Ultra-high frequency RFID near-field antenna, positioning system and positioning control method

Abstract

The present application discloses a ultra-high frequency RFID near-field antenna, a positioning system and a positioning control method. Among them, the ultra-high frequency RFID near-field antenna includes: a dielectric substrate and a metal ground, the metal ground is disposed on one side of the dielectric substrate; a radiation element, the radiation element is disposed on the dielectric substrate and on the other side of the dielectric substrate away from the metal ground, the radiation element is adapted to be connected to an RFID reader; a microstrip RF attenuator, the microstrip RF attenuator is disposed on the radiation element and connected to the metal ground, the microstrip RF attenuator is used to attenuate signals. The ultra-high frequency RFID near-field antenna realizes the identification and positioning functions of the object to be measured by loading the transmission line of the microstrip RF attenuator, using the stepped values of the identification signal intensities at different positions, and comparing the returned response signal intensity with a preset signal intensity threshold.

Description

Technical Field

[0001] This application relates to the field of radio frequency identification, and particularly to a ultra-high frequency RFID near-field antenna, a positioning system and a positioning control method. Background Art

[0002] With the development of radio frequency identification technology (RFID) and the increasing requirements of various industries for automatic and efficient work, this technology has been more and more widely used in various industries. However, in some application scenarios, such as archives, logistics warehousing or transfer centers, and inventory checking on goods conveyor belts, conventional RFID technology can only achieve inventory checking of goods, but cannot accurately locate the position of goods, making manual search difficult and time-consuming. In related technologies, when positioning goods, usually a relatively high requirement is imposed on the signal strength returned by RFID readers and electronic tags, and the implementation process requires a relatively high cost. Summary of the Invention

[0003] This application aims to solve at least one of the technical problems in the related technologies to some extent.

[0004] To this end, the first object of this application is to propose a ultra-high frequency RFID near-field antenna. This antenna can utilize the stepped values of the recognition signal strength at different positions, and by comparing with a preset response signal strength threshold, realize the functions of identifying and positioning the object to be measured.

[0005] The second object of this application is to propose a ultra-high frequency RFID near-field positioning system.

[0006] The third object of this application is to propose a control method for a ultra-high frequency RFID near-field positioning system.

[0007] To achieve the above object, the ultra-high frequency RFID near-field antenna proposed in the first aspect embodiment of this application includes: a dielectric substrate and a metal ground, the metal ground is provided on one side of the dielectric substrate; a radiation element, the radiation element is provided on the dielectric substrate and on the other side of the dielectric substrate away from the metal ground, the radiation element is adapted to be connected to an RFID reader; a microstrip radio frequency attenuator, the microstrip radio frequency attenuator is provided on the radiation element and connected to the metal ground, and the microstrip radio frequency attenuator is used to attenuate signals.

[0008] According to the ultra-high frequency RFID near-field antenna of this embodiment, by utilizing the stepped values of the recognition signal strength at different positions, comparing the returned response signal strength with a preset response signal strength threshold, the functions of identifying and positioning the object to be measured are realized.

[0009] To achieve the above object, the ultra-high frequency RFID near-field positioning system proposed in the second aspect embodiment of the present application includes: an RFID reader and an electronic tag; an ultra-high frequency RFID near-field antenna, where the ultra-high frequency RFID near-field antenna is the ultra-high frequency RFID near-field antenna according to the first aspect embodiment of the present application. The RFID reader is adapted to be connected to the radiation element, and the RFID reader is used to send a radio frequency carrier signal to the radiation element and read the radio frequency carrier response signal returned by the electronic tag.

[0010] According to the ultra-high frequency RFID near-field positioning system of this embodiment, a radio frequency carrier signal is sent through the ultra-high frequency RFID near-field antenna, and a radio frequency carrier response signal returned by the electronic tag is acquired, so as to be used for the process of judging the response signal strength and a preset response signal strength threshold, realizing the identification and positioning of the object to be measured.

[0011] To achieve the above object, a control method for an ultra-high frequency RFID near-field positioning system proposed in the third aspect embodiment of the present application, where the ultra-high frequency RFID near-field positioning system includes an ultra-high frequency RFID near-field antenna, an RFID reader and an electronic tag. The ultra-high frequency RFID near-field antenna includes a radiation element and a microstrip radio frequency attenuator. The RFID reader is adapted to be connected to the radiation element, and the microstrip radio frequency attenuator is arranged on the radiation element. The method is characterized in that it includes: the RFID reader sends a radio frequency carrier signal to the radiation element to make the electronic tag return a radio frequency carrier response signal; the RFID reader reads the radio frequency carrier response signal, compares the intensity of the radio frequency carrier response signal with a preset response signal strength threshold, and performs the identification and positioning of the object to be measured according to the comparison result.

[0012] According to the control method of the high-frequency RFID near-field positioning system of this embodiment, the RFID reader acquires the radio frequency carrier response signal returned by the electronic tag through the ultra-high frequency RFID near-field antenna, and realizes the identification and positioning of the object to be measured by comparing the intensity of the radio frequency carrier response signal with a preset response signal strength threshold.

[0013] Additional aspects and advantages of the present application will be given in part in the following description, become apparent in part from the following description, or be understood through the practice of the present application. Description of the Drawings

[0014] Figure 1 is a schematic structural diagram of an ultra-high frequency RFID near-field antenna according to an embodiment of the present application;

[0015] Figure 2 is a schematic structural diagram of the microstrip radio frequency attenuator 104 according to an embodiment of the present application;

[0016] Figure 3 It is a schematic structural diagram of a ultra-high frequency RFID near-field antenna according to a specific embodiment of the present application;

[0017] Figure 4 It is a schematic structural diagram of a high-frequency RFID near-field positioning system according to an embodiment of the present application;

[0018] Figure 5 It is a flowchart of a control method for a ultra-high frequency RFID near-field positioning system according to an embodiment of the present application. Detailed implementation manners

[0019] The embodiments of the present application will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present application and should not be construed as limiting the present application.

[0020] The ultra-high frequency RFID near-field antenna, positioning system and positioning control method of the embodiments of the present application will be described below with reference to the accompanying drawings.

[0021] Figure 1 It is a schematic structural diagram of a ultra-high frequency RFID near-field antenna according to an embodiment of the present application.

[0022] As Figure 1 shown, the ultra-high frequency RFID (Radio Frequency Identification) near-field antenna includes a dielectric substrate 101 and a metal ground 102. Among them, the metal ground 102 is provided on one side of the dielectric substrate 101; a radiation element 103, where the radiation element 103 is provided on the dielectric substrate 101 and on the other side of the dielectric substrate 101 away from the metal ground 102, and the radiation element 103 is adapted to be connected to an RFID reader 200; a microstrip radio frequency attenuator 104, where the microstrip radio frequency attenuator 104 is provided on the radiation element 103 and connected to the metal ground 102, and the microstrip radio frequency attenuator 104 is used to attenuate signals.

[0023] It can be understood that radio frequency identification technology (RFID) is a non-contact automatic identification technology. Its basic principle is to use radio frequency carrier signals and spatial coupling transmission characteristics to realize the automatic identification of target objects. The ultra-high frequency RFID near-field antenna in this embodiment is applicable to the application scenarios of passive electronic tags.

[0024] Specifically, in this embodiment, the RFID reader / writer 200 is connected to the radiation element 103. The RFID reader / writer 200 radiates energy through the radiation element 103 in the ultra-high frequency RFID near-field antenna, so that the electronic tag in the spatial coupling region of the radiation element 103 generates an induced current through electromagnetic induction. The induced current drives the chip circuit in the electronic tag to send the identification information stored in the tag to the RFID reader / writer 200 through the radiation element 103.

[0025] Exemplarily, the microstrip RF attenuator 104 is disposed at each reading position of the radiation element 103, and is used to attenuate the intensity of the signal radiated by the radiation element 103 outward and the intensity of the response signal returned by the electronic tag. It can be understood that one end of the radiation element 103 is connected to the RFID reader / writer 200, and the RFID reader / writer 200 transmits a radio frequency carrier signal through the radiation element 103. The radio frequency carrier signal propagates from the end connected to the RFID reader / writer 200 along the radiation element 103 to the other end. After passing through the microstrip RF attenuator 104 on the radiation element 103, the signal intensity will be attenuated. After passing through multiple microstrip RF attenuators 104, the signal radiation intensity will show a step-by-step decrease. Similarly, the radio frequency carrier response signals returned by the electronic tags at different positions are transmitted to the RFID reader / writer 200 through the radiation element 103. The more microstrip RF attenuators 104 the signal passes through, the greater the attenuation degree of the returned signal intensity.

[0026] Optionally, the radiation element 103 adopts a 50Ω transmission line mode, with a width of 2 mm, and the length can be set according to actual needs. One end of the radiation element 103 is connected to the RFID reader / writer 200 as the input port of the ultra-high frequency RFID near-field antenna, and the other end is connected to a 50Ω load at the tail as the output port of the ultra-high frequency RFID near-field antenna. The dielectric constant of the dielectric substrate 101 is 4.4, and the thickness is 1.6 mm, adopting a double-sided board structure.

[0027] It can be understood that when the radio frequency carrier signal is transmitted on the radiation element 103, as the number of microstrip RF attenuators 104 passed through increases, the attenuation degree of the signal will show a step-by-step decrease.

[0028] Exemplarily, at the position where one end of the radiation element 103 is connected to the RFID reader / writer 200, devices such as a tag radio frequency signal intensity and phase signal receiver, which have the functions of receiving and processing signals responsive to the electronic tag, can also be connected. The present application does not limit this.

[0029] The ultra-high frequency RFID near-field antenna according to this embodiment reduces the electromagnetic radiation impact of the antenna on adjacent tags by setting a microstrip radio frequency attenuator at the reading position of the radiation element, reduces the misreading rate of adjacent tags, and performs positioning based on the different response signal strengths brought by the microstrip radio frequency attenuator, requiring lower requirements for the RFID reader and signal judgment algorithm, reducing costs while improving positioning accuracy.

[0030] As a possible implementation, there are multiple microstrip radio frequency attenuators 104, and the multiple microstrip radio frequency attenuators 104 are connected in series in sequence.

[0031] Specifically, the microstrip radio frequency attenuators 104 are sequentially arranged in series along the transmission direction of the radio frequency carrier signal on the radiation element 103. The number of microstrip radio frequency attenuators 104 can be set accordingly according to the number of electronic tags, that is, one microstrip radio frequency attenuator 104 can be set at each reading position of the ultra-high frequency RFID antenna.

[0032] It should be noted that after the position of the microstrip radio frequency attenuator 104 is set accordingly according to the position of the electronic tag, the intensities of the radio frequency carrier signals returned by the electronic tags at different positions have large differences after passing through different numbers of attenuators, so that the positioning of the object to be measured can be performed according to the different signal intensities returned and the preset response signal intensity threshold.

[0033] Exemplarily, the attenuation values of the multiple microstrip radio frequency attenuators 104 are the same, and the attenuation value range is [2dB, 5dB]. In this attenuation range, it is ensured that the signal intensity presents a stepped effect, and at the same time, under the action of the microstrip radio frequency attenuator 104, the electromagnetic radiation impact of the radiation element 103 on adjacent electronic tags during radiation can be reduced, and the misreading rate of adjacent tags can be reduced.

[0034] As an example, along the length direction of the radiation element 103, the interval distances between any two adjacent microstrip radio frequency attenuators 104 are the same.

[0035] Specifically, the multiple microstrip radio frequency attenuators 104 are arranged on the radiation element 103 at equal intervals. The microstrip radio frequency attenuators 104 are arranged at equal intervals, and the influence of the radiation element 103 on adjacent tags during radiation is the same, which can improve the accuracy of positioning the object to be measured.

[0036] It can be understood that in actual applications, the positions of each electronic tag can be set at equal intervals according to actual needs, and the interval distances between multiple adjacent microstrip radio frequency attenuators 104 are determined according to the positions of the electronic tags to improve the accuracy of the object to be measured.

[0037] Furthermore, the radiation element 103 is formed with a bending portion protruding toward the same side of the radiation element 103, and the microstrip radio frequency attenuator 104 is arranged on the bending portion.

[0038] Specifically, as Figure 1 shown, the radiation element 103 is formed with a plurality of bent portions 110. The plurality of bent portions 110 are sequentially spaced apart along the length direction of the radiation element 103, and the spacing distance D1 between two adjacent bent portions 110 is the same.

[0039] It can be understood that the radiation element 103 is bent at equal intervals on the dielectric substrate 101, that is, the plurality of bent portions formed by the radiation element 103 face the same side, and each formed bent portion is the same.

[0040] Optionally, the spacing distance between two adjacent bent portions is D1, and the value of D1 can be determined according to the actual application scenario. For example, when the actual application scenario is a bookcase, the spacing distance D1 between two bent portions is relatively small, and the value range of D1 can be 0.3 cm ≤ D1 ≤ 10 cm; when the actual application scenario is a baggage conveyor belt or a cargo hold inventory conveyor belt, the spacing distance D1 between two bent portions is relatively large, and the value range of D1 can be 0.5 m ≤ D1 ≤ 1 m.

[0041] In order to ensure good positioning accuracy, the size specifications of the plurality of bent portions 110 formed by the radiation element 103 are the same, and the spacing distance D1 between each bent portion is the same.

[0042] As a possible implementation, at least one microstrip RF attenuator 104 is provided on each bent portion 110.

[0043] Exemplarily, each microstrip RF attenuator 104 is disposed at the center position of the convex side of each bent portion.

[0044] In some embodiments, the radiation element 103 includes a plurality of sub-radiation elements, and a microstrip RF attenuator 104 is connected between two adjacent sub-radiation elements.

[0045] It can be understood that both ends of the microstrip RF attenuator 104 are disposed at the bent portions formed by the radiation element 103, and the plurality of sub-radiation elements are connected in series by the microstrip RF attenuator 104 to form a complete RF sub-carrier signal transmission line, that is, the radiation element 103.

[0046] It can be understood that in this embodiment, the plurality of sub-radiation elements are connected by the microstrip RF attenuator 104, and are connected from one end connected to the RFID reader 200 to the tail to form a transmission line of the RF carrier signal.

[0047] Figure 2 It is a schematic structural diagram of the microstrip RF attenuator 104 according to an embodiment of the present application.

[0048] As Figure 2As shown, the microstrip RF attenuator 104 includes a first resistor R s1 , a second resistor R s2 and a ground resistor R p . The first resistor R s1 is in series with the second resistor R s2 . One end of the ground resistor R p is connected between the first resistor R s1 and the second resistor R s2 , and the other end of the ground resistor R p is connected to the metal ground 102.

[0049] It can be understood that the microstrip RF attenuator 104 can be a T-type attenuator. The first resistor R s1 and the second resistor R s2 are connected in series and bridged across the convex side of the bent portion of the radiating element 103.

[0050] As an example, in actual use, the attenuation value of the microstrip RF attenuator 104 can be set according to the transmission length of the near-field antenna. The corresponding resistor values of the microstrip RF attenuators 104 with different specifications are different. The attenuation value of the microstrip RF attenuator 104 can be adjusted by changing the resistance values of the first resistor R s1 , the second resistor R s2 and the ground resistor R p . For example, when the selected attenuation value of the microstrip RF attenuator 104 is 3 dB, the resistance value R1 of the first resistor R s1 and the second resistor R s2 satisfies the relation: 0.29 Ω ≤ R1 ≤ 0.3 Ω, and the resistance value R2 of the ground resistor R p satisfies the relation: 141 Ω ≤ R2 ≤ 142 Ω.

[0051] Among them, the first resistor R s1 and the second resistor R s2 are symmetrically designed and have the same resistance value. The impedance values Z0 at both ends where the first resistor R s1 and the second resistor R s2 are located are the same.

[0052] As an example, Figure 3 is a schematic structural diagram of a UHF RFID near-field antenna according to a specific embodiment of the present application. As Figure 3 shown, along the length direction of the radiating element 103, one end of the radiating element 103 is configured as an input end adapted to be connected to the RFID reader 200, and the other end of the radiating element 103 is connected to a load 105.

[0053] Optionally, the load 105 at the tail of the radiating element 103 is a 50 Ω resistor connected to the metal ground 102.

[0054] To implement the above embodiments, the present application also proposes a ultra-high frequency RFID near-field positioning system. Figure 4 It is a schematic structural diagram of a high-frequency RFID near-field positioning system according to an embodiment of the present application. As Figure 4 shown, the ultra-high frequency RFID near-field positioning system 400 includes: an RFID reader / writer 200, an electronic tag 300, and an ultra-high frequency RFID near-field antenna 100.

[0055] Among them, the ultra-high frequency RFID near-field antenna 100 is the ultra-high frequency RFID near-field antenna described in the above embodiments of the present application. The RFID reader / writer 200 is adapted to be connected to the radiation element 103. The RFID reader / writer 200 is used to send a radio frequency carrier signal to the radiation element 103 and read the radio frequency carrier response signal returned by the electronic tag 300.

[0056] Specifically, the electronic tag 300 is composed of a chip and a built-in antenna. The chip stores electronic data in a certain format as the identification information of the item to be identified, and is the data carrier of the ultra-high frequency RFID near-field positioning system. The RFID reader / writer 200 is a device used to read or read and write the information of the electronic tag. It mainly transmits a radio frequency carrier signal to the electronic tag 300 through the ultra-high frequency RFID near-field antenna 100, receives the radio frequency carrier response signal returned by the electronic tag 300 through the ultra-high frequency RFID near-field antenna 100, decodes the returned radio frequency carrier response signal, and transmits the processed information to the host for processing. The ultra-high frequency RFID near-field antenna 100 is a transmitting and receiving device for transmitting data between the RFID reader / writer and the electronic tag.

[0057] Exemplarily, as Figure 4 shown, the electronic tag 300 ( Figure 4 the electronic tag 300 in

[0058] It should be noted that Figure 4 the number and specific setting positions of the electronic tags 300 in

[0059] It can be understood that, in this embodiment, the electronic tags 300 can be placed at equal intervals at the spatially coupled positions of the ultra-high frequency RFID near-field antenna. The ultra-high frequency RFID near-field positioning system 400 first sends a tag reading and writing command as a transmission signal through the ultra-high frequency RFID near-field antenna 100. The electronic tags 300 within the spatial coupling range of the ultra-high frequency RFID antenna respond to the transmission signal, generate a response signal containing tag information, and send the modulated response signal to the ultra-high frequency RFID near-field antenna 100. The RFID reader / writer 200 reads the response signal sent by the electronic tag 300 through the ultra-high frequency RFID near-field antenna 100, and determines the position of the object to be measured by comparing the intensity of the response signal with a preset response signal intensity threshold.

[0060] Exemplarily, the frequency of the RFID reader / writer determines the operating frequency of the RFID system. In this embodiment, the operating frequency range of the RFID system is 920 MHz - 925 MHz.

[0061] It should be noted that objects to be measured with different materials have different dielectric constants, and different dielectric constants have different effects on the intensity of the radio frequency carrier response signal returned by the electronic tag 300. The signal intensity returned by different objects to be measured at different positions can be obtained in advance, and this returned signal intensity is used as the preset response signal intensity threshold. In practical applications, the intensity of the response signal is compared with the preset response signal intensity threshold to identify and locate the object to be measured.

[0062] Corresponding to the ultra-high frequency RFID near-field positioning system provided in the above embodiment, the present application also proposes a control method for an ultra-high frequency RFID near-field positioning system. Since the control method for the ultra-high frequency RFID near-field positioning system provided in the embodiments of the present application corresponds to the ultra-high frequency RFID near-field positioning system in the above embodiment, the implementation manners of the ultra-high frequency RFID near-field positioning system described above are also applicable to the control method for the ultra-high frequency RFID near-field positioning system in the present application. Among them, the ultra-high frequency RFID near-field positioning system includes an ultra-high frequency RFID near-field antenna, an RFID reader / writer, and an electronic tag. The ultra-high frequency RFID near-field antenna includes a radiation element and a microstrip radio frequency attenuator. The RFID reader / writer is adapted to be connected to the radiation element, and the microstrip radio frequency attenuator is arranged on the radiation element. Figure 5 It is a flowchart of a control method for an ultra-high frequency RFID near-field positioning system according to an embodiment of the present application. As Figure 5 shown, the control method for the ultra-high frequency RFID near-field positioning system includes the following steps:

[0063] S510, the RFID reader / writer sends a radio frequency carrier signal to the radiation element to cause the electronic tag to return a radio frequency carrier response signal;

[0064] The S520 RFID reader reads the radio frequency carrier response signal, compares the intensity of the radio frequency carrier response signal with a preset response signal intensity threshold, and identifies and locates the object to be measured according to the comparison result.

[0065] In addition, the other components and functions of the ultra-high frequency RFID near-field antenna in the embodiments of the present application are known to those skilled in the art. To reduce redundancy, they will not be described in detail here.

[0066] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application.

Claims

1. An ultra-high frequency RFID near-field antenna, characterized in that, Comprising: A dielectric substrate and a metal ground, the metal ground being disposed on one side of the dielectric substrate; A radiation element, the radiation element being disposed on the dielectric substrate and on the other side of the dielectric substrate away from the metal ground, the radiation element being adapted to be connected to an RFID reader; A microstrip RF attenuator, the microstrip RF attenuator being disposed on the radiation element and connected to the metal ground, the microstrip RF attenuator being used to attenuate signals, the microstrip RF attenuator being multiple, and the multiple microstrip RF attenuators being connected in series in sequence, and along the length direction of the radiation element, the spacing distance between any two adjacent microstrip RF attenuators is the same.

2. The ultra-high frequency RFID near-field antenna according to claim 1, characterized in that, The radiation element is formed with a bent portion protruding towards the same side of the radiation element, and the microstrip RF attenuator is disposed on the bent portion.

3. The ultra-high frequency RFID near-field antenna according to claim 2, characterized in that, The radiation element is formed with multiple bent portions, the multiple bent portions being spaced apart in sequence along the length direction of the radiation element, and the spacing distance between two adjacent bent portions is the same.

4. The ultra-high frequency RFID near-field antenna according to claim 3, wherein At least one microstrip RF attenuator is disposed on each bent portion.

5. The ultra-high frequency RFID near-field antenna according to claim 1, characterized in that, The radiation element includes multiple sub-radiation elements, and a microstrip RF attenuator is connected between two adjacent sub-radiation elements.

6. The ultra-high frequency RFID near-field antenna according to any one of claims 1-5, characterized in that, The microstrip RF attenuator includes a first resistor, a second resistor, and a ground resistor, the first resistor and the second resistor being connected in series, one end of the ground resistor being connected between the first resistor and the second resistor, and the other end of the ground resistor being connected to the metal ground.

7. The ultra-high frequency RFID near-field antenna according to claim 1, characterized in that Along the length direction of the radiation element, one end of the radiation element is configured as an input end adapted to be connected to the RFID reader, and a load is connected to the other end of the radiation element.

8. An ultra-high frequency RFID near-field positioning system, characterized in that, Comprising: An RFID reader and an electronic tag; A UHF RFID near-field antenna, the UHF RFID near-field antenna being the UHF RFID near-field antenna according to any one of claims 1-7, the RFID reader being adapted to be connected to the radiation element, and the RFID reader being used to send a radio frequency carrier signal to the radiation element and read a radio frequency carrier response signal returned by the electronic tag.

9. A control method for an ultra-high frequency RFID near-field positioning system, the ultra-high frequency RFID near-field positioning system comprising an ultra-high frequency RFID near-field antenna, an RFID reader / writer, and an electronic tag, the ultra-high frequency RFID near-field antenna comprising a radiation element and a microstrip radio frequency attenuator, the RFID reader / writer being adapted to be connected to the radiation element, the microstrip radio frequency attenuator being disposed on the radiation element, characterized in that, The microstrip RF attenuator is multiple, the multiple microstrip RF attenuators being connected in series in sequence, and along the length direction of the radiation element, the spacing distance between any two adjacent microstrip RF attenuators is the same, and the method includes: The RFID reader sends a radio frequency carrier signal to the radiation element to enable the electronic tag to return a radio frequency carrier response signal; The RFID reader reads the radio frequency carrier response signal, compares the intensity of the radio frequency carrier response signal with a preset response signal intensity threshold, and identifies and locates the object to be measured according to the comparison result.

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