Antenna array with large pitch between oscillators
By adopting large inter-vibration spacing and metasurface structures in the antenna, the multi-band antenna integration and interference problems are solved, and efficient frequency band integration and performance improvement are achieved.
Patent Information
- Application Number
- CN202280095794.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2022-07-19
- Publication Date
- 2024-12-17
AI Technical Summary
In 5G deployment, in order to support antenna designs of multiple frequency bands, it is difficult for the prior art to effectively integrate multiple frequency bands within size limitations without increasing the size of the antenna, and the large inter-vibrator spacing leads to an increase in side lobes, reducing antenna gain and generating interference.
Antenna structures with multiple radiator intervals are adopted, combined with reflectors and metasurface structures, by increasing the spacing between oscillators and using the metasurface structure to flatten the electric field phase, reduce the number of radiators, reduce interference, and control through multi-layer metasurface structures Reflective and transmissive phases.
It realizes increasing frequency band integration while the size remains unchanged, reducing interband interference, improving antenna performance and gain, and reducing manufacturing costs.
Smart Images
Figure CN119156744A_ABST
Abstract
Description
Technical Field
[0001] The present invention generally relates to antenna structures and metasurface structures. Background Art
[0002] With the deployment of 5G, in order to support the new 700M and 3.5G frequency bands, there is an increasing need to develop an antenna with more frequency bands (for example, 700M / 800M / 900M / 1.4G / 1.8G / 2.1G / 2.6G / 3.5G). In addition, in order to fully utilize the capabilities of the new air interface standards, the number of TRX / antenna ports and arrays / antenna columns for each frequency band must also be increased.
[0003] Despite the increase in frequency bands and the number of ports per band, the limit of one antenna per sector (or a maximum of two antennas in special cases) remains a very strict requirement. In addition, the size and wind load of the new antennas should be comparable to traditional products in order to facilitate site deployment and / or be able to reuse the existing mechanical structure of the site.
[0004] Therefore, it is desirable to be able to neatly integrate several frequency bands together without affecting the size of the antenna. One way to do this is to use arrays with large inter-element spacing (e.g., greater than one wavelength), thereby reducing the number of radiators per array. As a result, more frequency bands can be integrated into the antenna.
[0005] The total radiation field and directivity of the antenna depend largely on the dipole parameters, such as the spacing between the dipoles. As the spacing between the dipoles increases, side lobes appear in the array radiation pattern. For example, when the spacing increases to one wavelength, the side lobes can become as large as the main lobe. These can significantly reduce the antenna gain and cause interference. For antenna arrays with uniform spacing, side lobes can be eliminated by reducing the spacing between the dipoles. For non-uniform arrays, side lobes are more difficult to predict. Summary of the invention
[0006] The object of the present invention is to provide an antenna structure with a large inter-element spacing.
[0007] These and other objects are achieved by the features of the independent claims.
[0008] Further implementations are apparent from the dependent claims, the description and the drawings.
[0009] The first aspect of the present invention provides an antenna structure, which includes: a plurality of radiators arranged at intervals from each other, wherein the distance between adjacent radiators in at least some of the plurality of radiators is greater than a wavelength of the highest frequency in the working frequency band of the antenna; a reflector arranged below the plurality of radiators; and a metasurface structure arranged above the plurality of radiators.
[0010] Therefore, the spacing between radiators can be increased without affecting performance. By increasing the inter-element spacing, the number of radiators can be reduced, the number of output terminals of the phase shifter can be reduced, the manufacturing cost can be minimized, the integration of multiple frequency bands can be simplified, and the interference between frequency bands can be reduced by reducing the number of antennas.
[0011] In an implementation of the first aspect, the plurality of radiators may include a series of radiators arranged in a first direction, and the metasurface structure may include a plurality of parts arranged in the first direction, each part having a corresponding impedance value. Therefore, the phase of the electric field may be flattened, thereby reducing grating lobes associated with an increase in the spacing between dipoles, and improving the performance of the antenna structure by reducing interference caused by the grating lobes.
[0012] The plurality of portions may define a repeating pattern of impedance values. Thus, the repeating pattern may define a periodic variation of the impedance of the plurality of portions in the first direction.
[0013] The repeating pattern may repeat with a period that is the same as or an integer multiple of the distance between adjacent radiators.
[0014] The metasurface structure may include multiple layers. Thus, the control of the reflection and transmission phases may be enhanced.
[0015] Each of the multiple layers may have a corresponding impedance value. Therefore, the reflection introduced by the metasurface may be minimized, and the transmission phase may be adjusted as desired.
[0016] The layers in the plurality of layers may be spaced apart from each other.
[0017] The impedance of at least one of the portions may vary in a second direction orthogonal to the first direction.
[0018] The metasurface structure may include a substrate on which a conductive pattern is disposed. Thus, the impedance of the metasurface structure may be modified in a simple and economical manner.
[0019] The supersurface structure may further include a layer disposed on the conductive pattern and the substrate.
[0020] Each radiator of the plurality of radiators may be a dual-polarity radiator.
[0021] The antenna structure may further include a second plurality of radiators disposed with a spacing therebetween.
[0022] A second aspect of the present invention provides a metasurface structure for modifying the electric field phase of a radiating unit of an antenna structure, wherein the metasurface structure comprises a plurality of parts defining a repetitive pattern of impedance values, wherein the repetitive pattern comprises a plurality of parts, each part having a corresponding impedance value.
[0023] Therefore, the spacing between radiators can be increased without affecting performance. By increasing the inter-element spacing, the number of radiators can be reduced, the number of output terminals of the phase shifter can be reduced, the manufacturing cost can be minimized, the integration of multiple frequency bands can be simplified, and the interference between frequency bands can be reduced by reducing the number of antennas.
[0024] The repeating pattern may repeat with a period that is the same as or an integer multiple of the distance between adjacent radiators.
[0025] The plurality of portions may extend along a first direction, and the corresponding impedance value of a portion may vary along a second direction orthogonal to the first direction.
[0026] The imaginary part of the impedance of the metasurface structure may be lower within the operating frequency band than outside the operating frequency band. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Embodiments will now be described, by way of example only, with reference to the accompanying drawings, in which:
[0028] Figure 1 Schematically illustrates a side view of an antenna structure provided by an exemplary embodiment;
[0029] Figure 2 Schematically shows a top view of an antenna structure provided by an exemplary embodiment;
[0030] Figure 3 Schematically illustrates a metasurface structure provided by an exemplary embodiment;
[0031] Figure 4 Schematically illustrates the electric field phase flattening effect provided by an exemplary embodiment;
[0032] Figure 5 The metasurface impedance of multiple frequency bands is schematically shown. DETAILED DESCRIPTION
[0033] 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.
[0034] 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.
[0035] 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.
[0036] 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.
[0037] Antennas have a specific radiation pattern. When multiple antenna elements are combined into an array, the overall radiation pattern changes. Sidelobes are lobes in the far-field radiation pattern that are not in the main beam. The number of sidelobes increases with the number of elements. The main disadvantage of spacing elements larger than one wavelength of the highest frequency in the antenna operating band is the presence of high sidelobes in the array radiation pattern. These sidelobes are called grating lobes and can significantly reduce the antenna gain and cause interference. Grating lobes occur due to the discontinuity of the electric field phase along the extension direction of the antenna array.
[0038] According to one example, an antenna structure and a method for increasing the inter-element spacing in the antenna structure are provided so that the electric field phase of the radiator can be modified to reduce the far-field radiation pattern in a compact antenna structure with limited size.
[0039] Figure 1A side view of an antenna structure provided by an exemplary embodiment is schematically shown. The antenna structure 100 includes a plurality of radiators 103 spaced apart from each other. The antenna 100 includes a reflector 101 disposed below the plurality of radiators 103. The distance between adjacent radiators 103 in at least some of the plurality of radiators 103 is greater than one wavelength of the highest frequency of the operating frequency band of the antenna structure 100. The operating frequency band of an antenna refers to the frequency range in which the antenna can operate at an acceptable level of efficiency. The antenna is generally capable of operating outside a set range, but the gain, voltage standing wave ratio (VSWR) and radiation pattern of the antenna may be variable or non-constant. The spacing between at least some of the radiators 103 is greater than one λ of the highest frequency (i.e., upper limit) of the operating frequency band, as shown in the figure.
[0040] The antenna structure 100 further includes a metasurface structure 105. The metasurface structure is disposed above the plurality of radiators 103. The metasurface structure 105 may include an electromagnetic metasurface capable of manipulating electromagnetic waves, that is, an artificial thin sheet material having a sub-wavelength thickness.
[0041] The purpose of the metasurface structure 105 is to mitigate the negative effects caused by the increased spacing between the multiple radiators 103, which usually leads to the appearance of grating lobes in the radiation pattern, thereby reducing the antenna gain and generating interference. Specifically, these grating lobes appear because the electric field phase has discontinuities along the extension direction of the antenna array. By introducing the metasurface structure 105, the phase distribution of the electric field can be flattened, such as Figure 4 shown.
[0042] Figure 2 The schematic diagram shows a top view of an antenna structure 100 provided by an exemplary embodiment. The plurality of radiators 103 may include a series of radiators arranged in a first direction (as indicated by arrows). The metasurface structure 105 may include a plurality of portions 105-1, 105-2, ... 105-n arranged in the first direction, each portion 105-n having a corresponding impedance value Z N The corresponding impedance value Z N The impedance value Z of each portion 105-n may be different between adjacent portions, but the present invention is not limited thereto. N can be compared with the corresponding impedance values Z of other parts in the plurality of parts 105-n N different.
[0043] The plurality of portions 105-n may define a repetitive pattern of impedance values. Thus, the repetitive pattern may define a periodic variation of the impedance of the plurality of portions 105-n in the first direction. For example, the metasurface structure 105 may be divided into a plurality of portions, each with a different impedance, which is repeated according to a predefined period. By varying the impedance Z of each portion 105-n, the impedance of the plurality of portions 105-n may be varied. N , introducing different phase shifts into the electric field, thus being able to reshape the phase curve. This can be done by calculating the delays and impedances required to achieve the flattening of the curve. Again, Figure 4 , the input phase (below the metasurface structure 105 ) is represented as 401 , and the output phase (above the metasurface structure 105 ) is represented as 402 .
[0044] The impedance of at least one of the plurality of sections 105 - n may vary in a second direction orthogonal to the first direction. The repeating pattern may repeat with a period that is the same as the distance between adjacent radiators 103 or an integer multiple of the distance between adjacent radiators 103 .
[0045] The metasurface structure 105 may include multiple layers. Figure 1 In the example of , the metasurface structure 105 includes two layers, but the present invention is not limited thereto. Increasing the number of layers of the metasurface structure 105 can enhance the control of the reflection and transmission phases. In one embodiment, the metasurface structure 105 can include two or three layers.
[0046] Each layer in the multilayer may have a corresponding impedance value. The layers in the multilayer may be spaced apart from each other. Specifically, by changing the impedance of each layer of the metasurface structure 105, the reflection introduced by the metasurface structure 105 may be minimized, so that the transmission phase may be adjusted as needed.
[0047] Figure 5 The metasurface impedance of multiple frequency bands is schematically shown. Since the metasurface structure 105 is intended to be used in a multi-band environment, the metasurface structure 105 can be designed to be quasi-transparent to other frequency band radiators coexisting in the antenna structure 100. To achieve this, the corresponding impedance value Z N It should be relatively low in the operating frequency band 601, and very high in the rest of the frequency bands.
[0048] For example, the corresponding values may be such that the frequency at which the impedance of the metasurface structure 105 crosses the 0 ohm line (low impedance band 602) is outside the operating band, since this means that the metasurface structure 105 acts like a reflector, destroying the performance at that particular frequency. The high impedance band 603 represents an area where the equivalent impedance of the metasurface structure 105 is very high, appearing as an open circuit and being quasi-transparent. Arrays operating at this frequency can coexist in the same antenna structure 100 without any problems, since the metasurface structure 105 has little effect on this frequency band.
[0049] The metasurface structure 105 may include a substrate on which a conductive pattern is disposed. The metasurface structure 105 may also include a layer disposed on the conductive pattern and the substrate. This enables the impedance of the metasurface structure 105 to be varied.
[0050] Each radiator in the plurality of radiators 103 may be a dual-polarity radiator. The antenna structure 100 may include a second plurality of radiators spaced apart from each other between the plurality of radiators 103 .
[0051] Figure 3 The metasurface structure provided by an exemplary embodiment is schematically shown. Figure 3 The metasurface structure 300 shown may correspond to Figure 1 and Figure 2 The metasurface structure 105 is shown. The metasurface surface 300 for modifying the electric field phase of the radiating element of the antenna structure includes a plurality of portions 303, the plurality of portions 303 defining a repeating pattern of impedance values, the repeating pattern including a plurality of portions 303-n, each portion 303-n having a corresponding impedance value Z N . In one example, the impedance of a portion may vary with the width of the unit cell. The repetitive pattern may be repeated in a period that is the same as the distance between adjacent radiators or an integer multiple of the distance between adjacent radiators. Multiple portions 303 may extend along a first direction, and the corresponding impedance value of a portion may vary along a second direction orthogonal to the first direction. The magnitude of the imaginary part of the impedance of the metasurface structure 300 may be lower within the operating frequency band of the antenna structure including the metasurface structure 300 than outside the operating frequency band.
[0052] 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. An antenna structure, comprising: A plurality of radiators spaced apart from one another, wherein a distance between adjacent radiators in at least some of the plurality of radiators is greater than a wavelength of a highest frequency in an operating frequency band of the antenna; a reflector disposed below the plurality of radiators; and A metasurface structure is disposed above the plurality of radiators.
2. The antenna structure according to claim 1, characterized in that: The plurality of radiators include a series of radiators arranged in a first direction, and the metasurface structure includes a plurality of portions arranged in the first direction, each portion having a corresponding impedance value.
3. The antenna structure according to claim 2, characterized in that: The plurality of portions define a repeating pattern of impedance values.
4. The antenna structure according to claim 3, characterized in that: The repeating pattern repeats with a period that is the same as the distance between adjacent radiators or an integer multiple of the distance between adjacent radiators.
5. The antenna structure according to any one of the preceding claims, characterized in that: The metasurface structure includes multiple layers.
6. The antenna structure according to claim 5, characterized in that: Each of the multiple layers has a corresponding impedance value.
7. The antenna structure according to claim 5 or 6, characterized in that: The layers in the plurality of layers are spaced apart from each other.
8. The antenna structure according to claim 2, characterized in that: The impedance of at least one of the portions varies in a second direction orthogonal to the first direction.
9. The antenna structure according to any one of the preceding claims, characterized in that: The super surface structure includes a substrate, on which a conductive pattern is arranged.
10. The antenna structure according to claim 9, characterized in that: The super surface structure also includes a layer disposed on the conductive pattern and the substrate.
11. The antenna structure according to any one of the preceding claims, characterized in that: Each radiator of the plurality of radiators is a dipole radiator.
12. The antenna structure of any preceding claim, further comprising a second plurality of radiators, the second plurality of radiators being arranged with spaced relation between the plurality of radiators.
13. A metasurface structure for modifying the electric field phase of a radiating element of an antenna structure, the metasurface structure comprising: A plurality of sections define a repeating pattern of impedance values, the repeating pattern comprising a plurality of sections, each section having a corresponding impedance value.
14. The super surface structure according to claim 13, characterized in that: The repeating pattern repeats with a period that is the same as the distance between adjacent radiators or an integer multiple of the distance between adjacent radiators.
15. The supersurface structure according to claim 13 or 14, characterized in that: The plurality of sections extend along a first direction, and the corresponding impedance value of a section varies along a second direction orthogonal to the first direction.
16. The super surface structure according to any one of claims 13 to 15, characterized in that: The imaginary part of the impedance of the metasurface structure is lower in the working frequency band than outside the working frequency band.