ES2399909T3 - Antenna with variable beam control for a mobile communication base station - Google Patents

Abstract

An antenna with variable beam control for a mobile communication base station, comprising: at least two radiator parts (10, 20, 30) arranged in sequence vertically, each having a reflector (11, 21, 31) with at least one radiator (111-113, 211-213, 311-313) installed therein; at least one force generator (13, 23, 33) to provide a controlled rotational force by means of an external control signal; and a force transfer part (12, 22, 32) to transfer the rotational force generated from the force generator (13, 23, 33), at least, to a reflector (11, 21, 31) and, of that way, to rotate said at least one reflector (11, 21, 31); characterized in that said variable beam control antenna is adapted to control the horizontal width of a beam of said variable beam control antenna by said external control signal.

Description

Antenna with variable beam control for a mobile communication base station

BACKGROUND OF THE INVENTION

one.

 Field of the Invention

The present invention relates, in general terms, to an antenna in a mobile communication base station and, in particular, to an antenna with variable beam control configured to control the horizontal width of the antenna beam and also the horizontal orientation.

2.

 Description of the related technique

Although in the first stage of development a fixed antenna has been used as a base station antenna in a mobile communication system, due to its advantages a variable vertical downward tilting antenna has been widely used in recent years. The variable vertical downward tilt antenna adjusts the phase in a vertical range by using a phase shifter, thereby vertically controlling a beam of the antenna, according to the surplus of a cell site.

In recent years, a technique has also been developed to horizontally orientate antenna beams in sector directions, according to the distribution of subscribers within a cell site. For the purpose of horizontal control of the antenna beams, two possibilities have been considered: electrical control of the horizontal beam by means of the electrical phase control of a signal provided to each column, and mechanical horizontal orientation using a 1-column antenna.

Since the scheme of mechanical control of the beam is favorable in terms of cost and size of the antennas and has the electrical advantage of not causing a horizontal lateral lobe, it is widely used. It goes without saying that the vertical beam control scheme is carried out by an independent operation and, therefore, is applicable to both vertical inclination and horizontal orientation.

The use of an antenna equipped with two-dimensional control functions of the vertical inclination and horizontal orientation enables the dynamic optimization of the network depending on the distribution of the subscribers. However, problems may occur at the cell site itself with the use of two-dimensional beam control only. In the most common configuration of the sectors, that is to say a configuration of three sectors of 120 degrees, when the direction of horizontal orientation is regulated according to the distribution of the subscribers, shadow zones can be produced or an overlapped zone between sectors can be increased. Therefore, for the regulation of the horizontal orientation direction, it is necessary to modify the horizontal width of the beam to eliminate the formation of shadow zones and minimize the overlap zone.

Until now, a simple and low-cost implementation of a function of modifying the horizontal width of the beam has been very difficult. Conventionally, the horizontal width of the beam is modified in three ways.

One of these is to adjust the angle and length of a reflector on a 1 column antenna. It is a classic method used for a vertical polarization antenna. An example is disclosed in the document "Ref. Mobile Antenna System Handbook, K. Fujimoto and J. R. James pp. 133-134". However, characteristic drawbacks of the method of modifying the horizontal width of the beam are that the antenna becomes very large due to the valid length of the reflector, and that the isolation and transverse polarization of a dual-polarized antenna, currently used, are degraded widely.

Another way to modify the horizontal width of the beam is a usual antenna technique, in which an antenna of three or more columns is implemented horizontally, so that the width of the antenna beam is modified by controlling the phase and distribution ratio of each column. An example of this technique is found in Korean patent application number 2003-7000418, entitled "Cellular Antenna" and filed by "Andrew Corporation". This method is not viable for commercialization in a mobile communication base station.

While a predetermined beam width is achieved with the use of a single column or two column antenna in a common mobile communication base station, the prior art requires at least one three column antenna. Therefore, they increase the cost and size of the antenna. In addition, to modify the phase and the distribution ratio, expensive components with high loss rates are used, thereby reducing the antenna gain. Therefore, an antenna that uses this method is used for military purposes.

The other way is to horizontally implement an antenna of two or more columns, and the horizontal orientation directions of the reflectors in the columns are controlled so that they cross mechanically, to thereby control the width of the beam. In practice, with this kind of antenna it is difficult to manufacture a usual antenna beam suitable for a sector. An example of this technique is found in Korean patent application number 200395761, entitled "Apparatus for Controlling Antenna Beam in a Mobile Communication Base Station" and filed by the present applicant. When a wide beam width is obtained by modifying the antenna beam width, ripples are created in the front direction of the antenna, and a radiation pattern different from that of "sharp cut" increases an area of overlap between sectors. Also, this method needs at least a two-column antenna.

SUMMARY OF THE INVENTION

Therefore, an objective of the present invention is to disclose an antenna of a column configured to control the horizontal width of the beam.

Another objective of the present invention is to disclose an antenna with variable beam control in a mobile communication base station, which is an antenna of a column configured to control the horizontal width of the beam and, therefore, suitable for advanced functionality , low cost and network optimization.

A further objective of the present invention is to disclose an antenna with variable beam control in a mobile communication base station, which is an antenna of a column configured to control the horizontal beam width and horizontal orientation.

The above objectives are achieved by disclosing an antenna with variable beam control for a mobile communication base station. In the antenna, at least two radiator parts are arranged vertically in sequence, so that they have the same center of rotation, each having a reflector that has at least one radiator installed therein. At least one force generator provides rotational force, controlled by an external control signal, and a force transfer part transfers the rotation force generated by the force generator, at least, to a reflector and, at least therefore, rotate said at least one reflector.

The antenna is adapted to control the horizontal width of a beam of said antenna, by means of said external control signal.

It is preferable that the antenna additionally includes a second force generator to provide rotational force in order to rotate all the radiator parts, and a second force transfer part to transfer the rotation force generated by the second force generator to the radiators and, therefore, rotate all radiators.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a schematic view of an antenna with variable beam control installed in a mobile communication base station, in accordance with an embodiment of the present invention;

Figure 2 schematically shows an example of the rotational positions of the reflectors in the antenna shown in Figure 1;

Figure 3 is a schematic view of an antenna with variable beam control installed in a mobile communication base station, in accordance with another embodiment of the present invention;

Figure 4 is an exemplary view of the results of a simulation of control of the antenna beamwidth shown in Figure 1;

Figure 5 is an exemplary view of the results of a simulation of control of the antenna beamwidth shown in Figure 3;

Figures 6A, 6B and 6C are perspective views showing an important part of an antenna with variable beam control in a mobile communication base station, in accordance with the third embodiment of the present invention;

Figure 7 is a perspective view, partially enlarged, of the lower part of a second radiator in the important part of the antenna shown in Figures 6A, 6B and 6C; Y

Figures 8A and 8B are exemplary views of an antenna modified from the antenna shown in Figures 6A and 6B.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Preferred embodiments of the present invention will be described in detail below, with the accompanying drawings. Details such as specific components are described in the following description, and it is apparent to those skilled in the art that the details are provided for a thorough understanding of the present invention and, therefore, can be made on the same variations or modifications within the Scope of the present invention, as defined by the claims.

Figure 1 is a schematic view of an antenna with variable beam control installed in a mobile communication base station, according to an embodiment of the present invention, and Figure 2 schematically shows an example of the rotational positions of the reflectors in the antenna shown in figure 1.

Referring to Figures 1 and 2, an antenna for modifying the horizontal width of the beam according to an embodiment of the present invention is an antenna structure of a column. It has three independent radiator parts in the vertical direction. That is, a first radiator part 10, a second radiator part 20 and a third radiator part 30 are independently configured.

Each radiator part is configured to have a reflector with antenna devices that include at least one radiator properly disposed therein to receive and transmit radio signals for mobile communications.

In the example shown in Figure 1, the first radiator part 10 is provided with a first reflector 11 which includes a first, a second and a third radiator 111, 112 and 113. The second radiator part 20 is provided with a second reflector 21 which includes a fourth, a fifth and a sixth radiators 211, 212 and 213. The third part of radiator 30 is provided with a third reflector 31 which includes a seventh, an eighth and a ninth radiators 311, 312 and 313.

According to an embodiment of the present invention, the first, second and third reflectors 11, 21 and 31 are configured to rotate on the same center of rotation in the first, second and third radiator parts 10, 20 and 30. Or they may be configured to rotate over different centers of rotation, more or less outside the common center of rotation.

A first, second and third force generators 13, 23 and 33 are arranged to generate force for the first, second and third reflectors 11, 21 and 31, in response to an external control signal. These can be engines.

A first, a second and a third force transfer parts 12, 22 and 32 are arranged to transmit rotational force generated from the first, the second and the third force generators 13, 23 and 33 to the first, the second and the third reflectors 11, 21 and 31 and, therefore, rotate them. The first, second and third force transfer parts 12, 22 and 32 are configured to include a series of gears, a shaft and a bearing.

The external control signal that controls the operation of the first, second and third force generators 13, 23 and 33 can be provided by cable or wirelessly from a source, that is, from near the antenna, from a base station (not shown) or from a base station controller.

When a tall building or a new base station is constructed in a nearby area, or when the radiation environment changes due to a temporary increase in the number of calls, for optimal cell planning, an appropriate control signal is applied to the first, the second and third force generators 13, 23 and 33, to thereby rotate the first, second and third reflectors 11, 21 and 31 in an appropriate amount.

In the antenna with the configuration described above, the first, second and third radiator parts 10, 20, 30 are contained in a radome 50 which serves as a housing, which is closed with upper and lower covers (not shown). Thus, the radome 50 makes the first, second and third radiator parts 10, 20, 30 collectively have the appearance of a single antenna.

Figure 3 is a schematic view of an antenna with variable beam control installed in a mobile communication base station, in accordance with another embodiment of the present invention. The antenna is identical to the antenna shown in figure 1, in configuration and concept. While in the antenna of Figure 1 the radiators in the first, second and third reflectors 11, 21 and 31 have a structure of a column assembly, in the second embodiment of the present invention shown in Figure 3 the Radiators are arranged in two columns in the reflectors.

Figure 4 is an exemplary view of the results of the antenna beamwidth control simulation shown in Figure 1, and Figure 5 is an exemplary view of the results of a simulation of

5 control of the antenna beamwidth shown in Figure 3. Referring to Figures 4 and 5, variations in the horizontal beam width are shown as a function of the rotation angles (directions) of the first and third reflectors 11 and 31 with respect to the second reflector 21 located in the center, and it should be noted that a good beam formation is achieved. The simulation results shown in Figures 4 and 5 are summarized in the following table 1 and table 2.

10 (Table 1)

Beam width

65  90 120

Radiator Address

0 ± 41 ± 54

(Table 2)

Beam width

33  Four. Five 65 90

Radiator Address

0 ± 24 ± 30 ± 36

The antenna with variable beam control for a mobile communication base station according to the first and the

15 second embodiments of the present invention can control the horizontal width of the beam in a variable manner by the appropriate control of the mutual directions of rotation of the first, second and third radiator parts 10, 20 and 30 arranged vertically in a column, and can form a beam with less undulation in the front direction of the antenna.

Although it has been described that the first, second and third radiator parts 10, 20 and 30 are provided with their

20 respective first, second and third force generators 13, 23 and 33 to rotate the first, second and third reflectors 11, 21 and 31, it can be further contemplated that the first, second and third reflectors 11, 21 and 31 are partially or totally rotated by using a single force generator and a force transfer part with a series of gears and a gear shaft, to partially or totally transfer the force generated in the force generator to the first, the second and third radiator parts 10, 20 and 30.

Figures 6A, 6B and 6C are perspective views showing an important part of an antenna with variable beam control in a mobile communication base station, in accordance with the third embodiment of the present invention. Specifically, Figure 6A shows the back of said important part of the antenna seen from the upper left, Figure 6B shows the back of said important part of the antenna seen from the lower right and Figure 6C shows the part rear of said important part of the antenna seen

30 from a lower height than from the upper left. In Figure 6C, a force generator is not shown. Figure 7 is a perspective view, partially on a larger scale, of the lower part of a second radiator in said important part of the antenna shown in Figures 6A, 6B and 6C, equivalent to the view of the front part of said part important antenna from the upper left.

Referring to Figures 6A to 7, as in the antennas shown in Figures 1 and 3, this antenna has

35 three independent vertical radiator parts and a first, a second and a third reflectors 11 ', 21' and 31 'arranged vertically so that they have the same center of rotation. As in the first embodiment, the first, the second and the third reflectors 11 ', 21' and 31 'may not share the same center of rotation.

The second reflector 21 'is fixed to a radome (not shown) by fixing guides 440a and 440b of Figure 7, and the first and third reflectors 11' and 31 'are rotatably installed.

A force generator 33 'including a motor is installed below the third reflector 31', and the motor rotation axis is connected to the third reflector 31 'by means of the gear, so that the third reflector 31' rotates with the rotation the motor.

In this structure, the third reflector 11 'is configured to rotate in the opposite direction with the rotation of the third reflector 31', by means of a force transfer part with a series of gears and a gear shaft. The first to fifth gears 411 to 415 and a gear shaft 416 collectively form the force transfer part.

The first gear is coupled to an upper end portion of the third reflector 31 ', so that it can rotate with the rotation of the third reflector 31'. The second gear 412 is installed to rotate in engagement with the first gear 411, and the third gear 413 is installed to rotate in engagement with the second gear 412. The fifth gear 415 is coupled to a lower end portion of the first reflector 11 ', so that the first reflector 11 'can rotate with the rotation of the fifth gear 415. The second gear 414 is installed to rotate in engagement with the fifth gear 415.

The third gear 413 is connected to the fourth gear 414 by the gear shaft 416. When the third gear 413 rotates, it rotates this shaft 416, thereby causing the gear 414 to rotate.

When the third reflector 31 'rotates driven by force generator 33', the first to fifth gears 411 to 415 rotate in sequence. Therefore, the first reflector 11 'rotates in the opposite direction to the rotation of the third reflector 33'.

In this antenna with variable beam control in accordance with the third embodiment of the present invention, the first and third reflectors 11 'and 31' interact with each other with respect to the second reflector 21 'and thereby rotate in opposite directions. Therefore, the horizontal width of the beam can be controlled variably. Meanwhile, in Figures 6A to 7, support rods 430 are arranged in appropriate positions, to firmly support the second reflector 21 '.

Figures 8A and 8B are exemplary views of an antenna modified from the antenna shown in Figures 6A and 6B. Figure 8A shows the back of an important part of the antenna, seen from the upper left end, and Figure 8B shows the back of said important part of the antenna seen from the lower right end. Referring to Figures 8A and 8B, this antenna has almost the same configuration as the antenna of the third embodiment. This has a second force generator 53 with a motor (not shown) to rotate the entire first, second and third reflectors 11 ', 21' and 31 'in order to control the horizontal orientation as well as the horizontal beam width , and a second force transfer part 52.

The second force generator 53 operates in response to an external control signal. It is equipped with a motor to rotate the entire first, second and third reflectors 11 ', 21' and 31 '. The second force transfer part 52 is disposed in a lower part of a fixed structure of the force generator 33 '. Thus, the axis of rotation of the motor in the second force generator 53 is connected to the fixed structure of the force generator 33 'by means of the gear, so that the fixed structure is rotated with the rotation of the motor. Therefore, the rotation of the fixed structure in the force generator 33 'leads to the rotation of the entire first, second and third reflectors 11', 21 'and 31'.

Although it has been described that the second reflector 21 'is fixed to the radome (not shown) by fixing guides 440a and 440b in Figure 7, in Figures 6A, 6B and 6C the second reflector 21' is installed in a rotational manner and by therefore it is not fixed to a radome in the antenna configuration shown in figures 8A and 8B.

In the modified antenna, the first, second and third reflectors 11 ', 21' and 31 'are fully rotated, so that the horizontal orientation of the antenna can be controlled in a variable manner.

While it has been described that the antenna according to the embodiments of the present invention has three independent radiator parts, it can be further contemplated as additional embodiments having two or four, or more radiator parts. This configuration of the radiators can be properly designed taking into account the characteristics of the vertical lateral lobe, the complexity of the implementation and the cost.

In addition, although the radiator parts are configured to rotate by using a force generator and a force transfer part, that is, by a scheme of mechanical modification of the horizontal width of the beam, a electrical scheme of modification of the horizontal width of the beam, in which the horizontal width of the antenna beam is controlled by controlling the phases of signals transmitted from the radiators of the radiator parts, as an electrical scheme of horizontal orientation that controls horizontal orientation

As described above, the antenna with variable beam control for a mobile communication base station according to the present invention can be manufactured at low cost and allows a simple automatic optimization, necessary for a recent wireless communication network, because It is configured to be of an antenna of a column, capable of controlling the horizontal width of the beam. Although many kinds of antennas with different beam widths are conventionally necessary for the base station sectors, in the present invention this simple antenna easily modifies its beam width.

In addition, this single column antenna can control the horizontal orientation as well as the horizontal beam width.

Claims (11)

1. An antenna with variable beam control for a mobile communication base station, comprising: at least two radiator parts (10, 20, 30) arranged in sequence vertically, each having a reflector (11, 21, 31) with at least one radiator (111-113, 211-213, 311 -313) installed in it; at least one force generator (13, 23, 33) to provide a rotation force controlled by an external control signal; Y a force transfer part (12, 22, 32) to transfer the rotational force generated from the force generator (13, 23, 33), at least, to a reflector (11, 21, 31) and, of that way, rotate said at least one reflector (11, 21, 31); characterized in that said antenna with variable beam control is adapted to control the horizontal width of a beam of said antenna with variable beam control by said external control signal.

2.

 The antenna with variable beam control according to claim 1, wherein the reflectors (11, 21, 31) are installed within a radome (50) serving as a housing, sealed with upper and lower covers.

3.

 The antenna with variable beam control according to claim 1, wherein the reflectors (11, 21, 31) have the same center of rotation.

Four.

 The antenna with variable beam control according to claim 1, wherein the reflectors (11, 21, 31) have different centers of rotation.

5.

 The antenna with variable beam control according to any of claims 1 to 4, wherein the radiators (111-113, 211-213, 311-313) are arranged in one column or in two columns in the reflectors (11, 21, 31).

6.

 The antenna with variable beam control according to any of claims 1 to 4, further comprising:

a second force generator (53) to provide rotational force in order to rotate all radiator parts; Y a second force transfer part (52) for transferring the rotational force generated in the second force generator (53) to the radiators and thereby rotating all the radiators. 7. The antenna with variable beam control according to claim 1, wherein said at least two radiator parts comprise a first, a second and a third radiator parts (10, 20, 30) arranged in sequence vertically, in which said force generator (33 ') provides said rotational force to rotate the reflector (31') of the third radiator part, by means of said external control signal and in which said force transfer part (411-415) is adapted to rotate the reflector (11 ') of the first radiator part, in a direction opposite to the direction of rotation of the reflector (31') of the third radiator part, together with the rotation of the reflector (31 ') of the third radiator part. 8. The antenna with variable beam control according to claim 7, wherein the force transfer part comprises: a first gear (411) coupled to an end part of the reflector (31 ') of the third radiator part, to rotate with the rotation of the reflector (31') of the third radiator part; a second gear (412) to rotate in engagement with the first gear (411); a third gear (413) to rotate in engagement with the second gear (412); a gear shaft (416) to rotate with the rotation of the third gear (413); a fourth gear (414) connected to the third gear (413) by the gear shaft (416), so that it rotates with the rotation of the gear shaft (416); Y a fifth gear (415) coupled to an end part of the reflector (11 ') of the first radiator part, to rotate with the rotation of the fourth gear (414) and thereby rotate the reflector (11') of The first 5 radiator part.

9.

 The antenna with variable beam control according to claim 7, wherein the reflectors (11 ', 21', 31 ') are installed within a radome that serves as a housing, sealed with upper and lower covers.

10.

 The antenna with variable beam control according to any of claims 7, 8 and 9, wherein the radiators are arranged in one column or in two columns in the reflectors (11 ', 21', 31 ').

The antenna with variable beam control according to any of claims 7, 8 and 9, further comprising: a second force generator (53) to provide rotational force to rotate all the radiator parts, the force generator (33 ') and the force transfer part (411-415, 416); Y a second force transfer part (52) to transfer the rotational force generated by the 15 second force generator (53), at least, to the force transfer part (411-415, 416) and thereby rotate all the radiator parts, the force generator (33 ') and the force transfer part (411-415, 416). 12. The antenna with variable beam control according to any of claims 1 to 11, comprising: a phase shifter to control the phase of signals provided to the radiator parts, in response to the external control signal.