a pair of radiating elements whose one end is connected to the IC chip at the center point,
A loop line connecting all the radiating elements surrounding the center point in an endless shape in plan view,
The loop line is formed with a line width and a path length according to a preset imaginary part impedance ,
Wherein the set imaginary part impedance previously, the cross dipole antenna, wherein the imaginary part impedance der Rukoto at one pair of said two pairs of terminals. The loop line includes an inner loop line that surrounds the center point in an endless shape, and an outer loop line that surrounds the outer peripheral side of the inner loop line in an endless shape,
The cross dipole antenna according to claim 1, wherein the inner loop line and the outer loop line respectively connect all the radiating elements. The radiating element includes an inner radiating element portion closer to the center point than the inner loop line, and an outer radiating element portion farther from the center point than the outer loop line,
The inner loop line connects all the inner radiating element portions,
The outer loop line connects all the outer radiating element portions,
Between the inner loop line and the outer loop line, a gap surrounding the center point in an endless shape is formed,
The cross dipole antenna according to claim 2, wherein the gap is formed at an interval corresponding to a preset real part impedance. The loop line includes an even number of loop connection portions that connect a part of the inner loop line and a part of the outer loop line to form a shared line,
The inner loop line or the outer loop line is divided by the loop connection portion in plan view,
At least one of the inner radiating element portions is connected to a portion divided by two adjacent loop connection portions of the inner loop line,
The cross dipole antenna according to claim 3, wherein at least one of the outer radiating element portions is connected to a portion of the outer loop line divided by two adjacent loop connection portions.   A straight line connecting a pair of the outer radiating element portions facing each other with the center point interposed therebetween overlaps a line that bisects two adjacent inner radiating element portions in plan view. The cross dipole antenna according to claim 3 or 4. The cross dipole antenna is formed of a plurality of layers stacked in a direction perpendicular to a plane on which the plurality of dipole antennas are arranged,
The cross dipole antenna according to any one of claims 3 to 5, wherein the inner radiating element portion and the outer radiating element portion are formed in different layers among the plurality of layers. .   The cross dipole antenna according to any one of claims 1 to 6, wherein all of the radiating elements are formed in the same shape in a plan view. The loop line is formed in the same shape in each region obtained by equally dividing the cross dipole antenna by a plurality of straight lines passing through the center point in plan view,
8. The cross dipole antenna according to claim 1, wherein only one of the pair of radiating elements is disposed in each region. 9.   A non-contact communication medium comprising the cross dipole antenna according to any one of claims 1 to 8 and the IC chip.

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