Antenna device and base station

Abstract

An antenna device and a base station are provided, wherein the antenna device includes a first radiator configured to radiate low-frequency signals and a second radiator configured to radiate high-frequency signals. The first radiator includes at least one first stub and at least one second stub. One end of the first stub is connected to a first connection point on the first radiator, and the other end of the first stub is a free end. One end of the second stub is connected to a second connection point on the first radiator, and the other end of the second stub is a free end. The sum of the length of the first stub, the length of the second stub, and the length of the first radiator between the first and second connection points is determined based on a wavelength corresponding to a predefined high frequency. The applied stub creates one or more new current paths, thereby changing the resonant mode of the induced current on the low-frequency radiating arm at a high frequency.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to an antenna device and a base station. Background Art

[0002] An antenna is a conversion member that can convert guided waves on a transmission line into electromagnetic waves in free space, or vice versa.

[0003] With the development of wireless communication networks, base station antenna architectures are becoming increasingly complex. The allocation of new frequency bands and the drive for a universal solution (one antenna serving all bands and all network generations) have led to densely populated arrays of "multi-band radiators" on base station antenna reflectors.

[0004] While having a universal antenna solution (a multi-band antenna) is very good from a networking perspective, it presents various challenges from the antenna designer’s perspective. For example, the low-band radiator—which typically shadows the higher-band radiator (due to its large size)—can resonate at the higher-band operating frequencies and degrade the antenna’s higher-band radiation pattern.

[0005] Therefore, in a multi-band antenna environment, the above performance degradation problem has become increasingly concerned.

[0006] This background information is provided to reveal information that the applicant believes may be relevant to the present application. It is not necessary to admit, nor should it be construed, that any of the above information constitutes prior art with respect to the present application. Summary of the Invention

[0007] In view of this, in order to overcome the above problems, the present application provides an antenna device and a base station.

[0008] The above and other objects are achieved by the subject matter claimed in the independent claims. Other implementations will be apparent from the dependent claims, the description and the drawings.

[0009] A first aspect of the present application relates to an antenna device, which includes a first radiator configured to radiate low-frequency signals and a second radiator configured to radiate high-frequency signals, the first radiator including at least one first branch and at least one second branch; one end of the first branch is connected to a first connection point on the first radiator, and the other end of the first branch is a free end; one end of the second branch is connected to a second connection point on the first radiator, and the other end of the second branch is a free end; and the sum of the length of the first branch, the length of the second branch and the length of the first radiator between the first connection point and the second connection point is determined according to the wavelength corresponding to a predefined high frequency.

[0010] The antenna device of the present application redirects the induced current of a low-band radiator at high frequencies by introducing stubs at the separation points (also called vertices) of the dipole loops. These stubs alter the current path and, therefore, the resonant mode of the induced current in the low-band radiator at high frequencies. Therefore, the use of one or more stubs at the vertices helps reduce scattering of the low-band radiator at high frequencies.

[0011] In one implementation, each of the two monopole arms includes two pairs of first and second branches, and each pair of first and second branches is arranged on both sides of a separation point of the monopole arms. In one implementation, each of the two monopole arms includes three pairs of first and second branches, and each pair of first and second branches is arranged on both sides of a separation point of the monopole arms.

[0012] The scattering-free bandwidth can be further widened by using more branches.

[0013] In one implementation, the total number of the first branches and the second branches is determined by the width of a predefined working frequency band corresponding to a predefined high frequency.

[0014] In this way, performance can be adaptively adjusted according to actual needs.

[0015] A second aspect of the present application relates to a base station, which includes the antenna device of the first aspect or any implementation thereof and a reflector, wherein both the first radiator and the second radiator are fed through the reflector.

[0016] In the present application, the applied stub creates one or more new current paths and thus changes the resonance mode of the induced current on the low-frequency band radiating arm at the high-frequency band. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present application may be further understood with reference to the accompanying drawings, which constitute a part of the specification and are used together with the following detailed description to illustrate the present application, but should not be construed as limiting the present application. In the accompanying drawings:

[0018] Figure 1 The figure shows a schematic structural diagram of a dual-polarization dual-frequency antenna device in the prior art.

[0019] Figure 2 Shown Figure 1 A top view of one monopole arm of a low-band radiator is shown.

[0020] Figure 3 A schematic top view of a monopole arm of a low-frequency band radiator for a dual-polarization dual-band antenna device according to an embodiment of the present application is shown.

[0021] Figure 4aA schematic top view of a dipole arm of a low-frequency band radiator for a dual-polarization dual-band antenna device according to an embodiment of the present application is shown.

[0022] Figure 4b A perspective view of a dipole arm of a low-frequency band radiator for a dual-polarization dual-band antenna device according to an embodiment of the present application is shown.

[0023] Figure 4c Shown Figure 4a Schematic top view of the monopole arm of the dipole arm shown.

[0024] Figure 5 Shown by using Figure 2 、 Figure 3 and Figure 4c A graph of the radiated power of a dual-polarized radiator formed by the loop in FIG.

[0025] Figure 6 A schematic top view of a dipole arm of a low-frequency band radiator for a dual-polarization dual-band antenna device according to an embodiment of the present application is shown.

[0026] Figure 7 A schematic top view of a dipole arm of a low-frequency band radiator for a dual-polarization dual-band antenna device according to an embodiment of the present application is shown.

[0027] Figure 8 A schematic top view of a monopole arm of a dipole arm of a low-frequency band radiator of a dual-polarization dual-band antenna device according to an embodiment of the present application is shown.

[0028] Figure 9 A perspective view of a monopole arm of a low-frequency band radiator for a dual-polarization dual-band antenna device according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0029] In the following description, reference is made to the accompanying drawings that form part of this application, which illustrate, by way of illustration, specific aspects of the embodiments of the present application or specific aspects of the embodiments of the present application that may be used. It is understood that the embodiments of the present application may be used in other aspects and include structural or logical changes not shown in the drawings. Therefore, the following detailed description is not to be taken as limiting, and the scope of this application is defined by the appended claims.

[0030] The technical solution of the present application can be applied to various communication systems, such as global system of mobile communication (GSM), code division multiple access (CDMA) system, wideband code division multiple access wireless system, general packet radio service system, long term evolution (LTE) system, etc.

[0031] The base station may be a base station (base transceiver station (BTS)) in a GSM system, a GPRS system or a CDMA system, a base station (NodeB) in a CDMA2000 system or a WCDMA system, an evolved base station (evolved NodeB (eNB)) in an LTE system, or a base station (access service network basestation (ASN BS)) in an access service network of a WiMAX network or other network elements.

[0032] The terminal device - which may also be called user equipment, terminal station or user equipment - can be any of the following devices: a smartphone, a mobile phone, a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device capable of wireless communication, an airborne device, a wearable device, a computing device, or other processing device connected to a wireless modem.

[0033] Unless otherwise defined, the terms "high frequency" and "low frequency" mentioned throughout this document are used to describe relatively high and relatively low frequencies, respectively, and are not intended to limit specific frequency values. Similarly, unless otherwise defined, the terms "high frequency band" (or "higher frequency band") and "low frequency band" (or "lower frequency band") are used to describe higher and lower frequency bands. In addition, "low frequency band radiator" refers to a radiator in such a lower frequency band, and "high frequency band radiator" refers to a radiator in the higher frequency band.

[0034] As described in the background, while a single antenna for multiple frequency bands is desirable, there are some challenges. For example, a low-band radiator may resonate at the high-band operating frequency. This application aims to address this resonance issue in the arms of a low-band radiator when a high-band radiator is placed below the low-band radiator.

[0035] As is known in the art, there are various types of base station antennas, such as single-polarization antennas, dual-polarization antennas, etc. For ease of description, the following uses a dual-polarization antenna as an example. However, it should be noted that the technical solution of this application is also applicable to other types of antennas.

[0036] This article will refer to Figure 1 and Figure 2 The structure of a conventional antenna device will be described. Figure 1 The figure shows a schematic structural diagram of a dual-polarization dual-frequency antenna device in the prior art. Figure 2 Shown Figure 1 A top view of one monopole arm of a low-band radiator is shown.

[0037] Figure 1 The arrangement of the low-band radiator and the high-band radiator on the same reflector of the dual-polarization dual-band base station antenna is shown (side view). Here, the high-band radiator is located below the low-band radiator. However, Figure 1 The arrangement shown in is for illustrative purposes only, and other arrangements are possible.

[0038] The low-frequency band radiator is configured to radiate low-frequency signals and includes -45-degree (degree, Deg) and +45-degree polarized dipole arms. Similarly, the high-frequency band radiator is configured to radiate high-frequency signals and also includes -45-degree and +45-degree polarized dipole arms. The polarization of an antenna refers to the direction of the electric field strength formed when the antenna radiates: when the direction of the electric field strength is parallel to the ground, the polarization direction of the antenna is horizontal polarization; when the direction of the electric field strength is perpendicular to the ground, the polarization direction of the antenna is vertical polarization. Here, +45-degree polarization means that the direction of the electric field strength is at an angle of +45 degrees relative to the ground, and -45-degree polarization means that the direction of the electric field strength is at an angle of -45 degrees relative to the ground.

[0039] For simplicity, the figure shows only two radiators, one low-band radiator and one high-band radiator. However, more radiators can be placed on the reflector 100 as needed, and the number of radiators is not limited to this. In an interspersed design, the low-band radiators are typically located on an evenly spaced grid appropriate to the frequency, and the low-band radiators are placed at intervals that are n (integer) multiples of the intervals between the high-band radiators. In most cases, depending on the antenna architecture, the space between two low-band radiators is occupied by two high-band radiators at corresponding intervals.

[0040] like Figure 1 As shown, the common reflector 100 for the low-band radiator and the high-band radiator is a common ground. Figure 1 In the figure, one dipole of the low-band radiator includes two monopole arms 101 and 102, which form a dipole for one polarization; the other dipole of the low-band radiator is not visible but is symmetrical with the visible dipole; the low-band radiator is fed through baluns 103 and 104. For each monopole arm of the low-band radiator, for example, the two monopole arms 101-1 and 101-2 of the high-band radiator are arranged near the monopole arm 101 of the low-band radiator and are fed through baluns 105-1 and 105-2, respectively; similarly, the two monopole arms 102-1 and 102-2 of the high-band radiator are arranged near the monopole arm 102 of the low-band radiator and are fed through baluns 106-1 and 106-2, respectively; the other polarization arm of the high-band radiator is not visible but is symmetrical with the visible polarization arm.

[0041] Figure 2 Shown Figure 1 A monopole arm 101 of a low-band radiator is shown. The monopole arm 101 is shown as a rectangular metal ring and includes an inner periphery 201 and an outer periphery 202. In actual applications, the monopole arm can be other shapes, such as square, circular, etc., which is not limited in this article. In the following description, a rectangular monopole arm is taken as an example, but it should be understood that the same principle applies to monopole arms of other shapes. These styles of metal rings - which form dipoles of low-band radiators in pairs - have good radiation characteristics in the corresponding operating frequency bands. However, these rings will undergo undesirable resonance and thus scatter the radiation of the high-band radiator (in a multi-band antenna environment, the high-band radiator is located under these rings), and therefore the radiation pattern of the high-band radiator is significantly degraded.

[0042] As described above, the low-band radiators shown in the multi-band antenna environment will degrade the antenna's high-band radiation pattern due to resonance at the high-band operating frequency. The main challenge in designing such a multi-band antenna is to minimize the impact of scattering of the high-band signal caused by other lower-band radiators. The scattering mentioned here affects the beam width (BW), beam shape, cross-polarization level, front-to-back ratio (FBR), and all of these will vary randomly in azimuth and elevation cuts. While it is almost impossible to compensate for these scattering effects in narrowband antennas, it is extremely challenging to compensate for the scattering effects over a wide band by simply re-adjusting the relative positions of the low-band and high-band dipoles to move the resonance point or by other conventional means.

[0043] In order to solve this problem, the present application provides an arrangement of a low-frequency band radiator of a multi-band dual-polarized base station antenna and branches on the dipole arm of the low-frequency band radiator, so that the low-frequency band radiator does not radiate in the operating frequency band of the high-frequency band radiator. The following will be described only by way of example with reference to the accompanying drawings.

[0044] Embodiments of the present application generally relate to low-band radiators of dual-polarized multi-band base station antennas with interspersed radiators for cellular communications, and in some implementations, relate to antennas for low-band frequencies of 1695 MHz to 2690 MHz or portions thereof and high-band frequencies of 3300 MHz to 3800 MHz or portions thereof.

[0045] The following describes a dipole arm for a low-band dual-polarized radiator of a multi-band base station antenna. The following description sets forth numerous specific details, including the operating frequency band and bandwidth, dipole arm shape and material, and substrate material. However, based on this disclosure, it will be apparent to those skilled in the art that modifications and / or substitutions may be made without departing from the scope and spirit of the disclosure. In other cases, specific details may be omitted to avoid obscuring the disclosure.

[0046] Figure 3 A schematic top view of a monopole arm of a low-band radiator for a dual-polarized, dual-band antenna device according to an embodiment of the present invention is shown, which simply illustrates one monopole arm of the low-band radiator provided by the present invention. Regarding the dual-polarized antenna device, the first radiator 300 includes two dipole arms, wherein each dipole arm includes two monopole arms. Figure 3 Simply shows that there is Figure 2 Based on the original form, a pair (a set of two) of monopole arms with stubs are applied to the vertices of a rectangular metal ring. These paired stubs and the closed vertices (of the monopole arms) form new current paths for the induced current generated by the excitation of the high-frequency radiator. This will be described in detail below with reference to the accompanying drawings.

[0047] like Figure 3 As shown, the antenna device includes a first radiator 300 and a second radiator (not shown), and the first radiator 300 may include at least one first branch and at least one second branch. Figure 3 The first radiator 300 includes a first branch 301 and a second branch 302. The second radiator can be Figure 1 The high frequency band radiators shown are arranged in the same manner and are not described in detail for the sake of brevity. In addition, the first radiator can also be called a low frequency band radiator, and the second radiator can also be called a high frequency band radiator.

[0048] The first radiator 300 is configured to radiate a low-frequency signal, and the second radiator is configured to radiate a high-frequency signal. This description is made herein with reference to a dual-band antenna device. In actual applications, more radiators may be arranged to implement an antenna device operating in more frequency bands. In some implementations, low frequency or low frequency band refers to a lower frequency band, such as 1695MHz to 2690MHz, and high frequency or high frequency band refers to a higher frequency band, such as 3300MHz to 3800MHz. In some implementations, in a multi-band antenna environment, due to the presence of a 690MHz to 960MHz frequency band radiator (low-frequency band radiator), similar problems occur with a 1695MHz to 2690MHz frequency band radiator (high-frequency band radiator). In this case, the 1695MHz to 2690MHz frequency band may be a high-frequency band, and the 690MHz to 960MHz frequency band may be a low-frequency band. Of course, the frequency may be other values, which are not limited herein. Characteristics of particular interest are beam width (BW), beam shape, directivity, and S parameters. Here, the essence of the problem is the same, so the disclosed application can be applied to partially or fully solve the coupling / scattering problem of the multi-band antenna in this scenario.

[0049] As shown in the figure, one end of the first branch 301 is connected to a first connection point 3011 on the first radiator 300, and the other end 3012 of the first branch 301 is free. One end of the second branch 302 is connected to a second connection point 3021 on the first radiator 300, and the other end 3022 of the second branch 302 is free. The solid black circles representing the connection points are for illustrative purposes only.

[0050] In addition, the first branch 301 and the second branch 302 are arranged at specific positions so that a new current path is formed between the free end 3012 of the first branch 301 and the free end 3022 of the second branch 302 (eg, Figure 3 shown as dashed lines), which can be achieved by constraining the distance between them.

[0051] As described in the previous paragraphs, the purpose of the present application is to provide a low-frequency band radiator (first radiator) that is non-scattering in the high frequency band, which means that the radiation power of the low-frequency band radiator is relatively low in the target high frequency band. This can be achieved by arranging the branches in specific positions so that the length of the current path, that is, the distance between the two free ends of the two branches, is set to a predefined value. Specifically, the sum of the length of the first branch 301, the length of the second branch 302, and the length of the first radiator 300 between the first connection point 3011 and the second connection point 3021 is determined according to the wavelength corresponding to the predefined high frequency. Throughout the specification, the length of the branch and the length of the radiator refer to their physical lengths.

[0052] As those skilled in the art know, the product of frequency and wavelength equals the speed of light (note that if the dipole is made of PCB, the dielectric constant (ε) of the substrate is also considered). The wavelength is called the wavelength corresponding to the frequency. Therefore, once the frequency is determined, the wavelength corresponding to that frequency is also determined.

[0053] In one implementation, the predefined high frequency can be set according to actual needs. For example, the operating frequency of the second radiator (high frequency band radiator) is selected based on empirical testing. For example, the predefined high frequency can be the center operating frequency of the second radiator (high frequency band radiator). As described above, the wavelength corresponding to the predefined high frequency can be easily obtained by dividing the speed of light by the predefined high frequency. Then, the sum of the length of the first branch 301, the length of the second branch 302, and the length of the first radiator 300 between the first connection point 3011 and the second connection point 3021 can be determined based on the obtained wavelength. For example, according to actual needs, the sum can be set to 1 / 2 of the obtained wavelength, or 3 / 4 of the obtained wavelength. It should be noted that there are no specific requirements for each of the above three lengths, as long as their sum meets the restrictions. The first branch 301 and the second branch 302 can be placed at specific positions first, and the length of the first radiator 300 between the first connection point 3011 and the second connection point 3021 can be determined as L. Then, the sum of the length of the first branch 301 and the length of the second branch 302 can be determined as, for example, 1 / 2 of the obtained wavelength minus L. Therefore, the lengths of the two branches can be selected at will, as long as the sum of the lengths of the two branches is equal to 1 / 2 of the obtained wavelength minus L.

[0054] Typically, the physical length of a stub can be represented by its electrical length, which is a multiple of the wavelength. That is, the electrical length of the first stub 301 can be the ratio of the physical length of the first stub 301 to the obtained wavelength, the electrical length of the second stub 302 can be the ratio of the physical length of the second stub 302 to the obtained wavelength, and the electrical length of the first radiator 300 between the first connection point 3011 and the second connection point 3021 can be the ratio of its physical length to the obtained wavelength. As an embodiment, the electrical length of the first radiator 300 between the first connection point 3011 and the second connection point 3021 can be set to 1 / 4, and the electrical lengths of both the first stub 301 and the second stub 302 can be set to 1 / 8. The two stubs do not need to have the same size, and other selections can be made as long as the sum of the three electrical lengths is 1 / 2.

[0055] In one implementation, the first branch 301 and the second branch 302 are arranged on both sides of a separation point A of the monopole arm.

[0056] In one implementation, the first branch 301 and the second branch 302 are arranged around the first radiator 300 . As an implementation manner, the first branch 301 and the second branch 302 are arranged on the inner periphery of the first radiator 300 .

[0057] In one implementation, the second radiator may be made of a dual-polarization patch based on a printed circuit board (PCB).

[0058] In one implementation, the monopole arm of the first radiator 300 may be a rectangular metal ring (eg Figure 3 ), or other shapes such as square or circle. Figure 3 The shape of the monopole arm in is for illustration purposes only and the shape of the monopole arm is not limited thereto.

[0059] In addition, Figure 3 In the illustrated case, the length of the first radiator 300 between the first connection point 3011 and the second connection point 3021 refers to the shorter length therebetween. In the case where the monopole arm is rectangular, the length refers to the length of the first radiator 300 passing through the separation point A.

[0060] It should be noted that although the following description refers to a dual-polarized dual-band antenna device, the same principles apply to other antenna architectures, such as a single-polarized dual-band antenna device. In the case of a single-polarized dual-band antenna device, as an embodiment, the second radiator can be made of a single-polarized patch based on a PCB.

[0061] The radiator of the present application can be made of PCB or by die casting, wherein all elements / components are part of a single workpiece. Therefore, the overall antenna design is easy to manufacture and the manufacturing cost is lower.

[0062] The embodiments of the present application redirect the induced current of the low-band radiator in the high-frequency band by introducing a first branch and a second branch at the separation point (also called the vertex) of the dipole ring. These branches change the current path and thus change the resonant mode of the induced current on the low-band radiator in the high-frequency band. Therefore, the use of one or more branches at the vertex is beneficial to reduce the scattering of the low-band radiator in the high-frequency band. In the present application, the applied branches create one or more new current paths, thereby changing the resonant mode of the induced current on the low-band radiating arm in the high-frequency band.

[0063] To change the embodiment, those skilled in the art may change or modify the position of the branches, the number of branches in the ring, the shape and type of the ring, the thickness and width of the ring arms without departing from the scope of the present application.

[0064] The above embodiment illustrates a pair of branches, namely, a first branch and a second branch. In practical applications, the total number of first branches and second branches can be determined by the width of a predefined operating frequency band corresponding to a predefined high frequency. In one implementation, the wider the operating frequency band corresponding to the predefined high frequency, the more branches are used. The following details an example using more than two branches.

[0065] Figure 4a A schematic top view of a dipole arm of a low-frequency band radiator for a dual-polarization dual-band antenna device according to an embodiment of the present application is shown. Figure 4b A perspective view of a dipole arm of a low-frequency band radiator for a dual-polarization dual-band antenna device according to an embodiment of the present application is shown. Figure 4a and Figure 4b The difference between the two is that the former Figure 4a Made of PCB, which is Figure 4b Made by die casting or stamping. Figure 4c Shown Figure 4a Schematic top view of the monopole arm of the dipole arm shown. Figure 4c Shown in Figure 2 and Figure 3 The monopole loop has a pair of additional branches at the other vertex of the original form. In a multi-band antenna environment, these new branches and the closed vertex form another current loop for the induced current of the high-band radiator located below the low-band radiator.

[0066] refer to Figures 4a to 4c Each monopole arm of the dual-polarization radiator (low-frequency band radiator) has two pairs of branches, and each pair of branches is applied to the vertex of the monopole arm.

[0067] Specifically, first radiator 400 (low-band radiator) includes four rectangular metal rings 401 to 404, each with a side length of approximately one-quarter wavelength, forming +45-degree and -45-degree polarized dipole arms. Each metal ring serves as a monopole arm of first radiator 400 and includes two pairs of first and second branches, each pair of which is arranged on either side of the monopole arm's separation point.

[0068] In one implementation, the dipole arms are configured as a cross-dipole arrangement with a cross-center feed 405. The center feed 405 comprises two interlocking cross-PCB boards, with the respective dipole arms having baluns. Other types of feeds are possible, and those skilled in the art will appreciate the different configurations.

[0069] Taking the metal ring 401 as an example, the metal ring 401 has two pairs of first branches and second branches, namely, a pair of first branches 406 and second branches 407, and another pair of first branches 408 and second branches 409. Figure 4c As shown, the metal branches 406 and 407 form a new current path 410 for the induced current in the high frequency band together with the separation point (also called the closed vertex or corner point of the metal ring) B. Another pair of metal branches 408 and 409 form a new current path 411 for the induced current in the high frequency band together with the separation point C of the monopole arm. The length of the branch and its position can be adjusted according to the Figure 3 A pair of branches in the same way can be determined, refer to Figure 3 In one implementation, the current path 410 and the current path 411 may be set to a length of about half a wavelength of the high frequency band.

[0070] Now refer to Figure 5 Describe the performance of the provided antenna device. Figure 5 Shown by using Figure 2 、 Figure 3 and Figure 4c The results are shown here to illustrate the effect of the proposed scheme on the scattering characteristics of the low-frequency radiator in the high-frequency band.

[0071] Specifically, in Figure 5 In the figure, there are three lines showing the simulated radiated power (relative to frequency) for three cases, where each case represents a form of monopole arm. The lower the radiated power, the less impact it has on the performance of the radiator in the high frequency band. Figure 5 , the dotted line 501 (the first case, the original form of the monopole arm) is Figure 2 The relationship between the radiation power of the metal ring shown in FIG and the frequency, the solid black line 502 (the second case, a vertex of the monopole arm has a pair of branches) is Figure 3 The relationship between the radiation power of the metal ring and the frequency shown in FIG, and the dotted line 503 (the third case, the two vertices of the monopole arm have a pair of branches) is Figure 4c The figure shows the relationship between the radiation power of the metal ring and the frequency. Focusing on the performance around 4 GHz, it can be seen that without using stubs (as shown by line 501), the radiation power of the low-frequency radiator around 4 GHz is relatively high, which degrades the performance of the high-frequency radiator. When using a pair of stubs (as shown by line 502), the radiation power of the low-frequency radiator is reduced to approximately -58.22 dB at the trough around 4 GHz. When using two pairs of stubs (as shown by line 503), the radiation power of the low-frequency radiator is reduced even more at the trough around 4 GHz, to approximately -67.5 dB.

[0072] In fact, Figure 4cThe structure shown—in which the low-band dipole arm is formed by two rectangular metal rings with two pairs of branches at the apex of each ring—can reduce the radiated power passing through it by approximately -15dB; thus, the beam shape and cross-polarization characteristics in the azimuth and elevation planes are well restored. The low-band radiator in the multi-band antenna can have an operating bandwidth greater than 45% and a horizontal beamwidth ranging from 55 degrees to 75 degrees.

[0073] Furthermore, the trough becomes wider with the addition of more stubs. Stubs at the vertices of rectangular / square metal rings, or any other shape such as a circular ring, can be used to achieve dispersion-free operation at high frequencies. If additional stubs are applied to the ring's perimeter in addition to these two pairs, these new stubs can resonate with the existing stubs, further widening the dispersion-free bandwidth.

[0074] As an implementation method, Figure 6 Schematic top view of a dipole arm of a low-frequency band radiator for a dual-polarization dual-frequency antenna device according to an embodiment of the present application is shown. Figure 4a The difference is that, in Figure 6 In the embodiment, each monopole arm of the dual-polarization radiator (low-frequency band radiator) has three pairs of branches, and each pair of branches is applied at the vertex of the monopole arm.

[0075] Specifically, the first radiator 600 (low-band radiator) also includes four rectangular metal rings 601 to 604, each with a side length of approximately one-quarter wavelength, forming +45-degree and -45-degree polarized dipole arms. Each metal ring serves as a monopole arm of the first radiator 600 and includes three pairs of first and second branches, each pair of which is arranged on either side of the monopole arm's separation point.

[0076] In one implementation, the dipole arms are configured as a cross-dipole arrangement with a cross-center feed 605. The center feed 605 comprises two interlocking cross-PCB boards, with the corresponding dipole arms having baluns. Other types of feeds are possible, and those skilled in the art will appreciate different configurations.

[0077] Taking the metal ring 601 as an example, the metal ring 601 has three pairs of first branches and second branches, namely, a pair of first branches 606 and second branches 607, a pair of first branches 608 and second branches 609, and another pair of first branches 610 and second branches 611. The metal branches 606 and 607 together with the separation point D form a new current path 612 for the induced current in the high frequency band; a pair of metal branches 608 and 609 together with the separation point E of the monopole arm form a new current path 613 for the induced current in the high frequency band; and a pair of metal branches 610 and 611 together with the separation point F of the monopole arm form a new current path 614 for the induced current in the high frequency band. The lengths of the branches and their positions can be adjusted according to the Figure 3 A pair of branches in the same way can be determined, refer to Figure 3 In one implementation, the current paths 612 to 614 may be configured to have a length of approximately half a wavelength in the high frequency band.

[0078] use Figure 6 The structure shown can further broaden the scattering-free bandwidth.

[0079] Figure 7 A schematic top view of a dipole arm of a low-frequency band radiator for a dual-polarization dual-band antenna device according to an embodiment of the present application is shown.

[0080] Specifically, the first radiator 700 (low-frequency radiator) also includes four rectangular metal rings 701 to 704, each having a side length of approximately one-quarter wavelength, forming +45-degree and -45-degree polarized dipole arms. Each metal ring is a monopole arm of the first radiator 700 and has the same structure.

[0081] In one implementation, the dipole arms are configured as a cross-dipole arrangement with a cross-center feed 705. The center feed 705 comprises two interlocking cross-PCB boards, with the respective dipole arms having baluns. Other types of feeds are possible, and those skilled in the art will appreciate the different configurations.

[0082] Taking the metal ring 701 as an example, the metal ring 701 includes a first branch 706, a second branch 707 and a third branch 708, and the second branch 707 is arranged between the first branch 706 and the third branch 708. One end of the third branch 708 is connected to the third connection point on the first radiator (used to connect the third branch 708 to the first radiator, not shown in the figure), and the other end of the third branch 708 is a free end. The length of the first branch 706, the length of the second branch 707 and the length of the first radiator at the first connection point (used to connect the first branch 706 to the first radiator, not shown in the figure, can be referred to Figure 3The first connection point 3011 shown in FIG) and the second connection point (used to connect the second branch 707 to the first radiator, not shown in the figure, can refer to Figure 3 The sum of the lengths between the second connection point 3021) shown in the figure is determined according to the wavelength corresponding to the predefined high frequency, and the sum of the length of the second branch section 707, the length of the third branch section 708 and the length of the first radiator 700 between the second connection point and the third connection point is determined according to the wavelength corresponding to the predefined high frequency. Figure 7 The length and position of the first and second branches in the Figure 3 The length and position of the third branch 708 can be determined in a similar manner to the first branch 301 and the second branch 302. Figure 3 The first branch 301 and the second branch 302 in the embodiment are determined in a similar manner, and the sum can also be determined in the same manner as Figure 3 A similar method can be used to determine Figure 3 Therefore, something like Figure 3 In one implementation, the length of the first segment can be selected to be equal to the length of the second segment. In one implementation, the length of the second segment can be selected to be equal to the length of the third segment. It should be noted that these segments can have different lengths as long as the constraints on the sum are met.

[0083] Figure 7 In fact, another possible form of the dipole arm of the low-frequency radiator is shown, in which each monopole loop has only three branches to form two current paths 709 and 710. In this particular case, the two current loops share the second branch 707 located in the center. In fact, Figure 4a Compared with the structure shown in FIG, the second branch 707 shared by the two current loops is actually Figure 4c The performance of the two structures is roughly the same.

[0084] Figure 8 A schematic top view of a monopole arm of a dipole arm of a low-frequency band radiator of a dual-polarization dual-band antenna device according to an embodiment of the present application is shown. Figure 8 In fact, another possible embodiment is shown, in which new stubs are added to form new current paths and thus widen the non-radiating frequency band of the dipole arms of the low-band radiator.

[0085] and Figure 7 In comparison, Figure 8 In FIG, only one monopole arm of the dipole arm is shown, and an additional branch is added around the monopole arm. Specifically, Figure 8As shown, the monopole arm 801 includes a first branch 802, a second branch 803, a third branch 804 and a fourth branch 805, and the fourth branch 805 is arranged between the first branch 802 and the third branch 804. One end of the fourth branch 805 is connected to a fourth connection point on the first radiator (used to connect the fourth branch 805 to the first radiator, not shown in the figure), and the other end of the fourth branch 805 is a free end. Figure 8 In the embodiment, since there are four current paths 806 to 809, similar to the above embodiment, in addition to the current path 806 formed by the first branch 802 and the second branch 803 (similar to the current path 709) and the current path 807 formed by the second branch 803 and the third branch 804 (similar to the current path 710), a new current path 808 is formed by the third branch 804 and the fourth branch 805, and another new current path 809 is formed by the fourth branch 805 and the first branch 802. Therefore, similar restrictions apply to the following two sums: the sum of the length of the third branch 804, the length of the fourth branch 805, and the length of the first radiator between the third connection point (for connecting the third branch 804 to the first radiator, not shown in the figure) and the fourth connection point (which can be determined based on the wavelength corresponding to the predefined high frequency); and the sum of the length of the fourth branch 805, the length of the first branch 802, and the length of the first radiator between the fourth connection point (for connecting the fourth branch 805 to the first radiator, not shown in the figure) and the first connection point (which can be determined based on the wavelength corresponding to the predefined high frequency). The length of the fourth branch 805 and its position can be determined based on the wavelength corresponding to the predefined high frequency. Figure 3 The branches in are determined in a similar manner, and the sum can also be expressed as Figure 3 A similar method can be used to determine Figure 3 Therefore, similarly, in one implementation, the length of the third segment can be selected to be equal to the length of the fourth segment. In one implementation, the length of the second segment can be selected to be equal to the length of the third segment.

[0086] Figure 8 The embodiment shown in FIG can have particular advantages when the high frequency band is relatively wide, for example, 1695 MHz to 2690 MHz. By sharing the openings of branch 803 and branch 805, the presence of the new branch (fourth branch 805) forms two additional current paths, which will resonate at the operating frequency band of the high frequency radiator and thus achieve a wider non-radiation frequency band.

[0087] Figure 9 A perspective view of a monopole arm of a low-band radiator for a dual-polarization dual-band antenna device according to an embodiment of the present application is shown. The figure shows a monopole arm of a low-band radiator with four pairs of L-shaped branches. Figure 8 compared to, Figure 9 The stubs in the radiator are not physically connected to the monopole arm of the low-band radiator, but are optionally coupled around the vertex to positions almost identical to the stubs physically connected to the monopole arm. These coupled stubs are L-shaped, with the length of the section parallel to the monopole arm being shorter than the length of the section perpendicular to the monopole arm.

[0088] Specifically, if Figure 9 As shown, the monopole arm 900 has four pairs of branches, including a pair of branches 901a and 901b, a pair of branches 902a and 902b, a pair of branches 903a and 903b, and a pair of branches 904a and 904b, wherein each pair of branches is arranged on both sides of the separation point of the monopole arm. Each pair of branches can form a new current path as shown by the dotted lines in the figure, and only the current path formed by the pair of branches 901a and 901b is shown here as an example. Here, although the way these branches are combined in the radiating arm is different from the way applied in the previous embodiment of the present application, the working principle of these capacitively coupled branches is the same, that is, the same restriction is required on the sum of the branch lengths so that it does not radiate in the working frequency band of the high-frequency radiator. The length of the branches and their positions can be adjusted to the same as Figure 3 The branches in are determined in a similar manner, and for the sake of brevity, the details are not described in this article.

[0089] The embodiments of the present application redirect the induced current of a low-band radiator in the high-frequency band by introducing stubs at the separation points (also called vertices) of the dipole loop. These stubs change the current path and thus change the resonant mode of the induced current on the low-band radiator in the high-frequency band. Therefore, the use of one or more stubs at the vertices is beneficial for reducing the scattering of the low-band radiator in the high-frequency band. In the present application, the applied stubs create one or more new current paths, thereby changing the resonant mode of the induced current on the low-band radiating arm in the high-frequency band.

[0090] The present application also provides a base station, which includes the above-mentioned antenna device and a reflector, and the first radiator and the second radiator are both fed through the reflector.

[0091] It should be noted that there are no requirements for the connection method between the branch and the first radiator. The terms "connection point," "connected to," and "connected" are not intended to limit the connection method to a physical connection, but may refer to an electronic connection between two elements. This connection can be achieved in various forms, such as a direct physical connection or an indirect coupling.

[0092] Terms such as “first”, “second”, etc. in the specification and claims of this application and the drawings above are intended to distinguish different objects, but are not intended to limit a specific order.

[0093] Terms such as "and / or" in the embodiments of this application are only used to describe the association between associated objects, indicating that there may be three relationships. For example, A and / or B may mean that only A exists, both A and B exist, and only B exists.

[0094] The terms "a" or "an" are not intended to refer to one or a single element, but may be used to refer to multiple elements where appropriate.

[0095] In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate an illustration of an example or instance. In the embodiments of this application, any embodiment or design described as "exemplary" or "for example" should not be interpreted as being preferred or advantageous over other embodiments or designs. Specifically, the purpose of using "exemplary" or "for example" is to present the relevant concepts in a concrete way.

[0096] In one or more examples, the functions described may be implemented by hardware, software, firmware, or any combination thereof. If implemented by software, the functions may be stored in or transmitted via a computer-readable medium as one or more instructions or codes and executed by a hardware-based processing unit. A computer-readable medium may include a computer-readable storage medium, which corresponds to a tangible medium such as a data storage medium or a communication medium including any medium that facilitates, for example, transmitting a computer program from one place to another according to a communication protocol. In this manner, a computer-readable medium may generally correspond to (1) a non-transitory tangible computer-readable storage medium or (2) a communication medium such as a signal or carrier wave. A data storage medium may be any available medium that can be accessed by one or more computers or one or more processors to retrieve instructions, codes, and / or data structures for implementing the techniques described herein. A computer program product may include a computer-readable medium.

[0097] Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of the present invention, and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that the technical solutions described in the above embodiments may be modified, or certain technical features thereof may be replaced by equivalents, without departing from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An antenna device comprising a first radiator configured to radiate a low-frequency signal and a second radiator configured to radiate a high-frequency signal, wherein the first radiator comprises at least one first branch and at least one second branch; One end of the first branch is connected to a first connection point on the first radiator, and the other end of the first branch is a free end; One end of the second branch is connected to the second connection point on the first radiator, and the other end of the second branch is a free end; and The sum of the length of the first branch section, the length of the second branch section, and the length of the first radiator between the first connection point and the second connection point is determined according to a wavelength corresponding to a predefined high frequency, wherein: The sum of the lengths is equal to the length of the current path, and the sum of the lengths is 1 / 2 or 3 / 4 of the wavelength.

2. The antenna device according to claim 1, wherein The first radiator includes at least one dipole arm, each dipole arm of the at least one dipole arm includes two monopole arms, and the at least one first branch and the at least one second branch are connected to the at least one dipole arm.

3. The antenna device according to claim 2, wherein: Each of the two monopole arms comprises a first branch and a second branch arranged on both sides of a separation point of the monopole arms.

4. The antenna device according to claim 2, wherein: Each of the two monopole arms comprises two pairs of first branches and second branches, and each pair of first branches and second branches is arranged on both sides of a separation point of the monopole arms.

5. The antenna device according to claim 2, wherein Each of the two monopole arms comprises three pairs of first branches and second branches, and each pair of first branches and second branches is arranged on both sides of a separation point of the monopole arms. The antenna device according to claim 2 , wherein: Each of the two monopole arms comprises four pairs of first branches and second branches, and each pair of first branches and second branches is arranged on both sides of a separation point of the monopole arm.

7. The antenna device according to claim 1, wherein The total number of the first branches and the second branches is determined by the width of a predefined working frequency band corresponding to the predefined high frequency.

8. The antenna device according to claim 1, wherein The length of the first segment is equal to the length of the second segment.

9. The antenna device according to claim 2, wherein: Each of the two monopole arms comprises a first branch, a second branch and a third branch, wherein the second branch is arranged between the first branch and the third branch; One end of the third branch is connected to the third connection point on the first radiator, and the other end of the third branch is a free end; and The sum of the length of the second branch, the length of the third branch, and the length of the first radiator between the second connection point and the third connection point is determined according to a wavelength corresponding to the predefined high frequency.

10. The antenna device according to claim 9, wherein Each of the two monopole arms further comprises a fourth branch, wherein the fourth branch is arranged between the first branch and the third branch; One end of the fourth branch is connected to a fourth connection point on the first radiator, and the other end of the fourth branch is a free end; The sum of the length of the third branch, the length of the fourth branch, and the length of the first radiator between the third connection point and the fourth connection point is determined according to the wavelength corresponding to the predefined high frequency; and The sum of the length of the fourth branch, the length of the first branch, and the length of the first radiator between the fourth connection point and the first connection point is determined according to a wavelength corresponding to the predefined high frequency. The antenna device according to claim 10 , wherein: The length of the first segment is equal to the length of the fourth segment.

12. The antenna device according to any one of claims 9 to 11, wherein: The length of the first segment is equal to the length of the second segment.

13. The antenna device according to any one of claims 9 to 11, wherein: The length of the second segment is equal to the length of the third segment.

14. The antenna device according to any one of claims 2 to 11, wherein: The at least one first stub and the at least one second stub are coupled to the at least one dipole arm.

15. The antenna device according to claim 14, wherein The at least one first branch section and the at least one second branch section are L-shaped branches.

16. The antenna device according to any one of claims 2 to 6 and 9 to 11, wherein: The monopole arm is a rectangular or circular metal ring.

17. The antenna device according to any one of claims 2 to 11, wherein: The first radiator is a dual-polarization radiator including two dipole arms.

18. The antenna device according to claim 17, wherein: The second radiator is made of a dual-polarization patch based on a printed circuit board PCB.

19. The antenna device according to any one of claims 2 to 11, wherein: The first radiator is a single-polarization radiator including one dipole arm.

20. The antenna device according to claim 19, wherein The second radiator is made of a dual-polarization patch based on a printed circuit board PCB or a single-polarization patch based on a PCB.

21. The antenna device according to any one of claims 2 to 11, wherein: The second radiator is arranged below the first radiator.

22. The antenna device according to claim 16, wherein The first segment and the second segment are arranged on the inner periphery of the metal ring.

23. A base station comprising the antenna device according to any one of claims 1 to 22 and a reflector, wherein both the first radiator and the second radiator are fed through the reflector.

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