Bipolar antenna

Abstract

In some examples, a dual polarized antenna includes: a dual polarized radiator including a first radiator having a first polarity and a second radiator having a second polarity orthogonal to the first polarity; an auxiliary radiator; a feed network for feeding radio-frequency (RF) signals to the first radiator and the auxiliary radiator, thereby driving the first radiator to radiate waves having a first polarization, and causing a spurious wave to be radiated having a polarization orthogonal to the first polarization, and further driving the auxiliary radiator to radiate waves at least partially canceling the spurious wave.

Description

Technical Field

[0001] This invention generally relates to bipolar antennas, antenna arrays, and improved mechanisms for reducing interference caused by cross-polarized radiation. Background Technology

[0002] Massive multiple-input multiple-output (mMIMO) is one of the key technologies driving next-generation mobile communications. However, regulations in specific countries can be limiting factors when launching new services and telecommunications infrastructure.

[0003] For example, to facilitate site acquisition and comply with local regulations regarding site upgrades, the new antenna's dimensions should be comparable to those of conventional products. Furthermore, to maintain the site's mechanical support structure, the wind load exerted on the new antenna's exterior should be equal to or comparable to the wind load on conventional antennas. These factors result in very strict limitations on the new antenna's width and other specifications.

[0004] An antenna's directivity is limited by its aperture, and therefore by its width. This effect becomes particularly pronounced when multiple antenna arrays are housed within the same enclosure. Recently, mMIMO arrays have evolved to contain increasingly more radiating elements within the same volume, and even within the same frequency band. As the distance between radiating elements decreases, element coupling increases, leading to reduced efficiency and performance in both transmitting and receiving signals. Coupling can be considered interference because it is equivalent to radiating energy outside the intended area, thus degrading network performance.

[0005] To improve the throughput of an antenna system, dual-polarized antennas can be used. However, when the coupling between polarizations increases, for example due to the shortening of the distance between radiating elements, orthogonal radiation is generated, which adversely affects the antenna's cross-polar discrimination (XPD). Summary of the Invention

[0006] The purpose of this invention is to provide a bipolar antenna that can reduce interference caused by cross-polarization radiation, thereby improving XPD.

[0007] The above and other objectives are achieved by the features claimed in the independent claims.

[0008] Other implementations are obvious from the dependent claims, the specification and the drawings.

[0009] A first aspect of this disclosure provides a bipolar antenna comprising a bipolar radiator, the bipolar radiator including 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 feed network for feeding radio-frequency (RF) signals to the first radiator and the auxiliary radiator, thereby driving the first radiator to radiate a wave having a first polarization and causing it to radiate spurious waves 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 waves.

[0010] Therefore, the auxiliary radiator can be used to eliminate (at least partially) the electromagnetic field generated in the orthogonal polarization of the bipolar radiator, thereby reducing stray radiation generated in the orthogonal polarization. As a result, XPD is improved.

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

[0012] The power supply network can be used to make the amplitude of the RF signal at the auxiliary radiator lower than that 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 can be minimized, thereby simplifying manufacturing and reducing associated costs.

[0014] The monopole antenna can be placed symmetrically relative to the bipolar radiator. Therefore, array theory can be used to design different monopole configurations and specific pattern shapes to effectively eliminate various spurious waves.

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

[0016] A second aspect of this disclosure provides an antenna array comprising a plurality of bipolar antennas as described herein.

[0017] Therefore, the auxiliary radiator can be used to at least partially eliminate the field generated in the orthogonal polarization of the bipolar radiator, thereby reducing interference and improving XPD. This can be achieved by using the radiation from the auxiliary radiator to reduce the orthogonal radiation generated by the excitation of the bipolar radiator. Therefore, interference can be reduced.

[0018] The multiple bipolar antennas can form a massive multiple-input multiple-output (mMIMO) antenna array. Therefore, the bipolar antennas can be used in dense, next-generation antenna arrays.

[0019] A third aspect of this disclosure provides a method for transmitting a radio-frequency (RF) signal. The method includes feeding the RF signal to a first radiator having a first polarity and a first auxiliary radiator. This drives the first radiator to radiate a wave having a first polarization, and causes the radiation to have spurious waves with polarization orthogonal to the first polarization. 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 waves.

[0020] Therefore, the first auxiliary radiator can be used to eliminate the field generated in the orthogonal polarization of the bipolar radiator, thereby reducing the interference and improving the XPD.

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

[0022] The method may further include the following steps: feeding a second radio frequency (RF) signal to a second radiator and a second auxiliary radiator having a second polarity, 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 driving the second auxiliary radiator to radiate a wave that at least partially cancels out the spurious wave. Attached Figure Description

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

[0024] Figure 1 A bipolar antenna according to an example embodiment is schematically depicted;

[0025] Figure 2 A top view of a bipolar antenna according to an example embodiment is schematically depicted;

[0026] Figure 3A method for improving the radiative polarization purity between orthogonally polarized signals in a bipolar antenna, according to an example embodiment, is illustrated schematically.

[0027] Figure 4 The generation of pattern elimination according to an example embodiment is illustrated schematically;

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

[0029] Figure 6 A bipolar antenna according to an example embodiment is schematically depicted;

[0030] Figure 7 A top view schematically depicting two additional configurations of a bipolar antenna according to an example embodiment is shown.

[0031] Figure 8 A bipolar antenna according to another embodiment is schematically depicted. Detailed Implementation

[0032] The exemplary embodiments are described below in sufficient detail to enable those skilled in the art to implement and carry out 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 the examples described herein.

[0033] Therefore, while embodiments may be modified in various ways and take various alternative forms, specific embodiments thereof are shown in the accompanying drawings and described in detail below as examples. It is not intended to limit one to the specific forms disclosed. Rather, all modifications, equivalents, and alternatives falling within the scope of the appended claims should be included. Throughout all drawings and appropriate specific embodiments, elements of exemplary embodiments are consistently denoted by the same reference numerals.

[0034] The terminology used herein to describe embodiments is not intended to be limiting. The articles “a” and “described” are in the singular form because they refer to only one object, but their use herein should not preclude the existence of multiple objects referred to. In other words, unless the context clearly indicates otherwise, elements mentioned in the singular form may be one or more in number. It should be further understood that the term “comprising” as used herein is used to indicate the presence of the described feature, item, step, operation, element, and / or component, but does not preclude the presence or addition of one or more other features, items, steps, operations, elements, components, and / or combinations thereof.

[0035] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall be interpreted as their customary usage in the field. It should also be understood that, unless explicitly defined herein, terms in common usage shall also be interpreted as their customary usage in the relevant field, and not as having an idealized or overly formal meaning.

[0036] According to one example, a bipolar antenna is provided that improves the polarization purity between orthogonally polarized signals radiated by the bipolar antenna. At least one auxiliary radiator is provided to eliminate, deflect, or reduce stray fields associated with the desired polarization generated in vertical polarization, thereby improving cross-polar discrimination (XPD).

[0037] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus, and systems according to examples of the invention. Although the flowcharts described above show a specific execution sequence, the execution sequence may differ from that described. A box associated with one flowchart may be combined with a box from another flowchart. In some examples, certain boxes in the flowcharts may be unnecessary and / or additional boxes may be added.

[0038] Figure 1 A bipolar antenna according to an example embodiment is schematically depicted. The bipolar antenna 100 includes a bipolar radiator 102 comprising a first radiator 104 having a first polarity and a second radiator 106 having a second polarity. The bipolar antenna 100 also includes an auxiliary radiator 108 and a feed network 110 for feeding radio-frequency (RF) signals 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 radiating spurious (i.e., unwanted or undesirable) waves with polarization orthogonal to the first polarization, and further driving the auxiliary radiator 108 to radiate a wave that at least partially eliminates the spurious waves. In other words, the auxiliary radiator 108 can radiate a signal such that the cross-polarization components radiated by the first radiator 104 are at least partially eliminated, thereby reducing interference and improving XPD.

[0039] Those skilled in the art will understand that the exact hardware components chosen to implement the feed network 110 are not important, as long as the feed network 110 can provide a signal with the set amplitude, frequency, and waveform attributes. The RF signal fed through the feed network 110 can be generated internally (e.g., by the components / circuits constituting the feed network 110) or externally, enabling the feed network 110 to feed the signal to the desired components of the bipolar antenna 100.

[0040] The power supply network 110 may include one or more delay components to delay the signals fed to the first radiator 104 and the auxiliary radiator 108, thereby ensuring that the signal of the auxiliary radiator 108 is out of phase with the signal of the first radiator 104. This is in Figure 4 The text further explains that pattern elimination generation according to an example embodiment is schematically described. To eliminate cross-polarized radiation, an auxiliary radiator 108 can be used to generate a pattern as close as possible to the cross-polarized radiation and to radiate a signal in opposite phase in order to at least partially eliminate stray waves.

[0041] In one example, the feed network 110 can be used to ensure that the amplitude of the RF signal at the auxiliary radiator 108 is lower than the amplitude at the first radiator 104. The amplitude of the RF signal at the auxiliary radiator 108 can be tuned to the level of cross-polarization generated by the bipolar radiator 102. The frequencies of the signals fed to the first radiator 104 and the auxiliary radiator 108 through the feed network 110 can be the same or substantially the same, allowing the two units to radiate at the same frequency.

[0042] In one example, different cross-polarization components can be compensated for by employing different excitations (phase and amplitude) of the auxiliary radiator 108. Typically, the intensity of cross-polarization radiation will depend on the strength of the element coupling in the antenna, i.e., the distance 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 feed network 110 can depend on the intensity of the cross-polarization radiation caused by said coupling.

[0043] Figure 2 A top view of a bipolar 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 The monopole antennas are designated 108a and 108b. Those skilled in the art will understand that the number of monopole antennas can vary depending on the requirements of the antenna system, and dipole antennas can be used instead of monopole antennas. Monopole antennas 108a and 108b can be placed symmetrically with respect to the bipolar radiator 102. For example, monopole antennas 108a and 108b can be configured in an array concentric with the bipolar radiator 102.

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

[0045] See again Figure 1The auxiliary radiator 108 can be a first auxiliary radiator, the feed network 110 can be a first feed network, and the bipolar antenna 100 can further include a second auxiliary radiator and a second feed network. The second auxiliary radiator and the second feed network can correspond to or substantially correspond to the auxiliary radiator 108 and the feed network 110, respectively. The second feed network can be used to feed radio-frequency (RF) signals to the second radiator 106 and the second auxiliary radiator, thereby driving the second radiator 106 to radiate a wave with a second polarization and generating spurious waves with polarization orthogonal to the second polarization, and further driving the second auxiliary radiator to radiate a wave that at least partially eliminates the spurious waves.

[0046] Figure 3 A method for improving the radiated polarization purity between orthogonally polarized signals in a bipolar antenna, according to an example embodiment, is illustrated. For example, the bipolar antenna may be the bipolar antenna 100 described herein. The method includes, in block 301, feeding a radio-frequency (RF) signal 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 spurious waves with polarization orthogonal to the first polarization. In block 303, the method includes driving the first auxiliary radiator to radiate a wave that at least partially eliminates the spurious waves. In other words, the first auxiliary radiator may radiate a signal such that cross-polarization components radiated through the first radiator 104 are at least partially eliminated, thereby reducing generated interference.

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

[0048] The second field distribution can be generated based on a selected configuration of each of the multiple radiators in the subarray of auxiliary radiators forming the bipolar antenna. The second phase distribution can also be generated based on the cross-polarization components selected for the bipolar antenna.

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

[0050] Figure 5This is a flowchart of a method according to an example embodiment. In block 501, the antenna pattern of the bipolar antenna is determined. The antenna pattern represents a measure (in dB) of the directivity of the bipolar antenna as a function of phase and provides information about the main antenna pattern and unwanted components. In one example, the antenna pattern is determined in the environment where the antenna will be used. In block 503, the pattern of the auxiliary radiator is determined to complement the main antenna pattern to be corrected. In one example, the auxiliary radiator may include a monopole or dipole antenna. In block 505, the phase of the auxiliary radiator is calculated to generate the desired radiation pattern. In one example, the desired radiation pattern may include a radiation pattern having components that are substantially the same as those of the unwanted polarization pattern. In block 507, the amplitude of the auxiliary radiator required to eliminate the unwanted components of the main antenna pattern is calculated, and in block 509, the main antenna and auxiliary radiator are excited with calculated weights and a phase offset (between the main antenna and the auxiliary radiator). In one example, the phase offset enables the component to be eliminated from the main antenna to be out of phase with the component from the auxiliary radiator.

[0051] Figure 6 A bipolar antenna according to an example embodiment is schematically depicted. The bipolar antenna 600 corresponds to... Figure 1 A bipolar antenna 100. Antenna 600 includes a bipolar radiator 602 and an auxiliary radiator 608, as well as a ground 612. The distances a and b between the monopoles of the auxiliary radiator can be selected using array factor theory to shape the signal and eliminate unwanted orthogonal fields.

[0052] Figure 7 A top view schematically depicts two additional configurations of the bipolar antenna according to an example embodiment. In short, Figure 7 The settings described in the text Figure 2 This is an expansion based on a simpler description. The monopole of the auxiliary radiator 708 of the bipolar antenna 700 corresponds to... Figure 2 Monopoles 108a and 108b are shown. As shown, the monopoles of the auxiliary radiator 708 are arranged symmetrically with respect to the phase center of the bipolar radiator 702.

[0053] Figure 8 A bipolar antenna according to another embodiment is schematically depicted. The bipolar antenna 800 largely corresponds to the bipolar antenna described in the above figures. Figure 8 As shown, the bipolar radiator 802 can be implemented using a square dipole, and the auxiliary radiator 808 also includes a dipole. It should be understood that the radiators described herein can 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 forms disclosed. Many modifications and variations can be made without departing from the spirit and scope of the invention. The embodiments disclosed herein should be considered illustrative rather than restrictive in all respects. Reference should be made to the appended claims and their equivalents in determining the scope of the invention.

Claims

1. A bipolar antenna, characterized in that, The bipolar antenna includes: A bipolar radiator includes 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 radiator; A power supply network is used to feed radio frequency (RF) signals to the first radiator and the auxiliary radiator, thereby driving the first radiator to radiate a wave having a first polarization and causing the radiation to have spurious waves with polarization orthogonal to the first polarization, and further driving the auxiliary radiator to radiate a wave that at least partially eliminates the spurious waves. The power supply network includes one or more delay elements such that the signal fed to the auxiliary radiator is out of phase with the signal fed to the first radiator.

2. The bipolar antenna according to claim 1, characterized in that, The power supply network is used to ensure that the amplitude of the RF signal at the auxiliary radiator is lower than that at the first radiator.

3. The bipolar antenna according to claim 1 or 2, characterized in that, The auxiliary radiator includes two or more monopole antennas.

4. The bipolar antenna according to claim 1 or 2, characterized in that, The auxiliary radiator includes two or more dipole antennas.

5. The bipolar antenna according to claim 3, characterized in that, The monopole antenna is placed symmetrically relative to the bipolar radiator.

6. The bipolar antenna according to claim 4, characterized in that, The dipole antenna is placed symmetrically relative to the bipolar radiator.

7. The bipolar antenna according to claim 1 or 2, characterized in that, The auxiliary radiator is a first auxiliary radiator, the feed network is a first feed network, and the bipolar antenna further includes: Second auxiliary radiator and second feed network, The second feed network is used to feed radio frequency (RF) signals to the second radiator and the second auxiliary radiator, thereby driving the second radiator to radiate a wave with a second polarization and generating a spurious wave with 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.

8. An antenna array, characterized in that, The antenna array includes a plurality of bipolar antennas according to any one of claims 1 to 7.

9. The antenna array according to claim 8, characterized in that, Multiple of the aforementioned bipolar antennas form a massive multiple-input and multiple-output (mMIMO) antenna array.

10. A method for transmitting radio frequency (RF) signals, characterized in that, The method includes: The RF signal is fed to a first auxiliary radiator and a first radiator having a first polarity. The RF signal is delayed such that the signal fed to the first auxiliary radiator is out of phase with the signal fed to the first radiator, thereby: The first radiator is driven to radiate a wave with a first polarization, and the radiation is made to have stray waves with a polarization orthogonal to the first polarization. The first auxiliary radiator is driven to radiate a wave that at least partially eliminates the stray wave.

11. The method according to claim 10, characterized in that, The amplitude of the RF signal at the first auxiliary radiator is lower than the amplitude at the first radiator.

12. The method according to claim 10 or 11, characterized in that, The method further includes the following steps: A second RF signal is fed to a second auxiliary radiator and a second radiator having a second polarity, 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 driving the second auxiliary radiator to radiate a wave that at least partially eliminates the spurious wave.

Images