CN114865284A

CN114865284A - Annular UHF RFID label antenna capable of adapting to various environments

Info

Publication number: CN114865284A
Application number: CN202210545851.9A
Authority: CN
Inventors: 董元旦; 潘永生; 李仲卿; 傅博; 张庆信
Original assignee: Shanghai Inlay Link Inc
Current assignee: Shanghai Inlay Link Inc
Priority date: 2022-05-18
Filing date: 2022-05-18
Publication date: 2022-08-05

Abstract

The invention relates to an annular UHF RFID tag antenna capable of adapting to various environments, which adopts a brand new structure design, a matching groove (3) structure is additionally arranged aiming at a closed loop antenna body (2), a gap for disconnecting one side edge is arranged on one side edge of the matching groove (3), and the annular UHF RFID tag antenna is constructed by respectively connecting two radio frequency pins of a radio frequency tag chip (1) with two ends of the gap, has good adaptability to the external environment, can be adhered to various dielectric materials and always keep good performance, namely can adapt to the relative dielectric constants of different substrates.

Description

Annular UHF RFID label antenna capable of adapting to various environments

Technical Field

The invention relates to an annular UHF RFID tag antenna capable of adapting to various environments, and belongs to the technical field of radio frequency tags.

Background

RFID tag antennas are classified into two categories, namely far field and near field, wherein the read-write distance of the near field tag is short, usually within one wavelength (about 30 cm), and the read-write distance of the far field tag is long; when the RFID tag is actually used, the RFID tag often needs to be attached to media with different electromagnetic properties, and in order to reduce the influence of the environment on the tag, the existing scheme includes an anti-metal tag, a dipole antenna using a narrow slot, and a dipole antenna with matching branches added, where the anti-metal tag has a ground plane and can shield the external environment behind the anti-metal tag, so that the tag is less affected by the external environment, but the anti-metal tag usually needs to adopt a via hole, a short-circuit patch, and a dielectric substrate, so that the processing is complex, the cost is high, and the frequency band is narrow.

The narrow-slot dipole antenna is used, the particularly long and thin narrow slot is used for matching the chip, the change of the reactance of the antenna can be kept small on media with different dielectric constants, the antenna can adapt to materials with different dielectric constants, and the narrow slot of the narrow-slot dipole antenna needs to be particularly narrow to ensure good effect. When large-scale production is carried out, the width of the narrow groove is difficult to control, two ends are easy to adhere, and the yield is influenced.

The dipole antenna with the matching branches is added, a resonant circuit is added to the dipole by adding the pair of branches, the matching of the antenna on the surface of the liquid bottle can be kept good by adjusting the size and the shape of the branches, but the dipole antenna with the matching branches is complex in structure and longer in design period.

Disclosure of Invention

The invention aims to solve the technical problem of providing an annular UHF RFID tag antenna which can adapt to various environments, adopts a brand new structure design, can adapt to various application scenes through the combination of an antenna body and a matching groove, and ensures good radio frequency performance.

The invention adopts the following technical scheme for solving the technical problems: the invention designs an annular UHF RFID tag antenna capable of adapting to various environments, which comprises a radio frequency tag chip and a closed-loop antenna body, wherein matching grooves with preset lengths are arranged along the structural track of the closed-loop antenna body and penetrate through two sides of the surface of the closed-loop antenna body, a notch for disconnecting the side edge is arranged on one side edge of each matching groove, the radio frequency tag chip is arranged at the position of the notch, and two radio frequency pins of the radio frequency tag chip are respectively connected with two ends of the notch.

As a preferred technical scheme of the invention: the notch on the matching groove is arranged on the side edge of the matching groove corresponding to the inner side direction of the closed-loop antenna body.

As a preferred technical scheme of the invention: the notch on the matching groove is positioned at the middle point on the side edge of the matching groove.

As a preferred technical scheme of the invention: the whole structure of the closed-loop antenna body and the matching groove arranged on the closed-loop antenna body is in an axial symmetry structure, and the symmetry axis passes through the gap on the matching groove.

As a preferred technical scheme of the invention: the closed-loop antenna body is rectangular.

As a preferred technical scheme of the invention: the radio frequency tag chip is NXP UCODE 9.

Compared with the prior art, the annular UHF RFID tag antenna capable of adapting to various environments has the following technical effects by adopting the technical scheme:

the invention designs an annular UHF RFID tag antenna capable of adapting to various environments, which adopts a brand-new structural design, adds a matching groove structure aiming at a closed-loop antenna body, arranges a notch for disconnecting one side edge on one side edge of the matching groove, and constructs the designed annular UHF RFID tag antenna by respectively connecting two radio frequency pins of a radio frequency tag chip with two ends of the notch, has good adaptability to the external environment, can be adhered on various dielectric materials, can always keep good performance, can adapt to the relative dielectric constants of different substrates, can realize production by simple printing, and has the advantages of low cost and easy large-scale production.

Drawings

FIG. 1 is a schematic diagram of the present invention showing the construction of a loop UHF RFID tag antenna designed to accommodate a variety of environments;

FIG. 2 is a graph of simulated electric fields for a loop UHF RFID tag antenna designed to accommodate a variety of environments in accordance with the present invention;

FIG. 3 shows the variation of the simulated return loss with frequency when the embodiment of the designed annular UHF RFID tag antenna of the invention is pasted on a dielectric plate with the thickness of 5mm and different dielectric constants;

FIG. 4 shows the variation of the simulated peak gain with frequency when the embodiment of the designed annular UHF RFID tag antenna of the invention is pasted on a dielectric plate with the thickness of 5mm and different dielectric constants;

FIG. 5 is a schematic illustration of the present invention in which text is added to an embodiment of a design of a loop UHF RFID tag antenna;

the antenna comprises a radio frequency tag chip 1, a closed-loop antenna body 2 and a matching groove 3.

Detailed Description

The following description will explain embodiments of the present invention in further detail with reference to the accompanying drawings.

The invention designs an annular UHF RFID tag antenna capable of adapting to various environments, as shown in figure 1, the antenna comprises a radio frequency tag chip 1 and a closed loop antenna body 2, wherein a matching groove 3 which has a preset length and penetrates through two sides of the surface of the closed loop antenna body 2 is arranged along the structural track of the closed loop antenna body 2, a notch for disconnecting the side edge is arranged on one side edge of the matching groove 3, the radio frequency tag chip 1 is arranged at the notch, and two radio frequency pins of the radio frequency tag chip 1 are respectively connected with two ends of the notch.

Specifically, in the application of the above technical solution, for example, the notch on the matching slot 3 is designed to be disposed on the side edge of the matching slot 3 corresponding to the inner side direction of the closed-loop antenna body 2, and the position of the notch is specifically designed to be located at the midpoint position on the side edge of the matching slot 3.

In practical application, the closed-loop antenna body 2 and the matching slot 3 formed in the closed-loop antenna body 2 are designed to have an axisymmetric structure, and the symmetric axis passes through the notch of the matching slot 3.

The designed annular UHF RFID tag antenna capable of adapting to various environments is applied to practice, the radio frequency tag chip 1 is specifically selected from the radio frequency tag chip 1 of the NXP UCODE 9 model, the capacitive reactance is large, in order to keep matching, the tag antenna needs to be designed to have large inductive reactance, the specific inductive reactance is provided by the matching groove 3 on the closed loop antenna body 2, the matching groove 3 enables the two ends of the radio frequency tag chip 1 to be connected through a section of thin line to play an inductive role, and the provided inductive reactance counteracts the capacitive reactance of the chip.

In practical application, the designed annular UHF RFID tag antenna can reach the reading and writing distance of several meters, can be directly placed in the air, and can also be adhered to various medium materials such as paper, paperboard, wood boards, plastics, glass, cloth and the like, and the performance is always kept good, particularly, when the tag manufactured by using the antenna is adhered to a medium substrate, the tag can adapt to different substrate relative dielectric constants, and can be always well matched from 1 to 10, as shown in figure 3, when the relative dielectric constant of a medium plate with the thickness of 5mm is changed from 1 to 10, the echo loss of the designed annular UHF RFID tag antenna is always within an acceptable range. Meanwhile, the designed loop UHF RFID tag antenna has approximately the same peak gain, and the peak gain of the antenna is always kept at a better level, as shown in FIG. 4.

The design of the invention can realize larger bandwidth by combining the matching slot 3 and the closed-loop antenna body 2 and adjusting the sizes of the matching slot 3 and the closed-loop antenna body, and can cover various mainstream UHF RFID frequency bands, such as 865-868 MHz specified by ETSI and 902-928 MHz specified by FCC;

in practical use, various shapes, such as characters, trademarks and the like, can be flexibly added to the closed-loop structure of the closed-loop antenna body 2 to play a decorative role, and the influence on the performance of the antenna is small; and regarding the shape of the closed-loop antenna body 2, the design selects a rectangular shape, but not limited to a rectangle, and also can be various shapes such as a circle, an ellipse, a polygon, a special curve and a dog-leg shape such as a dumbbell shape, a serpentine line, etc., the closed-loop antenna body 2 can be regarded as a folded dipole, as shown in fig. 2, and a suitable radiation impedance can be realized, so that the antenna can be more easily matched with a tag.

The annular UHF RFID tag antenna designed by the whole scheme uses the matching groove 3 to provide inductive reactance, counteracts the capacitive reactance of the radio frequency tag chip 1 and realizes impedance matching; the closed-loop antenna body 2 is used to realize good radiation performance; the combination of the matching slot 3 and the closed-loop antenna body 2 and the proper parameter design realize large bandwidth and strong adaptability to the external environment; in addition, if necessary, various metal printed characters and figures, such as production information, slogans, advertisements, trademarks, two-dimensional codes and the like, can be flexibly added into the closed-loop antenna body 2 of the antenna, and an embodiment of adding characters is shown in fig. 5. The impact on antenna performance is small and it is easy to eliminate it by adjusting the antenna parameters.

The embodiments of the present invention have been described in detail with reference to the drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the gist of the present invention.

Claims

1. The utility model provides an annular UHF RFID label antenna that can adapt to multiple environment which characterized in that: including radio frequency tag chip (1) and closed loop antenna body (2), wherein, set up along closed loop antenna body (2) structure orbit and predetermine length, and run through matching groove (3) of closed loop antenna body (2) place both sides, set up the breach that is used for breaking off this side on one of them side in matching groove (3), this breach position is arranged in radio frequency tag chip (1), and the both ends of this breach are connected respectively to two radio frequency pins of radio frequency tag chip (1).

2. The multi-environment adaptable annular UHF RFID tag antenna of claim 1, wherein: and the notch on the matching groove (3) is arranged on the side edge of the matching groove (3) corresponding to the inner side direction of the closed-loop antenna body (2).

3. The multi-environment adaptable annular UHF RFID tag antenna of claim 1, wherein: the notch on the matching groove (3) is positioned at the middle point position on the side edge of the matching groove (3).

4. The multi-environment adaptable annular UHF RFID tag antenna of any of claims 1 to 3, wherein: the whole structure of the closed-loop antenna body (2) and the matching groove (3) arranged on the closed-loop antenna body (2) is in an axisymmetric structure, and the symmetric axis passes through the notch on the matching groove (3).

5. The multi-environment adaptable annular UHF RFID tag antenna of claim 4, wherein: the closed-loop antenna body (2) is rectangular.

6. The multi-environment adaptable annular UHF RFID tag antenna of claim 4, wherein: the radio frequency tag chip (1) is an NXP UCODE 9.