Patent Application
20200365967
The present invention relates to a low-profile RF tag antenna, an RF tag, and a method of manufacturing an RF tag antenna.
For example, the patent literature PTL 1 (Japanese Patent Laid-Open No. 2015-152827) discloses an RFID tag that can be manufactured with excellent production efficiency and prevent damage to an IC chip.
The RFID tag described in PTL 1 includes a substrate, a first adhesive layer, a peeling layer laminated upon the substrate via the first adhesive layer, and an RFID label having a removable second adhesive layer and an RFID inlet, where the peeling layer has a peeling part and a remaining part other than the peeling part, a slit for which forms an exposed section of the first adhesive layer by removal of the peeling layer is formed between the peeling part and the remaining part, and the RFID inlet is stuck via the second adhesive layer upon the remaining portion in the surface opposite to the surface of contact with the substrate or the first adhesive layer.
The patent literature PTL 2 (Japanese Patent Laid-Open No. 2016-170576) discloses an RFID label that has a simple structure, and is capable of separating an antenna section of an RFID from a metal article to which the RFID label is attached, and providing a sufficient communication distance.
In the RFID label described in PTL 2, which is an RFID label manufactured by pasting flexible exterior materials, from the front side and the rear side, to an inlet in which an RFID chip and an antenna for communications with external devices provided on a circuit board are electrically connected, the RFID label includes a portion where the inlet is included and another portion where the inlet is not included extending therefrom, and an adhesive means is provided on one of the surfaces of the exterior materials at the portion where the inlet is not included.
The patent literature PTL 3 (Japanese Patent Laid-Open No. 2014-194596) discloses an RF tag capable of being stuck on a curved-surface portion of the surface of a metal pipe forming a basket wagon or a cart rack.
In the RF tag described in PTL 3, the RF tag includes an inlay including an IC chip and an antenna, a planar auxiliary antenna laminated in an insulated state on the inlay, and a substrate having the laminated inlay and the auxiliary antenna mounted thereon and functioning as a dielectric constant adjustment layer in relation to the mounted inlay, where the substrate has flexibility allowing to be stuck in a strip like manner and in a surface contact state in a length direction on a surface of a metal columnar member.
The patent literature PTL 4 (Japanese Patent Laid-Open No. 2010-262091) discloses an RFID label and a slip having the RFID label having a preferable external appearance as a product, being capable of eliminating defective printing, and causing no glue remaining even when being removed from a target of adhesion.
In the RFID label described in PTL 4, a label is stuck to the surface of a ground paper, an RFID inlet is applied on a part corresponding to the label on the back surface of the ground paper, where a peeling part for removing from the label the outer part beyond the cut line of the ground paper is provided by the cut line which cuts the ground paper along the periphery of the RFID inlet and a releasable adhesive layer applied on the surface of the ground paper on the outer side relative to the cut line of the ground paper.
The patent literature PTL 5 (Japanese Patent Laid-Open No. 2008-097426) discloses an RFID medium exhibiting a fine curve while maintaining functionality of a reflection plate.
In the RFID medium described in PTL 5, a conductive antenna is formed on a base material having elasticity, where the RFID medium includes an inlet section including an IC chip connected to the antenna and capable of writing and/or reading information via the antenna in a non-contact state; and a reflection plate arranged on the side opposite to the surface of the base material on which the antenna is formed; and a non-conductive plate material having elasticity and provided between the inlet section and the reflection plate, the reflection plate having a plurality of slits extending at least in one direction.
An object of the present invention is to provide an RF tag antenna, an RF tag, and a method of manufacturing an RF tag antenna enabling low-profile configuration and capable of receiving omnidirectional radio waves.
In this case, as a result of the fact that the RF tag antenna is stuck on the conductive member, the capacitor section is formed by the first waveguide element section, the second waveguide element section, and the conductive member as well as the first insulating substrate. As a result, a resonant circuit is formed and efficient transmission and reception can be performed.
In addition, by sticking the second waveguide element section on the conductive member, the conductive member as such can be utilized as an antenna. By virtue of this, the communication sensitivity can be dramatically improved. Further, omnidirectional radio waves can be received.
In particular, when it is stuck to the conductive member, the RF tag antenna as such can be made low-profile. In other words, since the conductive member is utilized as an antenna and a capacitor plate, the configuration can be made low-profile by the size of the capacitor plate.
In this case, as a result of the fact that it is stuck on the conductive member, the capacitor section is formed by the first waveguide element section, the second waveguide element section, and the conductive member as well as the first insulating substrate. As a result, a resonant circuit is formed and efficient transmission and reception can be performed.
In addition, by sticking the second waveguide element section on the conductive member, the conductive member as such can be utilized as an antenna (L-type antenna, inverted L-type antenna). By virtue of this, the communication sensitivity can be dramatically improved. Further, omnidirectional radio waves can be received.
In particular, when it is stuck to the conductive member, the RF tag antenna as such can be made low-profile. In other words, since the conductive member is utilized as an antenna and a capacitor plate, the configuration can be made low-profile by the size of the capacitor plate.
In this case, since the first insulating substrate is only laminated upon the entire back surface of the first waveguide element section, as a result of the fact that it is stuck on the conductive member, it is made possible to readily form the capacitor section by the first waveguide element section, the second waveguide element section, and the conductive member as well as the first insulating substrate.
In this case, since the adhesive layer capable of adhering to the conductive layer is provided on the surface of the first insulating substrate, the RF tag antenna can be readily stuck on the conductive member.
In this case, the outer shape of the first waveguide element section is mainly defined by the flat rectangle shape. Alternatively, it may be defined by the long side and the short side. Further, the first inductor pattern forming section of the first waveguide element section which forms the inductor pattern section is mainly defined by the rectangular shape, and, by selecting the relative angle difference between the long side or the short side and the rectangular shape from any one of 0 degrees, 45 degrees, 90 degrees, 135 degrees, and 180 degrees, the inductor pattern L can be changed and thereby the frequency according to the specifications can be changed.
In this case, the outer shape of the first waveguide element section is mainly defined by the flat rectangle shape. Alternatively, it may be defined by the long side and the short side. Further, the first inductor pattern forming section of the first waveguide element section which forms the inductor pattern section is mainly defined by the rectangular shape, and the inductor pattern L can be changed without changing the coil inductance or the antenna size by changing the relative angle difference between the long side or the short side and the rectangular shape, which is defined according to the specifications, and thereby the frequency according to the specifications can be changed.
In this case, as the first inductor pattern forming section connects a part of the rectangular shape to the second waveguide element section, RF tag antenna resistant to noise can be formed.
In this case, the inductor pattern section is formed by the first waveguide element section, the short-circuiting section, the second waveguide element section, and the power feeding section, and the capacitor section is formed by the first waveguide element section, the second waveguide element section, and the conductive member as well as the first insulating substrate. As a result, a resonant circuit is formed and efficient transmission and reception can be performed.
In addition, by sticking the second waveguide element section on the conductive member, the conductive member as such can be utilized as an antenna. By virtue of this, the communication sensitivity can be dramatically improved. Further, omnidirectional radio waves can be received.
In particular, when it is stuck to the conductive member, the RF tag antenna as such can be made low-profile. In other words, since the conductive member is utilized as an antenna and a capacitor plate, the configuration can be made low-profile by the size of the capacitor plate.
In this case, the inductor pattern section is formed by the first waveguide element section and the capacitor section is formed by the first waveguide element section, the second waveguide element section, and the conductive member as well as the first insulating substrate. As a result, a resonant circuit is formed and efficient transmission and reception can be performed.
In addition, by sticking the second waveguide element section on the conductive member, the conductive member as such can be utilized as an antenna. By virtue of this, the communication sensitivity can be dramatically improved. Further, omnidirectional radio waves can be received.
In particular, when it is stuck to the conductive member, the RF tag antenna as such can be made low-profile. In other words, since the conductive member is utilized as an antenna and a capacitor plate, the configuration can be made low-profile by the size of the capacitor plate.
In this case, the resonant circuit can appropriately perform communications by specifying the resonant frequency with the inductance of the inductor pattern, the capacitance of the capacitor, and the equivalent capacitance inside the IC chip taken into account.
In this case, the inductor pattern section is formed by the first waveguide element section, the short-circuiting section, the second waveguide element section, and the power feeding section, and the capacitor section is formed by the first waveguide element section, the second waveguide element section, and the conductive member as well as the first insulating substrate. As a result, a resonant circuit is formed and efficient transmission and reception can be performed.
In addition, by sticking the second waveguide element section on the conductive member, the conductive member as such can be utilized as an antenna. By virtue of this, the communication sensitivity can be dramatically improved. Further, omnidirectional radio waves can be received.
In particular, when it is stuck to the conductive member, the RF tag antenna as such can be made low-profile. In other words, since the conductive member is utilized as an antenna and a capacitor plate, the configuration can be made low-profile by the size of the capacitor plate.
In this case, the inductor pattern section is formed by the first waveguide element section and the capacitor section is formed by the first waveguide element section, the second waveguide element section, and the conductive member as well as the first insulating substrate. As a result, a resonant circuit is formed and efficient transmission and reception can be performed.
In addition, by sticking the second waveguide element section on the conductive member, the conductive member as such can be utilized as an antenna. By virtue of this, the communication sensitivity can be dramatically improved. Further, omnidirectional radio waves can be received.
In particular, when it is stuck to the conductive member, the RF tag antenna as such can be made low-profile. In other words, since the conductive member is utilized as an antenna and a capacitor plate, the configuration can be made low-profile by the size of the capacitor plate.
In this case, the outer shape of the first waveguide element section is mainly defined by the flat rectangle shape. Alternatively, it may be defined by the long side and the short side. Further, the first inductor pattern forming section of the first waveguide element section which forms the inductor pattern section is mainly defined by the rectangular shape, and, by changing the relative angle difference between the long side or the short side and the rectangular shape, which is defined according to the specifications, the inductor pattern L can be changed without changing the coil inductance or the antenna size, and the frequency according to the design specifications can be changed.
The embodiment of the present invention will be described hereinbelow with reference to the drawings. In the following explanations, the same components are indicated by the same reference signs. Also, when the same reference signs are assigned to components, they are the same ones which have the same name and the same function. Accordingly, detailed explanations thereof will not be repeated.
As illustrated in
In the RF tag antenna 100 depicted in
The power feeding section 230 and the short-circuiting section 240 are formed at the short side of the rectangular shape of the first waveguide element section 210. The second waveguide element section 220 is formed in the power feeding section 230 and the short-circuiting section 240.
It should be noted that the first insulating substrate 300 is not provided at least on the back surface of the second waveguide element section 220.
As a result, in the RF tag antenna 100, the virtual surface FA of the surface of the first waveguide element section 210 and the surface of the second waveguide element section 220 reside at different positions. The surface of the first waveguide element section 210 and the surface of the second waveguide element section 220 do not reside in the same horizontal plane. In other words, the surface of the first waveguide element section 210 and the surface of the second waveguide element section 220 will have a positional relationship according to which a step equal to the thickness T of the first insulating substrate 300 is created. Detailed explanations of the individual portions will be given below.
The first waveguide element section 210 and the second waveguide element section 220 depicted in
The first waveguide element section 210 and the second waveguide element section 220 are formed by techniques such as etching or pattern printing. Accordingly, in the present embodiment, also in the power feeding section 230 and the short-circuiting section 240 which will be described later, the same or similar techniques are used to from them.
As illustrated in
The sum of the lengths of the perimeter sides 210a to 210d (including raised and recessed portions in the figures) defining the first waveguide element section 210 is indicated by the value “S1.” If the wavelength λ (lambda) of radio wave is drawn on, the value S1 is tuned to correspond to any one of λ/4, λ/2, 3λ/4, and 5λ/8.
It should be noted that the value S1 is more preferably half the length of the wavelength λ of the frequency in use.
In addition, a sum of the lengths of the sides 220a to 220d forming the second waveguide element section 220 is referred to as value “S2.” If the wavelength λ (lambda) of the radio wave is drawn on, the value S2 is tuned to correspond to any one of λ/4, λ/2, 3λ/4, and 5λ/8.
It should be noted that the value is more preferably half the length of the wavelength λ of the frequency in use.
In the present embodiment, the first insulating substrate 300 depicted in
It should be noted that the thickness of the first insulating substrate 300 is desirably in the range between 0.5 mm and 3 mm including these values.
It should be noted that in the present embodiment, it is made of polystyrene foam, but this does not constitute a limitation thereto, and any insulator may be used and other foams or materials having insulating property such as polyethylene, polyimide, and thin foam (volara) may be used.
As has been described in the foregoing, since polystyrene foam is used as the first insulating substrate 300 of the RF tag antenna 100 in the RF tag antenna 100 according to the present embodiment, an opening area of a certain size can be provided, the sensitivity of the plate-shaped antenna including the conductive member 900 which will be described later can be improved.
The adhesive layer 400 in the present embodiment depicted in
It should be noted that the adhesive layer 400 is composed of a double-sided tape in the present embodiment, but this does not constitute a limitation thereto, and it may also be provided by formation of other adhesive layers, application of adhesives, or the like. In
In the present embodiment, the reason that the double-sided tape has been described as an example is that, as will be described later, since the RF tag antenna 100 is stuck on the conductive member 900, the double-sided tape can be readily stuck thereon by removing the release paper of the double-sided tape.
As illustrated in
In addition, in the present embodiment, the power feeding section 230 and the short-circuiting section 240 are formed by techniques such as etching or pattern printing simultaneously with the formation of the first waveguide element section 210 and the second waveguide element section 220.
It should be noted that while the power feeding section 230 and the short-circuiting section 240 are formed by etching or pattern printing in the present embodiment, this does not constitute a limitation thereto, and it may be formed in a separate fashion and may be electrically connected to the first waveguide element section 210 and the second waveguide element section 220. For example, a power feeding pin or a short-circuit pin may be used. Also, the width of the short-circuiting section 240 or the power feeding section 230 may be widened.
The IC chip 500 is provided, as illustrated in
The IC chip 500 operates based on the radio waves received by the plate-shaped antenna of the RF tag antenna 100.
Specifically, the IC chip 500 according to the present embodiment first rectifies part of the carrier wave transmitted from the reading device and then generate power supply voltage necessary for the IC chip 500 itself to operate. Then the IC chip 500 causes the logic circuit for control in the IC chip 500 and non-volatile memory that stores product specific information or the like to operate by the power supply voltage that has been generated.
In addition, the IC chip 500 causes communication circuit or the like for performing transmission and reception of data with the reading device to operate.
The sheet member 600 is mainly made of polyethylene terephthalate. It should be noted that, in addition to polyethylene terephthalate, one or more types of materials or resins having insulating property such as polyimide and polyvinyl chloride may also be used as the sheet member 600.
The sheet member 600 is used to protect the first waveguide element section 210 and the second waveguide element section 220. For this reason, the sheet member 600 preferably has a thickness of several micrometers to several hundred micrometers, more preferably about several tens of micrometers.
Accordingly, while the sheet member 600 is to be provided in the present embodiment, this does not constitute a limitation thereto, and the sheet member 600 may not be provided and other insulation coating treatments may be used.
As illustrated in
In the present embodiment, the conductive member 900 is made of a conductive metal plate. Specifically, it has any appropriate metal portion such as a metal box, a box or a case containing a metal plate, a box or a case containing a metal member, etc.
It should be noted that while conductive adhesive 250 is to be used in
As illustrated in
The resonant frequency f (Hz) of this resonant circuit is given by the expression (1). The value of the resonant frequency f is tuned such that it falls within the frequency band of the radio waves transmitted from the reading device.
In the expression (1), La represents the inductance of the inductor pattern L, Ca represents the capacitance of the capacitor 240, and Cb represents the equivalent capacitance inside the IC chip 500.
Here, some components have a capacitor inside the IC chip 500 and the IC chip 500 has stray capacitance. For this reason, when the resonant frequency f of the resonant circuit is to be specified, it is preferable to take the equivalent capacitance Cb inside the IC chip 500 into consideration.
In other words, the resonant circuit should preferably have a resonant frequency f that has been specified with the inductance of the inductor pattern L, the capacitance of the capacitor 240, and the equivalent capacitance Cb inside the IC chip 500 taken into account. It should be noted that, as the Cb, for example, it is possible to use a capacitance value disclosed as part of the specifications of the IC chip to be used.
As has been described in the foregoing, by taking the equivalent capacitance Cb inside the IC chip 500 into account, the resonant frequency f of the resonant circuit can be accurately specified to fall within the frequency band of the radio waves. As a result, the reading performance of the RF tag antenna 100 can be further improved. Also, the power supply voltage generated by the IC chip 500 can be further increased.
It should be noted that the aspects differing from those of the RF tag antenna 100 according to the present embodiment will be described below.
As illustrated in
Here, all the side of the side 211a, the side 211b, the side 211c, the side 211d, the side 211e, and the rectangular shape 211f are provided with any one of 0 degree, 90 degrees, 180 degrees, and 270 degrees with respect to the long side or the short side of the first waveguide element section 210.
As illustrated in
In addition, as illustrated in
As illustrated in
In addition, as illustrated in
As a result, the resonant frequency f is determined by the perimeter length of the first waveguide element section 210, the coil L, and the capacitor C.
As has been described in the foregoing, in the RF tag antenna 100a depicted in
Next,
As illustrated in
Here, the side 212c and the side 212d are provided at 90 degrees with respect to the long side of the first waveguide element section 210. All the sides of the side 212a, the side 212b, the side 212e, the side 212f, and the rectangular shape 212g are provided at either 45 degrees or 135 degrees with respect to the long side of the first waveguide element section 210.
In other words, in the feature depicted in
By virtue of this, the lengths of the sides 212c, 212d of the coil section depicted in
Subsequently,
As illustrated in
In other words, in
By virtue of this, the lengths of the sides 213c, 213d of the coil section depicted in
It should be noted that, while the coil section is rotated by 45 degrees or 90 degrees about the axis of rotation RP in the present embodiment in order to change the inductor pattern L without changing the coil inductance or the antenna size, this does not constitute a limitation thereto, and the size of the coil section may be changed, the notch in the coil forming section as such for forming the inductor pattern L may be extended or shortened, and it may also be designed by rotating it at any other appropriate angles.
Subsequently,
As illustrated in
As illustrated in
Subsequently,
As illustrated in
Here, the side 215h and the side 215i are provided at 90 degrees with respect to the long side of the first waveguide element section 210. All the side of the sides 215a to 215g, and the rectangular shape 215j are provided at either 45 degrees or 135 degrees with respect to the long side of the first waveguide element section 210.
In other words, in
The coil section depicted in
As a result, an RF tag antenna 100e resistant to noise or the like can be obtained when compared with the RF tag antennas 100a, 100b, and 100c.
Subsequently,
As illustrated in
The coil section depicted in
As a result, an RF tag antenna 100f resistant to noise or the like can be obtained when compared with the RF tag antennas 100a, 100b, and 100c.
It should be noted that the RF tag antenna 100 in
Subsequently,
As illustrated in
As illustrated in
Subsequently,
As illustrated in
Subsequently,
As illustrated in
It should be noted that the RF tag antenna 100 in
As has been described in the foregoing, in the RF tag antennas 100 to 100i according to the present embodiment, since the first insulating substrate 300 is only laminated on the entire surface of the back side of the first waveguide element section 210, the capacitor section can be readily formed by the first waveguide element section 210, the second waveguide element section 220, and the conductive member 900 as well as the first insulating substrate 300 as a result of being stuck on the conductive member 900.
In addition, since the adhesive layer 400 capable of adhering to the conductive member is provided on the surface of the first insulating substrate 300, it can be readily stuck on the conductive member.
In addition, the outer shape of the first waveguide element section 210 is mainly made of a flat rectangle shape. Alternatively, it may be defined by the long side and the short side. Further, the sides of the first waveguide element section 210 forming the coil section mainly form a rectangular shape, and the relative angle difference between the long side or the short side and the rectangular shape is selected as any one of 0 degrees, 45 degrees, 90 degrees, 135 degrees, and 180 degrees, as a result of which the frequency according to the specifications can be changed by changing the inductor pattern L.
In addition, by changing the coil section to any appropriate relative angle about the axis of rotation RP according to the design specifications, the inductor pattern L can be changed without changing the coil inductance or the antenna size, and the frequency according to the design specifications can be changed.
In addition, by connecting a part of the sides of the rectangular shape of the coil section to the second waveguide element section 220, an RF tag antenna resistant to noise can be formed.
In addition, the inductor pattern L is formed by the first waveguide element section 210, the short-circuiting section 240, the second waveguide element section 220, and the power feeding section 230; and the capacitor C is formed by the first waveguide element section 210, the second waveguide element section 220, and the conductive member 900 as well as the first insulating substrate 300. As a result, a resonant circuit is formed and efficient transmission and reception can be performed.
In addition, by sticking the second waveguide element section 220 to the conductive member 900, the conductive member 900 as such can be utilized as an antenna.
In particular, when stuck on the conductive member 900, the RF tag antennas 100, 100a to 100i as such can be made low-profile.
In the present invention, the RF tag antennas 100, 100a to 100i correspond to the “RF tag antenna;” the conductive member 900 corresponds to the “conductive member,” the first waveguide element section 210 corresponds to the “first waveguide element section,” the second waveguide element section 220 corresponds to the “second waveguide element section,” the power feeding section 230 corresponds to the “power feeding section,” the short-circuiting section 240 corresponds to the “short-circuiting section,” the first insulating substrate 300 corresponds to the “first insulating substrate,” the adhesive layer 400 corresponds to the “adhesive layer,” the IC chip 500 corresponds to the “IC chip,” and any one of the RF tag antennas 100, 100a to 100i, the IC chip 500, and the conductive member 900 correspond to the “RF tag.”
Whilst one preferred embodiment of the present invention has been described in the foregoing, the present invention is not limited thereto. It will be appreciated that other various embodiments may be conceived without departing the purport and scope of the present invention. Further, while the operations and effects achieved by the features of the present invention have been described in the present embodiment, these operations and effects are merely examples by which the present invention is in no way limited.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2017-139233 | Jul 2017 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2018/026768 | 7/17/2018 | WO | 00 |
