Antenna structure and radio frequency identification tag
By designing an antenna structure with dipole radiating arms and inductor loops suitable for UHF tags, the problems of difficult antenna identification and chip damage in roll-to-roll production were solved, and the signal transmission capability in various media was improved, especially the good performance in air and paper media.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ARIZON RFID TECH YANGZHOU
- Filing Date
- 2025-05-28
- Publication Date
- 2026-05-08
AI Technical Summary
Existing UHF tags are difficult to track and identify during roll-to-roll production, the chips are easily damaged, and the signal transmission capability is insufficient in multiple application scenarios, especially in different media.
Design an antenna structure including a dipole radiating arm and an inductor loop. The dipole radiating arm consists of a straight section, a bent section, and a sheet-like section. The inductor loop has a recessed chip connection point and the feed point overlaps with the dipole radiating arm. It is suitable for carriers with different media.
It improves the product yield of roll-to-roll production, protects the chip from damage, ensures signal transmission capability in a variety of media, especially performs well in air and paper media, and achieves a balance between bandwidth and transmission efficiency.
Smart Images
Figure CN224217701U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of radio frequency tag technology, specifically relating to an antenna structure and a radio frequency identification tag. Background Technology
[0002] Radio frequency identification (RFID) tags are categorized by frequency, including low frequency (LF), high frequency (HF), and ultra-high frequency (UHF). As a core technology of the Internet of Things (IoT), RFID offers advantages such as contactless communication and multi-target identification, and is widely used in logistics, retail, and other fields. In the RFID market, roll-to-roll RFID products have become the mainstream technology for the mass production of UHF tags due to their cost advantage.
[0003] Existing UHF tags, when manufactured in roll-to-roll form, suffer from difficulties in antenna tracking and identification, and the inductor loop is frequently damaged during die-cutting. Furthermore, in multi-scenario applications, they cannot simultaneously maintain good signal transmission capabilities on air or paper media. Utility Model Content
[0004] This invention provides an antenna structure and a radio frequency identification tag to solve the problems existing in the roll-to-roll production process of current UHF tags, as well as the technical problem that they cannot maintain signal transmission capability in multiple media simultaneously during application.
[0005] The present invention provides an antenna structure comprising:
[0006] A dipole radiating arm includes a straight section, a bent section symmetrically arranged on both sides of the straight section, and a sheet-like section disposed on the outside of the bent section.
[0007] An inductor loop includes a chip connection point recessed at the upper edge of the inductor loop;
[0008] The feed point is the position where the inductor loop couples with the dipole radiating arm. The lower edge of the inductor loop overlaps with the straight section, and the width of the lower edge of the inductor loop is the same as the width of the straight section.
[0009] In this invention, the sheet-like portion of the dipole radiating arm can be used to guide sensors on production equipment, facilitating production process control; the recessed chip connection point can prevent chip damage during die-cutting; and the inductor loop and the feed point of the dipole radiating arm can balance bandwidth and transmission efficiency.
[0010] Furthermore: the outer dimensions of the dipole radiating arm are 71 mm in length and 8 mm in width;
[0011] The width of the straight section is 0.5~2mm;
[0012] The width of the bent line portion is 0.5~2mm, and the bent line portion includes 14~16 vertical lines;
[0013] The width of the sheet-like portion is 3~6mm. The beneficial effect of this step is that the desired electrical length can be obtained with a smaller external dimension.
[0014] Furthermore, the transition connection between the straight section and the bent section is designed as a teardrop shape. The beneficial effect of this step is that it can reduce the resistance value and improve the structural stability.
[0015] Furthermore, the linewidth of the inductor loop is 0.5~2mm, and the area is 80~120mm². The beneficial effect of this step is to balance the resistance loss of the inductor loop and the inductance per unit length.
[0016] This utility model also provides a radio frequency identification tag, including the antenna structure described in any one of the above;
[0017] The antenna structure is housed within the carrier.
[0018] This invention allows the antenna structure to be placed in different carriers, making it suitable for transmission environments with different media.
[0019] The beneficial effects of this utility model are:
[0020] 1. The antenna structure of this utility model consists of an inductor loop and a dipole radiating arm, which are separate structures. The sheet-like part of the dipole radiating arm is conducive to the detection of the sensor in the production equipment and to the process control. The chip connection point recessed in the inductor loop avoids the chip being damaged during the slitting process and facilitates the roll-to-roll production process.
[0021] 2. The adjustable feed point connection structure ensures that the feed point maintains a low mutual inductance value. Attached Figure Description
[0022] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0023] Figure 1 A schematic diagram of an antenna structure provided by this utility model;
[0024] Figure 2 A schematic diagram of the dipole radiating arm in an antenna structure provided by this utility model;
[0025] Figure 3 This utility model provides a schematic diagram of the inductor loop in an antenna structure.
[0026] Figure 4 A performance simulation diagram of a radio frequency identification tag provided for this utility model.
[0027] Figure label:
[0028] 1-Dipole radiating arm; 2-Inductor loop;
[0029] 11-Straight section; 12-Bent line section; 13-Sheet-shaped section; 14-Teardrop shape; 21-Chip connection point. Detailed Implementation
[0030] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the present invention and should not be construed as limiting the scope of protection of the present invention.
[0031] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application shall have the ordinary meaning as understood by one of ordinary skill in the art to which this utility model pertains.
[0032] Examples of embodiments of this utility model Figures 1-4 As shown, the antenna structure and RFID tag provided by this utility model can optimize roll-to-roll production process, improve product yield, and enhance antenna communication performance.
[0033] The following formulas express the relationships between relevant physical quantities:
[0034] Formula (1) L∝ln(W);
[0035] L is the unit inductance, W is the line width, and ∝ is the inverse ratio;
[0036] Formula (2) Q = (ω*Lant) / {(Rant + (ωM)2 / Rchip};
[0037] Q is the equivalent quality factor, ω = 2 * PI * f is the angular frequency, and Lant is the antenna inductance.
[0038] Rant is the antenna equivalent resistance, M is the mutual inductance, and Rchip is the chip equivalent resistance.
[0039] The present invention provides an antenna structure comprising:
[0040] The dipole radiating arm 1 includes a straight section 11, a bent section 12 symmetrically arranged on both sides of the straight section 11, and a sheet-like section 13 disposed outside the bent section 12.
[0041] The inductor loop 2 includes a chip connection point 21, which is recessed at the upper edge of the inductor loop 2, so that the chip layout has a certain safe distance from the edge of the antenna, thus protecting the chip during the production process.
[0042] The feed point is the position where the inductor loop 2 is coupled to the dipole radiating arm 1. The lower edge of the inductor loop 2 overlaps with the straight section 11, and the width of the lower edge of the inductor loop 2 is the same as the width of the straight section 11.
[0043] The inductor loop 2 and the dipole radiating arm 1 form a tuning circuit, enabling the antenna structure to resonate at a specific frequency. The use of a low mutual inductance feed point and the large-area overlap between the inductor loop 2 and the dipole radiating arm 1 can improve the performance bandwidth of the entire antenna structure, allowing the UHF tag made from this antenna structure to be used in both the 865MHz and 920MHz frequency bands.
[0044] In this invention, the sheet-like portion 13 of the dipole radiating arm 1 can be used to guide sensors on the production equipment. The sheet-like portion 13 has a large area, which facilitates monitoring by sensors on the production equipment, such as using a laser sensor to detect the width, and facilitates the control of the position of the dipole radiating arm 1 in the production process. The recessed chip connection point 21 can prevent the chip from being damaged during the die-cutting process. The inductor loop 2 and the feed point of the dipole radiating arm 1 can balance the bandwidth and transmission efficiency.
[0045] Based on the above technical solution, the outer dimensions of the dipole radiating arm 1 are 71mm in length and 8mm in width; the desired electrical length is obtained by using a smaller outer dimension.
[0046] The width of the straight section 11 is 0.5~2mm;
[0047] The width of the bent line portion 12 is 0.5~2mm, and the bent line portion 12 includes 14~16 vertical lines;
[0048] The width of the sheet portion 13 is 3-6 mm. The number of bends in the bending line portion 12 is related to the material of the item to which the label is applied. If the material has a high dielectric constant, the number of bends needs to be reduced; conversely, if the material has a low dielectric constant, the number of bends needs to be increased. Based on the target application, this design adopts a symmetrical design within a 71 mm length space. The width of the straight section 11 is the same as the width of the lower edge of the inductor loop 2, used for physical connection between the two, i.e., the feed point line. The bending line portion 12 contains 14-16*2 vertical lines (each line approximately 8 mm long and 0.5-2 mm wide), which is the main structure for increasing the electrical length. The sheet portion 13 is set as a single metal structure to increase the antenna bandwidth. The width of the sheet portion 13 is 3-6 mm. Another function of using a sheet metal structure in this area is to guide the sensors of the production equipment to track and identify the antenna production status, which is beneficial for production process control.
[0049] Based on the above technical solution, the transition connection between the straight section 11 and the bent section 12 is designed as a teardrop shape 14. The teardrop shape 14 reduces the resistance value and improves the structural stability.
[0050] Based on the above technical solution, the line width of the inductor loop 2 is 0.5~2mm and the area is 80~120mm². The inductor loop 2 is mainly used to match the capacitor of the chip. The line width and area of the inductor loop 2 need to be balanced. A larger line width can reduce resistance loss, but it will reduce the inductance per unit length (refer to formula (1)).
[0051] This utility model also provides a radio frequency identification tag, including the antenna structure described in any one of the above;
[0052] The antenna structure is housed within a carrier, which can be a composite film, paper, or plastic component, etc.
[0053] This invention allows the antenna structure to be placed in different carriers, making it suitable for transmission environments with different media.
[0054] In the above embodiments, the power supply point design has the following two characteristics.
[0055] 1. The location of the feed point determines the mutual inductance value M of the antenna structure and the chip. According to the formula (2) Q = (ω*Lan) / {(Rant + (ωM)2 / Rchip}, it can be seen that the mutual inductance strength and the equivalent quality factor are inversely proportional. A lower Q value corresponds to a wider frequency response, but the transmission efficiency is worse. By adjusting the appropriate feed position, a balance can be made between bandwidth and transmission efficiency.
[0056] 2. In this embodiment, the feed point is set at the horizontal middle of the antenna structure, away from the chip position, to obtain a wider frequency response; the inductor loop 2 and the dipole radiating arm 1 overlap over a large area, which can improve the energy transfer efficiency.
[0057] like Figure 4 As shown, the tag exhibits good recognition performance in both air and cardboard, and is applicable across a wide frequency range of 865–920 MHz. Test curves in a microwave anechoic chamber demonstrate that the reading distance is greater than 12 meters in both air and cardboard within the 865–920 MHz wide frequency band.
[0058] Numerous specific details are set forth in this specification. However, it will be understood that embodiments of this invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification. In the description of this specification, references to the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of the different embodiments or examples.
[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model, and they should all be covered within the scope of the claims and specification of this utility model.
Claims
1. An antenna structure, characterized in that, include: A dipole radiating arm includes a straight section, a bent section symmetrically arranged on both sides of the straight section, and a sheet-like section disposed on the outside of the bent section. An inductor loop includes a chip connection point recessed at the upper edge of the inductor loop; The feed point is the position where the inductor loop couples with the dipole radiating arm. The lower edge of the inductor loop overlaps with the straight section, and the width of the lower edge of the inductor loop is the same as the width of the straight section.
2. The antenna structure according to claim 1, characterized in that, The outer dimensions of the dipole radiating arm are 71 mm in length and 8 mm in width. The width of the straight section is 0.5~2mm; The width of the bent line portion is 0.5~2mm, and the bent line portion includes 14~16 vertical lines; The width of the sheet-like portion is 3~6mm.
3. The antenna structure according to claim 1, characterized in that, The transition between the straight section and the bent section is designed in the shape of a teardrop.
4. The antenna structure according to claim 1, characterized in that, The linewidth of the inductor loop is 0.5~2mm, and the area is 80~120mm².
5. A radio frequency identification tag, characterized in that, Including the antenna structure described in any one of claims 1 to 4; The antenna structure is housed within the carrier.