An antenna structure of a radio frequency chip

Abstract

The utility model discloses an antenna structure of radio frequency chip, including medium base plate, the antenna radiation layer and RFID chip of being located on the substrate. The antenna radiation layer contains central connecting point, the conductor ring of surrounding this connecting point and multiple sets of radiation branch, and central connecting point is located in the middle part of base plate, and the two electrodes of RFID chip are electrically connected central connecting point and conductor ring respectively, and multiple sets of radiation branch are center symmetry distribution with central connecting point as center. Conductor ring has energy feeding, impedance matching and signal equal division function, and the electric length of each radiation branch is configured to make the antenna radiation layer resonate in UHF frequency band. The design can solve the identification problem caused by the random posture of the label in the scene such as schoolbag, clothes etc. through the radiation branch covering multiple space directions, and ensure that at least one branch is aligned and coupled with the linear polarization electromagnetic wave of the reader-writer. The conductor ring reduces signal reflection loss, and the multi-branch redundant design improves the anti-shielding ability, which effectively activates the passive RFID chip and avoids the angle misplacement and shielding failure problem of the traditional single direction antenna.

Description

Technical Field

[0001] This utility model belongs to the field of radio frequency chip technology, specifically an antenna structure for a radio frequency chip. Background Technology

[0002] Radio frequency identification (RFID) technology, as a non-contact automatic identification technology, has been deeply integrated into logistics warehousing, retail management, and smart wearables due to its characteristics such as rapid identification, simultaneous reading of multiple targets, and large information storage capacity. Among them, passive UHF RFID tags, due to their lack of built-in power supply, low cost, and identification distance of several meters, have become the core choice for identifying and tracking everyday items such as bags, clothing, and personal accessories. As application scenarios extend to the personal consumer end, tags need to adapt to more complex usage environments, and the market has placed higher demands on their stable identification capabilities under non-fixed postures, driving the evolution of antenna structure design to adapt to diverse scenarios.

[0003] Traditional passive UHF RFID tags typically employ a unidirectional radiation antenna design, with a fixed main radiation direction and limited coverage angle. This design is intended to accommodate tags used in flat, fixed orientations. However, in everyday scenarios such as backpacks and clothing pockets, tags are often placed in random orientations (tilted, upright, or angled) due to pressure from items and carrying movements. This causes an angular misalignment between the antenna's radiation direction and the linearly polarized electromagnetic waves emitted by the reader. This misalignment significantly reduces signal coupling efficiency, ranging from shortened recognition distance to complete chip activation failure, resulting in orientation-sensitive malfunctions and severely limiting the reliability of RFID tags in flexible usage scenarios. Utility Model Content

[0004] The purpose of this invention is to provide an antenna structure for a radio frequency chip to solve the following technical problems mentioned in the background art:

[0005] Traditional unidirectional RFID antennas have a single radiation direction, which cannot adapt to the random postures of tags that are inevitably placed crookedly, vertically, or at an angle in everyday scenarios such as backpacks and clothing. The radiation direction is prone to angular misalignment with the linearly polarized electromagnetic waves of the reader, resulting in signal coupling failure and the tag being unable to be identified.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0007] An antenna structure for an RFID chip includes a dielectric substrate, an antenna radiating layer disposed on the dielectric substrate, and an RFID chip. The antenna radiating layer includes a central connection point, a conductor ring, and multiple sets of radiating branches. The central connection point is located in the middle of the dielectric substrate, and the conductor ring surrounds the central connection point. Two electrodes of the RFID chip are electrically connected to the central connection point and the conductor ring, respectively. The multiple sets of radiating branches are centrally symmetrically distributed around the central connection point. The conductor ring is configured to achieve energy feeding, impedance matching, and signal equalization. The electrical length of each radiating branch is configured to make the antenna radiating layer resonate in the UHF band, thereby achieving effective coupling with the reader signal through at least one radiating branch when the tag is in a random posture.

[0008] Furthermore, the number of radiating branches is four.

[0009] Furthermore, the four sets of radiating branches extend towards the four corners of the dielectric substrate, forming an X-shaped layout.

[0010] Furthermore, the conductor ring can be rhomboid, circular, rectangular, or square in shape.

[0011] Furthermore, the radiating branches are straight, bent, or curved, and are integrally formed with the conductor ring.

[0012] Furthermore, the antenna radiating layer also includes radiating elements corresponding to the number of radiating branches, with the radiating elements located at the end of the radiating branch furthest from the conductor ring.

[0013] Furthermore, the UHF band is from 860MHz to 960MHz.

[0014] Furthermore, the dielectric substrate is a flexible dielectric substrate made of PET, PI, or flexible plastic.

[0015] Furthermore, the RFID chip is electrically connected to the central connection point and the conductor ring via soldering.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] This design features a centrally symmetrical distribution of multiple radiating branches, covering multiple spatial directions. In daily use, regardless of the tag's orientation (tilted, upright, or angled) in a bag, clothing, or other environment, at least one radiating branch will align with the reader's linearly polarized electromagnetic waves, achieving optimal coupling and avoiding identification failures caused by angular misalignment in traditional unidirectional antennas. The impedance matching function of the conductor ring reduces signal reflection loss, ensuring that the weak energy captured by the radiating branches effectively activates the passive RFID chip. The redundant design of the multiple branches ensures that even if some branches are obstructed by objects, the unobstructed branches can still capture sufficient energy, which is then transferred to the chip through the conductor ring, overcoming the vulnerability of a single branch to obstruction. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0019] Figure 2 This is a cross-sectional view of the present invention;

[0020] Figure 3 This is a schematic diagram of the RFID chip connection structure of this utility model.

[0021] The markings in the diagram are: 1-dielectric substrate, 2-radiating unit, 3-radiating branch, 4-conductor ring, 5-central connection point, 6-RFID chip, 7-antenna radiating layer. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] Example:

[0024] An antenna structure for a radio frequency chip includes a dielectric substrate 1, an antenna radiating layer 7 disposed on the dielectric substrate 1, and an RFID chip 6. The antenna radiating layer 7 includes a central connection point 5, a conductor ring 4, and multiple sets of radiating branches 3. The central connection point 5 is located in the middle of the dielectric substrate 1, and the conductor ring 4 is arranged around the central connection point 5. The two electrodes of the RFID chip 6 are electrically connected to the central connection point 5 and the conductor ring 4, respectively. The multiple sets of radiating branches 3 are centrally symmetrically distributed with the central connection point 5 as the center. The conductor ring 4 is configured to realize energy feeding, impedance matching, and signal equalization. The electrical length of each radiating branch 3 is configured to make the antenna radiating layer 7 resonate in the UHF band, so that when the tag is in a random posture, effective coupling with the reader signal is achieved through at least one radiating branch 3.

[0025] Among them, the dielectric substrate 1 serves as the physical carrier of the entire antenna structure, providing a mounting base for the antenna radiating layer 7 and the RFID chip 6.

[0026] Central connection point 5 forms the ground or reference terminal of the circuit by connecting to one of the electrodes of the chip.

[0027] The conductor ring 4, surrounding the central connection point 5, transfers the electromagnetic wave energy captured by the reader / writer from the radiating branch 3 to the RFID chip 6, while simultaneously feeding the chip's response signal back to the radiating branch 3 for transmission. At the same time, the conductor ring 4 adjusts its distributed inductance and capacitance through its geometric parameters, achieving conjugate matching between the input impedance of the RFID chip 6 and the impedance of the radiating branch 3, minimizing signal reflection and energy loss. Furthermore, the conductor ring 4 utilizes a symmetrical structure to evenly distribute energy or signal across multiple sets of radiating branches 3, preventing partial branch failure due to energy imbalance between branches.

[0028] Multiple sets of radiating branches 3 are centrally symmetrically distributed to cover multiple directions in space, ensuring that regardless of the tag's orientation, there is always a branch that can align with the reader's linearly polarized electromagnetic waves. After optimization of the electrical length, the antenna resonates in the UHF band, at which point the energy conversion efficiency of the radiating branches 3 is at its highest, maximizing the capture of electromagnetic wave energy and converting it into electrical energy to activate the chip.

[0029] The RFID chip 6 is connected to the central connection point 5 and the conductor ring 4 through two electrodes to form a complete electrical circuit: it receives energy transmitted from the conductor ring 4 to activate its own circuit, and at the same time feeds back the stored information to the reader through the conductor ring 4 and the radiating branch 3 to complete the identification or data communication.

[0030] This design features multiple radiating branches 3 centrally symmetrically distributed, covering multiple spatial directions. In daily use, regardless of the tag's orientation (tilted, upright, or angled) in a bag, clothing, or other environment, at least one radiating branch 3 will align with the reader's linearly polarized electromagnetic waves, achieving optimal coupling and avoiding identification failures caused by angular misalignment in traditional unidirectional antennas. The impedance matching function of the conductor ring 4 reduces signal reflection loss, ensuring that the weak energy captured by the radiating branches 3 can effectively activate the passive RFID chip 6. The redundant design of the multiple branches ensures that even if some branches are blocked by objects, the unblocked branches can still capture sufficient energy, which is then transferred to the chip through the conductor ring 4, overcoming the vulnerability of a single branch to obstruction.

[0031] In a preferred embodiment, the number of radiating branches 3 is four groups. The four groups of radiating branches 3 are symmetrically distributed around the central connection point 5 and point towards the four corners of the dielectric substrate 1 to form an X-shaped layout, covering key spatial angles such as 0° and 45°. This can accurately adapt to the linearly polarized electromagnetic waves of the reader. When the tag is in a random posture, at least one group of branches can always achieve optimal coupling. At the same time, the multi-branch redundancy design improves the anti-masking capability, and the optimized electrical length ensures the resonant efficiency of the UHF band, helping the RFID chip 6 to be efficiently activated and communicate stably.

[0032] In a preferred embodiment, the four sets of radiating branches 3 extend towards the four corners of the dielectric substrate 1, forming an X-shaped layout. This X-shaped layout, with the four sets of radiating branches 3 pointing towards the four corners of the dielectric substrate 1, can fully cover key spatial angles such as 0°, 45°, and 90°, accurately adapting to the linearly polarized electromagnetic waves of the reader. Even under random tag postures, branches can still achieve optimal coupling. Simultaneously, multi-branch redundancy enhances anti-masking capabilities, and optimized electrical length ensures UHF band resonant efficiency, facilitating efficient activation and stable communication of the RFID chip 6.

[0033] In a preferred embodiment, the conductor ring 4 is rhomboid, circular, rectangular, or square in shape. The rhomboid, circular, rectangular, or square design of the conductor ring 4 ensures the core functions of energy delivery, impedance matching, and signal distribution. The rhomboid shape accommodates flexible substrates to release bending stress, while other shapes are compatible with different dielectric substrates 1 and processing technologies. The symmetrical structure ensures balanced energy distribution across multiple radiating branches 3, and the radiating branches 3 optimize UHF band resonance and signal coupling, improving the overall stability and adaptability of the antenna.

[0034] In a preferred embodiment, the radiating branch 3 is straight, bent, or curved, and is integrally formed with the conductor ring 4. The straight, bent, or curved design of the radiating branch 3 can flexibly adapt to different spatial layouts and processing techniques of the dielectric substrate 1. Furthermore, the integral formation with the conductor ring 4 can improve structural stability, reduce contact loss, and ensure efficient energy and signal transmission. Combined with symmetrical distribution and optimized electrical length, it ensures the resonance effect and signal coupling reliability in the UHF band.

[0035] In a preferred embodiment, the antenna radiating layer 7 further includes radiating units 2 corresponding to the number of radiating branches 3, with the radiating units 2 located at the end of the branch furthest from the conductor ring 4. The location of the radiating units 2, corresponding to the number of radiating branches 3, at the end of the branch furthest from the conductor ring 4 enhances radiation intensity and signal acquisition capability, maintains the quasi-omnidirectional characteristics of the symmetrical distribution of multiple branches, and, in conjunction with electrical length optimization, ensures UHF band resonance effect, improves the activation efficiency and communication stability of the RFID chip 6, while also adapting to the spatial layout requirements of different dielectric substrates 1.

[0036] In a preferred embodiment, the UHF band is 860MHz to 960MHz. The UHF band selected is 860MHz to 960MHz, which covers the mainstream passive RFID application band, has strong compatibility, and with the parameter optimization of the radiating branch 3 and the conductor ring 4, it can ensure that the antenna resonates stably in this band, improving signal coupling efficiency and read / write distance.

[0037] In a preferred embodiment, the dielectric substrate 1 is a flexible dielectric substrate made of PET, PI, or flexible plastic. The dielectric substrate 1 is made of PET, PI, or flexible plastic to form a flexible structure, which can adapt to complex installation scenarios such as curved surfaces and bends. At the same time, it releases mechanical stress during use to avoid structural breakage. Its stable dielectric properties ensure the radio frequency performance of the UHF band. Together with the integrally molded radiating branch 3 and conductor ring 4, it improves the mechanical reliability and scenario adaptability of the antenna.

[0038] In a preferred embodiment, the RFID chip 6 is electrically connected to the central connection point 5 and the conductor ring 4 by soldering. Soldering the RFID chip 6 to the central connection point 5 and the conductor ring 4 ensures stable electrical conduction, reduces contact loss and signal attenuation, guarantees impedance matching and efficient energy or signal transmission, improves the resonant stability and long-term reliability of the UHF band, and adapts to the needs of various application scenarios.

[0039] In the description of this utility model, it should be understood that the terms "coaxial", "bottom", "one end", "top", "middle", "other end", "upper", "side", "top", "inner", "front", "center", "both ends", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0040] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," "fixing," "screw connection," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0041] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An antenna structure for a radio frequency chip, characterized in that: It includes a dielectric substrate (1), an antenna radiating layer (7) disposed on the dielectric substrate (1), and an RFID chip (6); The antenna radiating layer (7) includes a central connection point (5), a conductor ring (4), and multiple sets of radiating branches (3); The central connection point (5) is located in the middle of the dielectric substrate (1), and the conductor ring (4) is arranged around the central connection point (5). The two electrodes of the RFID chip (6) are electrically connected to the central connection point (5) and the conductor ring (4) respectively. Multiple sets of radiating branches (3) are centrally symmetrically distributed with the central connection point (5) as the center. The conductor ring (4) is configured to achieve energy feeding, impedance matching and signal equalization; the electrical length of each radiating branch (3) is configured to make the antenna radiating layer (7) resonate in the UHF band, so that when the tag is in a random attitude, it can achieve effective coupling with the reader signal through at least one radiating branch (3).

2. The antenna structure for a radio frequency chip according to claim 1, characterized in that: The number of radial branches (3) is four.

3. The antenna structure for a radio frequency chip according to claim 2, characterized in that: The four sets of radiating branches (3) extend in the directions of the four corners of the dielectric substrate (1), forming an X-shaped layout.

4. The antenna structure for a radio frequency chip according to claim 1, characterized in that: The conductor ring (4) is rhomboid, circular, rectangular or square in shape.

5. The antenna structure for a radio frequency chip according to claim 1, characterized in that: The radiating branch (3) is straight, bent or curved, and is integrally formed with the conductor ring (4).

6. The antenna structure of a radio frequency chip according to claim 1, characterized in that: The antenna radiating layer (7) also includes radiating elements (2) corresponding to the number of radiating branches (3), with the radiating elements (2) located at the end of the radiating branch (3) away from the conductor ring (4).

7. The antenna structure for a radio frequency chip according to claim 1, characterized in that: The UHF band is from 860MHz to 960MHz.

8. The antenna structure of a radio frequency chip according to claim 1, characterized in that: The dielectric substrate (1) is a flexible dielectric substrate made of PET, PI or flexible plastic.

9. The antenna structure of a radio frequency chip according to claim 1, characterized in that: The RFID chip (6) is electrically connected to the central connection point (5) and the conductor ring (4) by welding.

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