JPH11289219A - Base station antenna system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce installation space in a base station antenna system allowed to be used for a base station in a mobile communication system, constituting a 60 deg. sector zone and adopting a space diversity system. SOLUTION: Transmitting/receiving antennas 11 and receiving antennas 12 in which the main beam half-value width of a horizontal plane directional characteristic is 60 deg. are arranged close to each other so that the horizontal intra-plane included angle of their main beam directions 14 (14A to 14F), 15 (15A to 15F) are 120 deg., each pair of antennas 11, 12 is united with each other by covering it with a radome 13 and six pairs of antennas 11, 12 are arranged at an interval of 60 deg.. The symbols of zones to be covered are allocated to beam direction numbers. For instance, a diversity antenna covering a zone A is constituted of the antenna 11 of the direction 14A in a zone B and the antenna 12 of the direction 15A in a zone F. The diameter of the radome 13 is reduced by about 20%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a base station antenna apparatus used for a base station in a mobile communication system, forming a 60.degree. Sector zone, and employing a space diversity system.

[0002]

2. Description of the Related Art In a radio zone configuration in a cellular mobile communication system, there is a sector zone configuration in which a horizontal plane is angularly divided and radiated by a directional antenna to form a plurality of zones for effective use of frequency. At this time, when a 6-sector wireless zone configuration is adopted, the half value width of the main beam of the horizontal plane directivity characteristics of the antenna is 60 ° (hereinafter, referred to as a 60 ° beam antenna), and one base station is equipped with six such antennas. Will be.

If the space diversity system is adopted to further improve the communication quality, one base station will be equipped with 12 antennas. A conventional antenna device of this type is shown in FIG. The transmission / reception antenna 11 and the reception antenna 12 are covered in the radome 13 as a pair. A set of such antennas 11 and 12 is 6 in a horizontal plane.
Six sets are arranged at an angular interval of 0 °. Antennas 11 and 12
Have a main beam half-width of 60 ° in the horizontal plane directivity characteristic, that is, are 60 ° beam antennas. These antennas 11 and 12 have narrow angles in their main beam directions (tip directions 14 and 15) in the same horizontal plane. It is arranged close to 60 °.

[0004] The portion between the lines 16 passing through the antennas 11 and 12 of each set and forming 30 ° with respect to both main beams constitutes a sector radio zone. As shown in the figure, these six wireless zones are A, B, C, D,
E and F. For example, the main beam direction 14 of the transmitting / receiving antenna 11 and the main beam direction 15 of the receiving antenna 12 in the wireless zone A are the same direction and are spatially separated, and both antennas are used as a space diversity antenna. . Each of the two sets of antennas is mounted on a steel tower 18 schematically shown.

[0005]

Since the antenna device is installed on a steel tower or a building roof, the number of antennas required and the number of antennas are reduced in order to reduce the antenna load (wind pressure load, own weight) and installation space. Miniaturization (reduction of wind receiving area) is an important issue in antenna design. As an example, the antenna 11 and the antenna 12 each have a diameter of 10
When the antenna fits in a 0 mm radome, the antenna is 120 ° so that the main beam narrow angle is 60 °.
Antennas 11 and 12 installed at an angle of 200 mm have a drawback that the radome 13 has a diameter of 200 mm and is not reduced in size by integrating the transmitting and receiving antennas 12 and the receiving antenna 11 in the adjacent zones, and the installation space is large. there were.

[0006]

According to the first aspect of the present invention, two antennas having a main beam having a horizontal directional characteristic having a width of 60 ° have a narrow angle in the horizontal plane of 120 ° in the direction of both main beams. Are arranged close at the same height so that
The antenna is covered by one radome, and two such antennas are arranged in six sets at 60 ° angular intervals in a horizontal plane.

According to the second aspect of the present invention, two antennas having a main beam having a horizontal plane directivity characteristic having a width of 60 ° are the same so that the narrow angle in the horizontal plane in the direction of both main beams is 120 °. It is arranged close to the height, and such an antenna 2
Two sets of the bases are arranged vertically close to each other, and the directions of the corresponding main beams are arranged at an angle of 60 ° in a horizontal plane, and these four antennas are covered with one radome. Three sets are arranged at 120 ° angular intervals in a horizontal plane.

One of the two antennas is a transmitting and receiving antenna, and the other is a receiving antenna.
A diversity antenna is constituted by a transmitting / receiving antenna and a receiving antenna which are separated by 20 ° and have the same main beam direction.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the first aspect of the present invention, and portions corresponding to those in FIG. The transmitting and receiving antennas 11 and the receiving antennas 12 are arranged in a single radome 13 as a set, and are arranged in six sets at an angular interval of 60 ° in a horizontal plane.

However, in this embodiment, the transmitting / receiving antenna 11
The angle between the main beam directions 14 and 15 in the horizontal plane between the antenna and the receiving antenna 12 is 120 °, and the angle between the transmitting / receiving antenna 11 and the receiving antenna 12 in the horizontal plane is 60 °.
It has been. Further, each set of antennas 11, 12 is located at the angular center of each 60 ° sector wireless zone.

The numbers "14" and "1" indicating the directions of the main beams, respectively.
"5" is a symbol for the wireless zone assigned to the antenna, AF
As can be understood from this, for example, the transmitting / receiving antenna 11 in the main beam direction 14A, which is in charge of the radio zone A, is in the adjacent radio zone B, and The 15A receiving antenna 12 is located in the wireless zone F on the opposite side. As described above, the transmission / reception antenna 11 and the reception antenna 12 are arranged separately in the wireless zone adjacent to the wireless zone for each wireless zone. As described above, the antennas are arranged outside the own zone. However, in practice, the six sets of the antennas 11 are arranged so close to each other that there is no problem with interference, so that the respective communication services cover the own wireless zone. .

By combining the transmitting and receiving antennas 11 and the receiving antennas 12 of the radio zones which are angularly separated from each other by covering one radome 13 and integrating them,
The longitudinal narrow angle of the antennas 11 and 12 in the horizontal plane is 60 °
When the diameter of the radome 13 is the same used wavelength, it is about 160 mm, which is about 20
% Can be reduced.

FIG. 2 shows an embodiment of the second aspect of the present invention, in which parts corresponding to those in FIG. The angle between the transmitting / receiving antenna 11 and the receiving antenna 12 in the horizontal plane is the same as that of the embodiment of FIG.
As shown in FIG. 2B, two sets of antennas 11 and 12 are arranged one above the other and covered within one radome 13.
Accordingly, four antennas are integrally held in one radome 13. In FIG. 2A, antennas 11 and 12 with characters “up” are on the upper side, and antennas 11 and 12 with characters “lower” are written.
Are disposed immediately below the upper antenna, and the directions of the main beams are shifted in the same direction by 60 ° in the horizontal plane.

As can be understood from the symbol for the arrow indicating the main beam direction, for example, the transmitting / receiving antenna 11 in the beam direction 14A covering the radio zone A is located below the center of the sector angle of the radio zone A, and Direction 15
The receiving antenna 12 of A is located below the center of the sector angle of the radio zone E. The transmitting / receiving antenna 11 in the beam direction 14F covering the radio zone F is located above the center of the sector angle in the radio zone A, and the beam direction 15
The receiving antenna 12 of F is located above the center of the sector angle of the wireless zone E.

In this case, only three antennas in which four antennas are integrated may be provided at an angular interval of 120 °.

[0016]

As described above, according to the present invention, the diameter of the radome can be reduced by about 20% as compared with the conventional one, and the antenna installation space can be reduced accordingly. According to the second aspect of the present invention, four antennas are integrated and only three sets need to be provided, and the setting space can be further reduced.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

FIG. 2A is a plan view in which a part of the embodiment of the invention of claim 2 is shifted in a plane, and FIG. 2B is a side view of the part.

FIG. 3 is a plan view showing a conventional base station antenna device.

Claims (3)

[Claims] 1. Two antennas having a main beam having a directional characteristic of a horizontal plane having a width of 60 ° are arranged close to each other at the same height so that the narrow angle in the horizontal plane is 120 °. A base station antenna device covered with one radome, and six such antennas are arranged at an angular interval of 60 ° in a horizontal plane. 2. Two antennas having a main beam having a directional characteristic of a horizontal plane having a width of 60 ° are arranged close to each other at the same height so that the narrow angle in the horizontal plane is 120 °. , Two sets of such two antennas are vertically adjacent,
The directions of the corresponding main beams are shifted by 60 ° in the horizontal plane, and these four antennas are covered by one radome. Three such antennas are arranged in a horizontal plane at 120 ° angular intervals. Base station antenna device. 3. One of the two antennas is a transmission / reception antenna, and the other is a reception antenna. The diversity antenna is composed of a transmission / reception antenna that is angularly separated from the other by 120 ° and has the same main beam direction, and a reception antenna. The base station antenna device according to claim 1 or 2, wherein: