RFID tag
By designing RFID tags suitable for various surfaces, employing a flat structure and shielded grounded antenna, the issues of tag applicability and encoding printing were resolved, achieving a stable radio frequency band and adjustable antenna length.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CONFIDEX OY
- Filing Date
- 2020-03-24
- Publication Date
- 2026-06-05
AI Technical Summary
Existing RFID tags are not suitable for every surface, cannot be encoded and printed simultaneously, and have complex antenna designs that may be too long.
An RFID tag suitable for different dielectric surfaces was designed. It adopts a flat structure, including a printable surface and a shielded grounded antenna design, which can stabilize the radio frequency band without increasing the bandwidth. It is manufactured by roll-to-roll process and supports near-field communication.
It enables the label to be applicable to a variety of surfaces, can encode and print simultaneously, has an adjustable antenna length without increasing the label size, and has a stable frequency band.
Smart Images
Figure CN115298666B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to an RFID tag having a front and a back, the RFID tag including an antenna and an integrated circuit on a chip. Background Technology
[0002] One of the problems associated with the aforementioned labels is that they may not fit every surface. Another issue is that the labels cannot be encoded and printed simultaneously. Yet another problem is that the antenna must be designed according to specific requirements, and it may be longer than intended. Summary of the Invention
[0003] The object of this invention is to provide an RFID tag to solve the aforementioned problems. This object is achieved by an RFID tag characterized by the features stated in the independent claims. Preferred embodiments of the invention are disclosed in the dependent claims.
[0004] The advantage of the RFID tag of this invention is that it is adaptable to every surface, meaning it is insensitive to the material to which it is attached. The same tag can be used on different dielectric surfaces, such as water tanks, plastics, or coated metals. The back of the tag serves both as a shielding ground and as part of the antenna. The tag has a narrow frequency band because a stable radio frequency band can be obtained without increasing the bandwidth.
[0005] Tags can be encoded and printed simultaneously. The antenna can be long, but it won't make the tag larger.
[0006] RFID tags are typically flat structures with a front and a back. An RFID tag may comprise several sheet-like layers stacked on top of each other. These layers are described herein from the front perspective. These layers can be thin and flexible. The layers on the front may have a printable surface. In this case, a printable surface means that the surface can be printed by a printer-encoder designed for printing RFID tags, and the print quality is sufficient, for example, for flawless barcodes. The printable surface can be a separate layer, such as a paper or plastic layer, or it can be a layer that already has a specific function in its structure and has a printable surface as an additional feature, i.e., there is no separate layer for printing. However, the printable surface may be covered with paint or a coating.
[0007] A label can be a tag. Tags can be thin and conformal, as they must pass through a printer-encoder. Tags may have an adhesive, such as pressure-sensitive adhesive, on their back.
[0008] RFID tags consist of an antenna and an integrated circuit on a chip electrically connected to the antenna. The antenna can operate at UHF frequencies between 850MHz and 960MHz.
[0009] An RFID tag (Radio Frequency Identification tag) comprises a dielectric substrate, a dielectric layer, and a ground plane beneath the dielectric substrate. In other words, the ground plane is located beneath the substrate, or it lies on its own ground plane substrate beneath the dielectric substrate. The dielectric substrate and dielectric layer can be made of plastic material. The dielectric substrate can be, for example, polyester. Paper can be used instead of plastic material.
[0010] The dielectric layer can be, for example, polypropylene. The dielectric layer is preferably made of foam, i.e., a lightweight porous material, wherein bubbles are formed during the manufacturing process. Instead of plastic materials, the dielectric layer can be a dielectric adhesive.
[0011] The substrate has a first side and a second side. The substrate includes an antenna on the first side of the substrate. The substrate may include a ground plane on the second side of the substrate. The antenna and ground plane may be etched or printed onto the substrate, but on opposite sides, or they may be etched or printed on their own substrate.
[0012] The antenna and ground plane are configured to overlap. They can overlap in such a way that the antenna on the first surface of the substrate extends at least partially over the ground plane on the second surface of the substrate, or the antenna on the dielectric substrate extends at least partially over the ground plane on its own ground plane substrate. In the prepared RFID tag, the dielectric substrate is folded onto the dielectric layer such that the ground plane is configured to cover the antenna on the back of the RFID tag. The ground plane can cover the entire back of the RFID tag. The ground plane stabilizes the radiation of the antenna.
[0013] The substrate can be folded onto one edge of the dielectric layer, or it can be folded onto two opposite edges of the dielectric layer. The antenna and the ground plane are coupled via capacitive coupling. Therefore, the ground plane can be used as a shielding ground and, together with the antenna, as a radiating element. RFID tags can be printed and encoded simultaneously because near-field communication with the antenna is possible from the back of the RFID transponder via the ground plane.
[0014] RFID tags can be manufactured using a roll-to-roll process. RFID tags can be adhered to release liner. They can be printed one after another while on the surface of a web or sheet. Attached Figure Description
[0015] In the following, the invention will be described in more detail with reference to the accompanying drawings, in which...
[0016] Figure 1 This shows a roll of material including a series of RFID tags, viewed from above.
[0017] Figure 2Another roll containing continuous RFID tags is shown, viewed from above;
[0018] Figure 3a It shows Figure 1 A cross-section of the RFID tag;
[0019] Figure 3b It shows Figure 1 Another cross-section of the RFID tag;
[0020] Figure 4 It shows Figure 2 A cross-section of the RFID tag;
[0021] Figure 5 The substrate is shown as viewed from above. Detailed Implementation
[0022] Figure 1 A roll 10 including a series of RFID tags 11 on a release pad 9 is shown. Spacers 12 may be present between the series of RFID tags 11 to prevent the printhead of the printer-encoder from falling into the gaps between the series of RFID tags 11.
[0023] The location of chip 4 and antenna 2 in the tag is shown in one of the RFID tags 11. Figure 1 The cross section AA in the figure is shown in Figure 3.
[0024] Figure 2 A roll 10 including a series of RFID tags 11 on a release pad 9 is shown. Spacers 12 may be present between the series of RFID tags 11 to prevent the printhead of the printer-encoder from falling into the gaps between the series of RFID tags 11.
[0025] The location of chip 4 and antenna 2 in the tag is shown in one of the RFID tags 11. Figure 2 In the cross section AA Figure 4 As shown in the image.
[0026] Figure 3a A possible structure of RFID tag 11 is shown. RFID tag 11 includes a substrate 1, a dielectric layer 7, and a surface layer 8. RFID tag 11 can be attached to a release liner 9. The substrate 1, dielectric layer 7, and surface layer 8 can be attached together using an adhesive. The dashed lines in Figure 3 indicate possible locations where adhesive is used.
[0027] The substrate 1 includes an antenna 2, a ground plane 3, and a chip 4. The chip is electrically connected to the antenna 2. The antenna 2 and the ground plane 3 are located on opposite sides of the substrate 1. The substrate 1 is folded onto the edge 7a of the dielectric layer 7 such that the ground plane 3 is configured to cover the antenna 2 on the back of the RFID tag.
[0028] In some cases, the surface layer 8 can be omitted. The front side of the substrate 1 facing the RFID tag 11 can be a printable surface. In this case, the substrate must be selected in a way that satisfies the prerequisite of a printable surface.
[0029] In some cases, such as Figure 3b As shown, the ground plane 3 can be on its own ground plane substrate 12 below the dielectric substrate 1.
[0030] Therefore, there may be a label 11 with an antenna 2 and a ground plane 3 on the same substrate 1, or there may be a label 11 with an antenna 2 and a ground plane 3 on separate substrates 1 and 12. Both of these alternatives are feasible with or without the surface layer 8.
[0031] Figure 4 Another possible structure for the RFID tag 11 is shown. The RFID tag includes a substrate 1, a dielectric layer 7, and a facet layer 8. The RFID tag can be attached to a release liner 9. The substrate 1, dielectric layer 7, and facet layer 8 can be attached together with an adhesive. Figure 4 The dashed lines in the diagram indicate possible locations where adhesive is used.
[0032] The substrate 1 includes an antenna 2, a ground plane 3, and a chip 4. The chip is electrically connected to the antenna 2. The antenna 2 and the ground plane 3 are located on opposite sides of the substrate 1. The substrate 1 is folded over two opposite edges 7a, 7b of the dielectric layer 7 such that the antenna 2 is wrapped around the dielectric layer 7. The ground plane 3 is configured to cover the antenna 2 on the back of the RFID tag.
[0033] In some cases, the surface layer 8 can be omitted. The front side of the substrate 1 facing the RFID tag 11 can be a printable surface. In this case, the substrate must be selected in a way that satisfies the prerequisite of a printable surface.
[0034] In some cases, the ground plane 3 can be on its own ground plane substrate below the dielectric substrate 1.
[0035] Therefore, there may be a tag 11 with an antenna 2 and a ground plane 3 on the same substrate 1, or there may be a tag 11 with an antenna 2 and a ground plane 3 on separate substrates 1 and 12, such as Figure 3b As shown. The same details can also be applied. Figure 4The structure described above is feasible with or without surface layer 8.
[0036] Figure 5 An example of the first surface of substrate 1 when it is in a straight form is shown. The substrate includes an antenna 2 on the first surface and a ground plane 3 (dashed line) on the second surface. The antenna 2 and the ground plane 3 can be formed by etching or printing. The antenna 2 and the ground plane 3 can be metallic materials, such as aluminum or copper, or they can be conductive polymers.
[0037] Antenna 2 and ground plane 3 overlap in region 6. Region 6 is only schematically shown. Figure 5 As shown in the figure, its length can vary depending on the location of use of the substrate 1.
[0038] The substrate 1 further includes an integrated circuit on a chip 4, which is electrically connected to the antenna 2 via conductors. The conductors of the chip 4 can be formed in the same manner as those of the antenna 2 and the ground plane 3. Figure 5 In this process, the conductor is formed by removing antenna material from space 5.
[0039] It will be apparent to those skilled in the art that the inventive concept can be implemented in various ways with advancements in technology. The invention and its embodiments are not limited to the examples described above but can be varied within the scope of the claims.
Claims
1. An RFID tag (11) having a front and a back, the RFID tag (11) comprising a printable surface (13), a dielectric substrate (1), a dielectric layer (7), and a ground plane (3), the dielectric substrate (1) having a first surface and a second surface opposite to the first surface, the dielectric substrate (1) comprising an antenna (2) located on the first surface of the dielectric substrate (1) and an integrated circuit located on a chip (4) electrically connected to the antenna (2), the dielectric substrate (1) being folded over at least one edge (7a, 7b) of the dielectric layer (7), characterized in that, A portion of the antenna (2) extends from one side of the dielectric layer (7) across at least one edge (7a, 7b) to the other side of the dielectric layer (7), and the ground plane (3) located on the second surface of the dielectric substrate (1) or on a separate ground plane substrate (12) is configured to overlap with the antenna (2) and at least partially cover the portion of the antenna (2) extending across at least one edge (7a, 7b) on the back side of the RFID tag (11).
2. The RFID tag according to claim 1, characterized in that, The dielectric substrate is folded onto two opposite edges (7a, 7b) of the dielectric layer (7).
3. The RFID tag according to claim 1 or 2, characterized in that, The dielectric layer (7) is foam.
4. The RFID tag according to claim 1, characterized in that, The printable surface (13) is a paper or plastic layer.
5. The RFID tag according to claim 1, characterized in that, The printable surface (13) is the second surface of the dielectric substrate (1) facing the front of the RFID tag (11).
6. The RFID tag according to claim 5, characterized in that, The second surface of the dielectric substrate (1) includes paint or coating.