Miniaturized reader antenna applied to UHF (Ultra High Frequency) band

Abstract

The utility model relates to the technical field of UHF (Ultra High Frequency) communication, solves the problems that a reader antenna in the prior art is relatively large in size, relatively few in array elements and relatively narrow in radiation range, and discloses a miniaturized reader antenna applied to a UHF (Ultra High Frequency) band, which comprises a PCB (Printed Circuit Board), a feed network and at least two radiation units, according to the antenna, the PCB is adopted as a base material of the feed network, the whole antenna has compactness and a low profile, miniaturization of the antenna is achieved, the feed network technology achieves the excellent circular polarization performance of the whole antenna, and the compactness of the whole structure of the antenna is kept; the radiation units of the antenna adopt an array mode, so that the beam forming of the antenna is realized, the radiation range of the antenna is widened, the gain is improved, and the 3dB bandwidth is increased.

Description

Technical Field

[0001] The present application relates to the field of UHF communication technology, and in particular to a miniaturized reader antenna used in the UHF frequency band. Background Art

[0002] As an indispensable part of the UHF wireless system, the reader antenna is mainly responsible for sending and receiving electromagnetic wave signals in the wireless communication system. As the application of UHF technology becomes more and more extensive, the structural size requirements for the reader antenna in different scenarios are getting higher and higher.

[0003] The most common reader antennas are large in size, with fewer array elements and a narrow radiation range, which results in blind spots for tag reading. Therefore, higher requirements are placed on reader antennas, such as miniaturization, wide beam, multiple array elements, etc. Utility Model Content

[0004] The purpose of the present application is to overcome the problems in the prior art of large reader antenna size, few array elements and narrow radiation range, and to provide a miniaturized reader antenna for use in the UHF frequency band.

[0005] Specifically, the miniaturized reader antenna applied to the UHF frequency band includes a PCB board, a feeding network and at least two radiating units mounted on the PCB board, and the radiating units are connected to the feeding network through feeding pins.

[0006] In some possible implementations, the radiation unit includes a radiation patch, a substrate, and a first metal ground plane that are stacked in sequence, wherein the radiation patch is connected to the feeding network via a feeding needle, and the radiation patch can be fed via the feeding network.

[0007] In some possible implementations, the feed needle passes through the substrate and the first metal ground plane, and both the substrate and the first metal ground plane are provided with through holes compatible with the feed needle. The radiation unit is connected to the feeding network using the feed needle, thereby ensuring the integrity of the antenna structure and achieving a low profile of the antenna.

[0008] In some possible implementations, the substrate is a high dielectric constant substrate, which can significantly reduce the size of the radiation unit, thereby reducing the overall size of the antenna.

[0009] In some possible implementations, a second metal ground plane bonded to the first metal ground plane is provided on one side of the PCB board, and the feeding network is arranged on the other side of the PCB board. Both the first metal ground plane and the second metal ground plane are metal planes, which act as metal grounding and reflection planes in antenna-related aspects.

[0010] In some possible implementations, the feeding network feeds the radiating elements simultaneously, in phase, and with equal amplitude, so as to achieve consistency in the excitation of the radiating elements. The consistency in the excitation of the radiating elements can ensure good final beamforming.

[0011] In some possible implementations, the distance between adjacent radiating units is 10-40 mm, and the gap between the radiating units is maintained at a half-wavelength distance, that is, between 10 mm and 40 mm, so as to balance the performance and miniaturization of the antenna.

[0012] In some possible implementations, the distance between adjacent radiating elements is 25-27 mm, so that the antenna achieves optimal performance while maintaining a small size.

[0013] In some possible implementations, the number of the radiating units is two and a 1×2 array is adopted. The radiating units are arranged in 1×2 and placed on the upper surface of the PCB board, and the feeding network part is arranged on the lower surface of the PCB board, thereby ensuring the overall compactness and low profile of the antenna and realizing the miniaturization of the antenna.

[0014] The present application has the following beneficial effects: the radiation unit of the present application adopts a high dielectric substrate, which realizes the miniaturization of the antenna and has good radiation characteristics; the feeding network technology realizes the excellent circular polarization performance of the antenna as a whole and maintains the compactness of the overall structure of the antenna; the antenna as a whole adopts an array method to realize the beam forming of the antenna, broaden the radiation range of the antenna, improve the gain, and increase the 3dB bandwidth. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application.

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 This is a schematic structural diagram of a miniaturized reader antenna applied to the UHF frequency band according to an embodiment of the present application;

[0018] Figure 2 This is an exploded view of a radiation unit in a miniaturized reader antenna applied to a UHF frequency band according to an embodiment of the present application;

[0019] Figure 3is a return loss curve diagram of a miniaturized reader antenna applied to a UHF band according to an embodiment of the present application;

[0020] Figure 4 : is a gain curve diagram at different frequencies of a miniaturized reader antenna applied to a UHF band according to an embodiment of the present application;

[0021] Figure 5 It is the normalized radiation pattern of the miniaturized reader antenna applied to the UHF band according to the embodiment of the present application.

[0022] Reference numerals:

[0023] 1. PCB board; 2. feeding network; 3. radiating unit; 31. radiating patch; 32. substrate; 33. first metal ground plane; 4. feeding pin; 5. through hole; 6. second metal ground plane. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application; obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application without making creative work are within the scope of protection of the present application.

[0025] In the description of the present application, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present application. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0026] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "set / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0027] See also Figure 1 and Figure 2A preferred embodiment of the present application is a miniaturized reader antenna for use in the UHF band, comprising a feed network 2 and two radiating units 3. The radiating units 3 are two independent high dielectric constant substrates 32, as well as a radiating patch 31 arranged on the upper surface of the high dielectric constant substrate 32 and a first metal ground plane 33 arranged on the lower surface of the high dielectric constant substrate 32. Below the radiating unit 3 is the feed network 2, which is connected to the radiating unit 3 via a feed pin 4. The substrate of the feed network 2 is a PCB board 1, which can ensure the miniaturization and high cost performance of the feed network 2. The antenna radiating units 3 are arranged in a 1×2 pattern and are placed on the upper surface of the PCB board 1. The feed network 2 is partially arranged on the lower surface of the PCB board 1, and a second metal ground plane 6 is provided on the upper surface of the PCB board 1. This structure ensures the compactness and low profile of the antenna as a whole, and realizes the miniaturization of the antenna. The antenna as a whole adopts a 1×2 array mode, which realizes the beamforming of the antenna, broadens the radiation range of the antenna, improves the gain, and increases the 3dB bandwidth.

[0028] It should be noted that the substrate 32 of the radiation unit 3 adopts a high dielectric constant substrate 32, which greatly reduces the size of the radiation unit 3 of the antenna. Each radiation unit 3 is designed to be circularly polarized through the coordinated design of the radiation patch 31 and the feeding network 2 to achieve better reading effect.

[0029] like Figure 1 and Figure 2 As shown, the feed needle 4 passes through the substrate and the first metal ground plane 33, and both the substrate and the first metal ground plane 33 are provided with a through hole 5 adapted to the feed needle 4, and the antenna radiation unit 3 is connected to the feeding network 2 by the feed needle 4, thereby ensuring the integrity of the antenna structure and achieving a low profile of the antenna.

[0030] In order to ensure the performance and miniaturization of the antenna, the gap between the radiating elements 3 of the antenna should be maintained at a half-wavelength distance, that is, between 10mm-40mm. When the distance between the radiating elements 3 is 26±1mm, the antenna achieves optimal performance while maintaining a small size.

[0031] In this embodiment, a first feeding network 2 that can realize one-to-two equal-radiation in-phase feeding is used between the radiating units 3, and the first feeding network 2 should be connected to the second feeding network 2 of each radiating unit 3 to form the overall feeding network 2 part of the antenna. The first feeding network 2 can be understood as a power divider but is not limited to a power divider. The function of the first feeding network 2 is that power can be input from one port and two powers with the same phase and equal magnitude can be output. In this embodiment, the two radiating units 3 can be fed simultaneously, in phase, and with equal amplitude, so as to achieve consistency in the excitation of the radiating units 3. The consistency in the excitation of the radiating units 3 can ensure good beamforming in the end.

[0032] It should be noted that, in order to achieve good performance of the reader antenna in the above embodiment in the cabinet, the preferred installation method of the present invention is:

[0033] The reader antenna is installed on the top of the cabinet to facilitate reading the tag to be tested;

[0034] In a further embodiment, the long side of the reader antenna should be placed perpendicular to the direction of the cabinet door, so that the main radiation direction of the antenna after array formation can completely include the tag to be tested;

[0035] In a further embodiment, the short side of the reader antenna should be close to the cabinet door, and the main radiation direction of this embodiment can completely include the tag to be tested through the reflection shaping of the metal cabinet door and the metal walls on both sides;

[0036] In a further embodiment, the distance between the short side of the reader antenna and the cabinet door is 20-90 mm, which can ensure the antenna has the best reading performance for the tag;

[0037] Preferably, the reader antenna should be placed between the insulating plugs to be tested in items A and B of the cabinet (facing the insulating plugs, the two plugs on the left are items A and B), so that the power spectral density of the plane where the tags to be tested are located in the cabinet in this embodiment is optimal.

[0038] like Figure 3 As shown in the return loss curve of the reader antenna in this embodiment, it can be seen that the reader antenna can fully meet the UHF (902-928MHz) operating frequency band while maintaining miniaturization, ensuring a relatively wide bandwidth, and the return loss center frequency is as low as -35dB.

[0039] like Figure 4 As shown, it is a gain curve diagram of the reader antenna at different frequency points in this embodiment. It can be seen that the average gain of the reader antenna in the working frequency band reaches more than 4dBi, which is at a relatively good level among small-sized antennas.

[0040] like Figure 5 As shown, it is the normalized radiation pattern of the reader antenna in this embodiment. It can be seen that the 3dB bandwidth of the reader antenna in the main radiation direction reaches 120°, which is greatly improved compared with the antenna with a single radiation unit 3.

[0041] The above are only preferred specific implementations of the present application; however, the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solution and its improved ideas of the present application within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.

Claims

1. A miniaturized reader antenna for use in the UHF band, characterized in that: It comprises a PCB board, a feeding network and at least two radiating units mounted on the PCB board, wherein the radiating units are connected to the feeding network through feeding pins.

2. The miniaturized reader antenna for use in the UHF band according to claim 1, characterized in that: The radiation unit comprises a radiation patch, a substrate and a first metal ground plane which are stacked in sequence, wherein the radiation patch is connected to the feeding network via a feeding pin.

3. The miniaturized reader antenna for use in the UHF band according to claim 2, characterized in that: The feeding needle passes through the substrate and the first metal grounding surface, and both the substrate and the first metal grounding surface are provided with through holes matched with the feeding needle.

4. The miniaturized reader antenna for use in the UHF band according to claim 2, characterized in that: A second metal ground plane bonded to the first metal ground plane is disposed on one side of the PCB board, and the feeding network is arranged on the other side of the PCB board.

5. The miniaturized reader antenna for use in the UHF band according to claim 1, characterized in that: The feeding network feeds the radiating units simultaneously, in phase and with equal amplitude.

6. The miniaturized reader antenna for use in the UHF band according to claim 1, characterized in that: The distance between adjacent radiation units is 10-40 mm.

7. The miniaturized reader antenna for use in the UHF band according to claim 1, characterized in that: The distance between adjacent radiation units is 25-27 mm.

8. The miniaturized reader antenna for use in the UHF band according to any one of claims 1 to 7, characterized in that: The number of the radiation units is two and they are arranged in a 1×2 array.

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