WO2006133609A1

WO2006133609A1 - High separation flat directional smart antenna array

Info

Publication number: WO2006133609A1
Application number: PCT/CN2005/002284
Authority: WO
Inventors: Binlong Bu; Fengzhang Xue; Shuai Xu; Enpeng Liu; Xiaoshi Huang
Original assignee: Comba Telecom Technology (Guangzhou) Ltd.
Priority date: 2005-06-13
Filing date: 2005-12-22
Publication date: 2006-12-21
Also published as: CN100341198C; CN1710751A

Abstract

A high separation flat directional smart antenna array is disclosed. The antenna array includes a metallic reflecting plate, a radome, and radiation arrays. Each radiation array consists of several dipoles arranged in a single row. The radiation array is arranged on the metallic reflecting plate, and the metallic reflecting plate is covered with the radome. On the metallic reflecting plate, at least two radiation arrays, which are aligned parallel, are arranged. The radiation arrays are feed in parallel, and at least one metallic separating bar is arranged between the adjacent radiation arrays. The bars are in parallel with the radiation arrays. Thus, compared to the existing art, the invention can not only improve the separation of the directional smart antenna array greatly, but also make the presetting of the down-tilt and the forming of the beam more easily by feeding in parallel.

Description

High isolation plate-shaped directional smart antenna array

[Technical Field]

The invention relates to a smart antenna array, in particular to a high isolation plate-shaped directional smart antenna array. 【technical background】

The concept of smart antenna was proposed for the needs of mobile communication technology in the late 1980s. It can improve the channel reuse rate and base station coverage of mobile communication systems, and overcome the increasingly serious interference problems such as co-channel and multipath fading. .

Smart antennas are currently mainly used for base stations. From the perspective of reception, the base station uses the smart antenna to estimate the direction of arrival (DOA) of the multipath radio wave from the mobile station, and performs spatial filtering to suppress other mobile stations and multipath interference. From the perspective of transmission, the base station uses the smart antenna to downlink beamform the transmitted signal, so that the base station transmit signal can be sent back to the mobile station along the direction of the incoming wave of the mobile station, thereby reducing the transmit power and reducing interference to other mobile stations.

The existing array of plate-shaped directional smart antenna arrays is fed in series, and there is no other supporting measures. Therefore, the isolation between adjacent units is only about 15 dB.

Due to the low isolation, the base station uses the smart antenna to estimate the direction of arrival of the multipath radio waves from the mobile station, which causes:

1. Beam tracking error, the base station cannot effectively transmit signals to the mobile station.

2. The zero point is not correct, and the ability to suppress interference is reduced.

3. When the beam is scanned, the impedance mismatch is very serious due to the strong mutual coupling between adjacent columns. There may be scanning blind spots, which may result in a decrease in the use of the smart antenna.

Therefore, it is necessary to find ways to improve the isolation of the plate-shaped directional smart antenna array.

[Contents] Confirmation The object of the present invention is to provide a high isolation plate-shaped directional smart antenna array capable of greatly improving the isolation and maintaining the isolation while maintaining the other characteristics of the planar smart antenna array.

The object of the present invention is achieved by the following technical solutions: The high isolation plate-shaped directional smart antenna array comprises a metal reflector, a radome and a radiation array consisting of a single column comprising a plurality of radiating elements, the radiation array being arranged in the metal reflection On the board, the radome is disposed on the metal reflector, wherein the metal reflector has at least two rows of radiation arrays arranged side by side, and the radiation arrays are fed in parallel, and between the adjacent two radiation arrays At least one longitudinal metal strip spaced alongside it is added.

Compared with the prior art, the invention has the advantages that: on the one hand, the isolation of the directional plate-shaped smart antenna array can be greatly improved; on the other hand, since the parallel feeding is adopted, the preset downtilt angle can be conveniently realized. Beamforming.

The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[Description of the Drawings]

Figure 1 is a perspective view of the present invention, in which a part of the radome is removed;

2 is a schematic diagram of a radiation array, a radiation oscillator, and a feed network of the present invention;

Figure 3 is a typical pattern of a single radiation array horizontal plane of the present invention;

Figure 4 is a typical isolation curve between adjacent radiation arrays of the present invention;

Figure 5 is a diagram showing a typical vertical direction of the preset 6 downtilt and upper side lobes suppressed to 18 dB;

Figure 6 is a perspective view of a second embodiment of the present invention, in which a part of the radome is removed;

7 is a schematic diagram of a radiation array, a radiation oscillator, and a feed network according to a second embodiment of the present invention, wherein FIG. 7a is a partial enlarged view of a lower left corner portion of FIG. 7b;

Figure 8 is a typical pattern of a single radiation array horizontal plane of the present invention;

Figure 9 is a typical isolation curve between adjacent radiation arrays in accordance with a second embodiment of the present invention. 【detailed description】

Referring to FIG. 1 , the high isolation plate-shaped directional smart antenna array of the present invention comprises a metal reflector 1, a radome 4, eight radiation arrays 2 and nine metal isolation strips 3, and the radiation array 2 is disposed on the metal reflector. 1 , the radome 4 is disposed on the metal reflector 1 , and the nine longitudinal metal barrier strips 3 are respectively placed on the symmetry axis between the adjacent two radiation arrays 2 , and the metal reflectors 1 are arranged side by side. The radiation array 2 should not be less than two, so that parallel feeding can be used between the radiation arrays 2.

Referring to FIG. 2, the radiation array 2 is composed of a single array of eight radiating elements 11 and a cable power dividing network 12. As long as the feed line length of each of the radiating elements 11 is changed, the downtilt angle presetting can be realized; if the power dividing ratio and the feeder length of each of the power splitters 13 are simultaneously adjusted, the downtilt angle presetting and the upper side lobe suppression can be realized.

Increasing the spacing between the radiation arrays can easily reduce the mutual coupling, thereby increasing the isolation, but will increase the total width of the antenna array, increase the size and weight of the antenna array, and the array spacing is too large. In the present invention, the reference surface of the radiating element of each radiation array is constrained from the metal reflector by a distance of 1/3 to 1/5 wavelength, specifically 1/4. At the wavelength, the radiation array spacing is constrained to 1/2 wavelength at the center.

By adding metal isolation strips 3 between adjacent two radiation arrays 2, a symmetric electric wall is formed, so that the power lines excited by the left and right radiation elements 11 are blocked by the metal isolation strips 3, and cannot reach the opposite radiation element 11 The mutual coupling is small, which improves the isolation. The parallel feeding can achieve uniform feeding, and the mutual coupling of the radiating elements 11 is the same, and the isolation can also be improved.

The metal spacer strip 3 is split into two or more segments, and may be a plurality of side by side, and the cross section may be of any shape, including a circle, a triangle, a square or a rectangle.

By comparing Figure 3, Figure 4 and Figure 5, the typical pattern of a single radiation array 2 horizontal plane, the typical isolation curve between adjacent radiation arrays 2, the preset 6 downtilt and the upper sidelobe suppression to 18 dB The typical pattern of the vertical plane can analyze the effects of the present invention. Please refer to FIG. 6 and FIG. 7 again, which is another embodiment of the present invention. The only difference from the previous embodiment is that the radiation array 2 is composed of eight printed symmetric vibrators 11 and one microstrip line. Network 12, composed. 8 and 9 respectively show a typical pattern of a single radiation array horizontal plane and a typical isolation curve between adjacent radiation arrays of the present embodiment, which are hereby incorporated by reference.

In summary, the present invention has the following effects through a series of technical improvements:

1. By adding two metal strips and adopting parallel feeding, the isolation of the present invention relative to the existing directional panel smart antenna is improved by 7~8dB, wherein when the array spacing is constrained to 1/2 wavelength, The isolation can reach 23 dB.

2. The use of parallel feed enables the present invention to conveniently implement preset downtilt and beamforming.

3. The invention also has the characteristics of simple and compact structure, easy manufacture and convenient installation and use.

The present invention has been shown and described with respect to the preferred embodiments thereof, and the invention is not to be construed as limiting the scope of the invention. Under the premise, it can be changed in form and detail. All such changes and modifications that come within the spirit and scope of the invention are covered by the appended claims.

Claims

Claim

1. A high isolation plate-shaped directional smart antenna array comprising a metal reflector, a radome and a radiation array comprising a single column comprising radiating elements, the radiation array being disposed on a metal reflector, the radome being disposed on the metal Above the reflector, the metal reflector is provided with at least two rows of radiation arrays arranged side by side, and each radiation array is fed in parallel, and at least one of the adjacent two radiation arrays is added side by side. Longitudinal metal strips.

2. The high-isolation plate-shaped directional smart antenna array according to claim 1, wherein: the reference surface of the radiating element of each of the radiation arrays is 1/3 to 1/5 wavelength from the metal reflector. Between the radiation array spacing is 1/2 wavelength at the center frequency.

3. The high-isolation plate-shaped directional smart antenna array according to claim 2, wherein: the metal spacers are disposed on a symmetry axis of two adjacent radiation arrays.

4. The high-isolation panel-shaped directional smart antenna array according to claim 3, wherein: the metal spacer strip is split into two or more segments.

The high-isolation plate-shaped directional smart antenna array according to any one of claims 1 to 4, wherein the metal spacer has a circular cross section.

The high-isolation plate-shaped directional smart antenna array according to any one of claims 1 to 4, characterized in that: the metal spacer has a rectangular cross section.

The high-isolation plate-shaped directional smart antenna array according to any one of claims 1 to 4, wherein the metal spacer has a square cross section.

The high-isolation plate-shaped directional smart antenna array according to any one of claims 1 to 4, characterized in that: the metal spacer has a triangular cross section.