Low-profile multi-frequency micro base station antenna

Abstract

The utility model discloses a low-profile multi-frequency micro base station antenna, and relates to the technical field of base station antennae, the low-profile multi-frequency micro base station antenna comprises a first frequency band module, a second frequency band module, a reflecting plate and a cover plate; the first frequency band module comprises a plurality of first radiation units, a first power distribution plate used for exciting the first radiation units and a parasitic unit, and the parasitic unit is provided with a first groove used for filtering to improve the isolation of the micro base station antenna; the second frequency band module comprises a plurality of second radiation units and a second power distribution plate used for exciting the second radiation units, the second power distribution plate comprises a second power divider corresponding to the second radiation units, and the second power divider is provided with an open-circuit branch structure used for filtering to improve the isolation degree of the micro base station antenna; the first frequency band module and the second frequency band module are accommodated through the reflecting plate and the cover plate. The isolation degree of the base station antenna is improved, and the overall efficiency of the base station antenna is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of base station antennas, in particular to a low-profile multi-frequency micro base station antenna. BACKGROUND

[0002] Currently, the methods for improving the isolation of base station antennas mainly include frequency selective surface technology, coplanar waveguide feeding technology and integrated filtering technology. For the integrated filtering technology, the integrated filtering applied to base station antennas is mainly to integrate the filtering structure on the radiator of the antenna, which will introduce additional loss and reduce the overall efficiency of the antenna, especially in high frequency applications. In addition, this design method requires precise design and tuning, and poor design may result in poor antenna isolation. CONTENT OF THE UTILITY MODEL

[0003] The present application aims to at least solve one of the technical problems existing in the prior art, and provides a low-profile multi-frequency micro base station antenna, which aims to improve the isolation of the base station antenna and improve the overall efficiency of the base station antenna.

[0004] The present application provides a low-profile multi-frequency micro base station antenna, which comprises a first frequency band module, a second frequency band module, a reflector and a cover plate.

[0005] The first frequency band module comprises a plurality of first radiating units, a first power distribution plate for exciting the first radiating units and a parasitic unit, and the parasitic unit is provided with a first groove for filtering to improve the isolation of the micro base station antenna.

[0006] The second frequency band module comprises a plurality of second radiating units and a second power distribution plate for exciting the second radiating units, the second power distribution plate comprises a second power distributor corresponding to the second radiating units, and the second power distributor is provided with an open-circuit stub structure for filtering to improve the isolation of the micro base station antenna, and the working frequency bands of the first frequency band module and the second frequency band module are different.

[0007] The first frequency band module and the second frequency band module are accommodated by the reflector and the cover plate, and the reflector is used for reflecting the antenna radiation.

[0008] According to the technical scheme of the embodiment of the present application, the first frequency band module and the second frequency band module are both radiation modules for realizing antenna radiation, the working frequency bands of the first frequency band module and the second frequency band module are different, and the first frequency band module and the second frequency band module realize multi-band of the base station antenna. In addition, the first frequency band module comprises a parasitic unit, the parasitic unit is provided with a first groove for improving the isolation of the micro base station antenna, and the power divider of the second frequency band module is provided with an open stub structure for filtering to improve the isolation of the micro base station antenna. The filtering structures of the two different frequency band modules are not arranged on the radiators, which can reduce the additional loss introduced, thereby improving the overall efficiency of the antenna, and through the structure of the two different frequency band modules, the isolation of the micro base station antenna can be effectively improved.

[0009] According to some embodiments of the present application, the first frequency band module comprises two same first radiation units, each of the first radiation units comprises two first radiators, the second frequency band module comprises two same second radiation units, and each of the second radiation units comprises two second radiators.

[0010] According to some embodiments of the present application, the first power distribution board comprises a first directional coupler and two first power dividers corresponding to the two first radiators, the first directional coupler is provided with a first port, the first power dividers are provided with second ports, the first directional coupler is used for coupling the two first power dividers through the first port, and the first power dividers are used for exciting the corresponding first radiators through the second ports.

[0011] The second power distribution board comprises a second directional coupler and two second power dividers corresponding to the two second radiators, the second directional coupler is provided with a third port, the second power dividers are provided with fourth ports, the second directional coupler is used for coupling the two second power dividers through the third port, and the second power dividers are used for exciting the corresponding second radiators through the fourth ports.

[0012] According to some embodiments of the present application, the first radiator is a microstrip patch radiator.

[0013] According to some embodiments of the present application, the first groove is a C-shaped groove, and the length of the first groove is 1 / 4 of the wavelength of the working frequency of the second frequency band module.

[0014] According to some embodiments of the present application, the second radiator comprises two pairs of dipole antenna arms, the two pairs of dipole antenna arms are arranged in cross, the dipole antenna arm comprises two radiation arms, the radiation arms are provided with second grooves, and the second grooves are used for adjusting the working bandwidth of the second frequency band module.

[0015] According to some embodiments of the present application, a first protrusion is arranged between two adjacent radiation arms, and the first protrusion is used to adjust the working bandwidth of the second frequency band module.

[0016] According to some embodiments of the present application, the second frequency band module further comprises a support plate corresponding to each of the second radiators, the support plate comprises a first support plate and a second support plate, the support plate is arranged between the second radiator and the second power distribution plate, the first support plate and the second support plate are clamped, one side of the first support plate and the second support plate is provided with a feed balun structure, the other side of the first support plate and the second support plate is provided with a metal connecting line, the feed balun structure is connected to the second power distribution plate, and both ends of the metal connecting line are respectively connected to the second radiator and the reflecting plate.

[0017] According to some embodiments of the present application, the feed balun structure comprises a plurality of rectangular microstrip lines with different widths.

[0018] According to some embodiments of the present application, the open stub structure is an S-shaped open stub, and the length of the open stub structure is 1 / 4 of the wavelength of the working frequency of the first frequency band module.

[0019] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent from the description, or can be learned by practice of the present application. The objects and other advantages of the present application will be realized and achieved by means of the structures particularly pointed out in the description and the appended claims. BRIEF DESCRIPTION OF DRAWINGS

[0020] The accompanying drawings are included to provide a further understanding of the technical scheme of the present application, and constitute a part of the specification, and are used together with the embodiments of the present application to explain the technical scheme of the present application, and do not constitute a limitation on the technical scheme of the present application.

[0021] The present application will be further described below in combination with the drawings and embodiments;

[0022] Figure 1 is a structure explosion view of a low-profile multi-frequency micro base station antenna provided by an embodiment of the present application;

[0023] Figure 2 is a structure view of a first frequency band module of a low-profile multi-frequency micro base station antenna provided by another embodiment of the present application;

[0024] Figure 3 is a structure view of a second frequency band module of a low-profile multi-frequency micro base station antenna provided by another embodiment of the present application;

[0025] Figure 4 is a structure diagram of a second frequency band module of a low-profile multi-frequency micro base station antenna provided by another embodiment of the application;

[0026] Figure 5a is a front view of a first support plate of a low-profile multi-frequency micro base station antenna provided by another embodiment of the application;

[0027] Figure 5b is a front view of a second support plate of a low-profile multi-frequency micro base station antenna provided by another embodiment of the application;

[0028] Figure 5c is a back view of a support plate of a low-profile multi-frequency micro base station antenna provided by another embodiment of the application;

[0029] Figure 6 is a structure diagram of a support plate of a low-profile multi-frequency micro base station antenna provided by another embodiment of the application;

[0030] Figure 7 is a test result diagram of an isolation experiment of a low-profile multi-frequency micro base station antenna provided by another embodiment of the application;

[0031] Figure 8 is a test result diagram of a standing wave ratio experiment of a low-profile multi-frequency micro base station antenna provided by another embodiment of the application.

[0032] BRIEF DESCRIPTION OF DRAWINGS: 100, first frequency band module; 200, second frequency band module; 300, reflecting plate; 400, cover plate; 110, first radiation unit; 120, first power distribution plate; 130, parasitic unit; 131, first groove; 210, second radiation unit; 220, second power distribution plate; 221, second power distributor; 2211, open stub structure; 111, first radiator; 211, second radiator; 121, first directional coupler; 122, first power distributor; 222, second directional coupler; 2111, dipole antenna arm; 21111, radiation arm; 21112, second groove; 21113, first protrusion; 140, support plate; 141, first support plate; 142, second support plate; 143, feed balun structure; 144, metal connecting line. DETAILED DESCRIPTION

[0033] This part will describe the specific embodiments of the application in detail, the preferred embodiments of the application are shown in the drawings, the role of the drawings is to supplement the description of the text part with figures, so that people can intuitively and visually understand each technical feature and the overall technical scheme of the application, but it cannot be understood as a limitation on the protection scope of the application.

[0034] In the description of the present application, it should be understood that the orientation description, such as the orientation or position relationship indicated by the upper, lower, front, rear, left, right and the like, is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0035] In the description of the present application, the meaning of several is one or more, the meaning of multiple is more than two, greater than, less than, more than and the like are understood as not including the number, above, below, within and the like are understood as including the number. If the first, second is described, it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the order of technical features indicated

[0036] In the description of the present application, unless otherwise explicitly limited, the words such as setting, installing, connecting and the like should be broadly understood, and the person skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical solution.

[0037] The present application will be further described below with reference to the drawings.

[0038] As shown in the drawings, Figure 1 Figure 1 is an exploded view of a low-profile multi-frequency micro base station antenna structure provided by an embodiment of the present application. The low-profile multi-frequency micro base station antenna includes a first frequency band module 100, a second frequency band module 200, a reflector plate 300 and a cover plate 400.

[0039] The first frequency band module 100 includes a plurality of first radiation elements 110, a first power distribution plate 120 for exciting the first radiation elements 110 and a parasitic element 130, and the parasitic element 130 is provided with a first groove 131 for filtering to improve the isolation of the micro base station antenna.

[0040] The second frequency band module 200 includes a plurality of second radiation elements 210 and a second power distribution plate 220 for exciting the second radiation elements 210, and the second power distribution plate 220 includes a second power distributor 221 corresponding to the second radiation elements 210, and the second power distributor 221 is provided with an open stub structure 2211 for filtering to improve the isolation of the micro base station antenna. The working frequency bands of the first frequency band module 100 and the second frequency band module 200 are different.

[0041] The first frequency band module 100 and the second frequency band module 200 are accommodated by the reflector plate 300 and the cover plate 400, and the reflector plate 300 is used for reflecting the antenna radiation.

[0042] Reference is made to Figure 1 ​In the embodiment, the micro base station antenna includes a first frequency band module 100 and a second frequency band module 200, and the working frequency bands of the first frequency band module 100 and the second frequency band module 200 are different, so as to be able to cover different wireless communication frequency bands and meet the needs of various network services. It can be understood that the first frequency band module 100 and the second frequency band module 200 can be a low frequency module and a high frequency module respectively, for example, the working frequency band of the first frequency band module 100 can be 700MHz, 800MHz, etc., for wide coverage and indoor penetration, providing voice communication, general data service, or as a communication frequency band of Internet of Things (IoT) devices; the working frequency band of the second frequency band module 200 can be 1.8GHz, 2.1GHz, 2.6GHz, etc., for providing higher data transmission rate, for supporting 4G LTE or 5G NR service.

[0043] Reference Figure 2 , Figure 2 is a structural diagram of a first frequency band module 100 of a low profile multi-frequency micro base station antenna provided by another embodiment of the present application, the first frequency band module 100 includes a plurality of first radiation units 110, a first power distribution plate 120 for exciting the first radiation units 110, and a parasitic unit 130. It can be understood that the radiation unit is the basic component of the antenna, which is used to convert the fed radio frequency signal into electromagnetic wave radiation, therefore, the first radiation unit 110 is designed to optimize the working frequency band of the first frequency band module 100, so as to ensure good radiation characteristics and impedance matching in the frequency band, the plurality of first radiation units 110 of the first frequency band module 100 can have a plurality of different arrangement modes, for example, arranged in a row or formed into an array, so as to enhance the directivity of the antenna or realize beamforming; the first power distribution plate 120 is used to distribute the feeder signal from the antenna to each radiation unit, and the design of the first power distribution plate 120 is matched with the impedance of the first radiation unit 110, so as to reduce signal loss and reflection, thereby improving the efficiency and performance of the entire antenna system;

[0044] The parasitic unit 130 is a radiation unit not directly connected to the feeder, which can be used to improve the bandwidth, directivity or impedance matching of the antenna by affecting the radiation characteristics of the antenna through electromagnetic coupling with the main radiation unit. By adjusting the size, position and shape of the parasitic unit 130, the performance of the antenna in a specific frequency band can be optimized, so that the first frequency band module 100 can work efficiently within the specified frequency band while maintaining isolation from the second frequency band module 200, reducing mutual interference; In this embodiment, the parasitic unit 130 is provided with a first groove 131 for filtering to improve the isolation of the micro base station antenna, it can be understood that the parasitic unit 130 realizes filtering through the first groove 131 structure, the first groove 131 can be used to introduce additional electromagnetic paths on the parasitic unit 130 to suppress unwanted frequency components, thereby improving the selectivity of the antenna system; The first groove 131 can also act as a band-stop filter to prevent signals of a specific frequency from passing through, reducing interference with other frequency bands, for example, to suppress signals generated by the second frequency band module 200, etc., in this way, the isolation between the first frequency band module 100 and the second frequency band module 200 can be increased, thereby reducing their mutual influence; In addition, the size, shape and position of the first groove 131 are designed according to the working frequency of the first frequency band module 100 to ensure the filtering effect on a specific frequency, that is, the different size, shape and position of the first groove 131 determine the filtering frequency band and filtering effect of the first frequency band module 100, therefore, the design of the first groove 131 can be optimized through electromagnetic simulation and experimental verification to ensure the expected filtering effect, and the influence of the first groove 131 on the overall mechanical strength and durability of the micro base station antenna needs to be considered, and the introduction of the first groove 131 may affect other performance parameters of the micro base station antenna, such as bandwidth, gain and radiation efficiency, so trade-offs need to be made during design.

[0045] Reference Figure 3 , Figure 3 is a structural diagram of a second frequency band module 200 of a low-profile multi-frequency micro base station antenna according to another embodiment of the present application, the second power distribution plate 220 includes a second power distributor 221 corresponding to the second radiation unit 210, and the second power distributor 221 is provided with an open stub structure 2211 for filtering to improve the isolation of the micro base station antenna;

[0046] The second frequency band module 200 comprises a plurality of second radiating elements 210 and a second power distribution board 220 for exciting the second radiating elements 210. The second radiating elements 210 are basic radiating elements of the second frequency band module 200 for converting the fed radio frequency signals into electromagnetic wave radiation. Similarly, the second radiating elements 210 are designed for the working frequency band of the second frequency band module 200 to ensure good radiation characteristics and impedance matching in the frequency band. The plurality of second radiating elements 210 of the second frequency band module 200 can also have a plurality of different arrangements, for example, arranged in a row or forming an array to enhance the directivity of the antenna or to realize beamforming. The second power distribution board 220 is used to distribute the feed line signals from the antenna to each radiating element. The design of the second power distribution board 220 is matched with the impedance of the second radiating elements 210 to reduce signal loss and reflection, thereby improving the efficiency and performance of the entire antenna system.

[0047] The second power distribution board 220 comprises a plurality of second power distributors 221 corresponding to the second radiating elements 210. The second power distributors 221 are provided with open stub structures 2211 for filtering to improve the isolation of the micro base station antenna. It can be understood that the open stub structures 2211 provided on the second power distributors 221 are used to improve the performance of the antenna. The open stub structures 2211 can act as a simple band-stop filter to suppress unwanted frequency components by introducing impedance discontinuity at a specific frequency, thereby improving the selectivity of the antenna. In addition, the electromagnetic field distribution on the power distributor can be adjusted to reduce the mutual coupling between different radiating elements, thereby improving the isolation. In this embodiment, the open stub structure 2211 can be a short-circuit line or stub that produces a reactance at the working frequency of the second frequency band module 200, thereby affecting the input impedance and radiation characteristics of the antenna. When the signal frequency matches the resonant frequency of the open stub structure 2211, the stub produces high impedance to prevent the signal from passing through, thereby achieving the effect of filtering.

[0048] In addition, the size, shape and position of the open stub structure 2211 are designed according to the working frequency of the second frequency band module 200 and the required filtering characteristics to ensure the filtering effect on a specific frequency. That is, the different size, shape and position of the open stub structure 2211 determine the filtering frequency band and filtering effect of the second frequency band module 200. Therefore, the design of the open stub structure 2211 can be optimized through electromagnetic simulation and experimental verification to ensure the expected filtering effect. In addition, the influence of the open stub structure 2211 on the overall mechanical strength and durability of the micro base station antenna needs to be considered, as well as the influence of the open stub structure 2211 on the overall size, weight and cost of the antenna.

[0049] In the embodiment, the first radiating unit 110 or the second radiating unit 210 can adopt a microstrip patch form, thereby realizing the low profile characteristic of the micro base station antenna.

[0050] It can be understood that the first frequency band module 100 and the second frequency band module 200 are accommodated by the reflector plate 300 and the cover plate 400 as the shell of the micro base station antenna, and the reflector plate 300 is used for reflecting the antenna radiation. It can be understood that the reflector plate 300 is placed behind the first frequency band module 100 and the second frequency band module 200 to ensure that the waves reflected from the first frequency band module 100 and the second frequency band module 200 and the reflector plate 300 reach in space with the same phase, thereby enhancing each other; the reflector plate 300 can change the radiation pattern of the antenna, so that the main radiation direction of the antenna is more concentrated, thereby improving the directivity of the antenna and reducing the loss of energy in the non-target direction. Therefore, by reflecting the radiation through the reflector plate 300, the micro base station antenna obtains higher gain in a specific direction and forms a specific radiation mode, such as a heart shape, a fan shape or other customized shape, to meet specific coverage requirements. In an embodiment, the reflector plate 300 can also be used to compensate for the phase difference between the antenna elements, thereby optimizing the performance of the antenna.

[0051] Based on this, the low profile multi-frequency micro base station antenna provided by the embodiments of the present application can flexibly support multi-band operation, can design a filter structure for each frequency band to avoid mutual interference between frequency bands, and is suitable for multi-frequency applications such as 5G and Internet of Things; and compared with the existing integrated filtering technology, the filtering effect is more effective, the mutually coupled frequency signals can be filtered out earlier, unnecessary frequency components are prevented from being transmitted into the antenna, and high-order harmonics and parasitic signals are prevented from affecting the main frequency band radiation of the antenna, thereby improving the performance of the main frequency band.

[0052] In the low profile multi-frequency micro base station antenna provided by some embodiments of the present application, the first frequency band module 100 includes two same first radiating units 110, each of which includes two first radiating bodies 111, and the second frequency band module 200 includes two same second radiating units 210, each of which includes two second radiating bodies 211.

[0053] Reference Figure 1In the embodiment, the first frequency band module 100 includes two same first radiating units 110, each of which includes two first radiators 111, that is, the first frequency band module 100 adopts a dual-polarized design in the form of a 2x2 array distribution, and the first radiators 111 of each first radiating unit 110 adopt the same design structure, and each first radiating unit 110 also adopts the same design structure. It can be understood that the dual-polarized design enables each first radiating unit 110 to send two vertically polarized waves, for example, horizontal polarization and vertical polarization, which can increase channel capacity and anti-interference capability. For example, at the receiving end, the dual-polarized antenna can separate signals from different polarizations, thereby improving signal quality. The 2x2 array distribution form can provide array gain, and the multiple first radiators 111 work together to enhance the radiation intensity in a specific direction, thereby improving the overall gain of the micro base station antenna. By adjusting the phase and amplitude of each first radiating unit 110 in the array, specific beamforming can be achieved, so that the antenna has higher radiation intensity in a specific direction. The beam direction can be adjusted according to actual coverage requirements to optimize the signal coverage range.

[0054] In the embodiment, the first radiators 111 are circular metal radiation patches printed on a dielectric substrate, and the second radiators 211 are metal radiation patches printed on a dielectric substrate.

[0055] In the low-profile multi-frequency micro base station antenna provided in some embodiments of the present application, as shown in Figure 2 and Figure 3 The first power distribution plate 120 includes a first directional coupler 121 and two first power distributors 122 corresponding to the two first radiators 111. The first directional coupler 121 is provided with a first port, and the first power distributor 122 is provided with a second port. The first directional coupler 121 is used to couple the two first power distributors 122 through the first port, and the first power distributor 122 is used to excite the corresponding first radiator 111 through the second port.

[0056] The second power distribution plate 220 includes a second directional coupler 222 and two second power distributors 221 corresponding to the two second radiators 211. The second directional coupler 222 is provided with a third port, and the second power distributor 221 is provided with a fourth port. The second directional coupler 222 is used to couple the two second power distributors 221 through the third port, and the second power distributor 221 is used to excite the corresponding second radiator 211 through the fourth port.

[0057] In the embodiment, the first power distribution board 120 comprises a first directional coupler 121 and two first power distributors 122 corresponding to the two first radiators 111. It can be understood that the two first power distributors 122 corresponding to the two first radiators 111 are two power distributors with one-to-two equal-amplitude and in-phase outputs. The first directional coupler 121 is provided with a first port. By exciting the first port, the first directional coupler 121 can couple energy into the two first power distributors 122, so as to calibrate the micro base station antenna. Then, the two first radiators 111 are excited respectively through the second ports provided on the first power distributors 122, so as to realize the two polarization directions of ±45° of the micro base station antenna.

[0058] Similarly, the second power distribution board 220 comprises a second directional coupler 222 and two second power distributors 221 corresponding to the two second radiators 211. It can be understood that the two second power distributors 221 corresponding to the two second radiators 211 are two power distributors with one-to-two equal-amplitude and in-phase outputs. The second directional coupler 222 is provided with a third port. By exciting the third port, the second directional coupler 222 can couple energy into the two second power distributors 221, so as to calibrate the micro base station antenna. Then, the two second radiators 211 are excited respectively through the fourth ports provided on the second power distributors 221, so as to realize the two polarization directions of ±45° of the micro base station antenna.

[0059] In the low-profile multi-frequency micro base station antenna provided in some embodiments of the application, the first radiators 111 of the first radiation unit 110 are microstrip patch radiators.

[0060] It can be understood that the first radiators 111 of the first radiation unit 110 adopt a microstrip patch form, i.e., a microstrip planar structure, so as to reduce the overall profile height of the base station antenna and realize the low-profile characteristic of the micro base station antenna.

[0061] In an embodiment, the profile height of the micro base station antenna is 7.5 mm.

[0062] In the low-profile multi-frequency micro base station antenna provided in some embodiments of the application, the first groove 131 is a C-shaped groove, and the length of the first groove 131 is 1 / 4 of the wavelength of the working frequency of the second frequency band module 200.

[0063] Reference Figure 2In the embodiment, the parasitic element 130 is a circular metal sheet, the first groove 131 of the parasitic element 130 is a C-shaped groove, the first groove 131 contains a plurality of first grooves 131, and the parasitic element 130 can be placed about 6.7 mm above the first radiating element 110; through the parasitic element 130, the working bandwidth of the first frequency band module 100 can be expanded, and the directivity of antenna radiation can be provided, thereby improving the radiation gain of the antenna.

[0064] It should be noted that the length of the first groove 131 is about 1 / 4 of the wavelength of the working frequency of the second frequency band module 200, so that the influence of the scattering of high-frequency induced current on the radiation performance of the first radiating element 110 can be offset, thereby improving the isolation between high-frequency working frequency ports, and the isolation between the second radiating element 210 and the first radiating element 110 is less than 30 dB.

[0065] In the low-profile multi-frequency micro base station antenna provided in some embodiments of the application, the second radiating body 211 includes two pairs of dipole antenna arms 2111, the two pairs of dipole antenna arms 2111 are cross arranged, the dipole antenna arm 2111 includes two radiation arms 21111, and the second groove 21112 is arranged on the radiation arm 21111. The second groove 21112 is used to adjust the working bandwidth of the second frequency band module 200.

[0066] Reference Figure 3 In the embodiment, the second radiating body 211 is a radiation patch printed on a dielectric substrate, the second radiating body 211 includes two pairs of dipole antenna arms 2111, the two pairs of dipole antenna arms 2111 are cross arranged, in an embodiment, the two pairs of dipole antenna arms 2111 are cross arranged at ±45°, and each pair of dipole antenna arms 2111 includes two radiation arms 21111. It can be understood that the radiation patch forms an antenna structure by printing a conductive pattern on the dielectric substrate, the dipole antenna arm 2111 includes two symmetrical radiation arms 21111, the two radiation arms 21111 are connected at a center feeding point, the radiation arms 21111 are physically separated but electrically connected to each other, forming a pair of dipole antenna arms 2111, one end of each radiation arm 21111 is connected to the feeding point, and the other end is open, forming a radiation part of the micro base station antenna; the two pairs of dipole antenna arms 2111 are cross arranged, so that the micro base station antenna radiates electromagnetic waves in two orthogonal planes, that is, a polarization direction of ±45° is formed to realize a dual polarization characteristic, in addition, the cross arranged dipole antenna arms 2111 can improve the isolation between different polarization directions and reduce cross polarization interference.

[0067] It should be noted that the micro base station antenna can radiate energy because its size and shape are carefully designed so that the micro base station antenna resonates at a specific frequency, which is called a resonance point. In this embodiment, there are multiple resonance points within the operating frequency range of the second radiator 211, one of which is caused by the size of the antenna radiation arm 21111, so by adjusting the length of the radiation arm 21111, the resonance point can be moved to a lower frequency.

[0068] In addition, the radiation arm 21111 is provided with a second groove 21112, which is used to adjust the operating bandwidth of the second frequency band module 200. The second groove 21112, as a tuning element, can affect the electromagnetic properties of the radiation arm 21111, thereby adjusting the operating bandwidth of the antenna. Because the introduction of the second groove 21112 will generate additional capacitance or inductance on the radiation arm 21111, in this embodiment, the resonance points within the operating frequency range of the second radiator 211 also include resonance points caused by the size of the second groove 21112. By adjusting the position, width and length of the second groove 21112, the resonance point can be moved to a higher frequency. Therefore, by providing the second groove 21112, a simple and effective method of fine-tuning the operating frequency range of the antenna can be provided without changing the basic structure of the antenna or using additional components. In practical applications, the size of the groove can be optimized through simulation and experiment to ensure that the antenna has good performance throughout the operating frequency range, including sufficient gain, low VSWR (Voltage Standing Wave Ratio) and good matching.

[0069] In the low-profile multi-frequency micro base station antenna provided in some embodiments of the present application, a first protrusion 21113 is arranged between two adjacent radiation arms 21111, and the first protrusion 21113 is used to adjust the operating bandwidth of the second frequency band module 200.

[0070] In this embodiment, the first protrusion 21113 is arranged between two adjacent radiation arms 21111, and the gap width between the first protrusions 21113 is smaller than the spacing width between the adjacent radiation arms 21111, so as to improve the isolation of the vibrator and adjust the antenna lobe width. Referring to Figure 3 , the first protrusion 21113 is a tapered gap, and the spacing between the adjacent radiation arms 21111 becomes narrower from the center of the second radiator 211 as the reference point

[0071] It can be understood that the first protrusion 21113 is used to adjust the working bandwidth of the second frequency band module 200, and the first protrusion 21113, as a tuning element, can affect the electromagnetic characteristics of the radiation arm 21111, so as to adjust the working bandwidth of the antenna, because the introduction of the first protrusion 21113 will generate additional capacitance or inductance on the radiation arm 21111, therefore, in the embodiment, the resonance points within the working frequency band of the second radiator 211 also include resonance points caused by the size of the first protrusion 21113, by adjusting the position, width and length of the first protrusion 21113, the resonance points can be moved to high frequency; therefore, through the setting of the first protrusion 21113, a simple and effective method of fine-tuning the working frequency band of the antenna can be provided without changing the basic structure of the antenna or using additional components. In actual application, the size of the first protrusion 21113 can be optimized through simulation and experiment to ensure that the antenna has good performance in the entire working frequency band, including sufficient gain, low VSWR (voltage standing wave ratio) and good matching.

[0072] In the low-profile multi-frequency micro base station antenna provided by some embodiments of the present application, the second frequency band module 200 further comprises a support plate 140 corresponding to each second radiator 211, the support plate 140 is arranged between the second radiator 211 and the second power distribution plate 220, the support plate 140 comprises a first support plate 141 and a second support plate 142, the first support plate 141 and the second support plate 142 are clamped, one side of the first support plate 141 and the second support plate 142 is provided with a feed balun structure 143, the other side of the first support plate 141 and the second support plate 142 is provided with a metal connecting line 144, the feed balun structure 143 is connected to the second power distribution plate 220, and both ends of the metal connecting line 144 are connected to the second radiator 211 and the reflector plate 300 respectively.

[0073] Reference Figure 4 , Figure 5 and Figure 6 Wherein, Figure 4 is a structure diagram of the second frequency band module 200 of the low-profile multi-frequency micro base station antenna provided by another embodiment of the present application; Figure 5a is a front view of the first support plate 141 of the low-profile multi-frequency micro base station antenna provided by another embodiment of the present application; Figure 5b is a front view of the second support plate 142 of the low-profile multi-frequency micro base station antenna provided by another embodiment of the present application; Figure 5c is a back view of the support plate 140 of the low-profile multi-frequency micro base station antenna provided by another embodiment of the present application; Figure 6Figure 7 is a structural diagram of a support plate 140 of a low-profile multi-frequency micro base station antenna provided by another embodiment of the present application; in this embodiment, the second frequency band module 200 further includes a support plate 140 corresponding to each second radiator 211, the support plate 140 is arranged between the second radiator 211 and the second power distribution plate 220, the support plate 140 includes a first support plate 141 and a second support plate 142, and it can be understood that the first support plate 141 and the second support plate 142 are used as support between the second radiator 211 and the second power distribution plate 220 to stabilize the positional relationship between the second radiator 211 and the second power distribution plate 220, and to ensure that the second radiator 211 can normally radiate, as shown in Figure 8. Figure 6 As shown in Figure 7, the first support plate 141 is provided with a first clamping groove, and the second support plate 142 is provided with a second clamping groove, and the first support plate 141 and the second support plate 142 are firmly clamped through the first clamping groove and the second clamping groove.

[0074] One side of the first support plate 141 and the second support plate 142 is provided with a feed balun structure 143, and the other side of the first support plate 141 and the second support plate 142 is provided with a metal connecting line 144, the feed balun structure 143 and the metal connecting line 144 form a balun structure on the first support plate 141 and the second support plate 142, the feed balun structure 143 is in feed connection with a feed network on the second power distribution plate 220, the top of the metal connecting line 144 is connected with the second radiator 211 through a rectangular hole on the dielectric substrate, and in addition, the bottom of the metal connecting line 144 is connected with the reflector plate 300 through a metal via, so that a complete radiation path is formed between the second radiator 211, the support plate 140 and the second power distribution plate 220 in the second frequency band module 200, and the reflector plate 300.

[0075] In the low-profile multi-frequency micro base station antenna provided by some embodiments of the present application, the feed balun structure 143 includes a plurality of rectangular microstrip lines with different widths.

[0076] One side of the first support plate 141 and the second support plate 142 is provided with a feed balun structure 143, and the feed balun structure 143 on the first support plate 141 and the second support plate 142 can be the same or different.

[0077] It is particularly pointed out that the feed bar structure 143 includes a plurality of rectangular microstrip lines with different widths, that is, the feed bar structure 143 can be a longer microstrip line, and includes a plurality of segments of rectangular microstrip lines with different widths, which are connected to form the feed bar structure 143. Different lengths and widths of each segment of the rectangular microstrip line affect impedance matching of the circuit of the second radiation module. Therefore, by reasonably setting the width of each segment of the microstrip line, impedance matching of the circuit can be achieved, thereby effectively improving the standing wave ratio of the second radiation module and reducing the profile height, so that the profile height is only 1 / 8 of the wavelength at the frequency of 3.8 GHz.

[0078] In the low-profile multi-frequency micro base station antenna provided in some embodiments of the present application, the open stub structure 2211 is an S-shaped open stub, and the length of the open stub structure 2211 is 1 / 4 of the wavelength of the working frequency of the first frequency band module 100.

[0079] It is particularly pointed out that the second power divider 221 is provided with an open stub structure 2211 for filtering to improve the isolation of the micro base station antenna. In an embodiment, the open stub structure 2211 can be provided on two second power dividers 221, that is, the open stub structure 2211 is loaded on the main stub of the two power dividers with one-to-two equal-amplitude and in-phase output. The open stub structure 2211 is an S-shaped open stub, and the length of the open stub structure 2211 is about 1 / 4 of the wavelength of the working frequency of the first frequency band module 100. In this way, low-frequency signals in the second frequency band module 200 can be effectively filtered out, thereby effectively reducing the influence of the second frequency band module 200 on the performance of the first frequency band module 100, and further improving the isolation of the antenna system.

[0080] In an embodiment, the first frequency band module 100 is a low-frequency module, and the second frequency band module 200 is a high-frequency module. Referring to Figure 7 and Figure 8 , Figure 7 is a test result graph of an isolation experiment of a low-profile multi-frequency micro base station antenna provided in another embodiment of the present application, Figure 8 is a test result graph of a standing wave ratio experiment of a low-profile multi-frequency micro base station antenna provided in another embodiment of the present application. The bandwidth of the low-frequency radiation element antenna of the first frequency band module 100 is within 1.71-1.88 GHz, and the standing wave ratio is substantially less than 1.5. The isolation between the low-frequency radiation elements within the frequency band is less than 27.5 dB. The bandwidth of the high-frequency radiation element antenna of the second frequency band module 200 is within 3.3-3.8 GHz, and the standing wave ratio is less than 1.4. The isolation between the high-frequency radiation elements within the frequency band is substantially less than 25 dB.

[0081] The embodiments of the present application are described in detail above with reference to the drawings, but the present application is not limited to the above-described embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the spirit of the present application.

Claims

1. A low profile multi-band microcell antenna, characterized by, The utility model relates to a micro base station antenna, comprising: a first frequency band module (100) comprising a plurality of first radiating elements (110), a first power distribution plate (120) for exciting the first radiating elements (110), and a parasitic element (130) provided with a first groove (131) for filtering to improve the isolation of the micro base station antenna; a second frequency band module (200) comprising a plurality of second radiating elements (210) and a second power distribution plate (220) for exciting the second radiating elements (210), the second power distribution plate (220) comprising a second power distributor (221) corresponding to the second radiating elements (210), the second power distributor (221) being provided with an open stub structure (2211) for filtering to improve the isolation of the micro base station antenna, the first frequency band module (100) and the second frequency band module (200) having different operating frequency bands; a reflector plate (300) and a cover plate (400) for accommodating the first frequency band module (100) and the second frequency band module (200), the reflector plate (300) being used for reflecting antenna radiation.

2. A low profile multi-band microcell antenna according to claim 1, characterised in that, The first frequency band module (100) comprises two identical first radiating elements (110), each of the first radiating elements (110) comprising two first radiators (111), and the second frequency band module (200) comprises two identical second radiating elements (210), each of the second radiating elements (210) comprising two second radiators (211).

3. A low profile multi-band microcell antenna according to claim 2, characterised in that, The first power distribution plate (120) comprises a first directional coupler (121) and two first power distributors (122) corresponding to the two first radiators (111), the first directional coupler (121) being provided with a first port, the first power distributors (122) being provided with a second port, the first directional coupler (121) being used for coupling the two first power distributors (122) through the first port, and the first power distributors (122) being used for exciting the corresponding first radiators (111) through the second port. The second power distribution plate (220) comprises a second directional coupler (222) and two second power distributors (221) corresponding to the two second radiators (211), the second directional coupler (222) being provided with a third port, and the second power distributors (221) being provided with a fourth port, the second directional coupler (222) being used for coupling the two second power distributors (221) through the third port, and the second power distributors (221) being used for exciting the corresponding second radiators (211) through the fourth port.

4. The low profile multi-band microcell antenna of claim 2, wherein, The first radiators (111) are microstrip patch radiators.

5. The low profile multi-band microcell antenna of claim 1, wherein, The first groove (131) is a C-shaped groove, and the length of the first groove (131) is 1 / 4 of the wavelength of the working frequency of the second frequency band module (200).

6. The low profile multi-band microcell antenna of claim 2, wherein, The second radiator (211) comprises two pairs of dipole antenna arms (2111), and the two pairs of dipole antenna arms (2111) are arranged in a cross manner; each dipole antenna arm (2111) comprises two radiation arms (21111), and a second groove (21112) is arranged on each radiation arm (21111); and the second groove (21112) is used for adjusting the working bandwidth of the second frequency band module (200).

7. A low profile multi-band microcell antenna according to claim 6, characterised in that, A first protrusion (21113) is arranged between the two adjacent radiation arms (21111), and the first protrusion (21113) is used for adjusting the working bandwidth of the second frequency band module (200).

8. A low profile multi-band microcell antenna according to claim 3, characterised in that, The second frequency band module (200) further comprises a support plate (140) corresponding to each second radiator (211), and the support plate (140) is arranged between the second radiator (211) and the second power distribution plate (220); the support plate (140) comprises a first support plate (141) and a second support plate (142), and the first support plate (141) and the second support plate (142) are clamped together; one side of the first support plate (141) and the second support plate (142) is provided with a feed balun structure (143), and the other side of the first support plate (141) and the second support plate (142) is provided with a metal connecting line (144); the feed balun structure (143) is connected to the second power distribution plate (220), and the two ends of the metal connecting line (144) are respectively connected to the second radiator (211) and the reflector plate (300).

9. A low profile multi-band microcell antenna according to claim 8, characterised in that, The feed balun structure (143) comprises a plurality of rectangular microstrip lines with different widths.

10. The low profile multi-band microcell antenna of Claim 1, wherein, The open stub structure (2211) is an S-shaped open stub, and the length of the open stub structure (2211) is 1 / 4 of the wavelength of the working frequency of the first frequency band module (100).

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