WO2019225526A1

WO2019225526A1 - Rf tag antenna, rf tag and rf tag with conductor

Info

Publication number: WO2019225526A1
Application number: PCT/JP2019/019826
Authority: WO
Inventors: 詩朗杉村
Original assignee: 株式会社フェニックスソリューション
Priority date: 2018-05-24
Filing date: 2019-05-20
Publication date: 2019-11-28
Also published as: JP6998086B2; JPWO2019225526A1

Abstract

[Problem] To provide an RF tag antenna, an RF tag, and an RF tag with a conductor that are omnidirectional and nondirectional, and have a long communication distance. [Solution] An RF tag antenna 100 to which an IC chip 500 is attached comprises: an insulating base material 140 having a first surface, a second surface formed opposite to the first surface, and a thickness between the first surface and the second surface; a flat plate-like antenna part 120 provided on the first surface; a flat plate-like ground part 130 provided on the second surface and disposed opposite to the antenna part 120, a short-circuit part 160 provided so as to electrically short-circuit between the antenna part 120 and the ground part 130; and a power supply part 170 provided on the first surface and configured to supply power to the IC chip 500. The antenna part 120 includes a first antenna part 121 and a second antenna part 122 that are disposed to extend in directions orthogonal to each other, and the ground part 130 includes a first ground part 131 and a second ground part 132 that are disposed to extend in directions orthogonal to each other.

Description

RF tag antenna, RF tag, and RF tag with conductor

The present invention relates to an RF tag antenna, an RF tag, and an RF tag with a conductor.

In recent years, RFID (Radio Frequency Identification) technology has been used in management systems that perform inventory management, logistics management, and the like of products and parts. In a system using this RFID technology, wireless communication is performed between an RF tag and a reader / writer (hereinafter referred to as a reader), and identification information stored in the RF tag is read by the reader.

For example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2012-253700) discloses a wireless communication device that facilitates attachment of a radiation conductor and a ground conductor and improves connection reliability between conductors, a manufacturing method thereof, and wireless communication A metal article with a device is disclosed.

A wireless communication device described in Patent Document 1 includes a dielectric block having a first main surface and a second main surface facing the first main surface, and a radiation conductor provided on the first main surface of the dielectric block; , A ground conductor provided on the second main surface of the dielectric block, a wireless IC element for processing a high-frequency signal, a feed conductor for connecting the radiation conductor and the ground conductor, and a short-circuit conductor for connecting the radiation conductor and the ground conductor A radio communication device including an inverted F-type antenna including at least a radiation conductor, a ground conductor, a feeding conductor, and a short-circuit conductor, each of which is configured as a flat metal conductor. The radiation conductor portion is disposed on the first main surface of the dielectric block, the ground conductor portion is disposed on the second main surface of the dielectric block, and the feeding terminal portion is mainly on the side surface of the dielectric block. It is location, in which short-circuiting conductor portions are mainly disposed on a side surface of the dielectric block.

Patent Document 2 (Japanese Patent Application Laid-Open No. 2007-124696) discloses a communication system that requires an ultra-wideband and small antenna device such as a Broadband-PAN (Personal Area Network) using UWB (Ultra Wide Band) technology. Discloses a low-profile wideband antenna apparatus that can also be used in Japan.

The wideband antenna device described in Patent Document 2 is a wideband antenna device including a conductive ground plane and a radiating conductor plate that are disposed so that at least a part of each is opposed to each other, and the conductive ground plane and the radiating conductor. A magnetic material having a relative magnetic permeability of greater than 1 and approximately 8 or less is interposed between the plates.

Patent Document 3 (Japanese Patent Laid-Open No. 2013-110585) discloses a thin antenna for reading an RFID tag that is used for radio waves in the UHF band and that can perform good communication even when attached to a metal member. Yes.

A thin antenna tire described in Patent Document 3 includes a magnetic sheet, an antenna portion disposed on one surface of the magnetic sheet, and a conductor ground plane disposed on the other surface of the magnetic sheet, and the magnetic sheet When viewed in the thickness direction, the antenna section and the conductor ground plane are arranged so that at least a part thereof overlaps, and the thickness of the magnetic sheet is 200 μm or more and 600 μm or less.

JP 2012-253700 A JP 2007-124696 A JP 2013-110585 A

Prior Document 1 discloses an inverted-F type RF tag antenna. However, there is a problem that long-distance reading cannot be performed even if a dielectric is used.

Further, in Patent Documents 2 and 3, since the structure is complicated such as feeding using a coaxial line or a strip line, there is a problem that the manufacturing cost increases, and furthermore, it is difficult to adjust the resonance frequency according to the application. There was a problem.
In addition, when the RF tag is brought close to the conductor, there is a problem that the resonance frequency shifts and hinders communication, or there is a problem that communication is not possible when radio waves are irradiated on the back surface of the RF tag installation surface.

Furthermore, Patent Document 1 discloses a metal article with a wireless communication device, but there is a problem that the direction of directivity is limited and reading cannot be performed easily.

The main object of the present invention is to provide an RF tag antenna, an RF tag, and an RF tag with a conductor, which are omnidirectional, so-called omnidirectional and have a long communication distance.

(1)
An RF tag antenna according to one aspect is an RF tag antenna to which an IC chip is attached, and has a thickness between a first surface, a second surface formed opposite to the first surface, a first surface, and a second surface. An insulating base material having a flat plate-like antenna portion provided on the first surface, a flat plate-like ground portion provided on the second surface and disposed opposite to the antenna portion, and the antenna portion and the ground portion. Including a short-circuit portion provided to electrically short-circuit the gap and a power-feed portion provided on the first surface and configured to feed power to the IC chip, and the antenna portions are arranged long in the orthogonal directions, respectively. The first and second antenna portions are included, and the ground portion includes a first ground portion and a second ground portion that are long in the orthogonal direction.

The antenna portion is formed in a so-called L shape by the first antenna portion and the second antenna portion. The ground portion is formed in a so-called L shape by the first ground portion and the second ground portion. An L-shaped antenna portion is formed on the first surface of the insulating base, and an L-shaped ground portion is formed on the second surface of the insulating base at a position facing the antenna portion.
Therefore, since the planes of polarization of the electromagnetic waves radiated from the first antenna unit and the second antenna unit are orthogonal to each other, the omnidirectional omnidirectionality between the RF tag and the reader is obtained by using the RF tag antenna of the present invention. Communication becomes possible. In other words, the antenna characteristics can be improved by extending the antenna in two directions. Therefore, the RF tag including the RF tag antenna can stably communicate with the reading device regardless of the orientation of the antenna.

(2)
An RF tag antenna according to a second aspect of the present invention is the RF tag antenna according to one aspect, wherein the inductor pattern portion includes at least a short-circuit portion and a power feeding portion, and the capacitor portion includes at least an antenna portion, a ground portion, and an insulating base. Thus, a resonance circuit that resonates in the frequency band of the radio wave transmitted from the reading device is configured.
In this case, by providing an IC chip in the inductor pattern portion, a resonant circuit is formed by the inductor pattern portion, the capacitor portion, and the electrostatic capacity inside the IC chip. In addition, since the inductor pattern portion is formed by cutting out a flat plate, it is possible to reduce the thickness.

(3)
An RF tag antenna according to a third aspect of the present invention is the RF tag antenna according to any one of the second aspect of the present invention, wherein the insulating base has an L-shape having a first insulating base and a second insulating base. The first and second antenna parts of the antenna part formed in an L-shape are provided on the first surfaces of the first insulating base and the second insulating base, respectively. The first ground portion and the second ground portion of the L-shaped ground portion are respectively provided on the second surface of the second insulating base material, and the short-circuit portion is provided on the side surface of the corner portion of the insulating base material. May be.

In this case, since the antenna portion is provided on the first surface of the insulating base formed in an L shape and the ground portion is provided on the second surface, each member is formed in an L shape and has a wide range of radiation directivity. It can be. In addition, a capacitor is constituted by the insulating base, the antenna portion, and the ground portion. Furthermore, the antenna portion and the ground portion are connected via a short-circuit portion provided on the side surface of the corner portion of the insulating base material. With such a configuration, the RF tag antenna can be easily manufactured and can be thinned.

(4)
An RF tag antenna according to a fourth aspect of the present invention is the RF tag antenna according to any one of the third aspect to the third aspect of the present invention, wherein the power feeding unit includes a first power feeding unit and a second power feeding unit connected to the short circuit unit. The first power supply unit and the second power supply unit may be configured to connect the IC chip between the first power supply unit and the second power supply unit.

In this case, since the short-circuit portion and the power feeding portion can be formed of continuous conductive members, the short-circuit portion and the power feeding portion can be easily formed, and the thickness of the tag can be reduced. In addition, when the IC chip is bridged between the first power supply unit and the second power supply unit, a resonance circuit is formed by the inductor pattern unit, the capacitance inside the IC chip, and the insulating base material, and is omnidirectional. RF tags can be formed.

(5)
An RF tag antenna according to a fifth aspect of the present invention is the RF tag antenna according to any one of the fourth aspect of the present invention, wherein a notch portion is formed between the antenna portion and the short-circuit portion, and a power feeding portion is provided in the notch portion. It may be formed.

In this case, a thin and compact RF tag can be constructed. In addition, since the inductor pattern portion is formed by cutting out a flat plate, it is possible to reduce the thickness.

(6)
An RF tag antenna according to a sixth aspect of the present invention is the RF tag antenna according to any one of the fifth aspect, wherein a slit is formed between the first antenna portion and the second antenna portion, and the slit is notched. It may communicate with the part.

In this case, the slit formed between the first antenna portion and the second antenna portion can cause the slit-side end portions of the first antenna portion and the second antenna portion to act as an inductance component. The impedance of the antenna portion and the IC chip can be matched.

(7)
An RF tag antenna according to a seventh aspect of the present invention is the RF tag antenna according to any one of the sixth aspect to the sixth aspect of the present invention, wherein the set internal area is between the short-circuit portion and the first and second feeding portions. A space region having a gap may be formed.

In this case, the impedance of the inductor pattern portion can be made constant by setting the internal area of the inductor pattern portion constituted by at least the short-circuit portion, the first power feeding portion, and the second power feeding portion.

(8)
An RF tag antenna according to an eighth aspect of the present invention is the RF tag antenna according to any one of the seventh aspect to the seventh aspect of the present invention, wherein the antenna portion and the ground portion are formed in a flat plate-like shape formed in an X shape in plan view. It is configured by bending the member, providing one conductive element body adjacent to the conductive member on the first surface of the insulating base material, and providing the other conductive element body adjacent to the conductive member on the second surface of the insulating base material. May be.

In this case, since the antenna portion and the ground portion can be formed by simply bending and sticking the X-shaped flat conductive member to the insulating base material, the manufacturing is extremely simple and the manufacturing cost is low.

(9)
An RF tag antenna according to a ninth aspect is the RF tag antenna according to any one of the eighth aspect to the eighth aspect, wherein the first antenna portion and the second antenna portion are formed from a rectangular plate-like conductive member, The first ground part and the second ground part may be formed of a rectangular plate-like conductive member.

In this case, the antenna part and the ground part can be manufactured very easily, and a small RF tag having stable omnidirectionality can be manufactured.

(10)
An RF tag antenna according to a tenth aspect of the present invention is the RF tag antenna according to any one of the ninth aspect to the ninth aspect, wherein the insulating base material is made of a dielectric.

In this case, since the insulating base material is made of a dielectric, it is possible to realize a small RF tag having omnidirectionality of several millimeters in all directions.

(11)
An RF tag antenna according to an eleventh aspect of the present invention is the RF tag antenna according to any one of the ninth aspect to the ninth aspect, wherein the insulating base material is made of polystyrene foam.

In this case, since the insulating substrate is made of expanded polystyrene, an RF tag having a size of several centimeters can be realized. Moreover, the insulating base material close | similar to air can be used by using a polystyrene foam.
Moreover, the opening part of an antenna part and a ground part can be taken large.

(12)
An RF tag antenna according to a twelfth aspect of the present invention is the RF tag antenna according to any one of the eleventh aspects of the present invention, wherein the insulating base material has a dielectric constant on the first surface side and a dielectric constant on the second surface side. And may be different from each other.

In this case, since the dielectric constant on the first surface side and the dielectric constant on the second surface side are different from each other, it is effective for obtaining the size or opening area of the plate-like conductive member on each surface side.

(13)
An RF tag antenna according to a thirteenth invention is the RF tag antenna according to any one of the twelfth inventions from one aspect, wherein the insulating base is reduced in diameter from the first surface side toward the second surface side. One or a plurality of holes having different diameters or different diameters may be formed.

In this case, the insulating base material is formed with one or a plurality of holes having the same diameter or different diameters from the first surface side toward the second surface side. This is effective for obtaining the size or opening area of the conductive member. In addition, adjustment of the dielectric constant can be handled by processing the insulating base material.

(14)
An RF tag antenna according to a fourteenth aspect of the present invention is the RF tag antenna according to any one of the thirteenth aspect of the present invention, wherein the dielectric constant on the first surface side is greater than the dielectric constant on the second surface side. May be formed to be smaller.

In this case, when the first surface side is the antenna portion and the second surface side is the ground portion according to the usage mode, the dielectric constant on the second surface side is larger than the dielectric constant on the first surface side. Even if the opening area is not changed, it is relatively large with respect to the ground side, so that the communication distance with the reader can be increased without increasing the size of the RF tag antenna.

(15)
An RF tag antenna according to a fifteenth aspect of the present invention is the RF tag antenna according to any one of the fourteenth aspect of the present invention, wherein the insulating base material forms a polystyrene foam layer on the first surface side, and the second surface side. Alternatively, a layer having a high dielectric constant may be formed.

(16)
An RF tag according to another aspect includes the RF tag antenna according to any one of claims 1 to 15 and an IC chip provided on the RF tag antenna.

In this case, by providing the IC chip, a resonance circuit is formed by the inductor pattern portion, the capacitance inside the IC chip and the insulating base material, and the communication distance can be extended, and the IC chip is placed on the metal member. You can also.
Further, an omnidirectional omni-directional RF tag can be formed.

(17)
Further, an RF tag according to another aspect includes an RF tag antenna according to any one of claims 1 to 15, an IC chip provided on the RF tag antenna, and a ground portion of the RF tag antenna, directly or electrically. And a conductor connected through a capacitor.

In this case, by providing the IC chip, a resonant circuit is formed by the inductor pattern portion, the capacitance inside the IC chip, and the insulating base material. Furthermore, a conductor can be used as an antenna.
Further, an omnidirectional omni-directional RF tag can be formed.

It is a typical perspective view which shows an example of RF tag. It is a typical development view showing an example of an antenna for RF tag. FIG. 3 is a detailed explanatory view showing a main part of the RF tag antenna of FIG. It is typical sectional drawing which shows the state which provided the sheet | seat member in RF tag. It is typical sectional drawing which shows the example which affixed RF tag to the electroconductive member. It is a schematic diagram which shows an example of the equivalent circuit of RF tag and an electroconductive member. It is a schematic diagram which shows the result of the reading experiment of RF tag. It is a schematic diagram which shows the radiation pattern of RF tag. It is a schematic diagram which shows the other example of an insulating base material. It is a typical sectional view showing other examples of an insulating substrate.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Moreover, in the case of the same code | symbol, those names and functions are also the same. Therefore, detailed description thereof will not be repeated.

[This embodiment]
FIG. 1 is a schematic perspective view showing an example of the RF tag 100 according to the present embodiment, and FIG. 2 is a schematic development view showing an example of the RF tag antenna 110 of the RF tag 100.

As shown in FIGS. 1 and 2, the RF tag 100 according to the present invention includes an RF tag antenna 110, an insulating base 140, and an IC chip 500.
The RF tag antenna 110 includes an antenna unit 120, a ground unit 130, an inductor pattern unit 150, a short circuit unit 160, and a power feeding unit 170.
The antenna unit 120 includes a first antenna unit 121 and a second antenna unit 122, and the ground unit 130 includes a first ground unit 131 and a second ground unit 132.

The first antenna part 121 and the second antenna part 122 are made of a rectangular planar conductive member. The first antenna unit 121 has a long side and a short side. The long side of the second antenna unit 122 is provided in a direction orthogonal to the long side of the first antenna unit 121. That is, the extending direction of the first antenna unit 121 and the extending direction of the second antenna unit 122 are in a state of 90 degrees (right angle, orthogonal).

In the present embodiment, the extending direction of the first antenna unit 121 and the extending direction of the second antenna unit 122 are orthogonal or L-shaped mainly refers to a case of 90 degrees. However, the present invention is not limited to the state of 90 degrees, and includes the case where the extending direction of the first antenna unit 121 and the extending direction of the second antenna unit 122 are provided in a range of 60 degrees to 120 degrees. That is, even when the first antenna unit 121 and the second antenna unit 122 are L-shaped or close to L-shaped, they are included in the L-shaped or orthogonal shape in this specification.

Note that the RF tag 100 shown in FIG. 1 may be entirely or partially wrapped by a sheet member 600 (see FIG. 4). Hereinafter, each part will be described.

(Insulating base material 140)
In the present embodiment, the insulating base material 140 is formed in an L shape and has a first insulating base material 141 and a second insulating base material 142. The first antenna portion 121 and the second antenna portion 122 of the antenna portion 120 that are also formed in an L shape are provided on the first surfaces of the first insulating base material 141 and the second insulating base material 142, respectively. A first ground portion 131 and a second ground portion 132 of the ground portion 130 that are also formed in an L shape are provided on the second surfaces of the base material 141 and the second insulating base material 142, respectively. Furthermore, the corner | angular part of the insulating base material 140 is notched, and the short circuit part 160 is provided in the side surface of this corner | angular part.

Further, in the present embodiment, the insulating base material 140 is made of polystyrene foam. Originally, it is most preferable to use air instead of the insulating base material, but maintenance of a predetermined distance between the first antenna portion 121 and the first ground portion 131, the second antenna portion 122 and the second ground portion 132 and prevention of contact are prevented. Therefore, it is preferable to use a polystyrene foam having 90% or more air.

As a result, the spatial distance between the first antenna part 121 and the first ground part 131, the second antenna part 122 and the second ground part 132 can be kept constant by the insulating base material 140. In addition, it is desirable that the relative dielectric constant of the insulating base material 140 be in the range of 1% to 20%.
When ceramic is used as the insulating base 140, the opening areas of the first antenna unit 121, the first ground unit 131, the second antenna unit 122, and the second ground unit 132 are reduced, and the communication distance is reduced. However, the RF tag 100 can be reduced in size.

On the other hand, when a material having a relative dielectric constant of 1% or more and 5% or less such as styrene foam is used as the insulating base 140, the opening area of the antenna unit 120 and the ground unit 130 can be maintained large, and the communication distance can be increased. Can extend from several meters to tens of meters.

In addition, the thickness of the insulating base material 140 made of expanded polystyrene is desirably in the range of 0.5 mm or more and 3 mm or less.
In this embodiment, the insulating base material 140 is made of foamed polystyrene, but is not limited to this, and may be an insulating material such as polyethylene, polyimide, thin foam (bola), or the like. Other foams or materials having the following may be used.
In the present embodiment, the insulating base 140 is composed of one member. However, the present invention is not limited to this, and the insulating base 140 according to the present invention is formed using a plurality of insulating bases. May be.

In the present embodiment, the planar shape of the first surface and the second surface of the insulating base 140 is substantially the same as that of the antenna portion 120 and the ground portion 130, but is not limited to this, and the insulating base is not limited thereto. The planar shape of 140 may be larger than the sizes of the antenna unit 120 and the ground unit 130.

For example, a flat insulating substrate 140 can be used. In that case, there is a region where the L-shaped antenna unit 120 is provided on the first surface of the insulating base 140 and the antenna unit 120 is not provided on the same first surface. Similarly, an L-shaped ground portion 130 is provided on the second surface of the insulating base material 140, and there is a region where the ground portion 130 is not provided on the same second surface.
The shape of the insulating substrate 140 may be a cubic shape. For example, the antenna part 120 which is continuous over the three surfaces of the first corner of the cubic-shaped insulating base is provided, and the three corners of the second corner facing or adjacent to the first corner. A continuous ground portion 130 may be provided.

As described above, the RF tag antenna 110 according to the present embodiment uses a polystyrene foam as the insulating base material 140 of the RF tag antenna 110. Therefore, an opening area of a certain size can be ensured, and the plate shape The sensitivity of the antenna can be improved.

In the above embodiment, the case where the polystyrene foam is used as the insulating base material 140 has been described, but a dielectric may be used. For example, the dielectric may be resin, ceramic, paper, or the like. Furthermore, the insulating substrate 140 may be in a foamed shape, may have one or more cavities, and may be made of a composite material in which different materials are mixed or laminated.

FIG. 3 is a detailed explanatory view showing a main part of the RF tag antenna 110 shown in FIG.

(Antenna part 120)
The antenna unit 120 includes a first antenna unit 121 and a second antenna unit 122 that are long in the orthogonal direction. That is, the second antenna unit 122 extends in a direction orthogonal to the extending direction of the first antenna unit 121.
As shown in FIG. 3, the first antenna unit 121 is formed of a rectangular plate-shaped conductive member, and the first antenna unit 121 includes a side 921, a side 922, a side 923, a side 924, a side 925, a side 926, It consists of a region surrounded by 927.
The second antenna portion 122 is formed of a rectangular plate-shaped conductive member, and the second antenna portion 122 is surrounded by a side 931, a side 932, a side 933, a side 934, a side 935, a side 936, and a side 937. Consists of regions.
The length of the extending direction of the 1st antenna part 121 and the 2nd antenna part 122 can be made the same. That is, the size of the 1st antenna part 121 and the 2nd antenna part 122 can be made the same.

Here, for the sake of explanation, the sum of the lengths of the side 921, the side 922, the side 923, the side 924, the side 925, the side 926, and the side 927 is defined as a value T1.
Further, the total of the lengths of the side 931, the side 932, the side 933, the side 934, the side 935, the side 936, and the side 937 is defined as a value T2.

In the present embodiment, the values T1 and T2 correspond to any one of λ / 4, λ / 2, 3λ / 4, and 5λ / 8 when the wavelength λ (lambda) of the radio wave is used. Designed to.

In the present embodiment, the values T1 and T2 are designed to be half the wavelength λ of the frequency to be used. The wavelength λ can be calculated by the propagation speed (light speed (c)) / frequency (F).
Specifically, when the frequency is 920 MHz, the propagation speed (light speed (c)) is 300 Mm / s, and the value T is T = (300 ÷ 920 MHz) / 2≈163 mm.
In this case, the length of each side is adjusted so that the values T1 and T2 are 163 mm. Since the values T1 and T2 are approximate values, the numerical values of the values T1 and T2 themselves may have an error of around ± 5%. This is because the reading distance of the RF tag 100 is shortened, but can be adapted to the specification by adjustment.

In the present embodiment, first antenna portion 121 and second antenna portion 122 are made of an aluminum metal thin film. Generally, the thin film in this embodiment is formed with a thickness of 3 μm or more and 35 μm or less.
The first antenna unit 121 and the second antenna unit 122 are formed by a technique such as etching or pattern printing.

The first antenna unit 121 and the second antenna unit 122 may be provided directly on the first surface of the insulating base 140, or the first antenna unit 121 and the second antenna unit formed of a conductive material on a resin film. 122 may be provided on the first surface of the insulating base material 140 by sticking it to the insulating base material 140 using an adhesive or the like.

(Ground part 130)
The ground portion 130 includes a first ground portion 131 and a second ground portion 132 that are long in the orthogonal direction. That is, the second ground part 132 extends in a direction orthogonal to the extending direction of the first ground part 131.
As shown in FIG. 2, the first ground portion 131 and the second ground portion 132 are made of an aluminum metal thin film. Generally, the thin film in this embodiment is formed with a thickness of 3 μm or more and 35 μm or less.

The first ground part 131 and the second ground part 132 are formed of a rectangular plate-like conductive member.
The lengths of the first ground part 131 and the second ground part 132 in the extending direction can be the same. That is, the sizes of the first ground part 131 and the second ground part 132 can be the same.
The first ground part 131 and the second ground part 132 are formed by a technique such as etching or pattern printing.
The first ground part 131 and the second ground part 132 may be provided directly on the second surface of the insulating base 140, or the first ground part 131 and the second ground part formed of a conductive material on a resin film. Alternatively, 132 may be provided on the second surface of the insulating base 140 by sticking the insulating base 140 to the insulating base 140 using an adhesive or the like.

As shown in FIG. 2, the antenna unit 120 and the ground unit 130 are formed by bending a flat plate-shaped conductive member formed in an X shape in a plan view into a U shape along two mountain fold lines shown in FIG. 3. One conductive element adjacent to the conductive member can be provided on the first surface of the insulating base 140, and the other conductive element adjacent to the conductive member can be provided on the second surface of the insulating base 140. .
In this case, an L-shaped antenna portion 120 is formed by one pair of conductive element bodies, and an L-shaped ground portion 130 is formed by the other pair of conductive element bodies. One conductive element body and the other conductive element body are formed substantially symmetrically.

When the conductive member is bent along the surface of the insulating base 140, a region between the two mountain fold lines shown in FIG. 3 is arranged on the side surface of the corner of the insulating base 140. A short-circuit portion 160 that connects the antenna portion 120 and the ground portion 130 is formed on the side surface of the insulating base 140.
A power feeding portion 170 and an inductor pattern portion 150 described below are formed in an intersecting region where one conductive element body and the other conductive element body intersect.

(Power supply unit 170)
The power feeding unit 170 is provided on the first surface of the insulating base 140 and configured to feed power to the IC chip 500.
That is, a notch portion 180 is formed between the antenna unit 120 and the short-circuit portion 160, and a power feeding portion 170 is formed in the notch portion 180. The power feeding unit 170 includes a first power feeding unit 171 and a second power feeding unit 172 connected to the short circuit unit 160. The first power feeding unit 171 and the second power feeding unit 172 are formed in an L shape with a relatively thin line pattern, and the leading ends of the first power feeding unit 171 and the second power feeding unit 172 face each other. A gap is formed between the tip portions of the second power feeding unit 172. The IC chip 500 is disposed in the gap, and the IC chip 500 is electrically connected to the first power feeding unit 171 and the second power feeding unit 172.

A space region having a set internal area S is formed in a region surrounded by the short-circuit portion 160, the first power feeding portion 171, and the second power feeding portion 172.
A slit 124 is formed between the first antenna part 121 and the second antenna part 122, and the slit 124 communicates with the notch part 180 (and the space region S).

(Inductor pattern 150)
The inductor pattern unit 150 includes at least a short-circuit unit 160 and a power feeding unit 170. That is, the power feeding unit 170 also serves as a part of the inductor pattern unit 150. With this configuration, the configuration of the inductor pattern unit 150 can be simplified.

The capacitor C includes at least the antenna unit 120, the ground unit 130, and the insulating base 140. The inductor pattern unit 150 and the capacitor C constitute a resonance circuit that resonates in the frequency band of a radio wave transmitted from a reading device (not shown). Details of the inductor pattern section 150 are as follows.

As shown in FIG. 3, the inductor pattern portion 150 includes edges of the short-circuit portion 160 and the power feeding portion 170, and includes a side 151, a side 152, a side 153, a side 154, a side 155, a side 156, a side 157, a

side

158, 159, side 160, and side 161. The inductor pattern portion 150 has a shape in which a space between the side 153 and the side 159 that are part of a ring-shaped circuit is cut out. That is, specifically, it consists of a C shape of an alphabetic character.

That is, the inductor pattern unit 150 has a region (internal area S) surrounded by the

sides

154, 155, 156, 157, and 158, as shown in FIG.
In addition, although the inductor pattern part 150 demonstrated the case where it cuts between the edge | side 153 and the edge | side 159, it is not limited to this, You may form an insulating part between the edge | side 153 and the edge | side 159.

In the present embodiment, inductor pattern portion 150 is made of an aluminum metal thin film. Generally, the thin film in this embodiment is formed with a thickness of 3 μm or more and 35 μm or less.
The inductor pattern portion 150 is formed by a technique such as etching or pattern printing. Moreover, it can form also by sticking the resin film in which the electroconductive pattern was formed to the insulating base material 140 with an adhesive agent.

In the present embodiment, the impedance of the inductor pattern portion 150 can be made constant by the internal area S of the inductor pattern portion 150.
Thereby, impedance matching between the antenna unit 120 and the processing circuit of the IC chip 500 can be achieved.

(IC chip 500)
The IC chip 500 is disposed on the upper surface side of the RF tag antenna 110 (on the same plane as the first antenna unit 121 and the second antenna unit 122). The IC chip 500 operates based on radio waves received by the antenna unit 120 of the RF tag antenna 110.

Specifically, the IC chip 500 according to the present embodiment first rectifies a part of the carrier wave transmitted from the reading device, and generates a power supply voltage necessary for the IC chip 500 itself to operate. Then, the IC chip 500 operates a non-volatile memory in which the control logic circuit in the IC chip 500, the unique information of the product, and the like are stored, according to the generated power supply voltage.
Further, the IC chip 500 operates a communication circuit or the like for transmitting / receiving data to / from the reading device.

(Sheet member 600)
FIG. 4 is a schematic partial cross-sectional view showing a state in which the sheet member 600 is provided on the RF tag 100 of FIGS. 1 to 3.
As shown in FIG. 4, the RF tag 100 may be surrounded by a sheet member 600.
The sheet member 600 is mainly made of an insulating resin sheet such as polyethylene terephthalate. In addition to polyethylene terephthalate, one or a plurality of insulating materials or resins such as polyimide and polyvinyl chloride may be used as the sheet member 600.

The sheet member 600 is for protecting the antenna unit 120 and the ground unit 130 provided on the first surface and the second surface of the insulating base 140 from the outside. Therefore, the thickness of the sheet member 600 is preferably several micrometers or more and several hundred micrometers or less, and more preferably about several tens of micrometers.
In the present embodiment, the sheet member 600 is provided. However, the present invention is not limited to this, and the sheet member 600 may not be provided, and the antenna unit 120 and the ground unit 130 are protected using another insulating coating process. You may make it do.
Further, the sheet member 600 may be provided separately in the first antenna part 121 and the second antenna part 122.

(RF tag antenna 110, IC chip 500 and conductive member 900)
FIG. 5 is a schematic cross-sectional view showing an example in which the RF tag 100 shown in FIG. 4 is attached to the conductive member 900.

As shown in FIG. 5, the RF tag 100 is attached to the conductive member 900 with a conductive adhesive or an adhesive layer 450 or the like. In the present embodiment, the conductive member 900 is made of a conductive metal plate. Specifically, it has an arbitrary metal part such as a metal box, a box including a metal plate, a case, a box including a metal member, or a case.

In FIG. 5, the conductive adhesive or the adhesive layer 450 is used. However, the conductive adhesive or the adhesive layer 450 is not limited thereto, and any conductive material such as double-sided tape, solder, one-component or two-component epoxy resin, or the like is used. An adhesive may be used.
Further, when the RF tag 100 and the conductive member 900 are indirectly electrically connected, the RF tag 100 may be attached to the conductive member 900 using an insulating adhesive or an adhesive layer.

FIG. 6 is a schematic diagram illustrating an example of an equivalent circuit of the RF tag 100 and the conductive member 900.

As shown in FIG. 6, in the equivalent circuit of the RF tag 100 and the conductive member 900, the inductor pattern L of the inductor pattern unit 150 and the capacitor Cb composed of the internal capacitance of the IC chip 500 are connected in parallel to each other. The inductor pattern L and the IC chip 500 constitute a resonance circuit that resonates in the frequency band of the radio wave transmitted from the reading device.
The resonance frequency f [Hz] of this resonance circuit is given by equation (1). The value of the resonance frequency f is set so as to be included in the frequency band of the radio wave transmitted from the reading device.

In the formula (1), L _a : inductance of the inductor pattern L, C _b : equivalent capacitance inside the IC chip 500.

Here, some IC chips 500 include capacitors therein, and the IC chip 500 has a stray capacitance. Therefore, when setting the resonance frequency f of the resonant circuit, which utilizes the equivalent capacitance C _b of the IC chip 500.
That is, the resonant circuit has the inductor pattern L inductance, and the interior of the equivalent capacitance C _b and considering the set resonance frequency f of the IC chip 500. In addition, as _Cb , for example, a capacitance value published as one of specifications of an IC chip to be used can be used.

As described above, by using the equivalent capacitance C _b of the IC chip 500, there is no need to provide a new capacitor. In addition, the resonance frequency f of the resonance circuit can be accurately set in the frequency band of radio waves. As a result, the reading performance of the RF tag 100 can be further improved. Further, the power supply voltage generated by the IC chip 500 can be further increased.

Further, as shown in FIG. 6, the conductive member 900 can be capacitively coupled to the RF tag 100 via the insulating base material 140. That is, the insulating base material 140 has a role of a capacitor.
As a result, since the conductive member 900 can be used in the same manner as the antenna unit 120, the radio wave of the reading device can be received from either the front surface side or the back surface side of the conductive member 900.

In the present embodiment, the case where the sheet member 600 is interposed between the first ground portion 131 and the second ground portion 132 of the RF tag 100 and the conductive member 900 has been described. It is only necessary to be directly or indirectly connected to.
Furthermore, in the present embodiment, conductive member 900 may be made of a metal plate. In the present application, the term “conductor” is typically exemplified by electrical conductivity and metal, as in a general dictionary sense. However, the “conductor” is not limited to metal, and may be, for example, a human body, vegetation, water, ground, or the like.

7 and 8 are schematic diagrams showing the results of the reading experiment of the RF tag 100 described with reference to FIGS.

As shown in FIG. 7A, a plurality of electromagnetic fields including at least orthogonal directions can be formed around the RF tag 100.
Further, although the case where the RF tag 100 is attached to the spherical conductor as shown in FIG. 7B has been described in FIG. 5, a large plurality of electromagnetic fields are formed. be able to. That is, the directivity in all directions can be enhanced.
It can be seen from FIG. 7 that the radiation directivity is nearly omnidirectional in all directions. Therefore, stable communication with the reading device is possible regardless of the orientation of the tag. Therefore, even when a plurality of products with tags are packed in a random orientation, communication with the tags of each product is possible.

Next, as shown in FIG. 8, the radiation pattern of the RF tag 100 is shown.
FIG. 8 shows an XY plane, a YZ plane, and a ZX when the first antenna portion and the second antenna portion of the RF tag according to the embodiment of the present invention for a vertical wave and a horizontal wave of 921 MHz are arranged on the X axis and the Y axis. The radiation directivity in the plane is shown.
From FIG. 8, even in the vertical wave, radiation could be confirmed in all of the YZ plane, ZX plane, and XY plane. Furthermore, it was possible to confirm radiation on the XY plane even with horizontal waves. From the above, it was found that the RF tag 100 according to the present embodiment can be read from all directions.

(Other insulating base materials)
FIG. 9 is a schematic view showing another example of the insulating base material 140.

As shown in FIG. 9, the insulating base material 140 may be formed of a laminate of a polystyrene foam material 145 and a resin material 146. In the present embodiment, the size lengths of both the polystyrene foam material 145 and the resin material 146 are designed to be the same.

Specifically, in the expanded polystyrene material 145, the wavelength λ1 is calculated assuming that the relative dielectric constant εa of the expanded polystyrene material 145 is 1.0 and the frequency is 900 MHz.
As a result, since the antenna unit 120 attached to the polystyrene foam material 145 is not affected by the dielectric constant, the wavelength λ1 is λ1 = (300/920 MHz) / 1 ² ≈333 mm.

On the other hand, for the resin material 146, the wavelength λ2 is calculated as the relative dielectric constant εb = 5.0 of the resin material 146, the frequency of 900 MHz, and the propagation speed of 300 Mm / s.
As a result, in the resin material 146, the wavelength λ2 is λ2 = (300/920 MHz) / 5 ² ≈149 mm.
The resin material 146 may be ceramic, paper, or the like.

Here, since the value T1 and the value T2 of the first antenna unit 121 or the second antenna unit 122 are 333 mm, respectively, resonance occurs at 402 MHz with a wavelength 333 / 149≈2.23 times longer.
That is, it is the same as that in which the first ground portion 131 and the second ground portion 132 having an apparent size of 744 mm are formed.
As a result, the RF tag 100 can be the same as the state in which the RF tag 100 is attached to the conductor 900, and the RF tag 100 having a sufficient communication distance corresponding to metal or nonmetal can be realized.

(Further other insulating base materials)
FIG. 10 is a schematic cross-sectional view showing still another example of the insulating base material 140.

As shown in FIG. 10, the insulating base 140 has a front surface 141 and a back surface 142.
In addition, one or a plurality of holes 143 whose diameter decreases from the front surface 141 toward the back surface 142 are provided. Here, the hole 143 is not limited to the one continuously reducing in diameter, but includes one having a diameter reduced stepwise.

In this embodiment, the case where the hole 143 has a stepped shape or a conical shape is described. However, the hole 143 is not limited thereto, and is a cylinder, a rectangular tube, or an elliptical tube that does not penetrate from the front surface 141 to the back surface 142. Alternatively, it may be a conical cylinder, a pyramid cylinder, or an elliptical cone cylinder that does not penetrate from the front surface 141 to the back surface 142 or penetrates.
Further, the shape may change from the front surface 141 toward the back surface 142. For example, the front surface 141 side may be a star-shaped hole, and the cross section of the hole may be circular toward the back surface 142 side.
Moreover, in FIG. 9, although the diameter of the hole 143 has demonstrated about the same case, it is not limited to this, It may be the same and may differ.

As described above, by changing the relative permittivity of the front surface 141 side and the back surface side 142, the first ground portion 131 and the second ground portion 132 that are apparently longer than the predetermined are formed. Alternatively, it is possible to realize the RF tag 100 that has a sufficient non-metallic communication distance.
Further, due to the difference in dielectric constant, the size of the plate-like conductive member on each side can be reduced, or the opening area can be made larger than the actual product. In addition, adjustment of the dielectric constant can be handled by processing the insulating base material.
That is, even if the size of the plate-like conductive member on each side is reduced, the performance is apparently the same as the state where the plate-like conductive member is enlarged, and the product can be downsized. Further, even if the opening area is reduced, the performance is apparently the same as when the opening area is increased, and the product can be reduced in size.

As described above, since the RF tag 100 and the conductive member 900 can use the conductive member 900 as the antenna unit 120 and have a large opening area, the sensitivity of the RF tag 100 can be improved. .

Further, since the conductive member 900 can be used as the antenna unit 120, reading from the back surface of the conductive member 900 on which the RF tag 100 is provided is possible.

In the present invention, the IC chip 500 corresponds to an “IC chip”, the RF tag antenna 110 corresponds to an “RF tag antenna”, the inductor pattern portion 150 corresponds to an “inductor pattern portion”, and the notch portion 180 corresponds to “ The antenna portion 120, the first antenna portion 121, and the second antenna portion 122 correspond to the “antenna portion”, and the ground portion 130, the first ground portion 131, and the second ground portion 132 correspond to the “ground portion”. The surface 141 corresponds to the “first surface”, the back surface 142 corresponds to the “second surface”, the insulating base 140 corresponds to the “insulating base”, and the values T and T2 are Corresponding to “peripheral length of antenna part”, resin material 146 corresponds to “dielectric”, foamed polystyrene material 145, foamed polystyrene corresponds to “foamed polystyrene”, and hole 143 is “one or more”. The RF tag 100 corresponds to the “RF tag”, the conductive member 900 corresponds to the “conductor”, and the conductive member 900 and the RF tag 100 correspond to the “RF tag with conductor”. To do.

The preferred embodiment of the present invention is as described above, but the present invention is not limited thereto. It will be understood that various other embodiments may be made without departing from the spirit and scope of the invention. Furthermore, in this embodiment, although the effect | action and effect by the structure of this invention are described, these effect | actions and effects are examples and do not limit this invention.

DESCRIPTION OF SYMBOLS 100 RF tag 110 RF tag antenna 120 Antenna part 121 1st antenna part 122 2nd antenna part 130 Ground part 131 1st ground part 132 2nd ground part 140 Insulation base material 141 Surface 142 Back surface 143 Hole 145 Styrofoam material 146 Resin material 150 Inductor pattern portion 170 Power feeding portion 180 Notch portion 500 IC chip 900 Conductive member, conductor T1, T2 value

Claims

An RF tag antenna to which an IC chip is attached,
A first surface, a second surface formed to face the first surface, an insulating substrate having a thickness between the first surface and the second surface;
An antenna portion having a flat plate shape provided on the first surface;
A flat ground portion provided on the second surface and disposed opposite to the antenna portion;
A short-circuit portion provided to electrically short-circuit between the antenna portion and the ground portion;
A power supply unit provided on the first surface and configured to supply power to the IC chip,
The antenna unit includes a first antenna unit and a second antenna unit that are disposed long in directions orthogonal to each other,
The RF tag antenna, wherein the ground part includes a first ground part and a second ground part that are long in the orthogonal direction.
An inductor pattern portion constituted by at least the short-circuit portion and the power feeding portion;
2. The RF according to claim 1, wherein a resonance circuit that resonates in a frequency band of a radio wave transmitted from a reading device is configured by at least the antenna unit, the ground unit, and the capacitor unit including the insulating base. Tag antenna.
The insulating base is formed in an L shape having a first insulating base and a second insulating base,
The first antenna part and the second antenna part of the antenna part formed in an L shape are respectively provided on the first surface of the first insulating base and the second insulating base,
The first ground part and the second ground part of the ground part formed in an L shape are respectively provided on the second surface of the first insulating base and the second insulating base,
The RF tag antenna according to claim 1, wherein the short-circuit portion is provided on a side surface of a corner portion of the insulating base material.
The power feeding unit includes a first power feeding unit and a second power feeding unit connected to the short-circuit unit, and the first power feeding unit and the second power feeding unit are between the first power feeding unit and the second power feeding unit. The RF tag antenna according to any one of claims 1 to 3, wherein the RF chip antenna is configured to connect the IC chip to each other.
The RF tag antenna according to any one of claims 1 to 4, wherein a notch portion is formed between the antenna portion and the short-circuit portion, and the feeding portion is formed in the notch portion.
The RF tag antenna according to any one of claims 1 to 5, wherein a slit is formed between the first antenna part and the second antenna part, and the slit communicates with the notch part.
7. The RF tag antenna according to claim 1, wherein a space region having a set internal area is formed between the short-circuit portion, the first feeding portion, and the second feeding portion. .
The antenna part and the ground part bend a flat conductive member formed in an X shape in plan view, and provide one conductive element body adjacent to the conductive member on the first surface of the insulating base. The RF tag antenna according to claim 1, wherein the other conductive element body adjacent to the conductive member is provided on the second surface of the insulating base material.
The first antenna part and the second antenna part are formed from a rectangular plate-shaped conductive member, and the first ground part and the second ground part are formed from a rectangular plate-shaped conductive member. The RF tag antenna according to any one of 1 to 8.
The RF tag antenna according to any one of claims 1 to 9, wherein the insulating base is made of a dielectric.
The RF tag antenna according to any one of claims 1 to 9, wherein the insulating substrate is made of polystyrene foam.
The RF tag antenna according to any one of claims 1 to 11, wherein the insulating base material has a dielectric constant on the first surface side and a dielectric constant on the second surface side different from each other.
The insulating base material according to any one of claims 1 to 12, wherein one or a plurality of holes having the same diameter or different diameters which are reduced in diameter from the first surface side toward the second surface side are formed. The described RF tag antenna.
The RF tag antenna according to any one of claims 1 to 13, wherein the insulating base is formed so that a dielectric constant on the first surface side is smaller than a dielectric constant on the second surface side.
The RF tag antenna according to any one of claims 1 to 14, wherein the insulating base material has a layer of polystyrene foam formed on the first surface side and a layer having a high dielectric constant formed on the second surface side. .
An RF tag antenna according to any one of claims 1 to 15,
An RF tag including an IC chip provided on the RF tag antenna.
An RF tag antenna according to any one of claims 1 to 15,
An IC chip provided on the RF tag antenna;
An RF tag with a conductor, comprising: a ground portion of the RF tag antenna; and a conductor connected directly or through a capacitor.