Dual-frequency RFID anti-metal antenna

Abstract

The utility model relates to the technical field of RFID, in particular to a double-frequency RFID anti-metal antenna, which comprises a metal plate shell, a high-frequency PCB coil antenna and an ultrahigh-frequency microstrip antenna, the high-frequency PCB coil antenna and the ultrahigh-frequency microstrip antenna are fixed on the metal plate shell, the high-frequency PCB coil antenna is hollow to form a mounting space, the ultrahigh-frequency microstrip antenna is arranged in the mounting space, and the ultrahigh-frequency microstrip antenna is arranged in the mounting space. And anti-metal wave-absorbing materials are arranged between the high-frequency PCB coil antenna and the metal plate shell and between the ultrahigh-frequency microstrip antenna and the metal plate shell. The antenna is a dual-frequency antenna, only occupies a small space, and meets the high-frequency and ultrahigh-frequency reading requirements at the same time.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of RFID technology, especially relates to a dual-frequency RFID metal-resistant antenna. BACKGROUND

[0002] With the rapid development of RFID technology, RFID technology has been widely used in the library field, and organically combined with automation technology, for example, self-service book return machine, greatly reduces the work pressure of library staff, reduces the waiting time of readers. But once the equipment is large, a larger antenna is needed to ensure the reading range, and a larger antenna will be accompanied by greater interference. The complex metal environment in the automation equipment, the electromagnetic interference generated by the motor, will greatly affect the reading quality of the RIFD antenna, and even cause the tag to be unreadable. In order to solve the above problems, some manufacturers choose a separate high-frequency metal-resistant antenna, plus a super high-frequency microstrip antenna scheme, but due to the limited space of some equipment, it is impossible to install two antennas at the same time.

[0003] Defects and deficiencies of prior art:

[0004] 1. The antenna is easily affected by environmental noise and cannot work;

[0005] 2. The high-frequency and super high-frequency two antennas occupy too much space, and the equipment cannot accommodate them;

[0006] 3. The antennas will affect each other after installation, and are greatly affected by environmental noise;

[0007] 4. The antenna installation in a narrow space is complicated. Utility model content

[0008] In order to solve the problem of too large space occupied by high-frequency and super high-frequency two antennas in the prior art, the utility model provides a dual-frequency RFID metal-resistant antenna which reduces the occupied space.

[0009] The technical scheme adopted by the utility model to solve its technical problems is:

[0010] A dual-frequency RFID metal-resistant antenna, comprising a sheet metal shell, a high-frequency PCB coil antenna and a super high-frequency microstrip antenna fixed on the sheet metal shell, the high-frequency PCB coil antenna is hollow to form an installation space, the super high-frequency microstrip antenna is arranged in the installation space, and the high-frequency PCB coil antenna and the sheet metal shell and the super high-frequency microstrip antenna and the sheet metal shell are provided with metal-resistant wave-absorbing materials.

[0011] Further, the high-frequency antenna tuning circuit of the high-frequency PCB coil antenna adopts adjustable capacitors, resistors, baluns and inductive coils fixed on the circuit board to jointly form an RLC series-parallel resonance circuit.

[0012] Further, the super high frequency microstrip antenna adopts two layers of FR4 substrates, the FR4 substrate close to the sheet metal shell is a bottom plate, and a main patch is fed by two probes connected to the microstrip line of the bottom plate.

[0013] Further, the interval of the two FR4 substrates is 18-22mm.

[0014] Further, the probe is connected to an ohmic radio frequency line through an sma joint, and a magnetic ring is sleeved on the ohmic radio frequency line.

[0015] Further, the ohmic radio frequency line is wound around the magnetic ring for two turns.

[0016] Further, the anti-metal wave-absorbing material is single-sided adhesive ferrite, the anti-metal wave-absorbing material is pasted on the inner surface of the sheet metal, and the super high frequency microstrip antenna is close to the anti-metal wave-absorbing material.

[0017] Further, the magnetic permeability of the anti-metal wave-absorbing material is 110-130U.

[0018] Further, the sheet metal shell is provided with a plurality of pressure rivet nut columns for fixing the super high frequency microstrip antenna and pressure rivet nut columns for fixing the high frequency PCB coil antenna.

[0019] Further, the sheet metal shell forms a drawer form and is pushed into the equipment along the sliding groove of the equipment.

[0020] Beneficial effects:

[0021] (1) The utility model discloses a dual-frequency antenna, which only occupies a small space and meets the reading requirements of high frequency and super high frequency at the same time.

[0022] (2) The utility model discloses an anti-interference antenna, which can be used in a harsh industrial environment.

[0023] (3) The utility model discloses an environment compatibility, which does not need to consider the back metal environment during installation, can be close to metal or non-metal, and is not affected.

[0024] (4) The utility model discloses a drawer type design, which does not need screws during installation, can be installed by pulling, and is more convenient for debugging and assembling.

[0025] (5) The utility model discloses an antenna with good reading performance, and the reading range covers a 500mm*500mm range above the antenna, and there is no blind area. DETAILED DESCRIPTION

[0026] In order to more clearly illustrate the technical scheme of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0027] Fig. 1 It is a structural schematic diagram of the dual-frequency RFID anti-metal antenna of the present application.

[0028] Fig. 2 It is a circuit diagram of the high-frequency PCB coil antenna.

[0029] 1, high-frequency PCB coil antenna, 2, ultra-high frequency microstrip antenna, 3, sheet metal shell, 4, anti-metal wave-absorbing material, 5, magnetic ring, 6, ohmic radio frequency line. DETAILED DESCRIPTION

[0030] The technical scheme in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, but not all the embodiments. The description of the at least one exemplary embodiment is actually only illustrative, but not as any limitation on the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0031] It should be noted that the terms used herein are only for the purpose of describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and furthermore, it should be understood that when the terms "comprise" and / or "include" are used in the specification, there is a feature, step, operation, device, component and / or combination thereof.

[0032] The foregoing description, for purposes of explanation, sets forth specific values and arrangements of components and steps that are subject to many options. The intent is to be accurate in describing the principles and novel features of the application. Thus, although the application has been described with reference to specific embodiments thereof, it will be apparent to those of ordinary skill in the art that a number of changes can be made to the embodiments described without departing from the spirit and scope of the application. For example, the various features of the application can be combined in any combination, where possible. Accordingly, the scope of the application is to be construed as encompassing modifications and variations of the specific examples described herein, subject only to the conditions of the prior art.

[0033] In the description of the present application, it is necessary to understand that the orientation words such as "front, back, up, down, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom" and the like indicated by the orientation or position relationship shown in the drawings are generally based on the orientation or position relationship shown in the drawings, only for the convenience of describing the present application and simplifying the description, without making the opposite statement, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, therefore, it cannot be understood as a limitation on the protection scope of the present application; the orientation words "inner, outer" refer to the inner and outer of the contour of each component itself.

[0034] For the convenience of description, spatial relative terms such as "on", "above", "upper surface", "upper" and the like can be used herein to describe the spatial position relationship of one device or feature with other devices or features as shown in the drawings. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the device described in the drawings. For example, if the device in the drawing is inverted, the device described as "above" or "on" other devices or structures will be positioned "below" or "under" other devices or structures. Thus, the example term "above" can include both "above" and "below" orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative description used herein is interpreted accordingly.

[0035] In addition, it should be noted that the use of the words "first", "second" and the like to define parts of components is only for the convenience of distinguishing the corresponding parts of components, and the above words have no special meaning unless otherwise stated, therefore, it cannot be understood as a limitation on the protection scope of the present application.

[0036] AsFigs. 1-2 The utility model provides a dual -frequency RFID anti -metal antenna, including sheet metal shell 3 and fixed on sheet metal shell 3 high frequency PCB coil antenna 1 and ultra -high frequency microstrip antenna 2, hollow formation installation space in high frequency PCB coil antenna 1, ultra -high frequency microstrip antenna 2 is set up in installation space, and high frequency PCB coil antenna 1 with sheet metal shell 3 between and ultra -high frequency microstrip antenna 2 with sheet metal shell 3 between be equipped with anti -metal wave -absorbing material 4.

[0037] High frequency PCB coil antenna 1 of high frequency antenna tuning circuit adopts adjustable capacitance, resistance, balun and inductive line coil and is fixed on the circuit board to jointly constitute RLC series -parallel resonance circuit. A 50 ohm radio frequency wire is connected through sma joint and is led out, and a magnetic ring 5 is sleeved on the radio frequency wire and is wound two turns, and the outer diameter of the magnetic ring is 60mm, and the inner diameter is 40mm. FR4 material is selected as the substrate of high frequency antenna, and the tuning circuit and the inductive coil are designed integrally. The middle part of the PCB coil is hollowed out, so that the signal of the ultra -high frequency microstrip antenna 2 can be transmitted unobstructed from the middle.

[0038] Ultra -high frequency microstrip antenna 2 adopts two layers FR4 substrate, and the spacing of the two FR4 substrates is 18-22mm, preferably 20mm. The FR4 substrate close to sheet metal shell 3 is the bottom plate, and a main patch is fed by two probes connected to the microstrip line of the bottom plate. The ultra -high frequency microstrip antenna selects microstrip antenna, which is composed of two layers of FR4 substrates stacked, and is installed in the hollowed part of the high frequency antenna. The antenna can cover the 902-928MHz frequency band. The diameter of the probe is d=0.1mm, and the probe is connected to a ohm radio frequency wire 6 through sma joint and is led out, and the ohm radio frequency wire 6 is a 50 ohm radio frequency wire. The ohm radio frequency wire 6 is sleeved with a magnetic ring 5. The ohm radio frequency wire 6 is wound two turns on the magnetic ring 5. The outer diameter of the magnetic ring 5 is 60mm, and the inner diameter is 40mm. The radio frequency wire of the utility model has two, which is a 50 ohm radio frequency wire. The two radio frequency wires are connected on the high frequency PCB coil antenna 1 and the ultra -high frequency microstrip antenna 2 respectively, and pass through the magnetic ring 5 and are wound two turns.

[0039] The anti -metal wave -absorbing material 4 is single -sided adhesive ferrite, and the thickness is 0.3mm. The anti -metal wave -absorbing material 4 is pasted on the inner surface of the sheet metal, that is, the inner surface of the back cover plate of the sheet metal shell 3. The ultra -high frequency microstrip antenna 2 is closely attached to the anti -metal wave -absorbing material 4. The magnetic permeability of the anti -metal wave -absorbing material 4 is 110-130U, preferably 120U.

[0040] The sheet metal shell 3 is provided with a plurality of press rivet screws for fixing the ultra-high frequency microstrip antenna 2 and press rivet nut columns for fixing the high frequency PCB coil antenna 1. The sheet metal thickness of the sheet metal shell 3 is 1mm, and the sheet metal shell 3 forms a drawer type and is pushed into the device along the sliding groove of the device. The sheet metal shell 3 is in the shape of a drawer, and the edge height is 33mm, so as to fix the high frequency PCB coil antenna 1 and the ultra-high frequency microstrip antenna 2 in the sheet metal shell 3. Optionally, the press rivet screw is of M3 type, and the number is 4; the press rivet nut column is of M3 type, the height is 30mm, and the number is 11.

[0041] When the antenna works, the metal plate of the bottom sheet metal shell 3 can shield the surrounding noise interference, and the anti-metal wave-absorbing material 4 inside the metal plate can reduce the absorption of electromagnetic energy by the metal, thereby realizing the anti-metal effect.

[0042] The magnetic ring 5 on the radio frequency line can filter the low frequency noise coupled on the radio frequency line, so as to ensure that the high frequency and ultra-high frequency microstrip antennas are not affected by the noise on the radio frequency line path when used.

[0043] The adjustable capacitor is on the front of the high frequency antenna, and the parameters of the adjustable capacitor can be directly adjusted outside, that is, the center frequency of the antenna can be adjusted, so that the resonance point is at the specified frequency, and the center frequency of the antenna meets the use requirement, and the debugging is completed.

[0044] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any skilled person in the art can make equivalent replacement or change according to the technical scheme and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

Claims

1. A dual frequency RFID anti-metal antenna, characterized in that: It comprises a sheet metal shell (3), a high-frequency PCB coil antenna (1) and an ultra-high-frequency microstrip antenna (2) fixed on the sheet metal shell (3), the high-frequency PCB coil antenna (1) is hollow to form a mounting space, the ultra-high-frequency microstrip antenna (2) is arranged in the mounting space, and the high-frequency PCB coil antenna (1) and the ultra-high-frequency microstrip antenna (2) are provided with anti-metal wave-absorbing material (4) between the high-frequency PCB coil antenna (1) and the sheet metal shell (3) and between the ultra-high-frequency microstrip antenna (2) and the sheet metal shell (3).

2. The dual-band RFID anti-metal antenna according to claim 1, wherein: The high-frequency antenna tuning circuit of the high-frequency PCB coil antenna (1) adopts adjustable capacitors, resistors, baluns and inductive coils fixed on the circuit board to jointly form an RLC series-parallel resonant circuit.

3. The dual-band RFID anti-metal antenna according to claim 1, wherein: The ultra-high-frequency microstrip antenna (2) adopts two-layer FR4 substrates, the FR4 substrate close to the sheet metal shell (3) is a bottom plate, and a main patch is fed by two probes connected to the microstrip line of the bottom plate.

4. The dual-band RFID anti-metal antenna according to claim 3, wherein: The distance between the two FR4 substrates is 18-22 mm.

5. The dual-band RFID anti-metal antenna according to claim 3, wherein: The probe is connected to an ohmic radio frequency line (6) through an sma joint, and the ohmic radio frequency line (6) is sleeved with a magnetic ring (5).

6. The dual-band RFID anti-metal antenna according to claim 5, wherein: The ohmic radio frequency line (6) is wound around the magnetic ring (5) for two turns.

7. The dual-band RFID anti-metal antenna according to claim 1, wherein: The anti-metal wave-absorbing material (4) is a single-sided adhesive ferrite, and the anti-metal wave-absorbing material (4) is pasted on the inner surface of the sheet metal, and the ultra-high-frequency microstrip antenna (2) is tightly attached to the anti-metal wave-absorbing material (4).

8. The dual-band RFID anti-metal antenna according to claim 1, wherein: The magnetic permeability of the anti-metal wave-absorbing material (4) is 110-130 U.

9. The dual-band RFID anti-metal antenna according to claim 1, wherein: The sheet metal shell (3) is provided with a plurality of press-in screw nuts for fixing the ultra-high-frequency microstrip antenna (2) and press-in screw nuts for fixing the high-frequency PCB coil antenna (1).

10. The dual-band RFID anti-metal antenna according to claim 1, wherein: The sheet metal shell (3) forms a drawer type, and is pushed into the equipment along the sliding groove of the equipment.

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