Bipolar antenna

Abstract

In some examples, a bipolar antenna includes: a bipolar radiator including a first radiator having a first polarity and a second radiator having a second polarity, the second polarity being orthogonal to the first polarity; an auxiliary radiator; and a feed network for feeding a radio frequency (RF) signal to the first radiator and the auxiliary radiator, thereby driving the first radiator to radiate a wave having a first polarization and such that the radiation has a stray wave having a polarization orthogonal to the first polarization, and further driving the auxiliary radiator to radiate a wave that at least partially cancels the stray wave.

Description

Technical Field

[0001] The present invention generally relates to dual polarity antennas, antenna arrays, and improved mechanisms for reducing interference resulting from cross polarization radiation. Background Art

[0002] Massive multiple-input and multiple-output (mMIMO) is one of the key technologies driving the next generation of mobile communications. However, country-specific regulations can be a limiting factor when rolling out new services and telecommunication infrastructure.

[0003] For example, to facilitate site acquisition and meet local regulations for site upgrades, the size of the new antenna should be comparable to that of the traditional product. In addition, to be able to maintain the mechanical support structure of the site, the loads imposed by the wind on the exterior of the new antenna structure should be equal or comparable to those of the traditional antenna. These factors lead to very strict restrictions on specifications such as the width of the new antenna.

[0004] The directivity of an antenna is limited by its aperture and therefore by the width of the antenna. This effect becomes particularly severe when multiple antenna arrays are placed in the same housing. Recently, mMIMO arrays have evolved to include more and more radiating elements in the same volume and even in the same frequency band. As the distance between radiating elements decreases, element coupling increases, resulting in reduced efficiency and performance of the antenna when sending and receiving signals. Coupling can be considered interference because it is equivalent to radiating energy outside the intended area, thereby degrading network performance.

[0005] To improve the traffic handling capacity of the antenna system, dual-polarized antennas can be used. However, when the coupling between polarizations increases, for example due to a shortened distance between radiating elements, radiation in orthogonal directions occurs, which adversely affects the cross-polar discrimination (XPD) of the antenna. Summary of the invention

[0006] The object of the present invention is to provide a dual-polarity antenna capable of reducing interference caused by cross-polarization radiation, thereby improving XPD.

[0007] These and other objects are achieved by the features claimed in the independent claims.

[0008] Further implementations are apparent from the dependent claims, the description and the drawings.

[0009] A first aspect of the present disclosure provides a dipole antenna, comprising a dipole radiator, the dipole radiator comprising a first radiator having a first polarity and a second radiator having a second polarity orthogonal to the first polarity, an auxiliary radiator, and a feeding network for feeding a radio-frequency (RF) signal to the first radiator and the auxiliary radiator, thereby driving the first radiator to radiate a wave having a first polarization and radiating a spurious wave having a polarization orthogonal to the first polarization, and further driving the auxiliary radiator to radiate a wave that at least partially eliminates the spurious wave.

[0010] Thus, the auxiliary radiator can be used to cancel (at least part of) the electromagnetic field generated in the orthogonal polarizations of the dual-polarity radiator, thereby reducing the stray radiation generated in the orthogonal polarizations. Therefore, XPD is improved.

[0011] In an implementation of the first aspect, the feed network may include one or more delay elements. Thus, the feed network may define the phase of the RF signal in a simple and low-cost manner.

[0012] The feed network may be configured to cause the amplitude of the RF signal at the auxiliary radiator to be lower than the amplitude at the first radiator.

[0013] The auxiliary radiator may include two or more monopole antennas. Therefore, the complexity of the components constituting the auxiliary radiator may be minimized, thereby simplifying manufacturing and reducing associated costs.

[0014] The monopole antenna can be placed symmetrically with respect to the dipole radiator. Therefore, array theory can be used to design different monopole configurations and specific directional pattern shapes to effectively eliminate various stray waves.

[0015] The auxiliary radiator may be a first auxiliary radiator, the feeding network may be a first feeding network, and the bipolar antenna may further include a second auxiliary radiator and a second feeding network, wherein the second feeding network is used to feed a radio-frequency (RF) signal to the second radiator and the second auxiliary radiator, thereby driving the second radiator to radiate a wave having a second polarization, and generating a spurious wave having a polarization orthogonal to the second polarization, and further driving the second auxiliary radiator to radiate a wave that at least partially eliminates the spurious wave. Therefore, the XPD of the bipolar radiator can be effectively improved.

[0016] A second aspect of the present disclosure provides an antenna array, comprising a plurality of dipole antennas as described herein.

[0017] Thus, the auxiliary radiator may be used to cancel the fields generated in the orthogonal polarizations of the bipolar radiator, at least to some extent, thereby reducing interference and improving XPD. This may be achieved by using the radiation from the auxiliary radiator to reduce the orthogonal radiation generated by the bipolar radiator excitation. Thus, interference may be reduced.

[0018] The plurality of dual-polarity antennas may form a massive multiple-input and multiple-output (mMIMO) antenna array. Therefore, the dual-polarity antenna may be used in a dense new generation antenna array.

[0019] A third aspect of the present disclosure provides a method for transmitting a radio-frequency (RF) signal. The method includes feeding a radio-frequency (RF) signal to a first radiator and a first auxiliary radiator having a first polarity. This drives the first radiator to radiate a wave having a first polarization and causes a spurious wave having a polarization orthogonal to the first polarization to be radiated. Feeding the RF signal to the first auxiliary radiator further drives the first auxiliary radiator to radiate a wave that at least partially eliminates the spurious wave.

[0020] Thus, the first auxiliary radiator may be used to cancel the fields generated in the orthogonal polarizations of the dual polarity radiator, thereby reducing the interference and improving the XPD.

[0021] The amplitude of the RF signal at the auxiliary radiator is lower than the amplitude at the first radiator.

[0022] The method may further include the steps of feeding a second radio-frequency (RF) signal to a second radiator having a second polarity and a second auxiliary radiator, thereby driving the second radiator to radiate a wave having a second polarization and causing a spurious wave having a polarization orthogonal to the second polarization to be generated, and driving the second auxiliary radiator to radiate a wave that at least partially cancels the spurious wave. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Embodiments will now be described by way of example only with reference to the accompanying drawings, in which:

[0024] Figure 1 schematically depicts a dual polarity antenna according to an example embodiment;

[0025] Figure 2 schematically depicts a top view of a dual polarity antenna according to an example embodiment;

[0026] Figure 3A method for improving radiated polarization purity between orthogonally polarized signals in a dual-polarity antenna according to an example embodiment is schematically described;

[0027] Figure 4 schematically depicts pattern cancellation generation according to example embodiments;

[0028] Figure 5 A method according to an example embodiment is schematically described;

[0029] Figure 6 schematically depicts a dual polarity antenna according to an example embodiment;

[0030] Figure 7 schematically depicts top views of two additional arrangements of a dual-polarity antenna according to example embodiments;

[0031] Figure 8 A dipole antenna according to another embodiment is schematically described. DETAILED DESCRIPTION

[0032] The exemplary embodiments are described below in sufficient detail to enable one of ordinary skill in the art to implement and practice the systems and processes described herein.It is important to understand that the embodiments may be provided in many alternative forms and should not be construed as limited to only the examples described herein.

[0033] Therefore, although the embodiments may be modified in various ways and take various alternative forms, specific embodiments thereof are shown in the drawings and described in detail below as examples. It is not intended to be limited to the specific forms disclosed. On the contrary, all modifications, equivalents and alternatives within the scope of the appended claims should be included. In all drawings and appropriate specific embodiments, the elements of the exemplary embodiments are consistently represented by the same reference numerals.

[0034] The terms used herein to describe the embodiments are not intended to limit the scope. The articles "a" and "the" are singular forms because they have only one referent, but the use of the singular form herein should not exclude the presence of multiple referents. In other words, unless the context otherwise clearly indicates, the elements mentioned in the singular form can be one or more in number. It should be further understood that the term "comprising" used herein is used to illustrate the presence of the features, items, steps, operations, elements and / or parts, but does not exclude the presence or addition of one or more other features, items, steps, operations, elements, parts and / or combinations thereof.

[0035] Unless otherwise defined, all terms (including technical and scientific terms) used in this article should be interpreted as customary usage in the art. It should also be understood that unless explicitly defined in this article, terms in common usage should also be interpreted as customary usage in the relevant art, and should not be interpreted as idealized or overly formal meanings.

[0036] According to an example, a dual-polarity antenna is provided, wherein the polarization purity between orthogonal polarization signals radiated by the dual-polarity antenna is improved. At least one auxiliary radiator is provided to eliminate, offset or reduce stray fields related to a desired polarization generated in vertical polarization, thereby improving cross-polar discrimination (XPD).

[0037] The present invention is described with reference to the flowchart and / or block diagram of the method, device and system according to the example of the present invention. Although the flowchart described above shows a specific execution order, the execution order may be different from that described. The frame associated with a flow chart can be combined with the frame of another flow chart. In some examples, some frames of the flow chart may be unnecessary and / or additional frames may be added.

[0038] Figure 1 A dipole antenna according to an example embodiment is schematically described. The dipole antenna 100 includes a dipole radiator 102, which includes a first radiator 104 having a first polarity and a second radiator 106 having a second polarity. The dipole antenna 100 also includes an auxiliary radiator 108 and a feeding network 110, which is used to feed a radio-frequency (RF) signal to the first radiator 104 and the auxiliary radiator 108, thereby driving the first radiator 104 to radiate a wave having a first polarization, and causing the radiation to radiate a spurious (i.e., undesirable or undesirable) wave having a polarization orthogonal to the first polarization, and further driving the auxiliary radiator 108 to radiate a wave that at least partially eliminates the spurious wave. In other words, the auxiliary radiator 108 can radiate a signal so that the cross-polarization component radiated by the first radiator 104 is at least partially eliminated, thereby reducing interference and improving XPD.

[0039] Those skilled in the art will appreciate that the exact hardware components selected to implement the feed network 110 are not important as long as the feed network 110 is capable of providing a signal having the specified amplitude, frequency, and waveform properties. The RF signal fed by the feed network 110 may be generated internally (e.g., by the components / circuits that make up the feed network 110) or externally, so that the feed network 110 can feed the signal to the desired components of the dual-polarity antenna 100.

[0040] The feed network 110 may include one or more delay components to delay the signals fed to the first radiator 104 and the auxiliary radiator 108 to ensure that the signal of the auxiliary radiator 108 is in anti-phase with the signal of the first radiator 104. Figure 4 , which schematically describes the pattern cancellation generation according to an example embodiment. To cancel the cross-polarization radiation, the auxiliary radiator 108 can be used to generate a pattern as close as possible to the cross-polarization radiation and radiate the signal in anti-phase to at least partially cancel the stray waves.

[0041] In one example, the feed network 110 may be used to cause the amplitude of the RF signal at the auxiliary radiator 108 to be lower than the amplitude at the first radiator 104. The amplitude of the RF signal at the auxiliary radiator 108 may be tuned to the level of the cross-polarization produced by the dual-polarity radiator 102. The frequencies of the signals fed to the first radiator 104 and the auxiliary radiator 108 by the feed network 110 may be the same, or substantially the same, so that both units may radiate at the same frequency.

[0042] In one example, different cross-polarization components can be compensated by using different excitations (phase and amplitude) of the auxiliary radiator 108. In general, the strength of the cross-polarization radiation will depend on the strength of the element coupling in the antenna, i.e., the distances between the radiating elements of the antenna system. Therefore, the signal strength of the RF signal that needs to be fed to the auxiliary radiator 108 through the feeding network 110 may depend on the strength of the cross-polarization radiation caused by the coupling.

[0043] Figure 2 A top view of a dual-pole antenna 100 according to an example is schematically depicted. In one example, the auxiliary radiator 108 may include two or more monopole antennas. Figure 2 108a and 108b. Those skilled in the art will appreciate that the number of monopole antennas may vary depending on the requirements of the antenna system, and that dipole antennas may be used in place of monopole antennas. Monopole antennas 108a, 108b may be symmetrically placed relative to dipole radiator 102. For example, monopole antennas 108a, 108b may be arranged in an array configuration concentric with dipole radiator 102.

[0044] The dipole radiator 102 and the auxiliary radiator 108 may include a common phase center. The monopole antennas 108a, 108b may be arranged in a symmetrical array configuration with respect to the phase center.

[0045] Refer to Figure 1, the auxiliary radiator 108 may be a first auxiliary radiator, the feeding network 110 may be a first feeding network, and the dual-polarity antenna 100 may further include a second auxiliary radiator and a second feeding network. The second auxiliary radiator and the second feeding network may correspond to or substantially correspond to the auxiliary radiator 108 and the feeding network 110, respectively. The second feeding network may be used to feed a radio-frequency (RF) signal to the second radiator 106 and the second auxiliary radiator, thereby driving the second radiator 106 to radiate a wave having a second polarization, and generating a spurious wave having a polarization orthogonal to the second polarization, and further driving the second auxiliary radiator to radiate a wave that at least partially eliminates the spurious wave.

[0046] Figure 3 A method for improving the polarization purity of radiation between orthogonal polarized signals in a dual-polarity antenna according to an example embodiment is schematically described. For example, the dual-polarity antenna can be the dual-polarity antenna 100 described herein. The method includes: in box 301, a radio-frequency (RF) signal is fed to a first radiator and a first auxiliary radiator having a first polarity, thereby driving the first radiator to radiate a wave having a first polarization, and causing the radiation to have a spurious wave having a polarization orthogonal to the first polarization. In box 303, the method includes driving the first auxiliary radiator to radiate a wave that at least partially eliminates the spurious wave. In other words, the first auxiliary radiator can radiate a signal so that the cross-polarization component radiated by the first radiator 104 is at least partially eliminated, thereby reducing the interference generated.

[0047] In one example, an improvement in radiated polarization purity between orthogonally polarized signals in a dual-polarity antenna may be achieved by determining a measurement of a first field distribution of a first field radiated from a dual-polarity radiator of a dual-polarity antenna, and generating a second field distribution using an auxiliary radiator of the dual-polarity antenna, wherein the first field distribution and the second field distribution include out-of-phase phase distributions. The amplitude of the signal used to generate the second field distribution may be adjusted so that the generated spurious (e.g., unwanted or undesired) radiated power of the first field may be adjusted.

[0048] The second field distribution may be generated based on a selected configuration for each radiator of the plurality of radiators forming a subarray of auxiliary radiators of the dual-polarity antenna.The second phase distribution may also be generated based on a cross-polarization component selected for the dual-polarity antenna.

[0049] In one example, phase values ​​of the first and second field distributions may be selected and the phase of the signal may be adjusted to generate a phase difference between the first and second phase distributions at the selected phase value representing a predetermined amount. The predetermined amount may be 180 degrees.

[0050] Figure 5is a flow chart of a method according to an example embodiment. In box 501, an antenna pattern of a dual-polarity antenna is determined. The antenna pattern represents a measure of the directivity of the dual-polarity antenna (in dB) as a function of phase and provides information of the main antenna pattern and the undesired components. In one example, the antenna pattern is determined in the environment in which the antenna is to be used. In box 503, the pattern of the auxiliary radiator is determined to supplement the main antenna pattern to be corrected. In one example, the auxiliary radiator may include a monopole or dipole antenna. In box 505, the phase of the auxiliary radiator is calculated to generate a desired radiation pattern. In one example, the desired radiation pattern may include a radiation pattern having substantially the same components as the pattern of the undesired polarization. In box 507, the amplitude of the auxiliary radiator required to eliminate the undesired components of the main antenna pattern is calculated, and in box 509, the main antenna and the auxiliary radiator can be excited with the calculated weights and phase offsets (between the main antenna and the auxiliary radiator). In one example, the phase offset can cause the component to be eliminated from the main antenna to be in anti-phase with the component from the auxiliary radiator.

[0051] Figure 6 A dual-polarity antenna according to an example embodiment is schematically depicted. The dual-polarity antenna 600 corresponds to Figure 1 The antenna 600 includes a dipole radiator 602 and an auxiliary radiator 608 and a ground 612. The distance a and the distance b between the monopoles of the auxiliary radiator can be selected using array factor theory to shape the signal to eliminate unwanted orthogonal fields.

[0052] Figure 7 Schematically depicts top views of two additional configurations of a dual-polarity antenna according to example embodiments. In brief, Figure 7 The settings described in Figure 2 The monopole of the auxiliary radiator 708 of the dual-polarity antenna 700 corresponds to Figure 2 The monopole 108a and the monopole 108b are shown. As shown, the monopoles of the auxiliary radiator 708 are arranged in a symmetrical configuration with respect to the phase center of the dipole radiator 702.

[0053] Figure 8 Schematically depicts a dipole antenna according to another embodiment. The dipole antenna 800 corresponds to the dipole antenna described in the above figures to a large extent. Figure 8 As shown, the dual-polarity radiator 802 may be implemented using a square dipole, and the auxiliary radiator 808 also includes a dipole. It should be appreciated that the radiators described herein may be implemented using any suitable components and / or configurations.

[0054] The above description is provided to enable those skilled in the art to best utilize the various aspects of the exemplary embodiments disclosed herein. This exemplary description is not intended to be exhaustive or limited to any precise form disclosed. Many modifications and variations may be made without departing from the spirit and scope of the present invention. The embodiments disclosed herein should be considered illustrative and not restrictive in all aspects. When determining the scope of the present invention, reference should be made to the attached claims and their equivalents.

Claims

1. A dual-polarity antenna, characterized in that: The dual-polarity antenna comprises: A dual polarity radiator comprising a first radiator having a first polarity and a second radiator having a second polarity, the second polarity being orthogonal to the first polarity; Auxiliary radiators; A feeding network is used to feed a radio-frequency (RF) signal to the first radiator and the auxiliary radiator, thereby driving the first radiator to radiate a wave with a first polarization and radiating a stray wave with a polarization orthogonal to the first polarization, and further driving the auxiliary radiator to radiate a wave that at least partially eliminates the stray wave.

2. The dual-polarity antenna according to claim 1, characterized in that: The feed network includes one or more delay elements.

3. The dipole antenna according to claim 1 or 2, characterized in that: The feeding network is used to make the amplitude of the RF signal at the auxiliary radiator lower than the amplitude at the first radiator.

4. A dipole antenna according to any one of the preceding claims, characterized in that: The auxiliary radiator includes two or more monopole antennas.

5. The dipole antenna according to any one of the preceding claims, characterized in that: The auxiliary radiator includes two or more dipole antennas.

6. The dipole antenna according to claim 4, characterized in that: The monopole antenna is positioned symmetrically with respect to the dipole radiator.

7. The dual-polarity antenna according to claim 5, characterized in that: The dipole antenna is positioned symmetrically with respect to the dual-polarity radiator.

8. The dipole antenna according to any one of the preceding claims, characterized in that: The auxiliary radiator is a first auxiliary radiator, the feeding network is a first feeding network, and the bipolar antenna further includes: a second auxiliary radiator and a second feeding network, The second feeding network is used to feed a radio-frequency (RF) signal to the second radiator and the second auxiliary radiator, thereby driving the second radiator to radiate a wave having a second polarization and generating a spurious wave having a polarization orthogonal to the second polarization, and further driving the second auxiliary radiator to radiate a wave that at least partially eliminates the spurious wave.

9. An antenna array, characterized in that: The antenna array comprises a plurality of dipole antennas according to any one of the preceding claims.

10. The antenna array according to claim 9, characterized in that: The multiple dual-polarity antennas form a massive multiple-input and multiple-output (mMIMO) antenna array.

11. A method for transmitting a radio-frequency (RF) signal, characterized in that: The method comprises: The RF signal is fed to the first auxiliary radiator and the first radiator having the first polarity, thereby: driving the first radiator to radiate a wave having a first polarization and to radiate a spurious wave having a polarization orthogonal to the first polarization; The first auxiliary radiator is driven to radiate a wave that at least partially cancels the stray wave.

12. The method according to claim 11, characterized in that The amplitude of the RF signal at the auxiliary radiator is lower than the amplitude at the first radiator.

13. The method according to claim 11 or 12, characterized in that: The method further comprises the following steps: A second RF signal is fed to a second auxiliary radiator and a second radiator having a second polarization, thereby driving the second radiator to radiate a wave having a second polarization and causing a spurious wave having a polarization orthogonal to the second polarization to be generated, and driving the second auxiliary radiator to radiate a wave that at least partially eliminates the spurious wave.

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