Abstract:
A small-sized base station employed in a mobile communication system is disclosed. To this end, the small-sized base station in a mobile communication system, according to one embodiment of the present invention, is a base station device in a mobile communication system comprising: a case which has the shape of a polyhedron and is hollow inside; a housing accommodated inside the case and having the same polyhedron shape as the case; and at least one board which is positioned between the case and the housing.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of International Application No. PCT/KR2013/010428 filed on Nov. 15, 2013, which claims priority to Korean Applications No. 10-2012-0130257 filed on Nov. 16, 2012, which applications are incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates to a base station device in a mobile communication system and, more particularly, relates to a compact base station device installed outdoors. 
       BACKGROUND ART 
       [0003]    A base station in a mobile communication system refers to a system for relaying electric waves of portable terminals in a cell. The base station is mainly located on the roof of a building to relay the electric waves of the portable terminals. Accordingly, base stations exist in units of cells and control incoming/outgoing signal transmission, traffic channel definition, and traffic channel monitoring in addition to interface functions between portable terminals and switching stations in units of cells. 
         [0004]    In addition, thanks to many advantages, control antennas capable of performing beam tilting in a vertical or horizontal direction have been widely used as antennas employed for base stations. 
         [0005]    Furthermore, compact base stations that can reduce frequency loads and enhance call quality have been installed as systems for covering much smaller areas than the existing mobile communication service coverage. Such base station systems are used to receive data traffic intensively generated in small-scale areas. The compact base stations may be installed in buildings or homes, thereby making it possible to resolve dead spots and provide more enhanced network and convergence services. 
         [0006]    However, the compact base stations employed for the conventional mobile communication systems have limitations in making the overall size smaller because major components mounted in the base stations, for example, a main board, a power supply unit, an antenna, a filter, a power amplification unit, and the like are stacked one above another. 
         [0007]    In particular, although the conventional compact base stations have stable antenna characteristics with increasing cavity spaces arranged in a filter, the cavities are arranged to be narrow in a line. Therefore, the horizontal and vertical sizes of the filter having the cavities arranged therein are made larger in order to maintain the antenna characteristics satisfying customers&#39; demands. 
         [0008]    Particularly, since the main board and the power amplification unit are formed on one board in the conventional compact base stations, the overall size of the main board becomes large, and a problem of heat dissipation of the power amplification unit arises. 
       SUMMARY 
       [0009]    Accordingly, an aspect of the present disclosure is to provide a compact base station device in a mobile communication system in which major components, for example a plurality of boards, are arranged in three dimensions on the inner surfaces of an enclosure functioning as an external case, thereby advantageously achieving compactness. 
         [0010]    Another aspect of the present disclosure is to provide a compact base station device in a mobile communication system in which heat dissipation parts, for example heat sinks, are arranged on the outer surfaces of an enclosure in order to dissipate heat generated from a plurality of boards arranged in three dimensions in the right places on the outer surfaces of the enclosure, thereby achieving an excellent heat dissipation effect and compactness. 
         [0011]    Another aspect of the present disclosure is to provide a compact base station device in a mobile communication system that is mainly suitable for outdoor use. 
         [0012]    Another aspect of the present disclosure is to provide a compact base station device in a mobile communication system in which a plurality of power amplification units are disposed to be spaced apart from each other with the greatest possible distance therebetween, thereby minimizing a problem of heat dissipation. 
         [0013]    Another aspect of the present disclosure is to provide a compact base station device in a mobile communication system in which a plurality of cavities of a filter are configured to be stacked on each other (to face each other) in the up-down direction, thereby resulting in wide cavity spaces and thus enhancing an antenna characteristic. 
         [0014]    In order to solve such problems, the present disclosure proposes a compact base station having boards mounted on the inner surfaces of an enclosure in three dimensions and heat dissipation parts on the outer surfaces thereof. 
         [0015]    Specifically, the compact base station, which is a base station device in a mobile communication system, includes: a hollow case having a polyhedral shape; a housing that is received in the case and has the same polyhedral shape as the case; and one or more board parts located between the case and the housing. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    The above and other aspects, features, and advantages of the present disclosure will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: 
           [0017]      FIG. 1  is a perspective view illustrating an external appearance of a compact base station according to the present disclosure; 
           [0018]      FIG. 2  is an exploded perspective view illustrating a configuration of the compact base station according to the present disclosure; 
           [0019]      FIG. 3  is a perspective view of an antenna unit of the compact base station according to the present disclosure, with an antenna of the antenna unit omitted; 
           [0020]      FIG. 4  is a sectional view of the antenna unit of the compact base station according to the present disclosure; 
           [0021]      FIG. 5  is a plan view of the antenna unit of the compact base station according to the present disclosure, with the antenna of the antenna unit omitted; 
           [0022]      FIG. 6  is a perspective view of the antenna of the compact base station according to the present disclosure; 
           [0023]      FIG. 7  is a plan view illustrating an arrangement state before boards are mounted on inner surfaces of an enclosure, respectively, according to the present disclosure; 
           [0024]      FIG. 8  illustrates an example of mounting a board on an inner surface of the enclosure according to the present disclosure; 
           [0025]      FIG. 9  illustrates another example of mounting a board on an inner surface of the enclosure according to the present disclosure; 
           [0026]      FIG. 10  is an exploded perspective view of an antenna base station according to one of various embodiments of the present disclosure; 
           [0027]      FIGS. 11 and 12  illustrate a state in which boards are mounted to a filter housing in the antenna base station illustrated in  FIG. 10 ; 
           [0028]      FIG. 13  is a schematic sectional view of the antenna base station illustrated in  FIG. 11 ; and 
           [0029]      FIG. 14  illustrates a state in which the antenna base station illustrated in  FIG. 11  is assembled. 
       
    
    
     DETAILED DESCRIPTION 
       [0030]    Hereinafter, the present disclosure will be described with reference to the accompanying drawings. Identical reference numerals indicate identical elements. 
         [0031]    In describing a compact base station according to the present disclosure, the rectangular coordinate system illustrated in  FIGS. 1 and 2  is used. ‘X axis’ refers to a horizontal direction, ‘Y axis’ refers to a vertical direction, and ‘Z axis’ refers to a direction perpendicular to the horizontal and vertical directions. The base station, according to the present disclosure, has a small horizontal length, a small vertical length, and a small thickness, compared to the related art, and despite the compactness, maintains the existing performance thereof. That is, the compactness means that the overall size of the base station is made smaller in the three axis directions than in the related art, and namely, means that one of the horizontal and vertical lengths and the thickness is made smaller. In addition, it should be noted that the base station, according to the present disclosure, is suitable for an outdoor base station with a high output level and has no problem of heat dissipation of a board despite the compactness thereof. 
         [0032]      FIG. 1  illustrates an external appearance of a compact base station (hereinafter, referred to as a ‘base station’) in a mobile communication system according to the present disclosure. The illustrated base station is suitable for outdoor use in pursuit of compactness. Since an outdoor base station has a high output level, compared to an indoor base station, the outdoor base station has to allow for heat generated from boards while pursuing compactness thereof. Accordingly, the purpose of the present disclosure is to provide a compact base station for which a problem of heat dissipation is addressed. 
         [0033]      FIG. 1  illustrates the external appearance of the base station in a completely assembled state in which a cover  10  and an enclosure  11  are coupled to each other. The enclosure  11  has heat dissipation parts HS on outer surfaces thereof which function to dissipate heat of boards to be described below. The heat dissipation parts HS refer to heat sinks to be described below. Reference numeral  11  indicates an outer enclosure exposed to an external environment. The outer enclosure is hereinafter referred to as an ‘enclosure.’ 
         [0034]      FIG. 2  is an exploded perspective view illustrating a configuration of the base station according to the present disclosure. As illustrated in  FIG. 2 , the base station includes an antenna unit  15 , three or more boards (printed circuit boards) B 1  to B 4 , and a Power Supply Unit (PSU)  14 , which are arranged in three dimensions in the interior of the enclosure  11 , and the heat dissipation parts HS, for example, a plurality of heat sinks. The boards B 1  to B 4  are mounted on the inner surface of the enclosure  11 , and the heat dissipation parts HS are mounted on the outer surface of the enclosure  11 . 
         [0035]    The aforementioned ‘three dimensional arrangement’ of the plurality of boards does not mean stacking the boards on one axis but arranging major elements, for example the boards, in view of three axes, including X, Y, and Z axes. In particular, the three dimensional arrangement means an arrangement in which a plurality of other boards are disposed orthogonal to one board along the X and Y axes, and the remaining major elements are disposed along the Z axis. Due to such a three dimensional arrangement, the base station, according to the present disclosure, is very advantageous for compactness. In addition, the base station, according to the present disclosure, includes a configuration for solving a problem caused by heat generated from the boards according to the three dimensional arrangement, in addition to the three dimensional arrangement for the compactness of the major elements. 
         [0036]    With reference to  FIG. 7  together with  FIG. 2 , the enclosure  11  will be described below. The enclosure  11  has a polyhedral shape and is constituted by coupling a plurality of plate-shaped members that have a plurality of outer surfaces  111   a  to  114   a  and  135   a  and inner surfaces  111   b  to  114   b  and  135   b , respectively, and the antenna unit  15  is received in an inner enclosure that is on the rear side of the enclosure  11 . In particular, the enclosure  11  has an open-topped box shape and includes three or more inner surfaces and three or more outer surfaces. The five outer surfaces  111   a  to  114   a  and  135   a  and the five inner surfaces  111   b  to  114   b  and  135   b , included in the enclosure  11 , are illustrated in  FIGS. 2 and 7 . However, the number of inner and outer surfaces may vary with the shape of the enclosure  11 . 
         [0037]    The plurality of outer surfaces include the first and second outer surfaces  111   a  and  112   a  opposite to each other, and the third and fourth outer surfaces  113   a  and  114   a  opposite to each other between the first and second outer surfaces  111   a  and  112   a . The first and second outer surfaces  111   a  and  112   a  are parallel to each other, and the third and fourth outer surfaces  113   a  and  114   a  are parallel to each other. The first outer surface  111   a  is perpendicular to the third and fourth outer surfaces  113   a  and  114   a , and the second outer surface  112   a  is perpendicular to the third and fourth outer surfaces  113   a  and  114   a . In addition, the first to fourth outer surfaces  111   a  to  114   a  have a flat shape. Since the enclosure  11  has a rectangular parallelepiped shape, the first to fourth outer surfaces  111   a  to  114   a  have a rectangular shape. 
         [0038]    The enclosure  11  includes the plurality of outer surfaces. In terms of the shapes of the outer surfaces, among the outer surfaces, the first and second outer surfaces  111   a  and  112   a  may be constituted in the same rectangular or square shape, the third and fourth outer surfaces  113   a  and  114   a  may also be constituted in the same rectangular or square shape, and the outer bottom surface  135   a  may also be constituted in a rectangular or square shape. 
         [0039]    In addition, in terms of the sizes (areas) of the outer surfaces, the first and second outer surfaces  111   a  and  112   a  and the third and fourth outer surfaces  113   a  and  114   a  may be constituted by the same-sized rectangles, different-sized rectangles, or the same-sized squares. 
         [0040]    Among the outer surfaces, the outer bottom surface  135   a  located at the bottom of the enclosure  11  may be constituted by a rectangle or square and may be constituted in a shape larger or smaller than, or the same as those of the first to fourth outer surfaces  111   a  to  114   a . The enclosure  11 , according to the present disclosure, is preferably configured such that the outer bottom surface  135   a  is larger in area than the first and second outer surfaces  111   a  and  112   a  or the third and fourth outer surfaces  113   a  and  114   a . In  FIG. 2 , the outer bottom surface  135   a  is illustrated to be larger in area than the first to fourth outer surfaces  111   a  to  114   a . For the inner enclosure in the interior of the enclosure, the bottom surface thereof is configured to have the largest area, and the antenna unit  15  is preferably disposed on the bottom surface of the inner enclosure. 
         [0041]    The inner surfaces include the first and second inner surfaces  111   b  and  112   b  facing each other, and the third and fourth inner surfaces  113   b  and  114   b  facing each other between the first and second inner surfaces  111   b  and  112   b . The first and second inner surfaces  111   b  and  112   b  are parallel to each other, and the third and fourth inner surfaces  113   b  and  114   b  are parallel to each other. The first inner surface  111   b  is perpendicular to the third and fourth inner surfaces  113   b  and  114   b , and the second inner surface  112   b  is perpendicular to the third and fourth inner surfaces  113   b  and  114   b . In addition, the first to fourth inner surfaces  111   b  to  114   b  have a flat shape. Since the enclosure  11  has a rectangular parallelepiped shape, the first to fourth inner surfaces  111   b  to  114   b  have a rectangular shape. 
         [0042]    The enclosure  11  includes the plurality of inner surfaces. In terms of the shapes of the inner surfaces, among the inner surfaces, the first and second inner surfaces  111   b  and  112   b  may be constituted in the same rectangular or square shape, the third and fourth inner surfaces  113   b  and  114   b  may also be constituted in the same rectangular or square shape, and the inner bottom surface  135   b  may also be constituted in a rectangular or square shape. 
         [0043]    In addition, in terms of the sizes (areas) of the inner surfaces, the first and second inner surfaces  111   b  and  112   b  and the third and fourth inner surfaces  113   b  and  114   b  may be constituted by the same-sized rectangles, different-sized rectangles, or the same-sized squares. 
         [0044]    Among the inner surfaces, the inner bottom surface  135   b  located at the bottom of the enclosure  11  may be constituted by a rectangle or square and may be constituted in a shape larger or smaller than, or the same as those of the first to fourth inner surfaces  111   b  to  114   b . The enclosure  11 , according to the present disclosure, is preferably configured such that the inner bottom surface  135   b  is larger in area than the first and second inner surfaces  111   b  and  112   b  or the third and fourth inner surfaces  113   b  and  114   b . In  FIG. 2 , the inner bottom surface  135   b  is illustrated to be larger in area than the first and second inner surfaces  111   b  and  112   b  or the third and fourth inner surfaces  113   b  and  114   b.    
         [0045]    Specifically, the arrangement of the boards mounted on the inner surfaces of the enclosure  11  will be described. 
         [0046]    The plurality of boards B 1  to B 4  and the power supply unit  14  are disposed on the inner surfaces of the enclosure  11 . The plurality of boards includes the first to fourth boards B 1  to B 4 . The first board B 1  is disposed on the inner bottom surface  135   b  of the enclosure  11 . The second and third boards B 2  and B 3  are disposed on the first and second inner surfaces  111   b  and  112   b  of the enclosure  11 , respectively. The fourth board B 4  is disposed on the third inner surface  113   b . The power supply unit  14  is disposed on the fourth inner surface  114   b.    
         [0047]    The first board B 1  is a digital interface module and is disposed parallel to the inner bottom surface  135   b  of the enclosure while facing the inner bottom surface  135   b . The second board B 2  is a first power amplification unit (PAM) and is disposed parallel to the first inner surface  111   b  while facing the first inner surface  111   b . The third board B 3  is a second power amplification unit (PAM) and is disposed parallel to the second inner surface  112   b  while facing the second inner surface  112   b . The fourth board B 4  is an up/down converter and is disposed parallel to the third inner surface  113   b  while facing the third inner surface  113   b . The power supply unit  14  is disposed parallel to the fourth inner surface  114   b  while facing the fourth inner surface  114   b.    
         [0048]    As mentioned above, the first to fourth boards B 1  and B 4  and the power supply unit  14  have a plate shape and may be disposed to be brought close to the inner surfaces of the enclosure, specifically, the first to fourth flat inner surfaces  111   b  to  114   b  and the inner bottom surface  135   b , or may be disposed to be spaced apart from the inner surfaces with a gap therebetween. The first and second power amplification units B 2  and B 3  are parallel while facing each other. The up/down converter B 4  and the power supply unit  14  are parallel to and face each other while being spaced apart from each other. 
         [0049]    The first and second power amplification units B 2  and B 3  are disposed to be spaced apart from each other with the antenna unit therebetween in consideration of heat dissipation efficiency. That is, considering a problem of heat dissipation, a non-illustrated power amplification element is disposed in the first and second power amplification units B 2  and B 3 . In other words, in cases where the plurality of power amplification units B 2  and B 3  exist, it is most effective against heat dissipation to dispose the power amplification units with the largest separation distance therebetween. In cases where the enclosure  11  has a hexahedral shape as illustrated in the drawing, the power amplification units are most preferably disposed to face each other, and even when the enclosure  11  is embodied in a variety of shapes, it is most preferable to dispose the power amplification units with the largest separation distance therebetween. In addition, it will be sufficiently available to those skilled in the art to constitute each power amplification unit with two divided boards rather than one board in consideration of a problem of heat dissipation. 
         [0050]    Although it has been exemplified that the first and second power amplification units B 2  and B 3  are disposed on the first and second inner surfaces  111   b  and  112   b , respectively, the first and second power amplification units B 2  and B 3  may also be disposed on the third and fourth inner surfaces  113   b  and  114 . Also, while it has been exemplified that the up/down converter B 4  and the power supply unit  14  are disposed on the third and fourth inner surfaces  113   b  and  114   b , respectively, the up/down converter B 4  and the power supply unit  14  may also be disposed on the first and second inner surfaces  111   b  and  112   b  when the first and second power amplification units B 2  and B 3  are disposed on the third and fourth inner surfaces  113   b  and  114   b . The up/down converter B 4  and the power supply unit  14  are maintained to be spaced apart from each other while facing each other. The first power amplification unit B 2  is perpendicular to the digital interface module B 1 , the up/down converter B 4 , and the power supply unit  14 , and the second power amplification unit B 3  is perpendicular to the digital interface module B 1 , the up/down converter B 4 , and the power supply unit  14 . 
         [0051]    In the arrangement of the plurality of boards employed for the base station, the second to fourth boards B 2  to B 4  are disposed orthogonal to the first board B 1  along the periphery of the first board B 1 . 
         [0052]    Referring to  FIGS. 3 to 6 , the antenna unit  15  is disposed in the inner enclosure which is in the interior of the enclosure. The antenna unit  15  includes an antenna  150 , an antenna transmission/reception module, a reflection plate  151 , a ground plate  152 , and a plurality of radiating elements  153 . The ground plate  152  and the radiating elements  153  are electrically connected to transfer a radiometric signal therebetween. Each of the plurality of radiating elements  153  includes a radiating pattern section. The radiating pattern may be implemented to be a rectangular shape, a circular shape, a rectangular ring shape, or the like. 
         [0053]    As illustrated in  FIG. 4 , when the antenna unit  15  is disposed in the inner enclosure, four inner walls  136  function as an antenna reflection plate. 
         [0054]    In this embodiment, the inner enclosure has a rectangular parallelepiped shape, and filters having a cavity therein are illustrated as an example. However, the present disclosure is not limited thereto. The filter unit includes two or more filters (Tx, Rx) coupled to the interior of the inner enclosure to face each other. In  FIG. 4 , it is illustrated that the filters having the cavity are disposed to face each other in the up-down direction. 
         [0055]    In cases where the inner enclosure has a polyhedral shape, the antenna unit  15  is preferably disposed on the largest one of five outer surfaces of the inner enclosure. That is, since an RF characteristic is enhanced with the increasing allowable area of the reflection plate  151  of the antenna unit  15 , the antenna unit  15  is preferably mounted on the largest surface as illustrated in the drawing. 
         [0056]    A configuration of the outer surfaces of the enclosure  11  will be described with reference to  FIGS. 1 and 7 . The enclosure is formed of a metal material, for example aluminum, and performs a heat dissipation function when exposed to an external environment. In addition, it has been illustrated that the respective boards are mounted on the inner surfaces of the enclosure  11 , namely, the first to fourth inner surfaces and the inner bottom surface. 
         [0057]    In particular, the heat dissipation parts, for example, the heat sinks HS are additionally mounted on the outer surfaces  111   a  to  114   a  of the enclosure  11 . The heat dissipation parts HS mounted on the respective outer surfaces perform a function of transferring heat generated from the boards B 2  to B 4  and  14  to the outside. The heat dissipation parts HS mounted on the respective outer surfaces of the enclosure surround the exterior of the enclosure. The heat dissipation parts are mounted on the first to fourth outer surfaces  111   a  to  114   a , which are on four sides of the enclosure, and the outer bottom surface, respectively. 
         [0058]    Hereinafter, a mounting structure in which a board is mounted on the inner surface of the enclosure of the base station, according to the present disclosure, will be described with reference to  FIGS. 7 to 9 . 
         [0059]    In  FIG. 7 , the respective boards B 2  to B 4  and  14  are mounted on the first to fourth inner surfaces  111   b  to  114   b  constituting the enclosure  11 . The lateral appearance of the enclosure is formed by coupling four lateral members. The respective boards are mounted on the inner surfaces of the members, and then the member and the board, integrated into one body, are coupled to each other through a non-illustrated fastening element, for example a screw, to form the lateral appearance of the enclosure. At the same time, the boards are connected to the members using soldering, a connector, or the like. 
         [0060]    At this time, each of the boards may be mounted on the inner surface through the following two methods. 
         [0061]    As illustrated in  FIG. 8 , a board  80  may be mounted on an inner surface  820  of an enclosure member  82  through close surface-to-surface contact therebetween. That is, the board  80  has various electronic components mounted on the upper surface thereof, and the bottom surface of the board  80  is brought close to the inner surface  820 . As described above, the enclosure includes the four outer surfaces and the outer bottom surface, on which the heat dissipation parts HS, for example the heat sinks, are disposed. Meanwhile, the enclosure includes four inner surfaces and one inner bottom surface. The board is directly brought close to the inner surface, and thus heat generated from the board  80  is transferred to the outside through the heat sink HS mounted on the outer surface of the enclosure. 
         [0062]    As illustrated in  FIG. 9 , a board  90  may be mounted to an inner surface  920  of an enclosure member  92  while facing the inner surface  920  with a slight gap therebetween, namely, may be mounted to be spaced apart from the inner surface  920  of the enclosure member  92 . If various electronic components are mounted on the upper and lower surfaces of the board  90 , the board  90  may be mounted to the inner surface  920  with some distance therebetween. To this end, a plurality of spacers S is formed at predetermined locations of the inner surface. 
         [0063]    Among the above-described boards, the power amplification unit generates a larger amount of heat than the other boards due to the power amplification element. Accordingly, it is preferable that the power amplification unit be directly mounted to be brought close to the inner surface  820  through the method illustrated in  FIG. 8 . In addition, a board having various components mounted on the upper and lower surfaces thereof is preferably mounted on the inner surface through the method illustrated in  FIG. 9 . 
         [0064]    The enclosure of the base station, according to the present disclosure, is constituted by the members having the plurality of inner and outer surfaces. The members may be mechanically connected to each other by non-illustrated fastening elements, and the boards may be interconnected through non-illustrated connectors or soldering. Detailed descriptions related to the mechanical connection between the members or the electrical connection between the boards will be omitted in order not to unnecessarily obscure the features of the present disclosure. 
         [0065]    Hereinafter, another embodiment of an antenna base station will be described with reference to  FIGS. 10 to 14 . The antenna base station according to the above-described embodiment is the same as that according to this embodiment in that a board is coupled to be brought close to the interior of an enclosure, and heat generated from the board is released through an outer enclosure. However, the antenna base station, according to the above-described embodiment, is configured such that the board is coupled to the inner enclosure while being coupled to the interior of the outer enclosure in advance. In contrast, the antenna base station, according to this embodiment, is configured such that an outer enclosure covers an inner enclosure while a board is mounted in advance to the inner enclosure. Accordingly, the descriptions in the foregoing embodiment will be applied to the same configurations or contents as the above-described ones. 
         [0066]      FIG. 10  is an exploded perspective view of an antenna base station according to one of various embodiments of the present disclosure. Referring to  FIG. 10 , the antenna base station of the present disclosure may include a filter housing  120 , board parts B 1  and B 2  (including one or more boards, a power supply unit, etc.), and a case  110 . In the base station, an antenna unit  15 , the board parts B 1  and B 2 , and the case  110  may be arranged in the right places in three dimensions with respect to the filter housing  120 . As described above, the three dimensional arrangement means that major elements are arranged in consideration of three axes including X, Y, and Z axes. In particular, when such elements are arrange and assembled, ease of heat dissipation or assembly is considered. 
         [0067]      FIGS. 11 and 12  illustrate a state in which boards are mounted to the filter housing in the antenna base station illustrated in  FIG. 10 .  FIG. 13  is a schematic sectional view of the antenna base station illustrated in  FIG. 11 . Referring to  FIGS. 11 to 13 , the filter housing  120  corresponds to the inner enclosure, and the case  110  corresponds to the enclosure  11  in the foregoing embodiment. The filter housing  120  may be referred to as various other names, such as an enclosure (an inner enclosure), a filter unit, a main body, and the like, (hereinafter, referred to as the ‘filter housing  120 ’). The filter housing  120  of the present disclosure refers to an element that has a box shape and is included in the antenna base station by receiving the antenna unit  15  in the internal space thereof and mounting board parts B 1  to B 4  thereto. In addition, the case  110  may be referred to as various other names, such as an enclosure (an outer enclosure), a housing, a cover, and the like, (hereinafter, referred to as the ‘case  110 ’). The case  110  of the present disclosure refers to the outermost element of the antenna base station that covers the filter housing  120  having the antenna unit  15  therein and the board parts B 1  to B 4 . 
         [0068]    The filter housing  120  has a polyhedral shape and has a plurality of outer surfaces and an internal space according to the shape thereof. For example, it will be exemplified that the filter housing  120  of the present disclosure has a rectangular parallelepiped shape. The filter housing  120  having such a rectangular parallelepiped shape may have six outer surfaces and one internal space. The filter housing  120  includes two pairs of outer surfaces facing each other and one pair of outer top and bottom surfaces facing each other. That is, the filter housing  120  may be divided into the first and second outer surfaces  131  and  132 , the third and fourth outer surfaces  133  and  134  that are adjacent to the first and second outer surfaces  131  and  132  and face each other, the top surface  136 , and the bottom surface  135 . 
         [0069]    Mounting portions  121  are formed in the respective outer surfaces  131  to  136  in order to mount the board parts B 1  to B 4  thereon. The mounting portions  121  may have a recess shape that is depressed such that the board parts B 1  to B 4  mounted on the outer surfaces may be seated thereon. Accordingly, the filter housing  120  has such a shape that the antenna unit  15  is mounted therein and the recesses depressed in a predetermined shape are formed in the outer surfaces thereof. 
         [0070]    Connection openings  122  are formed in the mounting portions  121 . The connection openings  122  may make the adjacent mounting portions  121  communicate with each other, and connection terminals may be mounted to the connection openings  122  to electrically connect the boards seated on the adjacent outer surfaces. Accordingly, when the board parts B 1  to B 4  are mounted on the outer surfaces  131  to  136 , the adjacent board parts B 1  to B 4  may be electrically connected through the connection openings  122 . Therefore, the connection terminals are not exposed to the outside and the board parts B 1  to B 4 , after mounted to the filter housing  120 , may make surface-to-surface contact with the case  110  for heat dissipation (see  FIG. 11 ). 
         [0071]    Each of the board parts B 1  to B 4  and  14 , according to the embodiment of the present disclosure, has modules, for example chips, mounted on one surface thereof and is coupled to the mounting portion  121  such that the one surface of each board part orients toward the outer surface of the filter housing  120 . Accordingly, the other surface of each board part is exposed through the outer surface of the filter housing  120 , and when the case  110  to be described below covers the filter housing  120 , the other surface of the board part may make surface-to-surface contact with the inner surface of the case  110 , and heat generated from the board part may be released to the case  110  as well as the filter housing  120 . 
         [0000]    The board parts B 1  to B 4  and  14  may include boards including one or more of a digital interface module B 1  (DIM board), power amplification units B 2  and B 3  (PAM board), an up/down converter B 4  (also, referred to as an LAN board), and a power supply unit  14  (PSU board). It is apparent that the boards may be diversely arranged in three dimensions in view of the installation direction of the antenna base station or the performance of the internal elements thereof. 
         [0072]    In the present disclosure, it will be exemplified that the board parts B 1  to B 4  and  14  are provided on the outer surfaces  131  to  136 . The digital interface module B 1  (DIM board) is inserted into the mounting portion  121  of the bottom surface  135  of the filter housing  120  and disposed parallel to the bottom surface  135 , and the first power amplification unit B 2  (PAM board) is inserted into the mounting portion  121  of the first outer surface  131  and disposed parallel to the first outer surface  131 . The second power amplification unit B 3  (PAM board) is inserted into the mounting portion  121  of the second outer surface  132  and disposed parallel to the second outer surface  132 , and the up/down converter B 4  (LAN board) is inserted into the mounting portion  121  of the third outer surface  133  and disposed parallel to the third outer surface  133 . The power supply unit  14  (PSU board) is provided on the fourth outer surface  134  opposite to the third outer surface. Here, the first and second power amplification units B 2  and B 3  may be disposed to be spaced apart from each other while facing each other with the filter housing  120  therebetween, considering heat dissipation efficiency. That is, power amplification elements are disposed in the first and second power amplification units B 2  and B 3  and generate high-temperature heat. The heat generated from the power amplification elements have an influence on the radiation performance of the antenna unit  15  provided in the filter housing  120 . Therefore, when the first and second power amplification units B 2  and B 3  are provided to be adjacent to each other with the filter housing  120  therebetween, the heat generated from the power amplification elements may be concentrated on a side. Accordingly, in cases where a plurality of power amplification units are provided, the power amplification units may be disposed to face each other with the filter housing  120  therebetween to prevent heat from being concentrated on a side. 
         [0073]    As in the present disclosure, when the filter housing  120  has a rectangular parallelepiped shape, it is proposed that the first and second power amplification units B 2  and B 3  are formed to face each other. However, in cases where the filter housing  120  has a polyhedral shape, the power amplification units may be preferably mounted on the mounting portions  121  of the outer surfaces with the greatest distance therebetween. However, it is apparent to those skilled in the art that the board parts B 1  to B 4  and  14  may be mounted in view of the interference therebetween as well as a problem of heat dissipation. 
         [0074]    Although it has been exemplified that the first and second power amplification units B 2  and B 3  are disposed on the first and second outer surfaces  131  and  132 , respectively, the first and second power amplification units B 2  and B 3  may also be disposed on the third and fourth outer surfaces  133  and  134 . Also, while it has been exemplified that the up/down converter B 4  and the power supply unit  14  are disposed on the third and fourth outer surfaces  133  and  134 , respectively, the up/down converter B 4  and the power supply unit  14  may also be disposed on the first and second outer surfaces  131  and  132  when the first and second power amplification units B 2  and B 3  are disposed on the third and fourth outer surfaces  133  and  134 . The up/down converter B 4  and the power supply unit  14  are maintained to be spaced apart from each other while facing each other. The first power amplification unit B 2  may be perpendicular to the digital interface module B 1 , the up/down converter B 4 , and the power supply unit  14 , and the second power amplification unit B 3  may be perpendicular to the digital interface module B 1 , the up/down converter B 4 , and the power supply unit  14 . However, the mounting location thereof may be changed without any specific limitation. 
         [0075]    As described above, when the board parts B 1  to B 4  and  14  are fastened to the mounting portions  121 , with one surface of each board part orienting toward the corresponding outer surface, the board parts B 1  to B 4  and  14  may be electrically connected to each other through the connection openings  122 . Therefore, the adjacent board parts B 1  to B 4  and  14  may be interconnected only by fastening the board parts B 1  to B 4  and  14  to the mounting portions  121  of the filter housing  120  without using separate connection terminals. When the board parts B 1  to B 4  and  14  are coupled to the mounting portions  121 , the other surface of each board part forms an outer surface of the filter housing  120 . When the case  110  to be described below is fastened to cover the filter housing  120 , the other surface of each board part may make surface-to-surface contact with an inner surface of the case  110  (see  FIGS. 12 and 13 ). 
         [0076]    Since the board parts B 1  to B 4  and  14  are fastened to the filter housing  120  and make surface-to-surface contact with the inner surfaces of the case  110  at the same time, the heat generated from the power amplification elements, provided to the above-described power amplification units, may be released to the outside not only through the filter housing  120  but also through the case  110 , thereby enhancing a heat-dissipation effect. 
         [0077]    In this case, thermal pads  150  may be interposed between the board parts B 1  to B 4  and  14  and the case  110 . Even though the board parts B 1  to B 4  and  14  actually make surface-to-surface contact with the case  110 , a degree to which the board parts B 1  to B 4  and  14  and the case  110  are brought close to each other microscopically varies with the processed state thereof. Accordingly, the thermal pads  150  may be further included to increase the degree, thereby doubling the heat dissipation effect. 
         [0078]    As described above, the board parts B 1  to B 4  and  14  are seated on and coupled to the mounting portions  121  of the filter housing  120 . The board parts B 1  to B 4  may be fastened in various manners. For example, the board parts B 1  to B 4  and  14  may have holes formed therein to which screws are fastened and may be fastened to the mounting portions  121  through the screws, or the board parts B 1  to B 4  and  14  may be fastened to the mounting portions  121  using fastening members such as double-sided adhesive tape. However, it is apparent that the fastening element may be changed or modified without any specific limitation. The case  110  covers the filter housing  120  while the board parts B 1  to B 4  and  14  are fastened to the filter housing  120 . That is, in the foregoing embodiment, according to the assembly sequence, the board parts B 1  to B 4  and  14  are mounted on the case  110 , and the adjacent board parts B 1  to B 4  and  14  are coupled to the outer surface of the filter housing  120  while being electrically connected to each other. 
         [0079]    In addition, in this embodiment, when the board parts B 1  to B 4  and  14  are mounted on the mounting portions  121  of the filter housing  120 , the adjacent board parts B 1  to B 4  and  14  may be electrically connected to each other through the connection openings  122 . When the case  110  covers the filter housing  120  while being brought close to the outsides thereof in this state, the other surface of each board part is brought close to an inner surface of the case  110 , and the case  110  is assembled to the filter housing  120  while covering the same. 
         [0080]      FIG. 14  illustrates a state in which the antenna base station illustrated in  FIG. 11  is assembled. Referring to  FIG. 14 , although the case  110  covering the filter housing  120  may be an integrated cover, the case  110  configured to have a plurality of plates  111  to  114  coupled to each other and cover surfaces of a polyhedral shape will be exemplified in the embodiment of the present disclosure. 
         [0081]    The plates  111  to  114  include a heat dissipation part HS on the outer surface thereof which forms a heat sink having a plurality of sinks that are formed to be adjacent to each other. Due to this, inner surfaces  111   b  to  114   b  of the plates are brought close to and coupled to the other surfaces of the board parts B 1  to B 4  and  14  while facing the same. For the filter housing  120  having a cubic shape, the plates  111  to  114  may be provided to the respective outer surfaces thereof except for the outer top surface  137  through which the antenna unit  15  is mounted. 
         [0082]    The base station of the present disclosure is assembled by coupling the board parts B 1  to B 4  and  14  to the filter housing  120  and then coupling the plates  111  to  114  to the respective outer surfaces  131  to  136  of the filter housing  120 , thereby simplifying the assembly process. In addition, the board parts B 1  to B 4  and  14  coupled to the adjacent mounting portions  121  may be simply electrically connected to each other through the connection openings  122  without using separate connection wires. Accordingly, there are no externally exposed connection wires between the board parts, and thus current can more stably flow and the assembly process can be more simplified. 
         [0083]    Furthermore, as in the foregoing embodiment, the board parts B 1  to B 4  and  14  make surface-to-surface contact with the case  110  so that heat generated from the board parts B 1  to B 4  and  14  can be released to the outside through the case  110 . In addition, since the board parts B 1  to B 4  of the present disclosure are coupled to the filter housing  120 , the heat can also be dissipated through the filter housing  120 , thereby maximizing heat dissipation efficiency. 
         [0084]    As described above, according to the present disclosure, although a digital interface module and an antenna unit are disposed to be stacked on each other in the interior of an enclosure in the Z-axis direction, filters can be disposed to be stacked on each other, namely, to face each other in the up-down direction, and first and second power amplification units, an up/down converter, and a power supply unit can be arranged in three dimensions on the inner surfaces of the enclosure, thereby accomplishing the compactness of a base station. In particular, heat sinks can be constituted on the outer surfaces of the enclosure, thereby solving a problem of heat dissipation of the boards. 
         [0085]    In the antenna base station of the present disclosure, the boards can make surface-to-surface contact with a case, thereby efficiently dissipating heat generated from the boards. 
         [0086]    In addition, in cases where boards are mounted on mounting portions of a filter housing, the adjacent boards can be electrically connected to each other through connection openings of the mounting portions without being exposed to the outside, thereby increasing stability and simplifying the assembly process of the antenna base station.