Cylindrical RFID anti-metal tag antenna

Abstract

The invention provides a cylindrical RFID anti-metal tag antenna, and the antenna comprises a cylindrical metal housing which is provided with a slot on the curved surface; the first short-circuit surface and the second short-circuit surface are respectively positioned on the bottom surfaces of the two ends of the cylindrical structure; the short circuit ring is arranged outside the second short circuit surface and a gap is reserved between the short circuit ring and the second short circuit surface; the radiating surface is of a spiral ring structure, a tag chip is installed on the radiating surface, one end of the radiating surface is connected with the second short circuit surface, and the other end is suspended; the medium supporting body is used for supporting the radiating surface; two ends of the metal cylinder are respectively connected with the first short-circuit surface and the second short-circuit surface; wherein one end of the shell is connected with the edge of the first short circuit surface, and the other end is connected with the edge of the short circuit ring.

Description

Technical Field

[0001] This invention relates to the field of radio frequency identification (RFID) tag antenna technology, and specifically to a cylindrical RFID anti-metal tag antenna. Background Technology

[0002] Ultra-high frequency (UHF) radio frequency identification (RFID) technology, as a core sensing technology of the Internet of Things (IoT), is widely used in manufacturing, warehousing, retail, transportation, and medical fields due to its advantages such as long-range wireless identification and efficient batch reading. The tag antenna, as a crucial component of the RFID system, directly determines the overall system performance through its reading performance. However, in actual deployment, when the tag antenna comes into contact with a metal surface, a mirror current is generated on the metal surface, leading to a significant decrease in antenna radiation efficiency or even failure.

[0003] To address the interference issues of metallic environments on tag antennas, existing technologies have developed various anti-metal tag antenna design schemes. For example, adding a dielectric layer to isolate the tag from the metal surface reduces direct coupling between the two; designing the tag antenna as a planar inverted-F antenna (PIFA) or a planar inverted-L antenna (PILA) with its own metallic ground structure; or using a folded patch antenna design.

[0004] While the above solutions enable the application of tag antennas in metallic environments, existing anti-metal tags still have significant drawbacks: installation requires strict distinction between the front and back sides; the tag only functions correctly when a specific side is in contact with the metal surface, which significantly reduces efficiency. Therefore, developing tag antennas that can operate stably at any angle on a metal surface is of significant practical importance. Summary of the Invention

[0005] In view of the defects and shortcomings of the existing technology, the present invention provides a cylindrical RFID anti-metal tag antenna. The antenna, through a multi-layer collaborative cylindrical structure design, can be installed at any angle on a metal surface while maintaining stable radiation performance.

[0006] The antenna includes a cylindrical metal shell with grooves on its curved surface; a first short surface and a second short surface located on the bottom surfaces at both ends of the cylinder; a short-circuit ring disposed outside the second short surface with a gap therebetween; a radiating surface with a spiral ring structure, one end of which is connected to the second short surface and the other end is suspended, preferably with a ring line loaded at the edge where it connects to the second short surface, and a tag chip is installed on it; a dielectric support for supporting the radiating surface; and a metal cylinder with its two ends connected to the first short surface and the second short surface respectively; wherein, one end of the shell is connected to the edge of the first short surface and the other end is connected to the edge of the short-circuit ring.

[0007] The outer shell is made of conductive materials such as copper and aluminum, which can reduce interference from the external metal environment; the radiating surface is made by etching, printing and other processes, and is supported by a dielectric cylinder (such as non-metallic materials such as Teflon plastic); the coordinated connection of each component forms a stable electromagnetic coupling path, so that the resonant frequency, power transmission coefficient and reading distance remain stable when the antenna is placed on the metal surface at any angle.

[0008] The specific technical solution adopted by this invention to solve its technical problem is as follows: A cylindrical RFID anti-metal tag antenna, comprising: The outer shell is made of metal and is cylindrical with grooves on its curved surface; The first short road surface and the second short road surface are located at the bottom surfaces of the two ends of the cylindrical structure, respectively. A short-circuit ring is placed on the outside of the second short-circuit surface with a gap between it; A spiral ring structure with a radiating surface on which a tag chip is installed, one end of the radiating surface is connected to a second short road surface, and the other end is suspended in the air; A dielectric support body is used to support the radiating surface; A metal cylinder, with its two ends connected to a first short surface and a second short surface, respectively; One end of the outer shell is connected to the edge of the first short-circuit surface, and the other end is connected to the edge of the short-circuit ring.

[0009] Furthermore, the first short road surface, the second short road surface, the short-circuit ring, and the radial surface are all made of metal.

[0010] Furthermore, the dielectric support is a cylindrical structure made of non-conductive non-metallic material.

[0011] Furthermore, the first short road surface and the second short road surface are disc structures, the short-circuit ring is a ring structure, and the outer diameter of the short-circuit ring is adapted to the diameter of the second short road surface.

[0012] Furthermore, the slots of the outer shell are hollow structures with periodically arranged rectangular hollow grids, the grid direction being distributed along the long side of the cylindrical curved surface.

[0013] Furthermore, the radiating surface is a cylindrical surface with equally spaced helical rings, the number of helical rings being 2-16, and the pitch being 0.1-2 mm. A ring-shaped line, also made of metal, is provided at the edge of the radiating surface where it connects with the second short surface.

[0014] Furthermore, the radiating surface is formed on the surface of the flexible dielectric substrate by etching, corrosion, printing or transfer methods, and then wrapped around the outer surface of the dielectric support; or it is formed directly on the outer surface of the dielectric support.

[0015] Furthermore, the tag chip is installed in the gap at the middle position of the spiral ring of the radiating surface and is connected to the spiral ring.

[0016] Furthermore, the gap width between the short-circuit ring and the second short-circuit surface is 0.1-1.5 mm.

[0017] Furthermore, when the antenna is placed on a metal surface at any angle, its resonant frequency is 913-916MHz, its power transmission coefficient is 0.96-0.98, and its reading distance is approximately 15.7m.

[0018] Compared to existing technologies, this invention and its preferred embodiment utilize a cylindrical multi-layered collaborative structure design. The metal shell effectively mitigates the adverse effects of the external metal environment on the antenna, reduces interference from mirror currents on the metal surface, and minimizes performance fluctuations caused by electromagnetic wave reflection. The combination of the short-circuit surface, short-circuit ring, and metal cylinder forms a stable electromagnetic coupling path. Combined with the structural characteristics of the spiral ring radiating surface, the antenna maintains the stability of its resonant frequency, power transmission, and readout performance even when placed at any angle on the metal surface, thus improving the reliability of tag identification in complex metal environments.

[0019] Meanwhile, the radiating surface adopts a flexible manufacturing process that can adapt to different support shapes, enhancing the label's adaptability to curved and irregular metal surfaces. Each component uses conventional conductive and dielectric materials, taking into account both structural stability and manufacturing maturity, making it easy to promote and apply in scenarios such as industrial automation and smart warehousing, and providing more reliable technical support for metal asset management, dynamic inventory and other needs. Attached Figure Description

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of each component of the antenna according to an embodiment of the present invention; wherein, (a) is the external structure and (b) is the internal structure; Figure 3 This is a schematic diagram of the tag antenna placed on the metal plate 10 according to an embodiment of the present invention; Figure 4 This is a schematic diagram showing the resonant frequency and power transmission coefficient of the tag antenna in an embodiment of the present invention when it is placed at different angles α on the metal plate 10. Figure 5 This is a radiation pattern of the metal plate 10 according to an embodiment of the present invention; Figure 6 This is a schematic diagram illustrating the theoretical reading distance of the metal plate 10 according to an embodiment of the present invention; In the diagram, 1-shell, 2-first short path, 3-second short path, 4-short circuit ring, 5-radiating surface, 6-dielectric cylinder, 7-ring line, 8-metal cylinder, 9-tag chip, 10-metal plate. Detailed Implementation

[0021] To make the features and advantages of the present invention more apparent and understandable, specific embodiments are described below in detail: It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0022] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0023] like Figures 1-5 As shown, this invention proposes a cylindrical RFID anti-metal tag antenna, which is composed of a multi-layer cylindrical structure. When the tag antenna is placed at any angle on a metal surface, the resonant frequency and reading characteristics can be consistent. At the same time, with its good reading distance range, it can meet the tag recognition distance requirements of complex scenarios such as industrial automated production lines and intelligent warehousing and logistics.

[0024] The antenna structure is a multi-layer cylindrical structure consisting of a shell 1, a first short surface 2, a second short surface 3, a short-circuit ring 4, a radiating surface 5, a dielectric cylinder 6, a loop line 7, a metal cylinder 8, and a tag chip 9.

[0025] The outer shell 1 is made of metal and is cylindrical with a certain thickness. Its curved surface has a thin hollow slot to improve the consistency of radiation when the tag antenna is placed on the metal surface at different angles. The outer shell 1 serves as the ground plane when placed on the metal surface at any angle.

[0026] The radiating surface 5 is a spiral cylindrical surface with equal spacing, which is used to improve the consistency of radiation performance when the tag antenna is placed on the metal surface at different angles. It can be fabricated on the surface of a flexible thin dielectric substrate by etching, corrosion, printing or transfer and then wrapped around the outer surface of the dielectric cylinder 6, or it can be fabricated directly on the surface of the dielectric cylinder 6; the tag chip 9 is mounted on the spiral ring gap of the radiating surface 5.

[0027] A loop 7 is wrapped around the edge connecting the radiating surface and the short road surface to improve the consistency of the antenna's radiation performance when placed at different angles.

[0028] The outer shell 1, the first short-circuit surface 2, the second short-circuit surface 3, the short-circuit ring 4, the radiating surface 5, the ring line 7, and the metal cylinder 8 are all made of conductive metal materials, such as copper and aluminum; the dielectric cylinder 6 is made of non-conductive non-metallic materials, such as Teflon plastic, and serves as the support for the radiating surface 5.

[0029] As the two end faces of the antenna, the first short surface 2 and the second short surface 3 are disc structures, located on the two bottom surfaces of the cylinder respectively. The short-circuit ring 4 is a ring structure, located on the outside of the second short surface 3, and there is a gap between the short-circuit ring 4 and the second short surface 3 to improve the gain of the tag antenna.

[0030] One end of the metal cylinder 8 is connected to the first short surface 2, and the other end is connected to the second short surface 3; one end of the outer shell 1 is connected to the edge of the first short surface 2, and the other end is connected to the edge of the short-circuit ring 4; one end of the radiating surface 5 is connected to the second short surface 3, and the other end is suspended, which is used to improve the gain of the tag antenna.

[0031] When the tag antenna is installed on an external metal structure, the outer casing reduces the impact of the external metal environment on the tag antenna, giving the tag antenna anti-metal capability.

[0032] When the antenna is placed on a metal surface at any angle, its resonant frequency, power transmission coefficient, and reading distance remain basically the same.

[0033] When the tag antenna is mounted on the metal plate 10, the outer casing 1 is attached to the metal plate 10. The outer casing 1 reduces the influence of the external metal environment on the tag antenna, giving the tag antenna anti-metal capability.

[0034] When the tag antenna is placed on the metal plate 10 at different angles, its resonant frequency varies between 913-916MHz, and its maximum power transmission coefficient is between 0.96-0.98. Figure 4 As shown, it exhibits good radiation stability.

[0035] Compared with existing technologies, this invention is applied to the UHF band, and the metal casing effectively reduces the impact of the metal surface on the radiating surface. The radiating surface and the metal cylinder can adjust the input impedance of the tag antenna. When the tag antenna is placed on the metal plate 10 at different angles, its resonant frequency varies between 913-916MHz, the maximum power transmission coefficient is between 0.96-0.98, and the reading distance is approximately 15.7m, exhibiting good radiation stability. Figure 6 As shown.

[0036] It should be noted that, unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0037] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

[0038] This invention is not limited to the preferred embodiment described above. Anyone inspired by this invention can derive various other forms of cylindrical RFID anti-metal tag antennas. All equivalent variations and modifications made within the scope of the claims of this invention should be included within the scope of this invention.

Claims

1. A cylindrical RFID anti-metal tag antenna, characterized in that, include: The outer shell is made of metal and is cylindrical with grooves on its curved surface; The first short road surface and the second short road surface are located at the bottom surfaces of the two ends of the cylindrical structure, respectively. A short-circuit ring is placed on the outside of the second short-circuit surface with a gap between it; A spiral ring structure with a radiating surface on which a tag chip is installed, one end of the radiating surface is connected to a second short road surface, and the other end is suspended in the air; A dielectric support body is used to support the radiating surface; A metal cylinder, with its two ends connected to a first short surface and a second short surface, respectively; One end of the outer shell is connected to the edge of the first short-circuit surface, and the other end is connected to the edge of the short-circuit ring.

2. The cylindrical RFID anti-metal tag antenna according to claim 1, characterized in that: The first short road surface, the second short road surface, the short-circuit ring, and the radial surface are all made of metal.

3. The cylindrical RFID anti-metal tag antenna according to claim 1, characterized in that: The dielectric support is a cylindrical structure made of non-conductive non-metallic material.

4. A cylindrical RFID anti-metal tag antenna according to claim 1, characterized in that: The first and second short road surfaces are disc structures, the short-circuit ring is a ring structure, and the outer diameter of the short-circuit ring is adapted to the diameter of the second short road surface.

5. A cylindrical RFID anti-metal tag antenna according to claim 1, characterized in that: The slots of the outer shell are hollow structures with periodically arranged rectangular hollow grids, the grid direction being distributed along the long side of the cylindrical curved surface.

6. A cylindrical RFID anti-metal tag antenna according to claim 1, characterized in that: The radiating surface is a spiral cylindrical surface with equal spacing, and a ring line is provided at the edge of the radiating surface where it connects with the second short road surface.

7. A cylindrical RFID anti-metal tag antenna according to claim 1, characterized in that: The radiating surface is formed on the surface of the flexible dielectric substrate by etching, corrosion, printing or transfer methods, and then wrapped around the outer surface of the dielectric support; or it is formed directly on the outer surface of the dielectric support.

8. The cylindrical RFID anti-metal tag antenna according to claim 1, characterized in that, The tag chip is installed in the gap at the middle position of the spiral ring of the radiating surface and is connected to the spiral ring.

9. The cylindrical RFID anti-metal tag antenna according to claim 1, characterized in that, The gap width between the short-circuit ring and the second short-circuit surface is 0.1-1.5 mm.

10. The cylindrical RFID anti-metal tag antenna according to claim 1, characterized in that, When the antenna is placed on a metal surface at any angle, its resonant frequency is 913-916MHz and its power transfer coefficient is 0.96-0.98.

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