Reconfigurable base station antenna

BACKGROUND OF THE INVENTION

00011. Field of the Invention

0002The present invention relates to a base station antenna, and more particularly to a base station antenna supporting multiple antenna schemes.

00032. Description of the Related Art

0004Development of mobile communication technology is followed by expectations that, even before the 3G (3^rdGeneration) networks are saturated, 4G (4^thGeneration) networks will be constructed widely. One of international standards representing the 4G networks, i.e. Mobile WiMAX or LTE (Long Term Evolution) communication scheme, applies various technologies to increase the transmission rate per frequency band, i.e. capacity (bps/Hz), and, for the purpose of the most effective capacity increase, applies multiple antenna technology referred to as MIMO (Multi-Input Multi-Output).

0005The essentials of multiple antenna technology for base station antennas are based on baseband signal processing technology. However, the degree of capacity increase, when multiple antennas are used, heavily depends on the antenna configuration. The reason is as follows: the multiple antenna technology makes active use of a number of multi-path fading and, at the same time, seeks to remove interference signals from other subscribers. This means that, even if the antenna configuration is the same, the degree of capacity increase varies depending on the wave propagation environment and subscriber distribution of the area covered by the base station. Therefore, international standards do not include particulars regarding the antenna configuration and allow free installation of antennas, based on field situations, to maximize the capacity.

0006However, conventional multiple antenna technologies have a limitation in that, since the antenna beam is fixed, capacity increase can not be expected, once installation is completed, in adaptive response to the wave propagation environment and subscriber distribution, but solely by using baseband signal processing technology. If necessary, the operator may, for example, climb the tower and modify the antennas themselves or their configuration. However, this approach requires a large amount of time and budget for modification and optimization and cannot easily handle situations having time-varying wave propagation environment and subscriber distribution. In summary, conventional antenna technologies cannot reflect the condition of communication environment in real time to perform load balancing, and provide no method for directing the antenna beam towards a hotspot area at a remote location.

SUMMARY OF THE INVENTION

0007Accordingly, the present invention has been made to solve the above-stated problems occurring in the prior art, and the present invention provides a base station antenna capable of variously modifying the radiation direction of antenna beams at a remote location in response to wave propagation environment and subscriber distribution.

0008Further, the present invention provides a base station antenna capable of increasing cell capacity by modifying the antenna configuration in response to wave propagation environment and subscriber distribution.

0009Further, the present invention provides a base station antenna capable of reflecting the condition of communication environments in real time, performing a load balancing function accordingly, and directing antenna beams towards a hotspot area.

0010Further, the present invention provides a base station antenna configured to prevent distortion of its upper or lower portion during antenna angle modification.

0011In accordance with an aspect of the present invention, there is provided a base station antenna including: at least two reflection plates each having at least one radiation element; a radome forming an internal cavity and containing the at least two reflection plates; first and second caps coupled to cover openings formed on upper and lower portions of the radome, respectively; a reflection plate connection member connected to each of the at least two reflection plates and to the first and second caps so that the at least two reflection plates can rotate; a reflection plate rotation driving unit including at least one power generation unit configured to provide rotation power and at least one power transmission mechanism unit configured to provide at least one reflection plate with rotation power from the power generation unit and control the rotation angle of the reflection plate provided with the rotation power, one of the power generation unit and the power transmission mechanism unit being coupled to the at least two reflection plates, and the other being coupled to the first cap; a reflection plate retention unit coupled to the at least two reflection plates and to the second cap to guide rotation and retention of the reflection plates; and a reflection plate control unit configured to provide the reflection plate rotation driving unit and the reflection plate retention unit with a control signal for controlling rotation and standstill of the at least two reflection plates.

BRIEF DESCRIPTION OF THE DRAWINGS

0012The above and other aspects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

0013<figref idref="DRAWINGS">FIG. 1</figref><i>a </i>is a perspective view of a base station antenna according to a first embodiment of the present invention;

0014<figref idref="DRAWINGS">FIG. 1</figref><i>b </i>is a perspective view of the base station antenna shown in <figref idref="DRAWINGS">FIG. 1</figref><i>a</i>, with its radome removed;

0015<figref idref="DRAWINGS">FIG. 2</figref> is a sectional view illustrating a first example of reflection plate guide units of the base station antenna according to the first embodiment of the present invention;

0016<figref idref="DRAWINGS">FIG. 3</figref> is a sectional view illustrating a second example of reflection plate guide units of the base station antenna according to the first embodiment of the present invention;

0017<figref idref="DRAWINGS">FIG. 4</figref><i>a </i>is a sectional view illustrating a third example of reflection plate guide units of the base station antenna according to the first embodiment of the present invention;

0018<figref idref="DRAWINGS">FIG. 4</figref><i>b </i>is a partial top view of the upper cap, to which first and second retention units are coupled, shown in <figref idref="DRAWINGS">FIG. 4</figref><i>a; </i>

0019<figref idref="DRAWINGS">FIGS. 5</figref><i>a </i>to <b>5</b><i>e </i>illustrate exemplary beam patterns, which are radiated from the base station antenna shown in <figref idref="DRAWINGS">FIG. 1</figref>, and their directions;

0020<figref idref="DRAWINGS">FIG. 6</figref> is a perspective view of a base station antenna according to a second embodiment of the present invention; and

0021<figref idref="DRAWINGS">FIGS. 7</figref><i>a </i>to <b>7</b><i>e </i>illustrate exemplary beam patterns, which are radiated from the base station antenna shown in <figref idref="DRAWINGS">FIG. 6</figref>, and their directions.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENT

0022Hereinafter, the exemplary embodiments of the present invention will be described with reference to the accompanying drawings in detail. Further, various specific definitions found in the following description are provided only to help general understanding of the present invention, and it will be understood by those skilled in the art that various changes and modifications can be made thereto within the technical spirit and scope of the present invention. In the following description, a detailed explanation of known related functions and constitutions may be omitted to avoid unnecessarily obscuring the subject matter of the present invention.

0023Construction of a new communication service network (e.g. 4G network), while an existing communication service network (e.g. 2G or 3G network) is still being used to provide a mobile communication service, requires installation of a new base station site at a high cost. Therefore, construction of a new communication service network (e.g. 4G) using a site, which has an existing communication service network (e.g. 2G or 3G) installed therein, reduces the cost to install a new base station site. This means that construction of a new communication service network requires co-siting installation. More specifically, antennas necessary for the next-generation communication service network need to be installed together with antennas of the previously-constructed base station tower.

0024The present invention proposes a base station antenna which forms remotely-controllable antenna beams and adaptively modifies them in conformity with wave propagation environment and subscriber distribution, thereby maximizing capacity increase through multiple antenna technology. In addition, the direction of antenna beams is adjusted based on subscriber distribution to support an inter-sector load balancing function, the antenna beams can be directed towards a hotspot area within the service area, and, when the antenna angle is modified to direct the antenna beams, distortion of the upper or lower portion of the antenna is prevented.

0025<figref idref="DRAWINGS">FIG. 1</figref><i>a </i>is a perspective view of a base station according to a first embodiment of the present invention, and <figref idref="DRAWINGS">FIG. 1</figref><i>b </i>is a perspective view of the base station antenna shown in <figref idref="DRAWINGS">FIG. 1</figref><i>a</i>, with its radome removed.

0026Referring to <figref idref="DRAWINGS">FIG. 1</figref><i>a</i>, the base station antenna according to the first embodiment of the present invention has a contour defined by a radome <b>412</b>, the upper and lower portions of which are covered by upper and lower caps <b>411</b> and <b>413</b>, respectively.

0027Referring to <figref idref="DRAWINGS">FIG. 1</figref><i>b</i>, inside the radome <b>412</b> are installed a plurality of radiation elements <b>43</b> and <b>47</b>, a first reflection plate <b>42</b>, a second reflection plate <b>46</b>, and various types of equipment for retaining the plurality of radiation elements <b>43</b> and <b>47</b> and the first and second reflection plates <b>42</b> and <b>46</b>. Specifically, a base station antenna according to an embodiment of the present invention has reflection plate connection members <b>44</b> and <b>45</b> for rotatably retaining the plurality of radiation elements <b>43</b> and <b>47</b> and the first and second reflection plates <b>42</b> and <b>46</b>, as well as reflection plate rotation driving units <b>48</b>, <b>493</b>, and <b>495</b> for controlling rotation of the plurality of radiation elements <b>43</b> and <b>47</b> and the first and second reflection plates <b>42</b> and <b>46</b> at a remote location. The reflection plate rotation driving units <b>48</b>, <b>493</b>, and <b>495</b> include at least one power generation unit <b>48</b> and power transmission mechanism units <b>493</b> and <b>495</b>.

0028The reflection plate connection members <b>44</b> and <b>45</b> include a first hinge <b>44</b> fixed to the upper cap <b>411</b> and/or the lower cap <b>413</b> and a second hinge <b>45</b> mounted between the first and second reflection plates <b>42</b> and <b>46</b>.

0029The power generation units <b>48</b> of the reflection plate rotation driving units are configured to receive control signals from a remote location and generate power, in response to the control signals, to rotate the first and second reflection plates <b>42</b> and <b>46</b> and may be a motor, for example.

0030The power transmission mechanism units <b>493</b> and <b>495</b> of the reflection plate rotation driving units include external gears <b>493</b> fixed to the rotation shafts of the power generation units <b>48</b> and internal gears <b>495</b> formed on the lower cap <b>413</b> in conformity with the path of movement of the external gears <b>493</b>, which is defined by rotation of the first and second reflection plates <b>42</b> and <b>46</b>. This structure of the power transmission mechanism units <b>493</b> and <b>495</b> enables the base station antenna according to the present invention to drive the power generation units <b>48</b> based on control signals necessary to control rotation of the first and second reflection plates <b>42</b> and <b>46</b> at a remote location and, accordingly, control the rotation angle of the first and second reflection plates <b>42</b> and <b>46</b>. The base station antenna may further include auxiliary caps <b>49</b> for containing the power generation units <b>48</b>.

0031Those skilled in the art can understand that, although components of the power transmission mechanism units <b>493</b> and <b>495</b> have been exemplified as devices for rotating the first and second reflection plates <b>42</b> and <b>46</b> according to an embodiment of the present invention, the present invention is not limited thereto, and the power transmission mechanism units <b>493</b> and <b>495</b> may be structured in any manner as long as rotation of the first and second reflection plates <b>42</b> and <b>46</b> can be controlled by rotation power provided by the power generation units <b>48</b>.

0032In addition, the present invention is not limited to the exemplary external and internal gears <b>493</b> and <b>495</b>, which constitute the power transmission mechanism units <b>493</b> and <b>495</b> according to an embodiment of the present invention, and the power transmission mechanism units <b>493</b> and <b>495</b> may have any structure as long as rotation of the reflection plates <b>42</b> and <b>46</b> is controlled using control signals from a remote location.

0033According to another embodiment of the present invention, the reflection plate rotation driving units <b>48</b>, <b>493</b>, and <b>495</b> may be installed on the top portions of the first and second reflection plates <b>42</b> and <b>46</b>.

0034The base station antenna according to the first embodiment of the present invention further includes reflection plate guide units configured to support vibration reinforcement for the first and second reflection plates <b>42</b> and <b>46</b> and guide the rotation and retention of the reflection plates. Detailed construction of the reflection plate guide units is exemplified in <figref idref="DRAWINGS">FIGS. 2</figref>, <b>3</b>, <b>4</b><i>a</i>, and <b>4</b><i>b. </i>

0035<figref idref="DRAWINGS">FIG. 2</figref> is a sectional view illustrating a first example of the reflection plate guide units, <figref idref="DRAWINGS">FIG. 3</figref> is a sectional view illustrating a second example of the reflection plate guide units, and <figref idref="DRAWINGS">FIGS. 4</figref><i>a </i>and <b>4</b><i>b </i>are sectional views illustrating a third example of the reflection plate guide units.

0036Referring to <figref idref="DRAWINGS">FIG. 2</figref>, the first example of the reflection plate guide units <b>501</b><i>a</i>, <b>502</b><i>a</i>, <b>503</b><i>a</i>, <b>504</b><i>a</i>, <b>501</b><i>b</i>, <b>502</b><i>b</i>, <b>503</b><i>b</i>, and <b>504</b><i>b </i>may have reflection plate retention driving units <b>501</b><i>a </i>and <b>501</b><i>b </i>to have a structure similar to that of the reflection plate rotation driving units <b>48</b>, <b>493</b>, and <b>495</b>. Specifically, the reflection plate guide units <b>501</b><i>a</i>, <b>502</b><i>a</i>, <b>503</b><i>a</i>, <b>504</b><i>a</i>, <b>501</b><i>b</i>, <b>502</b><i>b</i>, <b>503</b><i>b</i>, and <b>504</b><i>b </i>include reflection plate retention driving units <b>501</b><i>a </i>and <b>501</b><i>b </i>coupled to the first and second reflection plates <b>42</b> and <b>46</b> through retention members <b>502</b><i>a </i>and <b>502</b><i>b</i>, respectively. The reflection plate guide units <b>501</b><i>a</i>, <b>502</b><i>a</i>, <b>503</b><i>a</i>, <b>504</b><i>a</i>, <b>501</b><i>b</i>, <b>502</b><i>b</i>, <b>503</b><i>b</i>, and <b>504</b><i>b </i>also include small external gears <b>503</b><i>a </i>and <b>503</b><i>b </i>and internal gears <b>501</b><i>a </i>and <b>501</b><i>b</i>. The small external gears <b>503</b><i>a </i>and <b>503</b><i>b </i>are coupled to rotation shafts of the reflection plate retention driving units <b>501</b><i>a </i>and <b>501</b><i>b</i>, and the internal gears <b>504</b><i>a </i>and <b>504</b><i>b </i>are formed on the upper cap <b>411</b> in conformity with the path of movement of the small external gears <b>503</b><i>a </i>and <b>503</b><i>b</i>. The reflection plate retention driving units <b>501</b><i>a </i>and <b>501</b><i>b </i>of the reflection plate guide units exemplified in <figref idref="DRAWINGS">FIG. 2</figref> may be controlled based on interworking with control signals for controlling the power generation units <b>48</b>. Specifically, driving of the power generation units <b>48</b> of the reflection plate rotation driving units is followed by driving of the reflection plate retention driving units <b>501</b><i>a </i>and <b>501</b><i>b </i>of the reflection plate guide units, and both the upper and lower portions of the first and second reflection plates <b>42</b> and <b>46</b> rotate at the same rate and angle. On the other hand, when the power generation units <b>48</b> of the reflection plate rotation driving units do not rotate and the power transmission mechanism units <b>493</b> and <b>495</b> retain the lower position of the first and second reflection plates <b>42</b> and <b>46</b>, the reflection plate retention driving units <b>501</b><i>a </i>and <b>501</b><i>b </i>of the reflection plate guide units do not rotate either, but retain the upper position of the first and second reflection plates <b>42</b> and <b>46</b> through the small external gears <b>503</b><i>a </i>and <b>503</b><i>b </i>and the internal gears <b>504</b><i>a </i>and <b>504</b><i>b. </i>

0037A second example of the reflection plate guide units, as shown in <figref idref="DRAWINGS">FIG. 3</figref>, may have non-excited brakes <b>511</b><i>a </i>and <b>511</b><i>b </i>as an alternative to the reflection plate retention driving units <b>501</b><i>a </i>and <b>501</b><i>b </i>of the first example. Specifically, the reflection plate guide units <b>511</b><i>a</i>, <b>512</b><i>a</i>, <b>513</b><i>a</i>, <b>514</b><i>a</i>, <b>511</b><i>b</i>, <b>512</b><i>b</i>, <b>513</b><i>b</i>, and <b>514</b><i>b </i>of the second example may include, in order to guide the movement of the first and second reflection plates <b>42</b> and <b>46</b>, non-excited brakes <b>511</b><i>a </i>and <b>511</b><i>b </i>retained through retention members <b>512</b><i>a </i>and <b>512</b><i>b </i>coupled to the first and second reflection plates <b>42</b> and <b>46</b>, respectively, small external gears <b>513</b><i>a </i>and <b>513</b><i>b </i>coupled to rotation shafts of the non-excited brakes <b>511</b><i>a </i>and <b>511</b><i>b</i>, and internal gears <b>514</b><i>a </i>and <b>514</b><i>b </i>formed on the upper cap <b>411</b> in conformity with the path of movement of the small external gears <b>513</b><i>a </i>and <b>513</b><i>b. </i>

0038The non-excited brakes <b>511</b><i>a </i>and <b>511</b><i>b </i>of the reflection plate guide units exemplified in <figref idref="DRAWINGS">FIG. 3</figref> may be controlled based on interworking with control signals for controlling the power generation units <b>48</b>. Specifically, during input of an actuation signal for rotation driving into the power generation units <b>48</b> of the reflection plate rotation driving units, the actuation signal is also inputted into the non-excited brakes <b>511</b><i>a </i>and <b>511</b><i>b </i>of the reflection plate guide units, and the small external gears <b>513</b><i>a </i>and <b>513</b><i>b</i>, which are coupled to the non-excited brakes <b>511</b><i>a </i>and <b>511</b><i>b</i>, then enable the first and second reflection plates <b>42</b> and <b>46</b> to rotate. Since the small external gears <b>513</b><i>a </i>and <b>513</b><i>b </i>coupled to rotation shafts of the non-excited brakes <b>511</b><i>a </i>and <b>511</b><i>b </i>are enabled to rotate, and since the power generation units <b>48</b> begin driving, the first and second reflection plates <b>42</b> and <b>46</b> are guided along the path provided by the small external gears <b>513</b><i>a </i>and <b>513</b><i>b </i>and the internal gears <b>514</b><i>a </i>and <b>514</b><i>b</i>. On the other hand, during input of a signal to deactivate the power generation units <b>48</b> of the reflection plate rotation driving units, the deactivation signal is also inputted to the non-excited brakes <b>511</b><i>a </i>and <b>511</b><i>b </i>of the reflection plate guide units, which then prevent the first and second reflection plates <b>42</b> and <b>46</b> from rotating. As a result, the small external gears <b>513</b><i>a </i>and <b>513</b><i>b </i>coupled to the non-excited brakes <b>511</b><i>a </i>and <b>511</b><i>b </i>engage with the internal gears <b>514</b><i>a </i>and <b>514</b><i>b </i>and retain the upper portion of the first and second reflection plates <b>42</b> and <b>46</b>.

0039A third example of the reflection plate guide units, as shown in <figref idref="DRAWINGS">FIG. 4</figref><i>a</i>, may have solenoid units <b>521</b><i>a</i>, <b>521</b><i>b</i>, <b>523</b><i>a</i>, and <b>523</b><i>b</i>, which include coil bodies <b>521</b><i>a </i>and <b>521</b><i>b </i>and retention pins <b>523</b><i>a </i>and <b>523</b><i>b</i>, as an alternative to the reflection plate retention driving units <b>501</b><i>a </i>and <b>501</b><i>b </i>of the first example.

0040The third example of the reflection plate guide units <b>521</b><i>a</i>, <b>522</b><i>a</i>, <b>523</b><i>a</i>, <b>524</b><i>a</i>, <b>521</b><i>b</i>, <b>522</b><i>b</i>, <b>523</b><i>b</i>, and <b>524</b><i>b </i>have solenoid units <b>521</b><i>a</i>, <b>521</b><i>b</i>, <b>523</b><i>a</i>, <b>523</b><i>b </i>for guiding the movement of the first and second reflection plates <b>42</b> and <b>46</b>, as well as first and second retention pin reception arrays <b>524</b><i>a </i>and <b>524</b><i>b</i>. The solenoid units <b>521</b><i>a</i>, <b>521</b><i>b</i>, <b>523</b><i>a</i>, and <b>523</b><i>b </i>are coupled to the first and second reflection plates <b>42</b> and <b>46</b>, respectively, and the first and second retention pin reception arrays <b>524</b><i>a </i>and <b>524</b><i>b </i>are provided on the upper cap <b>411</b> to retain the first and second reflection plates <b>42</b> and <b>46</b> in a rotated state. The first and second retention pin reception arrays <b>524</b><i>a </i>and <b>524</b><i>b </i>have the same structure, and detailed construction of the first retention pin reception array <b>524</b><i>a </i>will now be described with reference to <figref idref="DRAWINGS">FIG. 4</figref><i>b</i>, without repeating the same for the second retention pin reception array <b>524</b><i>b</i>. The first retention pin reception array <b>524</b><i>a </i>is coupled to the upper cap <b>411</b> and has a plurality of retention holes <b>525</b><i>a </i>configured to receive the retention pin <b>523</b><i>a </i>of the solenoid units <b>521</b><i>a</i>, <b>521</b><i>b</i>, <b>523</b><i>a</i>, and <b>523</b><i>b</i>. The plurality of retention holes <b>525</b><i>a </i>are positioned to correspond to the path of rotational movement of the first reflection plate <b>42</b>.

0041The reflection plate guide units <b>521</b><i>a</i>, <b>522</b><i>a</i>, <b>523</b><i>a</i>, <b>524</b><i>a</i>, <b>521</b><i>b</i>, <b>522</b><i>b</i>, <b>523</b><i>b</i>, and <b>524</b><i>b </i>are configured to operate based on interworking with control signals inputted to the power generation units <b>48</b>. To be specific, during input of an actuation signal for rotation driving into the power generation units <b>48</b> of the reflection plate rotation driving units, the actuation signal is inputted to the coil bodies <b>521</b><i>a </i>and <b>521</b><i>b </i>of the solenoid units, causing a current flow. The retention pins <b>523</b><i>a </i>and <b>523</b><i>b </i>are then pulled toward the coil bodies <b>521</b><i>a </i>and <b>521</b><i>b </i>and withdrawn from the first and second retention pin reception arrays <b>524</b><i>a </i>and <b>524</b><i>b</i>. On the other hand, during input of a signal to deactivate the power generation units <b>48</b> of the reflection plate rotation driving units, the deactivation signal is inputted to the coil bodies <b>521</b><i>a </i>and <b>521</b><i>b </i>of the solenoid units <b>521</b><i>a</i>, <b>521</b><i>b</i>, <b>523</b><i>a</i>, and <b>523</b><i>b</i>, allowing no more current flow. The retention pins <b>523</b><i>a </i>and <b>523</b><i>b </i>are then drawn towards the retention holes <b>525</b><i>a </i>and <b>525</b><i>b </i>of the first and second retention pin reception arrays <b>524</b><i>a </i>and <b>524</b><i>b</i>. In other words, the structure of the reflection plate guide units <b>521</b><i>a</i>, <b>522</b><i>a</i>, <b>523</b><i>a</i>, <b>524</b><i>a</i>, <b>521</b><i>b</i>, <b>522</b><i>b</i>, <b>523</b><i>b</i>, and <b>524</b><i>b </i>shown in <figref idref="DRAWINGS">FIGS. 4</figref><i>a </i>and <b>4</b><i>b </i>provides the following operation: during rotation of the power generation units <b>48</b> of the reflection plate rotation driving units, the retention pins <b>523</b><i>a </i>and <b>523</b><i>b </i>are pulled towards the coil bodies <b>521</b><i>a </i>and <b>521</b><i>b </i>and withdrawn from the first and second retention pin reception arrays <b>524</b><i>a </i>and <b>524</b><i>b</i>, allowing the first and second reflection plates <b>42</b> and <b>46</b> to rotate freely. On the other hand, during no rotation of the power generation units <b>48</b> of the reflection plate rotation driving units, the retention pins <b>523</b><i>a </i>and <b>523</b><i>b </i>are pulled into the retention holes <b>525</b><i>a </i>and <b>525</b><i>b </i>of the first and second retention pin reception arrays <b>524</b><i>a </i>and <b>524</b><i>b </i>to retain the first and second reflection plates <b>42</b> and <b>46</b>.

0042Referring to <figref idref="DRAWINGS">FIG. 1</figref><i>b </i>again, the base station antenna according to the first embodiment of the present invention may further include at least one rotation limit <b>461</b> and <b>462</b> for controlling the rotation angle of the first and second reflection plates <b>42</b> and <b>46</b>.

0043The rotation limits <b>461</b> and <b>462</b> may be coupled to the front surface (e.g. surface on which the plurality of radiation elements <b>43</b> and <b>47</b> are mounted) and the rear surface of the first and second reflection plates <b>42</b> and <b>46</b> so as to cross each other. Specifically, at least one of the rotation limits <b>461</b> and <b>462</b> may be coupled to the front surface (e.g. surface on which the plurality of radiation elements <b>43</b> and <b>47</b> are mounted) of the second reflection plate <b>46</b>, as shown in <figref idref="DRAWINGS">FIG. 1</figref><i>b</i>, and at least one on the rear surface of the first reflection plate <b>42</b>.

0044Alternatively, a set of rotation limits <b>461</b> and <b>462</b> may be mounted on the front surfaces (e.g. surfaces on which the plurality of radiation elements <b>43</b> and <b>47</b> are mounted) of the first and second reflection plates <b>42</b> and <b>46</b>, respectively, and another set on the rear surface thereof, respectively.

0045The rotation limits <b>461</b> and <b>462</b> may have the shape of a circular sector or a triangle, which has an angle (e.g. inner angle of 120°) determined to control the rotation of the first and second reflection plates <b>42</b> and <b>46</b>.

0046One ends of the rotation limits <b>461</b> and <b>462</b> of the above-mentioned structure are coupled to the first and second reflection plates <b>42</b> and <b>46</b>, which are then allowed to rotate within a first angle range. If the first and second reflection plates <b>42</b> and <b>46</b> rotate out of a second angle range, the other ends of the rotation limits <b>461</b> and <b>462</b> contact them and prevent further rotation.

0047Those skilled in the art can understand that, although the rotation limits <b>461</b> and <b>462</b> are coupled to the front and rear surfaces of the first and second reflection plates <b>42</b> and <b>46</b> so as to cross each other, or coupled to both the front and rear surfaces thereof, and have the shape of a circular sector or a triangle according to the first embodiment of the present invention, the present invention is not limited to the exemplary structure of the rotation limits, the coupling position or shape of which can be modified variously as long as they can limit the rotation angle of the first and second reflection plates <b>42</b> and <b>46</b>.

0048<figref idref="DRAWINGS">FIGS. 5</figref><i>a </i>to <b>5</b><i>e </i>exemplify beam patterns radiated from the base station antenna shown in <figref idref="DRAWINGS">FIG. 1</figref><i>b</i>, as well as their directions. The reflection plates <b>42</b> and <b>46</b> of the base station antenna according to the first embodiment of the present invention, as described above, can rotate as shown in <figref idref="DRAWINGS">FIGS. 5</figref><i>a </i>to <b>5</b><i>e</i>. Furthermore, the base station antenna according to the present invention can support an inter-sector load balancing function, direct antenna beams to a hotspot area within the service area, and variously modify the section management of the base station.

0049<figref idref="DRAWINGS">FIG. 6</figref> is a perspective view of a base station antenna according to a second embodiment of the present invention, and <figref idref="DRAWINGS">FIGS. 7</figref><i>a </i>to <b>7</b><i>e </i>illustrate exemplary beam patterns, which are radiated from the base station antenna shown in <figref idref="DRAWINGS">FIG. 6</figref>, and directions.

0050The base station antenna according to the second embodiment of the present invention has the same structure as the base station antenna according to the first embodiment, except for a difference in the number of reflection plates inside the radome <b>612</b> and the construction of equipment for rotation of the reflection plates.

0051To be specific, the base station antenna according to the second embodiment has three reflection plates, i.e. first, second, and third plates <b>62</b>, <b>64</b>, and <b>66</b> inside the radome <b>612</b>. With the first reflection plate <b>62</b> at the center, the second and third reflection plates <b>64</b> and <b>66</b> are positioned on both sides, respectively, and are connected to the first reflection plate <b>62</b> through reflection plate connection members <b>68</b> and <b>69</b>, respectively. The reflection plate connection members <b>68</b> and <b>69</b> are configured to retain the position of the first reflection plate <b>62</b> and to allow the second and third reflection plates <b>64</b> and <b>66</b> to rotate about center shafts of the reflection plate connection members <b>68</b> and <b>69</b>.

0052The base station antenna further includes, in order to control rotation of the second and third reflection plates <b>64</b> and <b>66</b> at a remote location, power generation units <b>705</b> and power transmission mechanism units <b>713</b> and <b>715</b>. The power transmission mechanism units <b>713</b> and <b>715</b> may include, as in the case of the first embodiment, external gears <b>713</b> and internal gears <b>715</b>.

0053The power transmission mechanism units <b>713</b> and <b>715</b> may further include auxiliary caps <b>70</b> for containing the power generation units <b>705</b>, and the auxiliary caps <b>70</b> may be mounted on the second and third reflection plates <b>64</b> and <b>66</b>, respectively.

0054The above-mentioned structure of the power generation units <b>705</b> and the power transmission mechanism units <b>713</b> and <b>715</b> enables the base station antenna to receive signals to control the power generation units <b>705</b>, which are necessary to control rotation of the second and third reflection plates <b>64</b> and <b>66</b>, from a remote location and, based on driving of the power generation units <b>705</b>, control the rotation angle of the second and third reflection plates <b>64</b> and <b>66</b>. As a result, the second and third reflection plates <b>64</b> and <b>66</b> can be rotated by the power generation units <b>705</b> as shown in <figref idref="DRAWINGS">FIGS. 7</figref><i>a </i>to <b>7</b><i>e. </i>

0055The base station antenna according to the second embodiment further includes reflection plate guide units configured to support vibration reinforcement for the reflection plates <b>62</b>, <b>64</b>, and <b>66</b> and to guide the rotation and retention of the reflection plates <b>62</b>, <b>64</b>, and <b>66</b>. The reflection plate guide units may have a construction and a structure similar to those of the reflection plate guide units of the base station antenna according to the first embodiment. Therefore, the structure of the reflection plate guide units according to the first embodiment will be referred to, instead of describing the same again.

0056The base station antenna according to the second embodiment of the present invention may further include at least one rotation limit <b>661</b>, <b>662</b>, <b>663</b>, and <b>664</b> to determine the rotation angle of the first, second, and third reflection plates <b>62</b>, <b>64</b>, and <b>66</b>. Those skilled in the art can understand that the coupling position or shape of the rotation limits <b>661</b>, <b>662</b>, <b>663</b>, and <b>664</b> can be modified variously as long as it can control the rotation angle of the second and third reflection plates <b>64</b> and <b>66</b>.

0057The above-mentioned structure of the base station antenna according to the second embodiment of the present invention makes it possible to simultaneously emit signals for providing different communication services through the first, second, and third reflection plates <b>62</b>, <b>64</b>, and <b>66</b>. Assuming that 2G (or 3G) and 4G communication services are provided in a co-siting manner, it is possible to emit signals for providing the 2G (or 3G) communication service through the first reflection plate <b>62</b> and emit signals for providing the 4G communication service through the second and third reflection plates <b>64</b> and <b>64</b>. Therefore, the base station antenna according to the second embodiment of the present invention has a considerable merit when a 2G (or 3G) communication service is still provided and a 4G network is newly constructed in a co-siting manner. Specifically, the existing 2G (or 3G) communication antenna is retained at the center, and new 4G communication antennas are provided on both sides. This can reduce signal correlation to a suitable level and create a proper level of space diversity. Furthermore, the mechanism-based adjustment of the radiation direction of antenna beams by the power generation units <b>705</b> and the power transmission mechanism units <b>713</b> and <b>715</b> creates a pattern diversity effect. In addition, the base station antenna according to the second embodiment of the present invention can, even if the newly designed communication network (e.g. 4G communication service network) differs from the previous communication network (e.g. 3G communication service network), operate the co-siting flexibly through control of beam radiation direction.

0058Furthermore, proper association of the base station antenna according to the present invention with baseband signal processing technology and combined operation can lead to evolution to HMAT (Hybrid Multiple Antenna Technology), which provides optimized operation of mobile communication networks. The optimized operation of mobile communication networks, in this connection, means that signal processing related to individual subscribers is performed in the baseband, and antenna beam formation based on subscriber distribution is performed by the base station antenna according to the present invention.

0059The base station antenna according to the present invention has the following advantageous effects:

0060First, control of the directing angle of a plurality of reflection plates inside one radome at a remote location makes it possible to reflect the condition of communication environments in real time, to perform a load balancing function accordingly, and to direct antenna beams towards a hotspot area without any limitation on space and time.

0061Second, reflection plates provided inside one radome are operated as antennas for different service networks so that co-siting is possible, i.e. different services can be provided simultaneously.

0062Third, antenna configuration is modified in response to wave propagation environment and subscriber distribution, thereby increasing cell capacity.

0063Fourth, during modification of the antenna directing angle, distortion of the upper or lower portion of the antenna is prevented.

0064While the present invention has been shown and described with reference to certain exemplary embodiments and drawings thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.