Tear-resistant, hanging radio frequency tag

Abstract

This invention relates to a tear-resistant hanging RFID tag, comprising an RFID chip (1), a coupling feed ring (2), a radiator (3), and a face material (4). The coupling feed ring (2) is bent and wrapped around the face material (4) to hang the designed tear-resistant hanging RFID tag on the target object. In application, the RFID tag structure can be adapted to various UHF RFID chip impedances without changing the RFID tag structure, and it has a stable frequency. Moreover, when the RFID tag is hung on target objects of different materials, its resonant frequency and distance will not change. Furthermore, by changing the coupling position between the RFID chip (1) and the radiator (3), the sensitivity of the RFID tag can be adjusted without changing the resonant frequency. In addition, whether the coupling feed ring (2) or the radiator (3) is damaged, the original performance of the RFID tag will be damaged, causing the RFID tag to fail, thus improving the safety of the RFID tag.

Description

Technical Field

[0001] This invention relates to a tear-resistant hanging RFID tag, belonging to the field of RFID tags. Background Technology

[0002] In conventional RFID antenna design, the antenna structure needs to be adjusted to achieve conjugate matching with the chip. Therefore, when using different chips with the same size antenna, a redesign is required. In addition, in existing RFID antennas, when the tag comes into contact with objects of different materials, the tag's performance (frequency, reading distance, etc.) will change to varying degrees due to the influence of materials with different dielectric constants, which will affect the performance of the existing RFID antenna. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a tear-resistant hanging RFID tag with a brand-new structural design. It has high-performance radio frequency operation and can effectively detect the tag tearing action and interrupt the tag operation in time.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: The present invention designs a tear-resistant hanging radio frequency tag for hanging on a target object, including a radio frequency chip, a coupling feed ring, a radiator and a surface material;

[0005] The coupling feed ring has a strip structure, and the radio frequency chip is located at one end of the coupling feed ring strip structure. The radiator is a coplanar structure formed by bending a single metal wire of a preset length in an S-shape. The S-shape structure forms a strip-shaped notch of a preset length and a preset width, and the preset width of the strip-shaped notch is greater than the width of the coupling feed ring strip structure. The other end of the coupling feed ring strip structure is located at the open position of the strip-shaped notch in the radiator.

[0006] When the RF chip on the coupled feed ring strip structure is located away from the radiator, and the coupled feed ring and the radiator are in a coplanar state, the shape and size of the overall structure of the coupled feed ring and the radiator are adapted to the shape and size of the surface material. The overall structure of the coupled feed ring and the radiator is set on the surface material with corresponding shape edges. The coupled feed ring bends with the bending of the local section on the surface material on which it is set.

[0007] Based on the coupling feed ring strip structure, the RF chip is bent and wrapped around the target object along the surface material towards the strip recess in the radiator, so that the RF chip on the coupling feed ring strip structure is connected to a preset position in the strip recess in the radiator, and a local segment of the RF chip on the coupling feed ring strip structure is arranged along the inside of the strip recess in the radiator, so as to realize the suspension of the tear-resistant hanging RF tag on the target object.

[0008] As a preferred technical solution of the present invention: the radiator is a coplanar axisymmetric structure formed by a single metal wire bent in an S-shape, and the two ends of the metal wire are located on both sides of the axis of symmetry, and the position of the metal wire corresponding to the axis of symmetry forms a strip-shaped notch along the direction of the axis of symmetry with a width greater than the width of the strip structure of the coupling feed ring.

[0009] As a preferred embodiment of the present invention, the straight line containing the coupled feed ring strip structure is collinear with the straight line containing the symmetry axis of the radiator.

[0010] As a preferred technical solution of the present invention: the coupling feed ring is bent and wrapped around the target object in the structure, and the inner side of the overall structure of the coupling feed ring and the local section of the surface material on which it is installed is in contact with the corresponding surface of the target object.

[0011] As a preferred technical solution of the present invention: the connection strength between the coupling feed ring and the radiator and the surface of the face material is less than the connection strength between the inner side of the overall structure of the coupling feed ring and the local section of the face material and the corresponding surface of the target object.

[0012] As a preferred technical solution of the present invention: the radio frequency chip is disposed at one end of the coupling feed ring strip structure by bonding or wire bonding.

[0013] As a preferred technical solution of the present invention: the coupling feed ring and the radiator are respectively disposed on the surface of the face material by means of adhesive bonding.

[0014] As a preferred embodiment of the present invention, the coupling feed ring and the radiator are made of easily tearable metal material.

[0015] As a preferred embodiment of the present invention, the easily tearable metal material is conductive ink or easily tearable aluminum film.

[0016] As a preferred embodiment of the present invention, the surface material is made of an easily tearable material.

[0017] The tear-resistant hanging RFID tag of the present invention, compared with the prior art, has the following technical advantages:

[0018] The tear-resistant hanging RFID tag designed in this invention includes an RFID chip, a coupling feed ring, a radiator, and a face material. These components are interconnected according to a design scheme. The coupling feed ring is bent and wrapped around the target object along with the face material. The RFID chip's terminal on the strip structure of the coupling feed ring is positioned at a predetermined depth within a strip-shaped recess in the radiator, thus enabling the tear-resistant hanging RFID tag to hang on the target object. In practical applications, the RFID tag structure does not need to be changed; the same RFID tag can be adapted to various UHF RFID chip impedances, and the frequency can be stabilized within a certain range. Moreover, when the RFID tag is hung on target objects of different materials, its resonant frequency and distance remain unchanged. Furthermore, by changing the coupling position between the RFID chip's terminal on the coupling feed ring and the radiator, the sensitivity of the RFID tag can be adjusted without changing the resonant frequency, thereby changing the RFID reading distance. Additionally, removing the RFID tag from the suspended target object, whether damaging the coupling feed ring or the radiator, will damage the original performance of the RFID tag, causing it to malfunction. This triggers an alarm through sensing, improving the safety of the RFID tag. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the tear-resistant hanging RFID tag designed in this invention;

[0020] Figure 2 This is a bending diagram of the tear-resistant hanging RFID tag designed in this invention.

[0021] Figure 3 This is a schematic diagram showing the resonant frequencies at which RFID tags operate after being bound to RFID chips from different manufacturers.

[0022] Figure 4 This is a schematic diagram of the tear-resistant hanging RFID tag designed in this invention, which is bent and suspended on a target metal object parallel to it.

[0023] Figure 5 This is a schematic diagram of the tear-resistant hanging RFID tag designed in this invention, which is bent and suspended on a bent target metal object.

[0024] Figure 6 This is a comparative diagram showing the performance of the tear-resistant hanging RFID tag designed in this invention when bent and hung on target objects of different shapes and materials.

[0025] Figure 7 This is a schematic diagram showing the radio frequency chip at different preset depth positions within the strip-shaped notch in the radiator in the design of this invention;

[0026] Figure 8 This is a comparative schematic diagram showing the reading distance performance of the radio frequency chip at different preset depth positions within the strip-shaped notch in the radiator in the design of this invention.

[0027] Among them, 1. Radio frequency chip, 2. Coupled feed loop, 3. Radiator, 4. Surface material. Detailed Implementation

[0028] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0029] The present invention designs a tear-resistant hanging radio frequency tag for hanging on a target object. In practical applications, it includes an radio frequency chip, a coupling feed ring 2, a radiator 3, and a face material 4.

[0030] Among them, such as Figure 1 As shown, the coupling feed ring 2 is a strip structure, and the RF chip is set at one end of the strip structure of the coupling feed ring 2 by bonding or wire bonding. The radiator 3 is a coplanar structure formed by a single metal wire of a preset length bent in an S-shape, and a strip-shaped notch of preset length and preset width is formed in the S-shape, and the preset width of the strip-shaped notch is greater than the width of the strip structure of the coupling feed ring 2. In practical applications, for the specific structural design of the radiator 3, the radiator 3 can be designed as a coplanar axisymmetric structure formed by a single metal wire bent in an S-shape, and the two ends of the metal wire are located on both sides of the axis of symmetry, and the position of the metal wire corresponding to the axis of symmetry forms a strip-shaped notch of preset length and preset width along the axis of symmetry, and the preset width of the strip-shaped notch is greater than the width of the strip structure of the coupling feed ring 2. The other end of the strip structure of the coupling feed ring 2 is located at the open position of the strip-shaped notch in the radiator 3.

[0031] like Figure 1 As shown, when the RF chip on the strip structure of the coupling feed ring 2 is located away from the radiator 3, and the coupling feed ring 2 and the radiator 3 are in a coplanar state, the shape and size of the overall structure of the coupling feed ring 2 and the radiator 3 are adapted to the shape and size of the surface material 4. The overall structure of the coupling feed ring 2 and the radiator 3 is set on the surface of the surface material 4 with corresponding shaped edges; the coupling feed ring 2 bends with the bending of the local section on the surface material 4 on which it is set.

[0032] Regarding the setting of the coupling feed ring 2 and the radiator 3 on the surface material 4, in practical applications, the overall structure of the coupling feed ring 2 and the radiator 3 is set on the surface of a large area of ​​the surface material 4. According to the outline of the overall structure of the coupling feed ring 2 and the radiator 3, the large area of ​​the surface material 4 is cut to obtain a surface material whose shape and size are adapted to the overall structure of the coupling feed ring 2 and the radiator 3.

[0033] like Figure 2 , Figure 4 , Figure 5 , Figure 7As shown, the RF chip on the strip structure of the coupling feed ring 2 is bent and wrapped around the target object along the direction of the strip recess in the radiator 3, so that the RF chip on the strip structure of the coupling feed ring 2 is connected to a preset position in the strip recess in the radiator 3, and a local segment of the RF chip on the strip structure of the coupling feed ring 2 is arranged along the inside of the strip recess in the radiator 3, so as to realize the suspension of the tear-resistant hanging RF tag on the target object.

[0034] Based on the above-mentioned design of the tear-resistant hanging RFID tag, a further optimized technical solution is designed, in which the straight line of the strip structure of the coupling feed ring 2 is collinear with the straight line of the symmetry axis of the radiator 3; in the structure in which the coupling feed ring 2 is bent and wrapped around the target object along with the face material 4, the inner side of the overall structure of the coupling feed ring 2 and the local section of the face material 4 is further designed to contact the corresponding surface of the target object around the same circumference.

[0035] Regarding the connection between the coupling feed ring 2 and the radiator 3 and the surface of the face material 4, in practical applications, the coupling feed ring 2 and the radiator 3 are respectively set on the surface of the face material 4 by adhesive bonding. Moreover, the bonding strength between the coupling feed ring 2 and the radiator 3 and the surface of the face material 4 is less than the bonding strength between the coupling feed ring 2 and the inner side of the overall structure of the local section of the face material 4 on which it is set and the corresponding surface of the target object.

[0036] In practical applications, the above-mentioned tear-resistant hanging RFID tag uses a coupling feed ring 2 and an radiator 3 made of easily tearable metal materials, such as conductive ink or fragile aluminum film; the face material 4 is made of easily tearable materials, such as paper.

[0037] The tear-resistant hanging RFID tag designed in this invention has four characteristics in practical applications. Firstly, the resonant frequency of the RFID tag is not affected by the chip; that is, under the same antenna, using chips from manufacturers such as NXP, Impinj, and Alien and bonding them to the antenna, their resonant frequencies are as follows: Figure 3 As shown, after the RFID tag is bound to RFID chips from different manufacturers, its resonant frequency is stable in the range of 915-925MHz. This indicates that the RFID tag designed in this invention can be matched with any UHF RFID chip. Therefore, the RFID tag design scheme of this invention can be adapted to various RFID chips on the market without changing the antenna.

[0038] Feature two: The performance of the RFID tag is unaffected by the contact material. In practical use, the RFID tag designed in this invention is generally suspended on a target object. Therefore, the coupling feed loop 2 needs to be in close contact with the surface of the target object. The target object can be made of metal or liquid-containing plastic, etc. Figure 4As shown, conventional RFID tags are affected by the substances in the object after contact, and their performance changes to varying degrees, especially when in contact with metal objects or liquids, where the performance weakens drastically. The RFID tag designed in this invention is not affected by direct contact with metals or liquids; however, the coupling effect between the metal object and the radiator 3, as well as the absorption of electromagnetic waves by the liquid, are unavoidable.

[0039] Taking one of Impinj's radio frequency chips as an example, such as Figure 6 As shown, when the RFID tag designed in this invention is suspended on a parallel metal object, its resonant frequency shifts to a lower frequency band, and its sensitivity and read distance decrease to some extent in the 915-925MHz frequency band. This is mainly due to the coupling effect between the metal object and the metal radiator 3, and not because of the contact of the coupling feed ring 2; Figure 5 As shown, the RFID tag designed in this invention is suspended on a bent metal target object, such as a bent metal object, and the portion of the metal object on which the RFID tag is suspended is parallel to the width direction of the metal radiator 3, as shown. Figure 6 As shown, the performance of the RFID tag is significantly closer to that in free space, which is the first proof of the second feature mentioned above. In addition, when the RFID tag is suspended on a plastic target object containing liquid, its performance curve is almost identical to that in free space, indicating that the coupling feed ring 2 does not affect the original performance of the RFID tag after it comes into contact with the target object, which is the second proof of the second feature mentioned above.

[0040] Thirdly, the preset depth position of the RF chip within the strip-shaped notch in the radiator 3 can control the reading distance of the RF tag, but it will not change the resonant frequency of the RF tag. RF tags have different performance requirements in different application scenarios. Generally, once an RF tag is determined, its performance is also determined and cannot be freely changed. When the RF tag is used in other scenarios, it is necessary to replace it with another RF tag because its performance cannot be changed, which greatly increases the complexity of the application.

[0041] The radio frequency tag designed in this invention, such as Figure 7 As shown, different read distance performances can be achieved by changing the preset depth position of the RF chip within the strip-shaped notch in radiator 3, without altering its resonant frequency. An example is an RF chip from Impinj. Figure 8 As shown, when the position of the RF chip within the strip notch in the radiator 3 moves sequentially upwards from its normal position, the resonant frequency of the RF tag stabilizes in the range of 915-925MHz, and its reading distance decreases sequentially. Therefore, by adjusting the position of the RF chip within the strip notch in the radiator 3 after the coupling feed ring 2 is bent, the reading distance of the RF tag can be freely controlled, thus making it suitable for different application scenarios.

[0042] By adjusting the position of the RF chip within the strip-shaped notch in radiator 3, the reading distance of the RF tag can be reduced to varying degrees. If the overall upper limit of the RF tag's reading capability is to be increased, the following solutions can be implemented:

[0043] Without changing the size and structure of the radiator 3, materials with higher electrical conductivity can be used, such as changing from aluminum to gold, silver, or copper, to make the radiator 3.

[0044] 2. Without changing the material of radiator 3, the gain and efficiency of radiator 3 can be improved by increasing the size of radiator 3, thereby improving readability. The principle that needs to be met when increasing the size is: the self-resonant frequency of radiator 3 remains unchanged before and after the increase.

[0045] Feature four: Tear-resistant RFID tags. The RFID chip carries a unique identification code, which can serve as an item's identity code for identification and anti-theft purposes. The anti-theft principle of UHF RFID tags is as follows: When the RFID chip and antenna are properly installed and matched, they can communicate and interact normally within the radiation field emitted by the RFID reader. However, if a part of the antenna structure is damaged, the original installation and matching are altered. When the RFID tag within the RFID reader's radiation field cannot communicate and be delivered normally, the system backend will issue an alarm due to data loss.

[0046] When using the tear-resistant hanging RFID tag designed in this invention, the coupling feed ring 2 needs to be passed through the target object where the RFID tag needs to be hung. The position of the RFID chip in the strip-shaped notch in the radiator 3 is precisely controlled by bending the pre-cut face material 4 according to its external dimensions. Then, the coupling feed ring 2 is brought into close contact with the surface of the target object. To ensure the tear-resistant effect of the designed RFID tag, the face material 4 can be made of easily tearable materials, such as paper. The metal used to make the coupling feed ring 2 and the radiator 3 is also easily broken, such as conductive ink or easily broken aluminum film. The metal is attached to the face material, and the adhesion between the coupling feed ring 2, the radiator 3 and the face material is less than the adhesion between the coupling feed ring and the hanging material. If the RFID tag is removed from the target object, the coupling feed loop 2 of the RFID tag must be cut. There are two possible scenarios for this cut: First, the cut directly damages a portion of the coupling feed loop 2, causing the closed loop between the RFID chip and the coupling feed loop 2 to fail. In this case, the RFID tag's communication and interaction capabilities within the RFID reader's radiation field are zero, and the RFID reader will trigger a background alarm due to the loss of the RFID tag's information. Second, the cut just happens to separate the coupling feed loop 2 from the radiator 3 without damage. In this case, the RFID tag loses the far-field radiation effect of the radiator 3. This results in a significant reduction in its own communication and interaction capabilities. If the communication and interaction range is insufficient to trigger the RF reader, the background will alarm. If the communication and interaction capabilities still meet the normal range of the RF reader, the background will not alarm. If the target object is to be removed, the coupling feed ring 2 must be separated from the target object. Since the adhesive force between the coupling feed ring 2 and the target object is greater than the adhesive force between the metal wire and the face material 4, some of the metal wires on the coupling feed ring 2 will inevitably separate from the face material 4, thereby damaging the structure of the coupling feed ring 2, causing the circuit to fail, and the communication and interaction capabilities to be zero.

[0047] The above analysis shows that by using fragile face material 4 and metal wire, along with the difference in peel strength between different materials, a perfect anti-tear and anti-theft effect can be achieved.

[0048] The tear-resistant hanging RFID tag designed in the above technical solution includes an RFID chip, a coupling feed ring 2, a radiator 3, and a face material 4. These components are interconnected according to the design. The coupling feed ring 2 is bent and wrapped around the face material 4 to attach to the target object. The end of the RFID chip on the strip structure of the coupling feed ring 2 is positioned at a predetermined depth within the strip-shaped recess in the radiator 3, thus achieving the hanging of the designed tear-resistant hanging RFID tag on the target object. In practical applications, the RFID tag structure does not need to be changed; the same RFID tag can be adapted to various UHF frequencies. The RFID chip impedance is stable within a certain range; its resonant frequency and distance remain unchanged when the RFID tag is suspended on target objects of different materials; and by changing the coupling position between the RFID chip terminal on the coupling feed ring 2 and the radiator 3, the sensitivity of the RFID tag can be adjusted without changing the resonant frequency, thereby changing the RFID reading distance; furthermore, removing the RFID tag from the suspended target object will damage the original performance of the RFID tag, causing it to fail, and thus triggering an alarm through induction, improving the safety of RFID tag use.

[0049] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A tear-resistant hanging RFID tag for hanging on a target object, characterized in that: It includes a radio frequency chip (1), a coupling feed loop (2), a radiator (3), and a surface material (4); Among them, the coupling feed ring (2) is a strip structure, and the radio frequency chip (1) is set at one end of the strip structure of the coupling feed ring (2); the radiator (3) is a coplanar structure formed by a single metal wire of a preset length bent in an S-shape, and a strip-shaped notch of a preset length and a preset width is formed in the S-shaped structure, and the preset width of the strip-shaped notch is greater than the width of the strip structure of the coupling feed ring (2); the other end of the strip structure of the coupling feed ring (2) is located at the open position of the strip-shaped notch in the radiator (3); When the RF chip (1) is located away from the radiator (3) on the strip structure of the coupling feed ring (2), and the coupling feed ring (2) and the radiator (3) are in a coplanar state, the shape and size of the overall structure of the coupling feed ring (2) and the radiator (3) are adapted to the shape and size of the surface material (4). The overall structure of the coupling feed ring (2) and the radiator (3) is set on the surface of the surface material (4) with corresponding shape edges; the coupling feed ring (2) bends with the bending of the local section on the surface material (4) on which it is set; Based on the strip structure of the coupling feed ring (2), the end of the radio frequency chip (1) is bent and wrapped around the target object in the direction of the strip recess in the radiator (3) along the surface material (4), so that the end of the radio frequency chip (1) on the strip structure of the coupling feed ring (2) is connected to the preset position in the strip recess in the radiator (3), and a local segment of the direction of the end of the radio frequency chip (1) on the strip structure of the coupling feed ring (2) is arranged along the inside of the strip recess in the radiator (3), so as to realize the suspension of the tear-resistant hanging radio frequency tag on the target object.

2. The tear-resistant hanging RFID tag according to claim 1, characterized in that: The radiator (3) is a coplanar axisymmetric structure formed by a single metal wire bent in an S-shape, and the two ends of the metal wire are located on both sides of the axis of symmetry. The position of the metal wire corresponding to the axis of symmetry forms a strip-shaped notch along the axis of symmetry with a width greater than the width of the strip structure of the coupling feed ring (2).

3. The tear-resistant hanging RFID tag according to claim 2, characterized in that: The straight line containing the strip structure of the coupling feed ring (2) is collinear with the straight line containing the axis of symmetry of the radiator (3).

4. The tear-resistant hanging RFID tag according to claim 1, characterized in that: The coupling feed ring (2) is bent and wound around the target object along with the surface material (4). The inner side of the overall structure of the coupling feed ring (2) and the local section of the surface material (4) is in contact with the corresponding surface of the target object.

5. The tear-resistant hanging RFID tag according to claim 4, characterized in that: The connection strength between the coupling feed ring (2) and the radiator (3) and the surface of the face material (4) is less than the connection strength between the inner side of the overall structure of the coupling feed ring (2) and the local section of the face material (4) and the corresponding surface of the target object.

6. The tear-resistant hanging RFID tag according to claim 1, characterized in that: The radio frequency chip (1) is attached to one end of the strip structure of the coupling feed ring (2) by bonding or wire bonding.

7. The tear-resistant hanging RFID tag according to claim 1, characterized in that: The coupling feed ring (2) and the radiator (3) are respectively attached to the surface of the face material (4) by adhesive bonding.

8. The tear-resistant hanging RFID tag according to claim 1, characterized in that: The coupling feed ring (2) and the radiator (3) are made of easily tearable metal material.

9. The tear-resistant hanging RFID tag according to claim 8, characterized in that: The easily tearable metal material is conductive ink or easily tearable aluminum film.

10. The tear-resistant hanging RFID tag according to claim 1, characterized in that: The face material (4) is made of an easily tearable material.

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