Base Station Antenna and Base Station

Abstract

The present application discloses a base station antenna and a base station, belonging to the field of communication technologies. The base station antenna includes a reflector, an antenna array disposed on the reflector. The operating frequency bands of the antenna array include a first frequency band and a second frequency band, wherein the first frequency band is higher than the second frequency band; a first decoupling surface disposed above the antenna array for decoupling and eliminating the coupled wave of the first frequency band by reflecting a part of the electromagnetic waves of the first frequency band transmitted by the antenna array; a second decoupling surface disposed above the first decoupling surface for decoupling and eliminating the coupled wave of the second frequency band by reflecting a part of the electromagnetic waves of the second frequency band transmitted by the antenna array.

Description

Technical Field

[0001] This application belongs to the field of communication technologies, and particularly relates to a base station antenna and a base station. Background Art

[0002] With the rapid development of mobile communication systems, the fifth-generation mobile communication technology (5G) has been fully commercialized. However, there is still a large demand for communication in the 3G / 4G frequency bands, which determines that the communication system will face the coexistence of multiple communication systems such as 3G / 4G and 5G for a long time. As an important part of the mobile communication system, the design of base station antennas will cover more frequency bands, and the array applications will also tend to be multi-band. In practical applications, due to the limited deployment space, in order to achieve the miniaturization design of the array, the antennas will be closely arranged with an element spacing less than half a wavelength. The too-close spacing will cause coupling problems between elements. In a multi-band array, the coupling between elements exists in each frequency band, seriously affecting the radiation performance of the array, resulting in problems such as poor impedance matching, pattern distortion, and reduced radiation efficiency. Currently, the proposed decoupling technologies include decoupling surfaces for array antennas, metasurface decoupling methods, self-decoupling arrays, electromagnetic transparent antennas, and isolation walls, etc. However, the above decoupling technologies mainly focus on single-band operation and cannot achieve independent decoupling in multiple frequency bands. Summary of the Invention

[0003] The embodiments of this application provide a base station antenna and a base station, which can solve the problem of how to achieve independent decoupling in multiple frequency bands.

[0004] In a first aspect, the embodiments of this application provide a base station antenna, including: a reflector, an antenna array disposed on the reflector, the operating frequency bands of the antenna array including a first frequency band and a second frequency band, wherein the first frequency band is higher than the second frequency band; a first decoupling surface disposed above the antenna array for decoupling and eliminating the coupling wave of the first frequency band by reflecting a part of the electromagnetic waves of the first frequency band transmitted by the antenna array; a second decoupling surface disposed above the first decoupling surface for decoupling and eliminating the coupling wave of the second frequency band by reflecting a part of the electromagnetic waves of the second frequency band transmitted by the antenna array.

[0005] In a second aspect, the embodiments of this application provide a base station, including the base station antenna described in the first aspect.

[0006] In an embodiment of the present application, after a first decoupling surface is disposed above an antenna array disposed on a reflector, the first decoupling surface can decouple and eliminate the coupled waves in the first frequency band by reflecting part of the electromagnetic waves in the first frequency band transmitted by the antenna array. At the same time, a second decoupling surface is disposed above the first decoupling surface, and the second decoupling surface can decouple and eliminate the coupled waves in the second frequency band by reflecting part of the electromagnetic waves in the second frequency band transmitted by the antenna array. Wherein, the first decoupling surface and the second decoupling surface are respectively connected to the reflector, and the first frequency band is higher than the second frequency band, realizing the regulation of space waves through two layers of decoupling surfaces, so that the base station antenna can decouple simultaneously in two frequency bands, or decouple independently, with simple operation, no mutual interference and high repeatability. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a schematic structural diagram of a base station antenna provided by an embodiment of the present application;

[0008] Figure 1a is a schematic working diagram of a base station antenna provided by an embodiment of the present application;

[0009] Figure 2 is a schematic structural diagram of a first decoupling surface provided by an embodiment of the present application;

[0010] Figure 2a is a schematic diagram of a metal pattern of a first decoupling unit provided by an embodiment of the present application;

[0011] Figure 2b is another schematic diagram of a metal pattern of a first decoupling unit provided by an embodiment of the present application;

[0012] Figure 2c is yet another schematic diagram of a metal pattern of a first decoupling unit provided by an embodiment of the present application;

[0013] Figure 2d is a schematic structural diagram of a first decoupling unit provided by an embodiment of the present application;

[0014] Figure 2e is another schematic structural diagram of a first decoupling surface provided by an embodiment of the present application;

[0015] Figure 2f is a schematic diagram of an affine result of a first decoupling surface provided by an embodiment of the present application;

[0016] Figure 3 is a schematic structural diagram of a second decoupling surface provided by an embodiment of the present application;

[0017] Figure 3a is a schematic structural diagram of a second decoupling unit provided by an embodiment of the present application;

[0018] Figure 3b It is another schematic structural diagram of the second decoupling surface provided by an embodiment of the present application;

[0019] Figure 3c It is a schematic diagram of the metal pattern of the second decoupling unit provided by an embodiment of the present application;

[0020] Figure 3d It is a schematic diagram of the affine result of the second decoupling surface provided by an embodiment of the present application;

[0021] Figure 4 It is another schematic structural diagram of the base station antenna provided by an embodiment of the present application;

[0022] Figure 4a It is another schematic working diagram of the base station antenna provided by an embodiment of the present application;

[0023] Figure 5 It is the front view of the original array provided by an embodiment of the present application.

[0024] Figure 6 It is the top view of the original array provided by an embodiment of the present application;

[0025] Figure 7 It is the schematic diagram of port numbering provided by an embodiment of the present application;

[0026] Figure 8 It is the schematic diagram of the array loaded with the first decoupling surface provided by an embodiment of the present application;

[0027] Figure 9 It is the comparison diagram of the co-polarization coupling between the low-frequency ports before and after loading the first decoupling surface provided by an embodiment of the present application;

[0028] Figure 10 It is the comparison diagram of the cross-polarization coupling between the low-frequency ports before and after loading the first decoupling surface provided by an embodiment of the present application;

[0029] Figure 11 It is the comparison diagram of the co-polarization coupling between the high-frequency ports before and after loading the first decoupling surface provided by an embodiment of the present application;

[0030] Figure 12 It is the comparison diagram of the co-polarization and cross-polarization coupling between the high-frequency ports before and after loading the first decoupling surface provided by an embodiment of the present application;

[0031] Figure 13 It is the schematic diagram of the array loaded with the composite decoupling surface provided by an embodiment of the present application;

[0032] Figure 14 It is the comparison diagram of the co-polarization coupling between the low-frequency ports before and after loading the composite decoupling surface provided by an embodiment of the present application;

[0033] Figure 15 is a comparison diagram of cross-polarization coupling between low-frequency ports before and after loading a composite decoupling surface provided by an embodiment of the present application;

[0034] Figure 16 is a comparison diagram of co-polarization coupling between high-frequency ports before and after loading a composite decoupling surface provided by an embodiment of the present application;

[0035] Figure 17 is a comparison diagram of co- and cross-polarization coupling between high-frequency ports before and after loading a composite decoupling surface provided by an embodiment of the present application;

[0036] Figure 18 is a comparison diagram of low-frequency radiation patterns before and after loading a composite decoupling surface provided by an embodiment of the present application;

[0037] Figure 19 is a comparison diagram of high-frequency radiation patterns before and after loading a composite decoupling surface provided by an embodiment of the present application. Detailed implementation manners

[0038] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without making creative efforts fall within the protection scope of the present application.

[0039] The terms "first", "second", etc. in the description and claims of the present application are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present application can be implemented in an order different from those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of the same category, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the description and claims means at least one of the connected objects, and the character " / " generally indicates an "or" relationship between the associated objects before and after.

[0040] To better understand the technical solutions provided by the present application, the technologies involved in the present application will be introduced first.

[0041] 1. Array antenna decoupling surface

[0042] The Array-Antenna Decoupling Surface (ADS) technology is to load a substrate printed with multiple small electrical-size metal patches above the array. By reflecting electromagnetic waves, a second signal transmission path is introduced, and the diffracted wave generated is equal in amplitude and opposite in phase to the original coupled wave, so that cancellation can be achieved and the decoupling effect can be obtained. In a two-dimensional 2×2 dual-polarized antenna array, decoupling of multiple paths can be achieved in the frequency band of 3.3 - 3.8 GHz.

[0043] The decoupling surface can achieve good decoupling effect with a simple structure, is applicable to various coupling types, and can be independent of antenna design. It can be applied in large arrays, but it only has a good decoupling effect for a single operating frequency band. When facing the multi-frequency situation, especially when the operating frequency band has a large span (such as 2 times frequency), it will face great limitations. Specifically, it is difficult for a single layer surface to cover all operating frequency bands. When multiple decoupling surfaces operating in different frequency bands are stacked, there will be a great influence between multiple layers, which is not conducive to independently regulating each frequency band.

[0044] 2. Metasurface Decoupling Method

[0045] The decoupling device of the Metasurface-based Decoupling Method (MDM) consists of a dielectric substrate and several metal patches placed above the antenna. Metal patches with different lengths constitute the dual-frequency characteristics. By regulating the surface coupling current between antennas through this device, decoupling in two frequency bands of 2.5 GHz and 3.5 GHz in a Multiple-Input Multiple-Output (MIMO) system can be achieved, and the Envelope Correlation Coefficient (ECC) between antennas can be significantly reduced.

[0046] The MDM method can achieve dual-frequency decoupling and has a simple structure. However, this method only involves microstrip antennas and does not introduce more types of antenna forms in practical applications. Moreover, this method only targets single-polarized arrays, and this technology faces certain limitations in dual-polarized or multi-polarized arrays.

[0047] 3. Self-Decoupling Dual-Frequency Base Station Antenna Array

[0048] A self-decoupling dual-band base station antenna array refers to a dual-band common-aperture antenna system. By loading a decoupling structure into multiple radiators of a low-frequency antenna, the radiator layer of the low-frequency antenna is designed as a partially reflective surface (PRS) of high-frequency electromagnetic waves. By adjusting the reflection and wave-transmission characteristics of the low-frequency antenna located above the array, part of the high-frequency electromagnetic waves can be reflected, thereby achieving the cancellation and decoupling of coupled waves.

[0049] The self-decoupling dual-band base station antenna array can integrate the decoupling structure with the antenna without an additional decoupling structure, which can simplify the array structure. However, this method only achieves the co-frequency decoupling of the high-frequency antenna and does not involve the co-frequency coupling problem of the low-frequency antenna in a larger array. Moreover, the low-frequency antenna has both radiation and high-frequency wave-transmission performance, which will limit the degree of freedom of antenna design to a certain extent.

[0050] In view of this, the present application proposes a base station antenna and a base station. Hereinafter, taking multi-column antenna units as horizontal column antenna units and vertical column antenna units as examples, the base station antenna and the base station provided by the embodiments of the present application will be described.

[0051] Figure 1 It is a schematic structural diagram of a base station antenna provided by an embodiment of the present application. As Figure 1 shown, the base station antenna includes: a reflector 110, an antenna array 120 disposed on the reflector, a first decoupling surface 130, and a second decoupling surface 140. Among them, the operating frequency band of the antenna array 120 includes a first frequency band and a second frequency band, where the first frequency band is higher than the second frequency band; the first decoupling surface 130 is connected to the reflector 110 through a non-metallic support structure such as a dielectric column, and is disposed above the antenna array 120 for decoupling and eliminating the coupled waves of the first frequency band by reflecting part of the electromagnetic waves of the first frequency band transmitted by the antenna array 120; the second decoupling surface 140 is connected to the reflector 110 through a non-metallic support structure such as a dielectric column, and is disposed above the first decoupling surface 130 for decoupling and eliminating the coupled waves of the second frequency band by reflecting part of the electromagnetic waves of the second frequency band transmitted by the antenna array 120.

[0052] Among them, the antenna array 120 can be formed by interspersing and arranging high-frequency oscillator units, dual-frequency oscillator units, and low-frequency oscillator units in the aperture plane, and its array form includes but is not limited to the following three types:

[0053] (1) A high-frequency antenna array composed only of high-frequency oscillator units and a low-frequency antenna array composed only of low-frequency oscillator units.

[0054] (2)A high-frequency antenna array composed of high-frequency oscillator units and dual-frequency oscillator units, and a low-frequency antenna array composed of low-frequency oscillator units and dual-frequency oscillator units.

[0055] (3)A high-frequency antenna array composed of high-frequency oscillator units and dual-frequency oscillator units, and a low-frequency antenna array composed only of dual-frequency oscillator units.

[0056] Among them, the working frequency band corresponding to the high-frequency antenna array in the above (1) to (3) is the first frequency band, and the working frequency band corresponding to the low-frequency antenna array 120 is the second frequency band. In the embodiments of this patent application, the array form in the above (3) is taken as an example for description, and the decoupling method of this array form can be applied to the other two forms mentioned above. For example Figure 1aAs shown, it is a schematic diagram of the decoupling operation of the first decoupling surface 130 and the second decoupling surface 140. A low-frequency antenna composed of a number of dual-frequency oscillator units and a high-frequency antenna composed of high-frequency oscillator units are alternately placed on the same reflector 110 to form an antenna array 120. Above the antenna array 120, the first decoupling surface 130 and the second decoupling surface 140 are placed in parallel. The two layers of decoupling surfaces can be connected to the reflector 110 through non-metal support structures such as dielectric columns. When the antenna array 120 operates in the first frequency band, the first decoupling surface 130 reflects part of the electromagnetic waves of the first frequency band transmitted by the antenna array 120 to decouple and eliminate the coupling waves of the first frequency band. Among them, the electromagnetic wave can be a high-frequency reflected wave. That is to say, when the antenna array 120 operates in the first frequency band, that is, the high-frequency band, the first decoupling surface 130 introduces part of the high-frequency reflected waves. When the high-frequency reflected wave and the high-frequency coupling wave have equal amplitudes and opposite phases, high-frequency electromagnetic wave cancellation decoupling can be achieved. At the same time, most of the other electromagnetic waves of the first frequency band except the electromagnetic waves used for decoupling, that is, the high-frequency transmitted waves, penetrate the first decoupling surface 130 and the second decoupling surface 140 and radiate into free space. When the antenna array 120 operates in the second frequency band, the second decoupling surface 140 reflects part of the electromagnetic waves of the second frequency band transmitted by the antenna array 120 to decouple and eliminate the coupling waves of the second frequency band. Among them, the electromagnetic wave can be a low-frequency reflected wave. That is to say, when the antenna array 120 operates in the second frequency band, that is, the low-frequency band, when the low-frequency reflected wave and the low-frequency coupling wave have equal amplitudes and opposite phases, low-frequency electromagnetic wave cancellation decoupling can be achieved. At the same time, most of the other electromagnetic waves of the second frequency band except the electromagnetic waves used for decoupling, that is, the low-frequency transmitted waves, penetrate the first decoupling surface 130 and the second decoupling surface 140 and radiate into free space. It can be understood that the first decoupling surface 130 and the second decoupling surface 140 have a wave-transmitting characteristic in the non-working frequency band, that is, independent regulation of the two frequency bands can be realized. In addition, since only part of the electromagnetic waves are introduced and most of the electromagnetic waves can still penetrate the decoupling surface and radiate into free space, the radiation pattern of the antenna array 120 after decoupling is less deformed than before decoupling. In one implementation, the decoupling method corresponding to this base station antenna can also be applied to a dual-polarized dual-frequency array base station antenna, and the dual-frequency decoupling operation is decomposed into independent decoupling operations for the high-frequency and low-frequency bands respectively. It can be understood that the antenna array 120 can also provide a dual-polarized dual-frequency base station antenna array with a loaded decoupling device. The dual-polarized dual-frequency base station antenna array includes a reflector, radiation units installed on the reflector, and the decoupling device. The radiation units include a number of co-radiators operating as low-frequency radiation units and a number of co-radiators operating as high-frequency radiation units. Among them, the decoupling device includes a first decoupling surface and a second decoupling surface.Further, the dual-polarization dual-band base station antenna array includes a first sub-array and a second sub-array. The first sub-array includes a plurality of dual-band radiation units and high-frequency radiation units alternately arranged in a row along the horizontal direction of the reflector. The second sub-array includes a plurality of high-frequency radiation units arranged in a row along the horizontal direction of the reflector. A plurality of first sub-arrays and second sub-arrays are alternately arranged in multiple rows along the vertical direction of the reflector, and adjacent sub-arrays are parallel to each other.

[0057] In the embodiment of the present application, after a first decoupling surface is arranged above the antenna array arranged on the reflector, the first decoupling surface can decouple and eliminate the coupled wave of the first frequency band by reflecting part of the electromagnetic waves of the first frequency band transmitted by the antenna array. At the same time, a second decoupling surface is arranged above the first decoupling surface. The second decoupling surface can decouple and eliminate the coupled wave of the second frequency band by reflecting part of the electromagnetic waves of the second frequency band transmitted by the antenna array. Wherein, the first decoupling surface and the second decoupling surface are respectively connected to the reflector, and the first frequency band is higher than the second frequency band. By regulating electromagnetic waves through two layers of decoupling surfaces, the base station antenna can decouple simultaneously or independently at two frequency bands, with simple operation, no interference with each other and high scalability.

[0058] It should be noted that, in addition to the first decoupling surface and the second decoupling surface included in the base station antenna, multiple other decoupling surfaces can also be integrated to eliminate the coupled waves of different frequency bands. The embodiment of the present application only takes two decoupling surfaces as an example for illustration. That is to say, no matter how many decoupling surfaces the base station antenna includes, the decoupling method in the embodiment of the present application is also applicable.

[0059] Figure 2 A structural schematic diagram of the first decoupling surface provided by the embodiment of the present application is shown in Figure 2As shown, the first decoupling surface may include: a first dielectric board 210 and a plurality of first decoupling units 220 disposed on the upper surface of the first dielectric board 210. Among them, the vertical projection of any one of the first decoupling units 220 on the reflector overlaps with a first radiation unit operating in the first frequency band, and the first decoupling units 220 correspond to the first radiation units one by one. It can be understood that the vertical projection of any one of the first decoupling units 220 on the reflector overlapping with the first radiation unit operating in the first frequency band means that when the first decoupling unit 220 is connected to the reflector through a non-metal support structure such as a dielectric column and projected in the upward direction above the reflector, the image formed by the projection overlaps with the first radiation unit. That is to say, the first radiation unit is disposed on the reflector, and the vertical projection of the first decoupling unit 220 has the same central position as the first radiation unit, but different sizes and shapes. In addition, the first dielectric board 210 may be made of FR4 material with a dielectric constant of 4.4, the thickness of the first dielectric board 210 may be 1 mm, and the size may be the same as Figure 1 the reflector 110 in

[0060] Among them, in another implementation manner, as Figure 2a shown, the first decoupling unit 220 includes a metal pattern composed of a plurality of metal strips 221. The length of any one of the metal strips is less than k1 times the wavelength of the first frequency band, and k1 is a rational number greater than 0 and less than 1. It can be understood that the metal pattern of each first decoupling unit 220 may be a combined shape of a plurality of metal strips 221, and the length of a single metal strip 221 needs to be less than k1 times the wavelength of the high frequency band, that is, the wavelength of the first frequency band, to avoid resonance in the operating frequency band. Among them, k1 may be 0.25.

[0061] Among them, in yet another implementation manner, the metal pattern composed of a plurality of the metal strips is a symmetric pattern. It can be understood that it is possible to avoid distortion of the radiation pattern of the antenna unit below due to an asymmetric decoupling unit. Exemplarily, as Figure 2b 、 2c and shown in 2d, it is a symmetric pattern composed of a plurality of the metal strips. It should be noted that the number and position of the metal strips can be used to adjust the intensity of the decoupled reflected wave. Exemplarily, as Figure 2e shown, it is a schematic structural diagram of the first decoupling surface in space, including a first dielectric board and a first decoupling unit disposed on the upper surface of the first dielectric board. The first decoupling surface includes an FR4 dielectric substrate with a thickness of 1 mm and several strip-shaped metal patches etched above. The strip-shaped metal patches are mainly composed of rectangular metal patches and L-shaped metal patches. The rectangular metal patches are arranged in a cross shape and an X shape, and the L-shaped metal patches are arranged in a square shape.

[0062] In the above embodiments, the first decoupling surface can decouple and eliminate the coupling wave of the first frequency band by reflecting part of the electromagnetic waves of the first frequency band transmitted by the antenna array.

[0063] In one implementation, the value range of the transmission coefficient of the first decoupling surface for the electromagnetic waves of the second frequency band is [0.5, 1]. It can be understood that since the first decoupling surface needs to produce a decoupling effect on the high-frequency array antenna without having any impact on the low-frequency antenna array, that is, it needs to be able to completely transmit the low-frequency electromagnetic waves. Therefore, when designing the first decoupling surface, the value range of the transmission coefficient for the low-frequency band can be designed as [0.5, 1]. The transmission coefficient refers to the attenuation degree of the decoupling surface for the electromagnetic waves. Generally, the transmission coefficient is around -1.5 dB, and the reflection coefficient is around -7 dB. If the coupling wave is relatively large, the reflection coefficient will be greater than -7 dB. As Figure 2f shown, in the embodiments of the present application, within the low-frequency band of 2.49 - 2.69 GHz, the transmission coefficient is close to 0 dB, achieving the wave-transmitting characteristic. That is to say, in the low-frequency band, the first decoupling surface has very low or no loss for the electromagnetic waves. That is, the value range of the ideal transmission coefficient is [0.5, 1]. Within the high-frequency band of 4.8 - 4.9 GHz, the transmission coefficient is -1.4 to -1.3 dB, and the reflection coefficient is -7.3 to -7.0 dB, achieving the partial reflection characteristic.

[0064] In one implementation, the distance between the first decoupling surface and the radiation surface of the antenna array is k2 times the wavelength of the first frequency band, where k2 is a rational number greater than 0.1 and less than 0.5. It can be understood that this radiation surface refers to the plane where the high-frequency oscillator unit and the dual-frequency oscillator unit are located. The first decoupling unit of the first decoupling surface can be arranged above each high-frequency oscillator unit and dual-frequency oscillator unit, and the distance to this radiation surface can be k2 times the wavelength of the first frequency band to control the phase of the decoupling reflected wave and the direct coupling wave to be opposite, achieving cancellation, where the value range of k2 can be (0.1, 0.5).

[0065] Figure 3 FIG. is a schematic structural diagram of the second decoupling surface provided by the embodiments of the present application, such as Figure 3As shown, the second decoupling surface includes: a second dielectric board 310 and a plurality of second decoupling units 320 disposed on the second dielectric board 310. Among them, the vertical projection of any one of the second decoupling units 320 on the reflector overlaps with the second radiation unit operating in the second frequency band, and the second decoupling units 320 correspond to the second radiation units one by one. It can be understood that the vertical projection of any one of the second decoupling units 320 on the reflector overlapping with the second radiation unit operating in the second frequency band means that when the second decoupling unit 320 is connected to the reflector through a non-metallic support structure such as a dielectric column and projected in the upward direction of the reflector, the image formed by the projection overlaps with the second radiation unit. That is to say, the second radiation unit is disposed on the reflector, and the vertical projection of the second decoupling unit 320 has the same central position as the second radiation unit, but different sizes and shapes. In addition, the second dielectric board 310 can be made of FR4 material with a dielectric constant of 4.4, the thickness of the second dielectric board 310 can be 1 mm, and the size can be the same as Figure 1 the reflector 110 in

[0066] Among them, in another implementation, as Figure 3a shown, the second decoupling unit includes: a metal layer 321 disposed on the upper surface of the second dielectric board 310, with a slit of a predetermined shape etched on the metal layer; a metal patch 322 of the predetermined shape disposed on the lower surface of the second dielectric board. Exemplarily, as Figure 3b shown, it is a schematic structural diagram of a second decoupling surface in space. Specifically, the second decoupling surface includes an FR4 dielectric substrate with a thickness of 1 mm, the pattern above the substrate is a square ring-shaped slit, and the pattern below is a ring-shaped metal patch. It can be understood that the second decoupling unit is composed of decoupling metal pattern units etched on both sides of the dielectric substrate. The metal pattern is composed of a slit etched on one layer of metal and a metal patch on one layer. Among them, the slit can be square ring-shaped, circular ring-shaped, cross-shaped, etc., and the metal patch can be square, circular, cross-shaped, etc. Exemplarily, as Figure 3c shown, it is an alternative pattern of the second decoupling unit.

[0067] In yet another implementation, the length of the second decoupling unit is less than k3 times the wavelength of the second frequency band, where k3 is a rational number greater than 0 and less than 1. It can be understood that the length of each second decoupling unit needs to be less than k3 times the wavelength of the low-frequency band, that is, the wavelength of the second frequency band, to avoid resonance in the operating frequency band. Among them, k3 can be 0.3.

[0068] In yet another implementation, the transmission coefficient of the second decoupling surface for electromagnetic waves in the first frequency band ranges from [0.5, 1]. It can be understood that since the second decoupling surface needs to produce a decoupling effect on the low-frequency array antenna and has no impact on the high-frequency antenna array, that is, it needs to be able to completely transmit low-frequency electromagnetic waves. Therefore, when designing the second decoupling surface, the transmission coefficient for the high-frequency band needs to be equal to 1; while low-frequency electromagnetic waves need to be partially reflected to cancel the coupled wave signal. Exemplarily, as Figure 3d shown, it can be learned from the simulation results that within the low-frequency band of 2.49 - 2.69 GHz, the transmission coefficient is -1 to -2 dB, and the reflection coefficient is -7.7 to -4.2 dB, achieving the partial reflection characteristic. Within the high-frequency band of 4.8 - 4.9 GHz, the transmission coefficient is close to 0 dB, achieving the wave-transmitting characteristic. That is to say, in the high-frequency band, the second decoupling surface has very low or no loss of electromagnetic waves, that is, the value range of the ideal transmission coefficient is [0.5, 1].

[0069] In yet another implementation, the distance between the second decoupling surface and the radiation surface of the antenna array is k4 times the wavelength of the second frequency band, where k4 is a rational number greater than 0.1 and less than 0.5. It can be understood that this radiation surface refers to the plane where the high-frequency oscillator units and the dual-frequency oscillator units are located. The second decoupling units of the second decoupling surface can be arranged above each high-frequency oscillator unit and dual-frequency oscillator unit, and the distance to this radiation surface can be k4 times the wavelength of the second frequency band to control the phase of the decoupled reflected wave and the direct coupled wave to be opposite, so as to achieve cancellation, where the value range of k4 can be (0.1, 0.5).

[0070] In the above embodiment, the second decoupling surface can decouple and eliminate the coupled wave in the second frequency band by reflecting part of the electromagnetic waves in the second frequency band sent by the antenna array.

[0071] Figure 4 Another structural schematic diagram of the base station antenna provided by the embodiment of the present application, as Figure 4 shown, the operating frequency band of the antenna array 420 further includes: a third frequency band, where the second frequency band is higher than the third frequency band; the base station antenna further includes: a third decoupling surface 450, connected to the reflector 410, arranged above the second decoupling surface 440, and used to decouple and eliminate the coupled wave in the third frequency band by reflecting part of the electromagnetic waves in the third frequency band sent by the antenna array 420. Exemplarily, in combination with Figure 4aDescribe the working principle of the base station antenna. The triple-band array is composed of three types of antenna elements, namely high-frequency antennas, medium-frequency antennas, and low-frequency antennas. Three decoupling surfaces are arranged above the triple-band array. The lowermost first decoupling surface 430 is used to reflect part of the high-frequency electromagnetic waves to achieve decoupling of the high-frequency band antennas, and at the same time ensure the transmission of medium- and low-frequency electromagnetic waves. Similarly, the second decoupling surface 440 and the third decoupling surface 450 are used to reflect part of the medium-frequency electromagnetic waves and low-frequency electromagnetic waves respectively to achieve decoupling of the corresponding frequency bands, and at the same time ensure the normal transmission of electromagnetic waves in other frequency bands.

[0072] The following will Figures 5 to 19 describe a specific embodiment of the present application.

[0073] As Figure 5 shown, it is the front view of the original array without adding a decoupling structure provided by the embodiment of the present application. Figure 6 It is the top view of the original array, including two groups of first sub-arrays 610 and one group of second sub-arrays 620. The first sub-array 610 includes 3 dual-frequency units 601 and 2 high-frequency units 602 placed alternately. The second sub-array includes 5 high-frequency units 602 placed side by side. This array can be extended to a dual-frequency array of any scale. Among them, the high-frequency unit 602 includes four radiation arms formed by meandering lines and two microstrip feed baluns. The dual-frequency unit 601 includes four circular radiation arms, a meandering line resonance ring above the radiation arms, four angular metal posts at the tails of the radiation arms, and two dual-frequency feed baluns. The metal flanges around the dual-frequency antenna are used to regulate the beam stability of the dual-frequency unit. The feed lines of all units are connected to the common reflector. When arranging the dual-frequency array, the spacing between the radiation units of antennas in different frequency bands is different. A reasonable unit spacing is 0.3 - 0.8 wavelengths at the center frequency of their respective operating frequency bands. In addition, the original array in the embodiment of the present application can be applied to a tightly arranged dual-antenna array. Setting the minimum unit spacing to be less than or equal to 0.5 times the center wavelength is beneficial to improving the aperture utilization rate of the array. In this dual-frequency array, the dual-frequency radiation unit can be regarded as a combination of a high-frequency radiation unit and a low-frequency radiation unit. The horizontal spacing d1 of the low-frequency unit is 58 mm, the vertical spacing d3 is 77 mm, the horizontal spacing d2 of the high-frequency unit is 29 mm, and the vertical spacing d4 is 38.5 mm.

[0074] In this embodiment, as Figure 7 shown, ports L1~L12 operate in the low-frequency band of 2.49~2.69 GHz, and ports 1~30 operate in the high-frequency band of 4.8~4.9 GHz.

[0075] As Figure 8 shown, a first decoupling surface is arranged 6.5 mm above the array.

[0076] Refer to Figure 9 andFigure 10 As shown, the dashed line is the simulation result of the isolation between the low-frequency ports of the original array without adding a decoupling structure, and the solid line is the simulation result of the isolation between the low-frequency ports after loading the first decoupling surface. Except for S(L1,L3), the addition of the first decoupling surface slightly improves the low-frequency isolation, but has no obvious effect.

[0077] See Figure 11 and Figure 12 As shown, the dashed line is the simulation result of the isolation between the high-frequency ports of the original array, and the solid line is the simulation result of the isolation between the high-frequency ports after loading the first decoupling surface. The addition of the first decoupling surface increases the isolation between co-polarized ports from a maximum of 14 dB to above 22 dB, and the isolation between cross-polarized ports from a maximum of 15.5 dB to above 19 dB. It can be seen that the first decoupling surface basically does not affect the performance of the antenna array in the low-frequency band, but has a significant decoupling effect in the high-frequency band. The independent decoupling of the high-frequency band of the array can be achieved by adjusting the first decoupling surface.

[0078] See Figure 13 As shown, at Figure 8 10 mm above the array with the first decoupling surface set as shown, a second decoupling surface is superimposed.

[0079] See Figure 14 and Figure 15 As shown, the dashed line is the simulation result of the isolation between the low-frequency ports of the original array, and the solid line is the simulation result of the isolation between the low-frequency ports after loading the composite decoupling surface. The addition of the second decoupling surface increases the isolation between co-polarized ports from a maximum of 19 dB to above 22 dB, and the isolation between cross-polarized ports from a maximum of 14 dB to above 20.5 dB.

[0080] See Figure 16 and Figure 17 As shown, the dashed line is the simulation result of the isolation between the high-frequency ports of the original array, and the solid line is the simulation result of the isolation between the high-frequency ports after loading the composite decoupling surface, which is basically the same as the result of only loading the first decoupling surface. It shows that the second decoupling surface has a significant decoupling effect on each port in the low-frequency band and does not affect the working performance of the high-frequency ports. The independent decoupling of the low-frequency band of the array can be achieved by adjusting the second decoupling surface.

[0081] See Figure 18 As shown, ports L1, L3, and L5 are fed. The curves in the figure are the normalized radiation patterns of the array in the low-frequency band without the decoupling structure and after loading the composite decoupling structure. The radiation patterns before and after loading the decoupling structure are both smooth and stable, with basically no distortion.

[0082] See Figure 19As shown, ports 11, 13, 15, 17, and 19 are fed. The curves in the figure are the normalized radiation patterns of the array in the high-frequency band without the decoupling structure and after loading the composite decoupling structure. Compared with the original array, the beam width of the radiation pattern becomes slightly narrower after loading the decoupling structure, but the gain is higher and the directivity is better. This shows that the addition of the decoupling structure has little impact on the radiation performance of the array and helps to improve the overall directivity.

[0083] In this embodiment, by loading two layers of composite decoupling surfaces above the antenna array, the port isolation between radiation units is improved, the good radiation performance of the array is maintained, and the decoupling surfaces are isolated from each other and can operate independently. The decoupling device has a simple structure, is easy to integrate, and is effective for multiple coupling types, and is applicable to large multi-band arrays.

[0084] The embodiment of the present application also provides a base station, which includes the base station antenna provided in each of the above embodiments. It can implement each process of the above Figures 1 to 19 shown embodiment and can achieve the same technical effects. To avoid repetition, it will not be elaborated here.

[0085] It should be noted that in this article, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, method, article or device including that element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in a reverse order according to the functions involved. For example, the described methods may be performed in an order different from that described, and various steps may be added, omitted or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0086] Through the description of the above embodiments, those skilled in the art can clearly understand that the above embodiment methods can be implemented by means of a computer software product plus a necessary general hardware platform, and of course, can also be implemented by hardware. The computer software product is stored in a storage medium (such as ROM, RAM, magnetic disk, optical disk, etc.) and includes several instructions for causing a terminal or a network-side device to execute the methods described in various embodiments of the present application.

[0087] The embodiments of the present application have been described above in conjunction with the accompanying drawings. However, the present application is not limited to the above specific implementation manners. The above specific implementation manners are merely illustrative rather than restrictive. Under the inspiration of the present application, those of ordinary skill in the art can also make many forms of implementation manners without departing from the purpose of the present application and the scope protected by the claims. All these implementation manners fall within the protection scope of the present application.

Claims

1. A base station antenna, characterized in that, Comprising: A reflector, An antenna array disposed on the reflector, the operating frequency band of the antenna array including a first frequency band and a second frequency band, wherein the first frequency band is higher than the second frequency band; the antenna array includes a first sub-array and a second sub-array, the first sub-array includes a first radiation unit and a second radiation unit, the first radiation unit and the second radiation unit are alternately arranged in a row along the horizontal direction of the reflector, the second sub-array includes a plurality of second radiation units, the plurality of second radiation units are arranged in a row along the horizontal direction of the reflector, the first sub-array and the second sub-array are alternately arranged in multiple rows along the vertical direction of the reflector, and adjacent sub-arrays are parallel to each other; the operating frequency band of the first radiation unit includes the first frequency band and the second frequency band, and the operating frequency band of the second radiation unit includes the first frequency band; A first decoupling surface, disposed above the antenna array, for decoupling and eliminating only the coupling wave of the first frequency band by reflecting a part of the electromagnetic waves of the first frequency band transmitted by the antenna array; wherein, the first decoupling surface includes: a first dielectric plate and a plurality of first decoupling units disposed on the upper surface of the first dielectric plate, wherein the vertical projection of any one of the first decoupling units on the reflector overlaps with the first radiation unit operating in the first frequency band, and the first decoupling unit corresponds to the first radiation unit one by one; the value range of the transmission coefficient of the first decoupling surface for the electromagnetic waves of the second frequency band is [0.5, 1]; the distance between the first decoupling surface and the radiation surface of the antenna array is k2 times the wavelength of the first frequency band, where k2 is a rational number greater than 0.1 and less than 0.5; A second decoupling surface, disposed above the first decoupling surface, for decoupling and eliminating only the coupling wave of the second frequency band by reflecting a part of the electromagnetic waves of the second frequency band transmitted by the antenna array.

2. The base station antenna according to claim 1, characterized in that, The first decoupling unit includes a metal pattern composed of a plurality of metal strips, and the length of any one of the metal strips is less than k1 times the wavelength of the first frequency band, where k1 is a rational number greater than 0 and less than 1.

3. The base station antenna according to claim 2, characterized in that, The metal pattern composed of the plurality of metal strips is a symmetric pattern.

4. The base station antenna according to claim 1, characterized in that, The second decoupling surface includes: a second dielectric plate and a plurality of second decoupling units disposed on the second dielectric plate, wherein the vertical projection of any one of the second decoupling units on the reflector overlaps with the second radiation unit operating in the second frequency band, and the second decoupling unit corresponds to the second radiation unit one by one.

5. The base station antenna according to claim 4, characterized in that, The second decoupling unit includes: A metal layer disposed on the upper surface of the second dielectric plate, and a slit with a predetermined shape is etched on the metal layer; The metal patch with the predetermined shape disposed on the lower surface of the second dielectric plate.

6. The base station antenna according to claim 4, characterized in that, The length of the second decoupling unit is less than k3 times the wavelength of the second frequency band, where k3 is a rational number greater than 0 and less than 1.

7. The base station antenna according to any one of claims 4 to 6, characterized in that, The value range of the transmission coefficient of the second decoupling surface for the electromagnetic waves of the first frequency band is [0.5, 1].

8. The base station antenna according to any one of claims 4 to 6, characterized in that, The distance between the second decoupling surface and the radiation surface of the antenna array is k4 times the wavelength of the second frequency band, where k4 is a rational number greater than 0.1 and less than 0.

5.

9. The base station antenna according to claim 1, characterized in that, The operating frequency band of the antenna array further includes: a third frequency band, where the second frequency band is higher than the third frequency band; The base station antenna further includes: a third decoupling surface, connected to the reflector and disposed above the second decoupling surface, for decoupling and eliminating the coupled wave of the third frequency band by reflecting part of the electromagnetic waves of the third frequency band transmitted by the antenna array.

10. A base station, characterized in that, A base station antenna according to any one of claims 1 to 9.

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