Patent Application
20250096484
The present invention relates generally to a dual polarity antenna, an antenna array, and an improved mechanism for reduction of interference generated by cross-polar radiation.
Massive multiple-input and multiple-output, mMIMO, is one of the key technologies driving a new generation of mobile communications. However, country specific regulations can be a limiting factor when rolling out new services and telecommunication infrastructures.
For example, in order to facilitate site acquisition and to meet the local regulations concerning site upgrades, the dimensions of new antennas should be comparable to legacy products. Additionally, in order to be able to maintain the mechanical support structures present at the sites, the load placed on the exterior of a new antenna structure by wind should be equivalent or comparable to the wind load of the legacy antennas. These factors lead to a very strict limitation in, e.g., the width of new antennas.
The directivity of an antenna is limited by its aperture, and, consequently, by the antenna width. This effect becomes critical when several antenna arrays are placed inside the same enclosure. Recently, mMIMO arrays have been evolving to enclose more and more radiating elements in the same volume, even for the same frequency band. As the distance between the radiating elements is reduced, element coupling increases, leading to a reduction in antenna efficiency and performance during both transmission and reception of signals. Coupling can be considered interference as it amounts to energy radiated outside of the intended area, thereby degrading network performance.
In order to increase traffic handling capacity of the antenna system, dual polarised antennas may be used. Unfortunately, when coupling between the polarisation increases, for example due to reduction in distance between radiating elements, radiation in the orthogonal direction is generated, which adversely affects the cross-polar discrimination (XPD) of the antenna.
An objective of the present disclosure is to provide a dual polarity antenna capable of reducing interference generated by cross-polar radiation, thereby improving XPD.
The foregoing and other objectives are achieved by the features of the independent claims.
Further implementation forms are apparent from the dependent claims, the description and the figures.
A first aspect of the present disclosure provides a dual polarity antenna comprising a dual polarity radiator comprising a first radiator having a first polarity and a second radiator having a second polarity orthogonal to the first polarity, an ancillary radiator, and a feeding network for feeding a radio-frequency, RF, signal to both the first radiator and the ancillary radiator, thereby driving the first radiator to radiate a wave having a first polarisation, and causing radiation of a spurious wave having a polarisation orthogonal to the first polarisation, and further driving the ancillary radiator to radiate a wave that cancels the spurious wave at least partly.
Accordingly, the ancillary radiator can be used to cancel (at least partly) the electromagnetic fields generated in the orthogonal polarisation of a dual polarity radiator, thereby reducing the spurious radiation generated in the orthogonal polarization. XPD is thus improved.
In an implementation of the first aspect, the feeding network may comprise one or more delay elements. Thus, the feeding network can define the phase of the RF signal in a simple, cost-effective manner.
The feeding network may be configured so that the RF signal has a lower amplitude at the ancillary radiator than at the first radiator.
The ancillary radiator may comprise two or more monopole antennas. Thus, the complexity of the components constituting the ancillary radiator can be minimised, thereby simplifying manufacturing and reducing costs associated therewith.
The monopole antennas may be placed symmetrically with respect to the dual polarity radiator. Thus, array theory can be utilised to design different monopole configurations and specific pattern shapes to effectively cancel various spurious waves.
The ancillary radiator may be a first ancillary radiator, the feeding network may be a first feeding network, and the dual polarity antenna may further comprise a second ancillary radiator and a second feeding network, wherein the second feeding network is configured for feeding a radio-frequency, RF, signal to both the second radiator and to the second ancillary radiator, thereby driving the second radiator to radiate a wave having a second polarisation and causing generation of a spurious wave having a polarisation orthogonal to the second polarisation, and further driving the second ancillary radiator to radiate a wave that cancels the spurious wave at least partly. Thus, XPD of the dual polarity radiator can be improved effectively.
A second aspect of the present disclosure provides an antenna array comprising a plurality of dual polarity antennas as described herein.
Accordingly, the ancillary radiator can be used to cancel, at least to a degree, the resultant fields generated in the orthogonal polarisation of a dual polarity radiator, thereby reducing interference and improving the XPD. This can be achieved by using the radiation from the ancillary radiator to reduce orthogonal radiation generated by the excitation of the dual polarity radiator. As such, a reduction in interference can be provided.
The plurality of dual polarity antennas may form a massive multiple-input and multiple-output, mMIMO, antenna array. As such, the dual polarity antennas can be utilised in a dense, new generation antenna arrays.
A third aspect of the present disclosure provides a method of transmitting a radio-frequency (RF) signal. The method comprises feeding a radio-frequency, RF, signal to a first radiator having a first polarity and a first ancillary radiator. This drives the first radiator to radiate a wave having a first polarisation and causes radiation of a spurious wave having a polarisation orthogonal to the first polarisation Feeding the RF signal to the first ancillary radiator further drives the first ancillary radiator to radiate a wave that cancels the spurious wave at least partly.
Accordingly, the first ancillary radiator can be used to cancel the resulting fields generated in the orthogonal polarisation of a dual polarity radiator, thereby reducing the interference and improving the XPD.
The RF signal may have a lower amplitude at the ancillary radiator than at the first radiator.
The method may further comprise the steps of feeding a second radio-frequency, RF, signal to a second radiator having a second polarity and a second ancillary radiator to thereby drive the second radiator to radiate a wave having a second polarisation and causing generation of a spurious wave having a polarisation orthogonal to the second polarisation, and driving the second ancillary radiator to radiate a wave that cancels the spurious wave at least partly.
Embodiments will now be described by way of example only with reference to the figures, in which:
Example embodiments are described below in sufficient detail to enable those of ordinary skill in the art to embody and implement the systems and processes herein described. It is important to understand that embodiments can be provided in many alternate forms and should not be construed as limited to the examples set forth herein.
Accordingly, while embodiments can be modified in various ways and take on various alternative forms, specific embodiments thereof are shown in the drawings and described in detail below as examples. There is no intent to limit to the particular forms disclosed. On the contrary, all modifications, equivalents, and alternatives falling within the scope of the appended claims should be included. Elements of the example embodiments are consistently denoted by the same reference numerals throughout the drawings and detailed description where appropriate.
The terminology used herein to describe embodiments is not intended to limit the scope. The articles “a,” “an,” and “the” are singular in that they have a single referent, however the use of the singular form in the present document should not preclude the presence of more than one referent. In other words, elements referred to in the singular can number one or more, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes,” and/or “including,” when used herein, specify the presence of stated features, items, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, items, steps, operations, elements, components, and/or groups thereof.
Unless otherwise defined, all terms (including technical and scientific terms) used herein are to be interpreted as is customary in the art. It will be further understood that terms in common usage should also be interpreted as is customary in the relevant art and not in an idealized or overly formal sense unless expressly so defined herein.
According to an example, there is provided a dual-polarity antenna with improved polarisation purity between orthogonal polarised signals radiated by the dual-polarity antenna. At least one ancillary radiator is provided to cancel, offset, or reduce the spurious fields generated in the perpendicular polarisation with regard to a desired polarisation, thereby improving cross-polar discrimination (XPD).
The present disclosure is described with reference to flow charts and/or block diagrams of the method, devices and systems according to examples of the present disclosure. Although the flow diagrams described above show a specific order of execution, the order of execution may differ from that which is depicted. Blocks described in relation to one flow chart may be combined with those of another flow chart. In some examples, some blocks of the flow diagrams may not be necessary and/or additional blocks may be added.
The skilled person would appreciate that the exact hardware components selected to implement the feeding network 110 are not important, as long as the feeding network 110 can provide a signal with set properties of amplitude, frequency, and wave shape. The RF signal fed by the feeding network 110 may be generated internally, e.g., by the components/circuitry constituting the feeding network 110, or externally, such that the feeding network 110 can feed the signal to the required components of the dual polarity antenna 100.
The feeding network 110 may comprise one or more delay components, so as to delay the signal to be fed to both the first radiator 104 and the ancillary radiator 108, thereby ensuring that the signal of the ancillary radiator 108 is counter phased to the signal of the first radiator 104. This is further illustrated in
In an example, the feeding network 110 may be configured so that the RF signal has a lower amplitude at the ancillary radiator 108 than at the first radiator 104. An amplitude of the RF signal at the ancillary radiator 108 may be tuned to the level of the cross-polarisation generated by the dual polarity radiator 102. A frequency of the signal fed by the feeding network 110 to the first radiator 104 and the ancillary radiator 108 may be the same, or substantially the same, such that both elements may radiate at the same frequency.
In an example, different cross-polar components may be compensated by employing different excitations (phase and amplitude) of the ancillary radiator 108. Generally, a strength of the cross-polar radiation will depend on how strong the element coupling in the antenna is, i.e., how far the radiating elements of an antenna system are with respect to each other. Consequently, signal strength of the RF signal required to be fed by the feeding network 110 to the ancillary radiator 108 may depend on the strength of the cross-polar radiation caused by said coupling.
The dual polarity radiator 102 and the ancillary radiator 108 may comprise a common phase centre. The monopole antennas 108a, 108b may be arranged in a symmetric array configuration with respect to the phase centre.
Referring back to
In an example, an improvement in radiated polarisation purity between orthogonal polarised signals in a dual polarity antenna may be achieved by determining a measure of a first field distribution of a first field radiated from a dual polarity radiator of the dual polarity antenna, and generating a second field distribution using an ancillary radiator of the dual polarity antenna, wherein the first field distribution and the second field distribution comprise phase distributions that are out of phase. An amplitude of the signal used to generate the second field distribution may be adjusted such that the resulting spurious (e.g., unwanted or undesirable) radiated power of the first field can be regulated.
The second field distribution may be generated on the basis of a selected configuration for each of multiple radiators of a sub-array forming the ancillary radiator of the dual polarity antenna. The second phase distribution may also be generated on the basis of a selected cross-polar component for the dual polarity antenna.
In an example, a phase value for the first field distribution and the second field distribution may be selected, and the phase of the signal may be adjusted to generate a difference in phase between the first phase distribution and the second phase distribution at the selected phase value representing the predetermined amount. The predetermined amount may be 180 degrees.
The preceding description has been provided to enable others skilled in the art to best utilize various aspects of the exemplary embodiments disclosed herein. This exemplary description is not intended to be exhaustive or to be limited to any precise form disclosed. Many modifications and variations are possible without departing from the spirit and scope of the instant disclosure. The embodiments disclosed herein should be considered in all respects illustrative and not restrictive. Reference should be made to the appended claims and their equivalents in determining the scope of the instant disclosure.
This application is a continuation of International Application No. PCT/EP2022/064782, filed on May 31, 2022, the disclosure of which is hereby incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/EP2022/064782 | May 2022 | WO |
| Child | 18959221 | US |
