Abstract:
There is disclosed an apparatus for mounting antennas on a utility pole. The apparatus comprises a group of brackets that encircle the utility pole and support the antennas. Each bracket comprises at least one support arm capable of attaching to an antenna and a faceplate that presses against the surface of the utility pole. The apparatus also includes tightening or closure means, such as nut and bolt assemblies, that connect the brackets together. When tightened, the tightening means draw the brackets encircling the utility pole closer together, thereby pressing the faceplates of each bracket more firmly against the utility pole. This clamps the apparatus tightly in place at selected points on the utility pole.

Description:
TECHNICAL FIELD OF THE INVENTION 
   The present invention is directed, in general, to antenna systems and, more specifically, to an apparatus for easily mounting and adjusting an antenna on a pole or similar fixture. 
   BACKGROUND OF THE INVENTION 
   In recent years there has been a rapid growth in the use of wireless devices, including one-way and two-way pagers, cellular phones, personal communication services (PCS) systems, and personal computers (PCs) equipped with cellular modems or wireless network cards. To support this growth, wireless service providers have dramatically increased the amount and the density of wireless network infrastructure deployed nationwide. 
   The large number of subscribers and the many applications for wireless communications have created a heavy subscriber demand for RF bandwidth. To maximize usage of the available bandwidth, a number of multiple access technologies have been implemented to allow more than one subscriber to communicate simultaneously with each base transceiver station (BTS) in a wireless system. These multiple access technologies include time division multiple access (TDMA), frequency division multiple access (FDMA), and code division multiple access (CDMA). These technologies assign each system subscriber to a specific traffic channel that transmits and receives subscriber voice/data signals via a selected time slot, a selected frequency, a selected unique code, or a combination thereof. 
   To further augment the capacity of their wireless networks and provide coverage to greater numbers of subscribers, wireless service providers increasingly are using a larger number of smaller-sized cell sites to cover the same amount of territory. Since each cell site covers a relatively smaller geographical area, each cell site generally also encompasses a smaller number of subscribers, all other things being equal. This allows greater reuse of frequency bands, time slots and codes in FDMA, TDMA and CDMA wireless networks. 
   However, the use of a larger number of smaller cell sites also increases the infrastructure equipment required by a wireless network. For example, doubling the number of cells sites covering a particular territory generally doubles the number of base transceiver stations, the number of antennas, the number of antenna poles, and the like. 
   To offset increased infrastructure equipment requirements, wireless service providers seek to minimize the equipment cost, installation costs, and maintenance costs. The use of standard commodity equipment is encouraged. It also is particularly helpful to use infrastructure equipment that is multi-purpose, adaptable, quickly installed, and easy to disassemble and service. 
   Much of the antenna equipment that has been installed, however, is inflexible, difficult to maintain, and/or custom-made to fit specific systems. For instance, many base station antennas are mounted on fixed platforms that are rigidly or permanently attached to utility poles. This makes moving, replacing, and/or adjusting the antennas difficult and more expensive. 
   There is therefore a need in the art for improved antenna mounting equipment that is more adaptable and easier to maintain and adjust. In particular, there is a need for antenna mounting equipment that is simple to attach to, or detach from, a utility pole. More particularly, there is a need for antenna mounting equipment that uses standard parts, but which can be adapted for use with utility poles of varying diameters and cross-sectional shapes. 
   SUMMARY OF THE INVENTION 
   To address the above-discussed deficiencies of the prior art, it is a primary object of the present invention to provide an apparatus for mounting a plurality of antennas on a utility pole. The apparatus comprises 1) a plurality of brackets capable of encircling the utility pole and supporting the plurality of antennas, each of the plurality of brackets comprising a) at least one support arm capable of attaching to a first selected one of the plurality of antennas; and b) a faceplate capable of engaging a surface of the utility pole; and 2) a plurality of tightening means, each of the tightening means connecting a first selected one of the plurality of brackets and a second selected one of the plurality of brackets, wherein the plurality of tightening means are capable of drawing the plurality of brackets encircling the utility pole closer together, such that the faceplate of the each of the plurality of brackets is pressed more firmly against the surface of the utility pole. 
   Accordingly in one embodiment of the apparatus, the plurality of brackets comprise three brackets. 
   In an alternate embodiment of the apparatus, the plurality of brackets comprise four brackets. 
   In another embodiment of the apparatus, at least a portion of a surface of the faceplate capable of engaging the surface of the utility pole is covered by a layer of rubber. 
   In still another embodiment of the apparatus, at least a portion of a surface of the faceplate capable of engaging the surface of the utility pole is covered by ridges. 
   In yet another embodiment of the apparatus, at least a portion of a surface of the faceplate capable of engaging the surface of the utility pole is covered by sharp points. 
   In a further embodiment of the apparatus, at least a portion of a surface of the faceplate capable of engaging the surface of the utility pole has a rough texture capable of increasing friction with the surface of the utility pole. 
   In a still further embodiment of the apparatus, each of the plurality of brackets comprises a first support arm and a second arm, wherein the first support arm is capable of attaching to one side of the first selected antenna and the second support arm is capable of attaching to an opposing side of the first selected antenna. 
   In a yet further embodiment of the apparatus, the plurality of tightening means comprise a plurality of bolts. 
   In another embodiment of the apparatus, the first selected antenna is adjustably attached to the at least one support arm, such that the first selected antenna may be tilted with respect to the horizon in a plurality of positions. 
   The foregoing has outlined rather broadly the features and technical advantages of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features and advantages of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art should appreciate that they may readily use the conception and the specific embodiment disclosed as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the invention in its broadest form. 
   Before undertaking the DETAILED DESCRIPTION, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document: the terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation; the term “or,” is inclusive, meaning and/or; the phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like; and the term “controller” means any device, system or part thereof that controls at least one operation, such a device may be implemented in hardware, firmware or software, or some combination of at least two of the same. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. Definitions for certain words and phrases are provided throughout this patent document, those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, wherein like numbers designate like objects, and in which: 
       FIG. 1  illustrates a perspective view of an exemplary multi-sector antenna system according to one embodiment of the present invention; and 
       FIG. 2  illustrates an exploded perspective view of an exemplary multi-sector antenna system according to another embodiment of the present invention. 
   

   DETAILED DESCRIPTION 
     FIGS. 1 and 2 , discussed below, and the various embodiments used to describe the principles of the present invention in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the invention. Those skilled in the art will understand that the principles of the present invention may be implemented in any suitably arranged multi-sector antenna. 
     FIG. 1  illustrates a perspective view of multi-sector antenna system  20  according to one embodiment of the present invention. Multi-sector antenna system  20  comprises three individual sector antennas, namely antenna  21 , antenna  22  and antenna  23 , mounted on utility pole  10 . Multi-sector antenna system  20  is associated with a single base transceiver station (BTS) that serves a single cell site in a wireless network. Each of antennas  21 – 23  transmits and receives signals in a specified 120° arc around the cell site. 
   Antenna  21  is attached to utility pole  10  by means of upper bracket  31  and lower bracket  41 . Upper bracket  31  comprises two parts: attachment bracket  31   a  and faceplate  31   b . Lower bracket  41  also comprises two parts: attachment bracket  41   a  and faceplate  41   b . Attachment bracket  31   a  comprises two support arms that extend outward from utility pole  10  to support antenna  21 . Attachment bracket  31   a  is removably attached to an upper portion of antenna  21 . Attachment bracket  41   a  also comprises two support arms that extend outward from utility pole  10  to support antenna  21 . Attachment bracket  41   a  is removably attached to a lower portion of antenna  21 . Attachment brackets  31   a  and  41   a  are fixedly attached to faceplates  31   b  and  41   b , respectively. Faceplates  31   b  and  41   b  connect to other faceplates associated with antennas  22  and  23  and are tightened into place to form a strong friction grip against utility pole  10 . To increase friction with utility pole  10 , the inner surfaces of faceplates  31   b  and  41   b  may be rubber coated, or covered by rough ridges or points, similar to the surface of a file or a rasp. 
   In a similar manner, antenna  22  is attached to utility pole  10  by means of upper bracket  32  and lower bracket  42 . Upper bracket  32  comprises attachment bracket  32   a  and faceplate  32   b . Lower bracket  42  comprises attachment bracket  42   a  and faceplate  42   b . Attachment bracket  32   a  comprises two support arms that extend outward from utility pole  10  to support antenna  22 . Attachment bracket  32   a  is removably attached to an upper portion of antenna  22  and attachment bracket  42   a  is removably attached to a lower portion of antenna  22 . Faceplates  32   b  and  42   b  connect to other faceplates (e.g., faceplates  31   b ,  41   b ) associated with antennas  21  and  23  and are tightened into place to form a strong friction grip against utility pole  10 . The inner surfaces of faceplates  32   b  and  42   b  also may be rubber coated, or covered by sharp ridges and/or points to give it a rough texture. 
   Finally, antenna  23  is attached to utility pole  10  by means of upper bracket  33  and lower bracket  43  (not visible). Upper bracket  33  comprises attachment bracket  33   a  and faceplate  33   b  (not visible). Lower bracket  43  comprises attachment bracket  43   a  and faceplate  43   b  (not visible). Attachment bracket  33   a  is removably attached to an upper portion of antenna  23  and attachment bracket  43   a  is removably attached to a lower portion of antenna  23 . Faceplates  33   b  and  43   b  connect to faceplates  31   b ,  32   b ,  41   b , and  42   b  on antennas  21  and  22  and are tightened against utility pole  10 . As before, the inner surfaces of faceplates  33   b  and  43   b  also may be rubber coated, or covered by sharp ridges and/or points to increase friction with utility pole  10 . 
   The upper portion of antenna  21  is attached to attachment bracket  31   a  by means of a bolt or dowel that is inserted through one of a plurality of holes in attachment bracket  31   a  and into a corresponding upper side hole in antenna  21 . Antenna  21  may be tilted upward or downward with respect to the horizon by inserting the bolt or dowel through selected holes in attachment bracket  31   a . The lower portion of antenna  21  is attached to attachment bracket  41   a  by means of a bolt or dowel that is inserted through an elongated slot (or hole) in attachment bracket  41   a  and into a corresponding lower side hole in antenna  21 . The bolt in the slot in attachment bracket  41   a  can slide up and down to accommodate different positions as antenna  21  is tilted up or down by selecting different holes in attachment bracket  31   a.    
   Antennas  22  and  23  may be positioned at different angles of downtilt in attachment brackets  32   a ,  33   a ,  42   a , and  43   a  in a manner similar to that described above with respect to antenna  21 . To avoid redundancy, further explanation of the tilting operations of antennas  22  and  23  is omitted. 
   Upper brackets  31 ,  32 , and  33  encircle utility pole  10  and are joined together by means of threaded bolts  51  in the flanges of faceplates  31   b ,  32   b , and  33   b . Similarly, lower brackets  41 ,  42 , and  43  encircle utility pole  10  and are joined together by means of threaded bolts  51  in the flanges of faceplates  41   b ,  42   b , and  43   b . Antennas  21 – 23  may be mounted on utility poles  10  of varying diameters by tightening or loosening bolts  51 , thereby increasing or decreasing the gaps separating faceplates  31   b ,  32   b , and  33   b  and drawing the inner surfaces of faceplates  41   b ,  42   b , and  43   b  closer together. Tightening the bolts effectively reduces the circumference of any cylinder (i.e., pole) that may be inserted within the inner surfaces of the faceplates  41   b ,  42   b , and  43   b.    
   Although three upper brackets  31 – 33  are used to attach the tops of antennas  21 – 23  to utility pole  10  and three lower brackets  41 – 43  are used to attach the bottoms of antennas  21 – 23  to utility pole  10 , different numbers of brackets may be used. For example, utility pole  10  may support four antenna units if the cell site in which utility pole  10  is located is divided into four (4) 90° sectors. In such a case, each antenna unit would be separated by four brackets at the top and four brackets at the bottom. Furthermore, there is no requirement that utility pole  10  have a circular cross-sectional area. For example, if utility pole  10  was hexagonal in its cross-sectional area, upper brackets  31 – 33  and lower brackets  41 – 43  may still be used to attach antennas  21 – 23 . If utility pole  10  is square in its cross-sectional area, a system of four upper brackets and four lower brackets may be used to attach four antenna units. 
     FIG. 2  illustrates an exploded perspective view of exemplary multi-sector antenna system  200  according to another embodiment of the present invention. For the purposes of brevity and clarity in explaining  FIG. 2 , only antenna  23  is shown and described. However, antennas  21  and  22  are mounted on utility pole  10  in a manner similar to antenna  23 . 
   In  FIG. 2 , the upper brackets and lower brackets used to attach antennas  21 – 23  are comprised of a single part, rather than two parts. The tops of antennas  21 – 23  are mounted on utility pole  10  by means of attachment brackets  131 – 133 , each of which has a flat faceplate portion that makes contact with utility pole  10 . For example, faceplate segment  177  of attachment bracket  132  makes contact with utility pole  10  when brackets  131 – 133  are tightened in place. The inner surface of faceplate segment  177  may be covered by a layer of rubber or by rough ridges or points in order to increase friction with utility pole  10 . 
   Similarly, the bottoms of antennas  21 – 23  are mounted on utility pole  10  by means of attachment brackets  141 – 143 , each of which has a flat faceplate portion that makes contact with utility pole  10 . For example, faceplate segment  176  of attachment bracket  142  makes contact with utility pole  10  when brackets  141 – 143  are tightened in place. The inner surface of faceplate segment  176  may also be covered by rubber or rough ridges/points in order to increase friction with utility pole  10 . 
   Bolt assemblies, including bolts  145 ,  146  and  150 , are used to tighten together attachment brackets  131 – 133  and attachment brackets  141 – 143 . An exploded view is shown of a bolt assembly comprising bolt  150 , washers  151 – 153 , and nut  154 . Bolt  150  is inserted through slots in attachment brackets  131  and  133 . Depending on how large the slots are, bolt  150  may slide outward by varying amounts with respect to utility pole  10  in order to accommodate different pole diameters. 
   Antenna  23  is mounted on upper attachment bracket  133  and lower attachment bracket  143  by means of bolts  160 ,  161  and  170  that are inserted through holes  181  in the support arms of upper attachment bracket  133  or through slots  182  in the support arms of lower attachment bracket  143  and then into corresponding sideholes  183  and  184  in antenna  23 . The bolt are secured in place with washers  171  and  172 . 
   Antenna  23  may be tilted upward or downward with respect to the horizon by inserting bolts  160  and/or  161  through different ones of holes  181  in upper attachment bracket  133  and then into sideholes  183  in antenna  23 . The lower portion of antenna  23  is rotatably mounted on lower attachment bracket  143  by means of bolt  170 , which is inserted through slot  182  in lower attachment bracket  143  and into corresponding sidehole  184  in antenna  23 . Bolt  170  can slide vertically and rotate in slot  182  to accommodate different positions as antenna  23  is tilted up or down by selecting different holes  181  in attachment bracket  133 . 
   The attachment brackets of the present invention provide a superior means for mounting antennas on a utility pole over the prior art. The attachment brackets accommodate poles of different diameters and may be attached using simple hand tools, such as wrenches. A technician may easily adjust the height at which antennas  21 – 23  are mounted on utility pole  10  by loosening bolts  145 / 146 / 150  in the upper and lower attachment brackets and then sliding the entire assembly up or down to the correct position. A technician also may easily adjust the tilt or antennas  21 – 23  by removing bolts  160  and  161  in the upper attachment bracket, tilting the antenna(s) to the correct angle, and then reinserting bolts  160  and  166 . The present invention also allows the antennas to be tilted independently. 
   Advantageously, the present invention obviates the need to modify or adapt the utility pole in any way in order to mount antennas thereon. The present invention can be quickly attached to different-sized utility poles that are part of the existing wireless infrastructure or to new utility poles without the need to drill, weld or otherwise alter the poles. 
   In alternate embodiments of the present invention, bolts  51 ,  145 ,  146 , and  150  may be replaced by other types of tightening means (or closure means) that secure the attachment brackets to the utility pole. For example, the attachment brackets may be mounted on the utility pole by means of a belt that is threaded through holes or slots in the attachment brackets and then is tightened, cinched or latched in place, similar to a radiator hose clamp. 
   Although the present invention has been described in detail, those skilled in the art should understand that they can make various changes, substitutions and alterations herein without departing from the spirit and scope of the invention in its broadest form.