CN111063995A

CN111063995A - Antenna applied to tunnel

Info

Publication number: CN111063995A
Application number: CN201911414487.7A
Authority: CN
Inventors: 陆尧; 李宗源; 费锦洲; 万江成; 林学进
Original assignee: Comba Telecom Technology Guangzhou Ltd
Current assignee: Comba Telecom Technology Guangzhou Ltd
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2020-04-24
Anticipated expiration: 2039-12-31
Also published as: CN111063995B

Abstract

The invention discloses an antenna applied to a tunnel, which comprises a reflecting plate, a first array, a second array and a third array, wherein the reflecting plate is arranged on the first array; the first array is arranged on the reflecting plate and comprises at least two first radiation units; the second array is arranged on the reflecting plate, the central line of the second array is parallel to the central line of the first array, and the second array comprises second radiation units which are arranged symmetrically to the first radiation units one by one; the third array is arranged on the reflecting plate and arranged between the second array and the first array, the third array comprises third radiation units, the first radiation units and the second radiation units are arranged in a staggered mode in different rows, and a third radiation unit is arranged between every two adjacent first radiation units. The antenna applied to the tunnel can restrain the horizontal plane side lobe level, optimize the axial cross polarization ratio and be beneficial to improving the signal coverage quality of the tunnel environment.

Description

Antenna applied to tunnel

Technical Field

The invention relates to the technical field of communication, in particular to an antenna applied to a tunnel.

Background

The landform and the topography of China are complex, the number of tunnels in high-speed, high-speed and subway lines is increasing in a blowout mode, and according to statistics, the proportion of the tunnels of the high-speed and high-speed railway lines to the positive line is more than 50%. The tunnel is a relatively closed environment, external signals are difficult to penetrate into the tunnel, and most of tunnels are still in a blind area covered by wireless communication signals at present. How to better realize the full coverage of the tunnel becomes an important target for building seamless coverage of mobile communication.

The conventional antenna index applied to the tunnel has high level sidelobe level value and poor axial cross polarization, and can form obvious multi-channel effect, so that the signal coverage is uneven, and the improvement of the communication quality in the tunnel is not facilitated.

Disclosure of Invention

Based on this, it is necessary to provide an antenna applied to a tunnel, which can suppress the horizontal plane side lobe level and optimize the axial cross polarization ratio; the method is applied to the tunnel, and is beneficial to improving the signal coverage quality of the tunnel environment.

The technical scheme is as follows:

in one aspect, the present application provides an antenna for a tunnel, including a reflector, a first array, a second array, and a third array; the first array is arranged on the reflecting plate and comprises at least two first radiation units; the second array is arranged on the reflecting plate, the central line of the second array is parallel to the central line of the first array, and the second array comprises second radiation units which are arranged symmetrically to the first radiation units one by one; the third array is arranged on the reflecting plate and arranged between the second array and the first array, the third array comprises third radiation units, the first radiation units and the second radiation units are arranged in a staggered mode in different rows, and a third radiation unit is arranged between every two adjacent first radiation units.

By the arrangement, the third radiation unit can form an array unit with the adjacent first radiation unit and the second radiation unit, the antenna is realized by the plurality of array units on the reflecting plate, the reflected electromagnetic wave components can be reduced and overlapped with each other, the phenomenon that the signal coverage is uneven due to large path loss is avoided, and the suppression of the horizontal plane side lobe level is facilitated; meanwhile, a third radiation unit is arranged between two adjacent first radiation units, so that the number of the radiation units of the third array is reduced, and the optimization of axial cross polarization is facilitated. The antenna applied to the tunnel can inhibit the horizontal plane side lobe level, optimize the axial cross polarization ratio and eliminate the interference in two directions; the method is applied to the tunnel, and is beneficial to improving the signal coverage quality of the tunnel environment.

The technical solution is further explained below:

in one embodiment, the excitation power ratio among the first radiating element, the second radiating element and the third radiating element is 1:1: 2.

In one embodiment, the first radiation unit, the second radiation unit and the third radiation unit are all high-frequency radiation units.

In one embodiment, the horizontal spacing between the first array and the third array is L1, the horizontal spacing between the second array and the third array is L2, and the central frequency wavelength of the working frequency band of the antenna applied to the tunnel is λ; wherein, L1 is (0.3-0.7) lambda, and L2 is (0.3-0.7) lambda.

In one embodiment, the third radiation unit is movably disposed on the reflection plate, so that a horizontal distance between the third radiation unit and the first radiation unit is adjustable, or a horizontal distance between the third radiation unit and the second radiation unit is adjustable.

In one embodiment, the longitudinal distance between the third radiating element and the adjacent first radiating element is L3, the longitudinal distance between the third radiating element and the adjacent second radiating element is L4, and the central frequency wavelength of the operating frequency band of the antenna applied to the tunnel is λ; wherein, L3 is (0.5-0.7) lambda, and L4 is (0.5-0.7) lambda.

In one embodiment, the longitudinal distances between two adjacent first radiation units in the first array are equal, the distance between two adjacent third radiation units is L5, and the central frequency wavelength of the working frequency band of the antenna applied to the tunnel is λ; wherein L5 is (1-1.4) lambda.

In one embodiment, the longitudinal intervals between the third radiation unit and the two adjacent first radiation units are all equal.

In one embodiment, the third radiating element, two adjacent first radiating elements and two adjacent second radiating elements form an "X" shaped array element, the distance between two adjacent third radiating elements is L6, and the central frequency wavelength of the operating frequency band of the antenna applied to the tunnel is λ; wherein L6 is (1.5 to 2.1) λ.

In one embodiment, the reflector plate includes two first reflective boundaries spaced apart on both sides of the reflector plate, a second reflective boundary disposed between the first array and the third array, and a third reflective boundary disposed between the second array and the third array.

In one embodiment, the heights of the first reflection boundary, the second reflection boundary and the third reflection boundary protruding out of the reflection plate are H, and the central frequency wavelength of the working frequency band of the antenna applied to the tunnel is lambda; wherein H ═ is (1.5 to 2.1) λ.

Drawings

Fig. 1 is a schematic view of an antenna structure applied to a tunnel according to a first embodiment;

FIG. 2 is an enlarged view of part A shown in FIG. 1;

FIG. 3 is a simulation diagram of the antenna level indicator applied to the tunnel shown in FIG. 1;

FIG. 4 is a simulation diagram of the antenna gain index applied to the tunnel shown in FIG. 1;

fig. 5 is a schematic view of an antenna structure applied to a tunnel according to the second embodiment;

fig. 6 is a simulation diagram of the horizontal plane index after the antenna applied to the tunnel shown in fig. 1 is excited.

Description of reference numerals:

100. a reflective plate; 110. a first reflective boundary; 120. a second reflective boundary; 130. a third reflective boundary; 200. a first array; 210. a first radiation unit; 300. a second array; 310. a second radiation unit; 400. a third array; 410. and a third radiation unit.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings and the detailed description. It should be understood that the detailed description and specific examples, while indicating the scope of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

It will be understood that when an element is referred to as being "secured to," "disposed on," "secured to," or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. Further, when one element is considered as "fixed transmission connection" with another element, the two elements may be fixed in a detachable connection manner or in an undetachable connection manner, and power transmission can be achieved, such as sleeving, clamping, integrally-formed fixing, welding and the like, which can be achieved in the prior art, and is not cumbersome. When an element is perpendicular or nearly perpendicular to another element, it is desirable that the two elements are perpendicular, but some vertical error may exist due to manufacturing and assembly effects. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only and do not represent the only embodiments.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

References to "first" and "second" in this disclosure do not denote any particular order or quantity, but rather are used to distinguish one element from another.

The conventional tunnel scheme at present has two kinds, one is to adopt the indoor distributed antenna system of coaxial feed, this scheme design is flexible and cover evenly, but the fabrication cost is high, the construction difficulty is great and it is inconvenient for the engineering to overhaul and maintain; the other is a repeater and a conventional antenna, and the scheme has the advantages of simple structure and construction and low cost. However, the antenna applied to the tunnel has a high level side lobe level value and poor axial cross polarization, and can form a significant multi-channel effect, so that signal coverage is uneven, and communication quality in the tunnel is seriously affected.

Based on this, as shown in fig. 1 and fig. 2, in the present embodiment, an antenna applied to a tunnel is provided, which includes a reflection plate 100, a first array 200, a second array 300, and a third array 400; the first array 200 is disposed on the reflection plate 100, and the first array 200 includes at least two first radiation units 210; the second array 300 is disposed on the reflection plate 100, and a center line of the second array 300 is parallel to a center line of the first array 200, and the second array 300 includes second radiation units 310 disposed in one-to-one symmetry with the first radiation units 210; the third array 400 is disposed on the reflective plate 100, the third array 400 is disposed between the second array 300 and the first array 200, the third array 400 includes a third radiation unit 410, the third radiation unit 410 is disposed in a staggered manner with respect to different rows of the first radiation unit 210 and the second radiation unit 310, and a third radiation unit 410 is disposed between two adjacent first radiation units 210.

As shown in fig. 3 and 4, with this arrangement, the third radiating element 410 can form an array element with the adjacent first radiating element 210 and second radiating element 310, and the antenna is implemented by a plurality of array elements on the reflection plate 100, which can reduce reflected electromagnetic wave components and overlap each other, avoid uneven signal coverage caused by large path loss, and is beneficial to suppressing horizontal plane side lobe level; meanwhile, a third radiation unit 410 is arranged between two adjacent first radiation units 210, which is beneficial to reducing the number of radiation units of the third array 400, reducing the cost and optimizing the axial cross polarization. The antenna applied to the tunnel can inhibit the horizontal plane side lobe level, optimize the axial cross polarization ratio and eliminate the interference in two directions; when the scheme is applied to the tunnel, the horizontal side lobe suppression can reach more than-15 dB, and the influence of high horizontal side lobe level value on the tunnel signal coverage is solved; compared with the traditional technical scheme, the scheme can optimize the axial cross polarization ratio to be more than 15dB, so that the interference in two directions can be eliminated, the wave beam narrowing is facilitated, and the signal coverage quality of the tunnel environment is improved.

It should be noted that an array is understood to mean that at least two radiating elements are aligned in the same direction. The "horizontal pitch" may be understood as a pitch in the width direction of the reflection plate 100, as shown in fig. 1 and 5. The "longitudinal interval" may be understood as an interval in a longitudinal direction of the reflection plate 100 or in a longitudinal direction of the display, as shown in fig. 1 and 5.

In an embodiment based on any of the above embodiments, the first radiation unit 210, the second radiation unit 310, and the third radiation unit 410 are all high-frequency radiation units. Thus, beams can be synthesized between the third array 400 and the first and

second arrays

200 and 300, which is beneficial to improving the signal coverage quality of the tunnel environment.

On the basis of any of the above embodiments, in an embodiment, the horizontal distance between the first array 200 and the third array 400 is L1, the horizontal distance between the second array 300 and the third array 400 is L2, and the central frequency wavelength of the operating band of the antenna applied to the tunnel is λ; wherein, L1 is (0.3-0.7) lambda, and L2 is (0.3-0.7) lambda. The horizontal sidelobe level is further inhibited, and the signal coverage quality of the tunnel environment is improved.

Specifically, L1 ═ 0.3 λ, 0.4 λ, 0.5 λ, 0.6 λ, or 0.7 λ, and L2 ═ 0.3 λ, 0.4 λ, 0.5 λ, 0.6 λ, or 0.7 λ.

On the basis of the above embodiments, in an embodiment, the longitudinal distance between the third radiation element 410 and the adjacent first radiation element 210 is L3, the longitudinal distance between the third radiation element 410 and the adjacent second radiation element 310 is L4, and the central frequency wavelength of the operating band of the antenna applied to the tunnel is λ; wherein, L3 is (0.5-0.7) lambda, and L4 is (0.5-0.7) lambda. Therefore, the axial cross polarization ratio is further improved, the cost is not increased, and the technical short board of the conventional tunnel antenna is solved.

Specifically, L3 ═ 0.5 λ, 0.6 λ, or 0.7 λ, and L4 ═ 0.5 λ, 0.6 λ, or 0.7 λ.

Based on the above embodiments, as shown in fig. 3 and fig. 4, in an embodiment, the longitudinal distances between two adjacent first radiation units 210 in the first array 200 are all equal, the distance between two adjacent third radiation units 410 is L5, and the central frequency wavelength of the operating band of the antenna applied to the tunnel is λ; wherein L5 is (1-1.4) lambda. Therefore, the antenna applied to the tunnel has the gain as high as 21.5dB, the horizontal half-power beam width of 27.4-33.6 degrees, the horizontal side lobe level inhibition of less than or equal to-15.8 dB and the axial cross polarization ratio of more than or equal to 24.1 dB.

Specifically, L5 ═ λ, 1.1 λ, 1.2 λ, 1.3 λ, or 1.3 λ.

In an embodiment, the longitudinal distance between the third radiation unit 410 and the adjacent two first radiation units 210 is equal.

On the basis of the above embodiments, as shown in fig. 5 and fig. 6, in another embodiment, the third radiating element 410, the two adjacent first radiating elements 210 and the two adjacent second radiating elements 310 form an "X" shaped array element, the distance between the two adjacent third radiating elements 410 is L6, and the central frequency wavelength of the operating band of the antenna applied to the tunnel is λ; wherein L6 is (1.5 to 2.1) λ. The antenna is composed of a plurality of array units arranged in an X shape, and the technical effects of improving the axial cross polarization ratio and further inhibiting the horizontal plane side lobe level can be realized.

In addition to any of the above embodiments, as shown in fig. 1 and fig. 2, in an embodiment, the reflective plate 100 includes two first reflective boundaries 110 disposed at two sides of the reflective plate 100 at intervals, a second reflective boundary 120 disposed between the first array 200 and the third array 400, and a third reflective boundary 130 disposed between the second array 300 and the third array 400. Therefore, interference is reduced, and the working performance of the antenna applied to the tunnel is improved.

Further, in an embodiment, the height of the first reflection boundary 110, the second reflection boundary 120, and the third reflection boundary 130 protruding from the reflection plate 100 is H, and the central frequency wavelength of the working band of the antenna applied in the tunnel is λ; wherein H ═ is (1.5 to 2.1) λ. In this way, the performance optimization of the antenna applied to the tunnel can be better adapted.

Specifically, H is 1.5 λ, 1.6 λ, 1.7 λ, 1.8 λ, 1.9 λ, 2 λ, 2.1 λ.

In an embodiment, based on any of the above embodiments, the excitation power ratio among the first radiation unit 210, the second radiation unit 310, and the third radiation unit 410 is 1:1: 2. Under the condition of ensuring the antenna gain, the horizontal side lobe suppression index of the antenna can be further improved.

In addition to any of the above embodiments, in an embodiment, the third radiation unit 410 is movably disposed on the reflection plate 100, so that a horizontal distance between the third radiation unit 410 and the first radiation unit 210 is adjustable, or a horizontal distance between the third radiation unit 410 and the second radiation unit 310 is adjustable. According to specific electrical requirements, the third array 400 or part of the third radiating elements 410 are displaced in the horizontal direction, so that the horizontal distance between three arrays is changed, the superposition of far-field lobe patterns of the antenna can be adjusted, and the optimization of horizontal plane half-power beam width, front-to-back ratio indexes and the like is realized.

The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above examples only show some embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. An antenna for use in a tunnel, comprising:

a reflective plate;

a first array disposed on the reflector plate, the first array including at least two first radiating elements;

the second array is arranged on the reflecting plate, the central line of the second array is parallel to the central line of the first array, and the second array comprises second radiation units which are arranged in one-to-one symmetry with the first radiation units; and

the third array is arranged on the reflecting plate, the third array is arranged between the second array and the first array, the third array comprises third radiation units, the third radiation units are arranged in a staggered mode in different rows between the first radiation units and the second radiation units, and one third radiation unit is arranged between every two adjacent first radiation units.

2. The antenna applied to the tunnel according to claim 1, wherein an excitation power ratio among the first radiation unit, the second radiation unit and the third radiation unit is 1:1: 2.

3. The antenna applied to the tunnel according to claim 1, wherein the first radiation unit, the second radiation unit and the third radiation unit are all high frequency radiation units.

4. The antenna of claim 1, wherein the first array is horizontally spaced from the third array by L1, the second array is horizontally spaced from the third array by L2, and the antenna for tunneling has an operating band center frequency wavelength λ; wherein, L1 is (0.3-0.7) lambda, and L2 is (0.3-0.7) lambda.

5. The antenna applied to the tunnel according to claim 1, wherein the third radiation unit is movably disposed on the reflection plate, so that a horizontal distance between the third radiation unit and the first radiation unit is adjustable, or so that a horizontal distance between the third radiation unit and the second radiation unit is adjustable.

6. The antenna applied to the tunnel according to claim 1, wherein a longitudinal distance between the third radiating element and the adjacent first radiating element is L3, a longitudinal distance between the third radiating element and the adjacent second radiating element is L4, and an operating band center frequency wavelength of the antenna applied to the tunnel is λ; wherein, L3 is (0.5-0.7) lambda, and L4 is (0.5-0.7) lambda.

7. The antenna for tunnel application according to claim 1, wherein the longitudinal spacing between two adjacent first radiating elements in the first array is equal, the spacing between two adjacent third radiating elements is L5, and the operating band center frequency wavelength of the antenna for tunnel application is λ; wherein L5 is (1-1.4) lambda.

8. The antenna applied to the tunnel according to claim 1, wherein the longitudinal intervals between the third radiation unit and the adjacent two first radiation units are all equal.

9. The antenna applied to the tunnel according to claim 8, wherein the third radiating element, two adjacent first radiating elements and two adjacent second radiating elements form an array element in an "X" shape, a distance between two adjacent third radiating elements is L6, and a center frequency wavelength of an operating band of the antenna applied to the tunnel is λ; wherein L6 is (1.5 to 2.1) λ.

10. The antenna applied to the tunnel according to any one of claims 1 to 9, wherein the reflector plate comprises two first reflecting boundaries disposed at two sides of the reflector plate at intervals, a second reflecting boundary disposed between the first array and the third array, and a third reflecting boundary disposed between the second array and the third array.

11. The antenna as claimed in claim 10, wherein the first, second and third reflective boundaries protrude from the reflector by a height H, and the operating band of the antenna for a tunnel has a center frequency wavelength λ; wherein H ═ is (1.5 to 2.1) λ.