Patent Publication Number: US-11664572-B2

Title: Ducted antenna housing for small cell pole

Description:
CROSS REFERENCE 
     The present application is a continuation of U.S. application Ser. No. 16/837,234 having a filing date of Apr. 1, 2020, the entire contents of which is incorporated herein by reference. 
    
    
     FIELD 
     The present disclosure is broadly directed to antenna housings utilized with small cell poles that provide coverage for local service areas. More specifically, the present disclosure is directed to antenna housings having internal ducting to provide venting for high power antennas. 
     BACKGROUND 
     In wireless communication networks, high-powered base stations (e.g., towers supporting antennas) commonly provide service over large geographic areas. Each base station is capable of serving wireless user devices in a coverage area that is primarily determined by the power of the signals that supported antennas can transmit. Frequently, high-powered base stations (e.g., macro stations) are located in a grid pattern with each base station mounting various antennas elevated on a tower. While such towers have previously provided adequate coverage for many wireless applications, such high-powered base stations tend to be too widely spaced for newer high-bandwidth wireless applications. 
     To improve wireless access, providers are moving toward smaller stations that provide enhanced coverage for more limited geographic areas. That is, to augment the coverage of the wireless network, wireless transceiver devices/antennas (e.g., access points) with relatively small coverage areas (and serving capacities) are deployed. Depending on their coverage area and serving capacities, these wireless transceiver devices are referred to as “femto” cells or “pico” cells. For simplicity and generality, the term “small cell pole” is used herein to refer to a wireless transceiver access point that is configured to serve wireless user devices over relatively small coverage areas as compared to a high-powered base station that is configured to serve a relatively large coverage area (“macro cell”). 
     The increasing use of RF bandwidth or ‘mobile data’ has required a corresponding increase in the number of access points to handle the increased data. By way of example, 5G wireless networks promise greatly improved network speeds and are currently being planned and implemented. Such networks typically require shorter RF transmission distances compared to existing networks and thereby require more dense networks of access points. Along these lines, access points are, in some instances, being installed in urban areas to serve several city blocks or even to serve a single city block. Such installations are often below roof-top level of surrounding buildings. That is, access points are being installed at ‘steel-level’ sites typically on small poles. The increasing number of access points is sometimes referred to as densification of wireless infrastructure. Residents often object to such densification in their neighborhoods due to the aesthetic concerns of numerous small cell poles. To help alleviate aesthetic concerns, wireless providers often attempt to at least partially conceal antennas supported by such small cell poles within shrouding. Further, to address densification issues, wireless service providers continue to install more powerful 5G antennas capable of handling greater data loads and/or operating at increased transmission distances. 
     SUMMARY 
     The present disclosure is directed to vented or ducted antenna housings for installation on a small cell poles that are primarily configured to provide local coverage. Aspects of the disclosure are based on the realization that the use of more powerful antennas in conjunction with the incorporation of enclosing or shrouding of antennas to address aesthetic concerns can result in thermal management concerns within a small cell pole. That is, in many instances a plurality of antennas may be disposed within a small cell pole installation. When these antennas are enclosed within a shrouding, heat generated by operation of the antennas is at least partially contained within the shrouding. This can result in the antenna(s) operating in a thermal environment above recommended operation temperatures. Accordingly, the present disclosure is directed to an antenna housing and/or shrouding assembly that allows for individually venting antennas to reduce the temperature within an interior of an antenna housing. Along these lines, a ducting system is provided that more effectively removes heat from one or more antennas disposed within an antenna housing. 
     In one implementation, an antenna housing is provided. The antenna housing is primarily configured to be mounted to a pole. However, the antenna housing may be a modular housing such that it may be mounted to and/or support another antenna housing. The antenna housing has an upper end and a lower end that are spaced to define an interior volume there between. A sidewall or shroud extends between the upper end and lower end and typically extends around at least a portion of peripheries of the upper and lower ends of the housing. The upper end, lower end and sidewall collectively define an at least partially enclosed interior area of the housing. This at least partially enclosed interior of the antenna housing may house one or more antennas. Typically, such an antenna(s) is at least partially disposed within the interior of the antenna housing such that it is partially or fully concealed. That is, the antenna(s) is at least partially enclosed within a sidewall and/or shrouding of the housing that extends between its upper and lower ends. When housing an antenna, an active or emitting surface of the antenna is typically directed outward from the interior of the housing. In some arrangements, an emitting surface may be exposed through an aperture in the sidewall and/or shrouding. One or support structures or struts may extend between the upper end and lower end within the at least partially enclosed interior of the housing. Such support structures may provide mounting surfaces for the antenna(s). 
     In order to provide cooling, when an antenna is disposed within the housing, the housing further includes an inlet duct and an outlet duct. These ducts extend through the sidewall or shroud to draw air into the housing and exhaust air from the housing. Such sidewall entry and exit are required if the housing is modular such that the lower end is mounted to a pole or underlying housing and the upper end supports another housing or other component. Typically, each duct has a substantially hollow sidewall that extends between an inlet end and an outlet end. The shape of the inlet and outlet ends as well as the shape of the duct sidewall may be selected based on intended use. By way of example, the outlet end of the inlet duct may be configured to engage a specific antenna unit disposed within the housing. Most commonly, the inlet and outlet ducts connect to a cooling duct within the interior of the housing. The inlet, cooling and outlet duct provide a closed (e.g., substantially sealed) airflow path into and out of the housing. To remove heat from an antenna, an interior of the cooling duct is typically in fluid communication with a heat rejecting surface of an antenna. In an arrangement, the cooling duct may be integrally formed within an antenna unit. In another arrangement, the cooling duct may have an opening that engages (e.g., receives) a surface of an antenna unit. In an arrangement, a blower or fan may be disposed within the closed airflow path to provide circulation through the airflow path. 
     In an arrangement, the upper and lower ends of the housing are formed of annular end plates, which need not be circular (e.g., octagonal). The annular end plates include one or more interior apertures that permit the passage of cables through the antenna housing. In one arrangement, the annular end plates include a plurality of apertures around their periphery to allow for connection to the pole, adjacent antenna housings or other structures. The plurality of apertures permit adjacent antenna support sections to be rotated relative to one another such that supported antennas may be directed in different directions. 
     In an arrangement, the sidewall extending between the upper and lower ends of the housing may be made of multiple independent sections. Such section may be termed shrouds. Each shroud may include an antenna aperture for exposing an emitting surface of an antenna within the interior of the housing. Each shroud may also include an inlet opening connectable to the inlet duct and an outlet opening connectable to the outlet duct. In an arrangement, the housing is configured to support three antennas disposed at 120 sectors. In such an arrangement, the housing may include three sets of inlet and outlet ducts. Each set of ducts may provide individual cooling for one of the antennas. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    illustrates one embodiment of a small cell pole. 
         FIG.  2    illustrate one embodiment of a small cell pole having vertically stacked antenna housings. 
         FIG.  3    illustrates an interior of one embodiment of an antenna housing. 
         FIG.  4 A  illustrates one embodiment of a ducted antenna housing. 
         FIG.  4 B  illustrates a partially exploded view of  FIG.  4 A . 
         FIGS.  5 A and  5 B  illustrate connection of inlet and outlet ducts to a wireless antenna unit. 
         FIGS.  6 A and  6 B  illustrate an inlet duct and an outlet duct, respectively. 
         FIGS.  7 A and  7 B  illustrate an inlet duct and outlet duct connected to a central plenum. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made to the accompanying drawings, which at least assist in illustrating the various pertinent features of the presented inventions. The following description is presented for purposes of illustration and description and is not intended to limit the inventions to the forms disclosed herein. Consequently, variations and modifications commensurate with the following teachings, and skill and knowledge of the relevant art, are within the scope of the presented inventions. The embodiments described herein are further intended to explain the best modes known of practicing the inventions and to enable others skilled in the art to utilize the inventions in such, or other embodiments and with various modifications required by the particular application(s) or use(s) of the presented inventions. 
     The present disclosure is broadly directed to wireless antenna housings that are primarily intended for use with small cell poles in urban environments. In various embodiments, the antenna housings are configured to at least partially conceal supported wireless antennas within an enclosed interior of the housing to minimize their aesthetic obtrusiveness. Various embodiments of the present disclosure are related to the recognition by the inventor that the use of increasingly more powerful wireless antennas in conjunction with the enclosing or shrouding of the antennas can result in thermal concerns within a small cell pole. That is, when one or more antennas are at least partially concealed within an enclosed interior of an antenna housing, heat generated during operation of the antenna(s) tends to build up within the housing. This can result in the antenna(s) operating in a thermal environment above recommended operation temperatures. Accordingly, the present disclosure is directed to an antenna housing and/or shrouding assembly that allows for individually venting antennas to reduce the temperature within an interior of the antenna housing and/or shrouding. More specifically, a ducting system is provided that more effectively removes heat from one or more antennas disposed within an interior or antenna housing. 
       FIG.  1    illustrates one embodiment of a small cell pole  10 . Various features of this small cell pole are disclosed in co-owned U.S. Patent Publication No. 2017/0279187, the entire contents of which are incorporated herein by reference. As shown, the cell pole includes a lower equipment housing  12  that includes an inner cavity (e.g., interior) configured to house, for example, cell control equipment. The equipment housing  12  has a lower flange  14  used to mount the housing to a surface (e.g., ground). Other installation methods are possible. Access panels and/or doors may be mounted to the equipment housing  12  to enclose equipment from the elements, while providing selective access, when desired, to modify, regulate, change out, or otherwise access the equipment within the housing  12 . The housing may include locks, hinges, access doors, vents for passive radiant cooling, and/or viewing ports. Cable ports and other features may be formed therein during manufacture. 
     Fasteners, such as threaded posts or bolts, are formed on an upper surface (e.g., flange; not shown) of the equipment housing  12  to facilitate attachment of a pole  20 , which may support an antenna housing  30 . In an embodiment, the antenna housing may include, for example, an omnidirectional antenna disposed within an RF transparent shroud that conceals the antenna. The cell pole  10  has a two-part design: the lower equipment housing  12  and the pole  20 . The two-part construction allows for easier construction and implementation during set-up. That is, the equipment housing  12  can be installed separately from the pole  20  and/or antenna housing  30 . Additionally, any equipment contained in the equipment housing may be installed at a later time. The present embodiment also illustrates a light mast or arm  16  attached to an upper portion of the pole  20 . The illustrated light mast  16  supports a street light  18 . As set forth in U.S. Patent Publication No. 2017/0279187, the interior of the equipment housing  12  may open into the generally hollow interior of the pole  20 . This allows passage of cables from the equipment housing(s) into the center of the pole for routing to, for example, one or more antennas and/or lights. 
     To better utilize a location where a small cell pole is located (e.g., access point), it is becoming increasingly common for a cell pole to support two or more sets of antennas, which may be disposed in vertically stacked antenna housings. In such an arrangement, wireless antennas of two or more separate wireless providers may be supported by a single pole.  FIG.  2    illustrates one embodiment of a small cell pole  10  that houses separate sets of antennas that are disposed in vertically stacked antenna housings. As illustrated, this embodiment of the cell pole  10  includes a lower equipment housing  12 , a support pole section or ‘monopole’  20  and three antenna support housings  30   a - 30   c  (hereafter  30  unless specifically referenced). 
     As illustrated in  FIG.  2   , a lower end of the monopole  20  is connected to the equipment housing  12 . Though illustrated as including the lower equipment housing  12 , it will be appreciated that not all embodiments of the cell pole  10  require such a lower equipment housing. Along these lines, the lower end of the monopole  20  may be configured for attachment to a ground surface and/or a subterranean equipment vault. An upper end of the monopole  20  is connected to and supports the lower end of the lower antenna housing  30   c . An upper end of the lower antenna housing  30   c  is connected to and supports the lower end of a middle antenna housing  30   b , which likewise supports and upper antenna housing  30   a . Though illustrated as having three antenna housings, it will be appreciated that the pole may support fewer antenna housings or more antenna housings. As shown, the use of the individual antenna housings allows the cell pole  10  to be a modular system that allows for adding additional antenna sections as desired. For instance, different wireless providers may utilize different antenna housings and/or different antenna housing may provide antenna coverage for different azimuth directions. 
       FIG.  3    illustrate one embodiment of an antenna housing  30  with external shrouding removed for illustration. The antenna housing  30  includes an upper end and a lower end. More specifically, the antenna housing includes an upper annular plate  32  and a lower annular plate  34 , respectively. The two plates  32 ,  34  each include multiple apertures, which permit the extension of wiring or cabling (not shown) through the antenna housing(s), when the small cell pole is assembled. Further, these apertures provide a pathway for airflow (e.g., natural or forced convection) through the antenna housing. As shown the two plates  32 ,  34  are disposed in a spaced relationship to define an interior volume there between. This interior volume is sized to house one or more antenna units  40  therein. 
     In the illustrated embodiment, three structural supports or struts  36  extend between the upper plate  32  and lower plate  34 . The ends of the struts  36  are fixedly attached (e.g., welded, bolted, integrally formed, etc.) to each plate. As will be appreciated, when utilized in an assembled cell pole, the antenna housing  30  may become a structural member that supports structures attached to its upper end such as, for example, upper antenna housings, lights etc. Thus, the antenna housing may be required to support loads such as compressive loads and/or moment loads (e.g., wind loading) applied by supported structures or elements. Accordingly, the struts  36  may include various bracing with the plates to provide adequate structural rigidity. Further, it will be noted that when multiple antenna housings are provided in a single cell pole, the configuration of adjacent antenna housings may be different. For instance, a lower housing may have thicker plates and/or struts (e.g., to support greater loads) while upper antenna housings may have thinner plates and/or struts and/or be made of different materials. 
     In the illustrated embodiment, the struts  36  also form antenna mounts, though separate antenna mounts are possible and considered within the scope of the present disclosure. The antenna units  40  supported by the antenna housing  30  may each have brackets (not shown) that are configured to attach to at least one of the struts. In various embodiments, such brackets may be affixed to the strut  36  when an antenna unit  40  is in a desired position. This may allow for fine-tuning the directionality of the antenna. The illustrated embodiment of the antenna housing  30  is configured to support three antennas units  40 . These three antennas may provide 360-degree coverage (e.g., three 120-degree sector antennas). 
     To further permit fine directional tuning of antennas supported by the illustrated antenna housing  30 , the upper and lower plates  32 ,  34  may each include a plurality of apertures  38  disposed about their periphery. These apertures  38  allow for connecting the antenna housing  30  to structures above and below utilizing one or more fasteners (e.g., bolts). Further, the apertures  38  allow for rotating each antenna housing relative to one or more adjacent antenna housings to align two or more adjacent antennas in different azimuth directions prior to affixing their relative positions, for example, by tightening one or more fasteners. Accordingly, this additional adjustment provides fine-tuning of the direction of antennas supported by the antenna housing  30 . A similar antenna housing to the one illustrated in  FIG.  3 B  is set forth in co-owned U.S. Pat. No. 10,505,271, the entire contents of which are incorporated herein by reference. 
     Once the antennas units  40  are disposed within the antenna housing  30 , the antenna units may be at least partially enclosed within the interior of the housing. In an embodiment, one or more shrouds  42  extend around the periphery of the housing and between the upper and lower plates. See  FIG.  2   . Effectively, the shrouds define a sidewall of the antenna housing between its upper end and its lower end. Though utilizing the term ‘shroud’, it will be appreciated that any component that at least partially encloses the antenna(s) within an interior of the housing between its upper and lower ends may be utilized. In any embodiment, it may be desirable to at least partially conceal the antennas to provide a finished look and to allow the resulting small cell pole to better blend in with its surroundings. If the shroud(s) covers an active surface of the antenna(s), the covering portion of the shroud is typically made of a material that is substantially transparent (e.g., transmission of greater than 90%) to radiofrequency (RF) waves. Such RF transparent materials include, without limitation, fiber glasses, polymers and/or fabrics. In other arrangements, the shroud  42  may have an antenna aperture  46  that exposes an active or emitter surface of the antenna unit  40 . See, e.g.,  FIG.  4 B . 
     As previously noted, wireless providers continue to increase the power of the antennas utilized for local coverage. By way of example, previous generations of antennas (e.g., 4G antennas) often had operational powers of around 150 watts. When an antenna housing held three such antennas, the total power of the enclosed antennas would be 450 watts. A thermal load generated by the enclosed antennas could be managed by providing vents  44  at or near the bottom of the housing  30 . See  FIG.  2   . Such vents  44  permit removal of heat from the housing via natural or forced convention. However, newer antennas (e.g., 5G antennas) having higher operational power (e.g., 400-500 watts) produce more heat than can be removed utilizing such simplified venting. For example, an antenna housing supporting three antennas has an operation power of 1200-1500 watts. When the antennas are enclosed within a shrouding, the heat generated during operation tends to build up. This is further complicated in applications where antenna housings are vertically stacked. Specifically, heat from a lower housing  30   c  tends to move upward into an upper housing  30   b , further increasing the temperature within the upper housing. Accordingly, it is desirable to more effectively vent heat generated by each antenna from the antenna housing. 
       FIGS.  4 A and  4 B  illustrate one embodiment of an antenna housing  50  that provides individual venting for each supported antenna. As illustrated, the antenna housing  50  shares many components with the antenna housing  30  described in  FIGS.  2  and  3    and common reference numbers are utilized to refer to the common components. As above, the antenna housing  50  includes an upper end  32 , a lower end  34  and a plurality of struts  36  extending there between. Further, the antenna housing  50  supports three antenna units  60  that are at least partially enclosed within the housing  50  by three shrouds  42  that generally define a sidewall or peripheral surface of the antenna housing between the upper end  32  and lower end  34 . In the illustrated embodiment, each antenna unit  60  attaches to two of the struts  36  via a mounting bracket  48 . In addition, the illustrated antenna housing  50  includes, for each supported antenna, a lower air intake vent  70  and an upper air outlet vent  80 , each extending through the sidewall or shroud  42  covering the antenna unit  60 . The intake vent  70  fluidly connects to an air inlet duct  72  that extends from the intake vent to a cooling duct (not shown) disposed near the bottom of the antenna  60 . Likewise, the outlet vent  80  fluidly connects to an air outlet duct  82  that extends from the outlet vent to the cooling duct (not shown) disposed near the top of the antenna  60 . The vents and ducts allow for individually cooling each antenna by drawing ambient air into the housing, passing the air over a heat rejection surface of the antenna and expelling the heated air from the housing. 
       FIGS.  5 A and  5 B  illustrate connection of the inlet duct  72  and outlet duct  82  to the antenna unit  60  having an integrally formed cooling duct. In the illustrated embodiment, the antenna unit  60  is a Streetmacro 6701 antenna produced by Ericsson. It will be appreciated that the antenna housing disclosed herein may be utilized with a variety of antenna units and that this particular antenna unit is presented by way of example only. Nonetheless, the Streetmarco antenna unit is representative of the general form of many 5G antenna units currently being installed. As illustrated, the antenna unit  60  includes a generally rectangular prism-shaped housing. A forward surface of the antenna unit  60  includes a front panel or radome  62 , which is a thin walled RF transparent area that protects the forward emitting surface of an RF antenna  63 . The housing of the antenna unit  60  includes an internal cooling duct  64  that passes through the rearward portion of the housing from an inlet  66  in the bottom surface to an outlet  68  in the top surface. The cooling duct passes over a heat rejection surface disposed within the interior of the antenna unit  60 . The heat rejection surface may be a finned surface  65  (e.g., aluminum) attached to a rearward surface of the antenna  63 . Commonly, the antenna unit will include a fan (not shown) to move air through the cooling duct  64  from the inlet  66  to the outlet  68 . Such air passes over the heat rejection surface cooling the antenna. 
     In the absence of the inlet duct  72  and outlet duct  82 , heat from internal cooling duct  64  of the antenna unit  60  would be drawn from the interior of the antenna housing  50  and expelled back into the interior of the antenna housing. This would result in inefficient cooling of the antenna and an increasing temperature within the antenna housing. To allow for drawing ambient air from outside of the antenna housing  50  to cool the antenna unit  60 , the inlet duct  72  is attached to the bottom surface of the antenna unit  60  such that a hollow interior of the inlet duct  72  is in fluid communication with the inlet  66  of the antenna cooling duct  64 . Likewise, to allow for exhausting air from the antenna housing, after the air passes over the heat rejection surface of the antenna unit  60 , the outlet duct  82  is attached to the top surface of the antenna unit such that a hollow interior of the outlet duct  82  is in fluid communication with the outlet  68  of the antenna cooling duct  64 . That is, once connected to the cooling duct  64  of the antenna unit  60 , the ducts  72 ,  82  each vent through a sidewall surface (e.g., shroud) of the antenna housing. More specifically, air from outside the housing enters the inlet duct  72 , passes through the antenna duct  64 , passes through the outlet duct  82  and exhausts outside of the housing. The air used to cool the antenna never comingles with air in the interior of the housing. This arrangement significantly reduces the internal temperature of the antenna housing. 
       FIG.  6 A  illustrates a perspective view of a non-limiting embodiment of the inlet duct  72 . The inlet duct  72  is a generally hollow structure having a sidewall  73  that extends from an inlet opening  74  to an outlet opening  76 . In the illustrated embodiment, the inlet opening  74  includes two openings disposed side-by-side. However, it will be appreciated that a single opening may be utilized. As shown, front edge surfaces of the two inlet openings  74  are curved for substantially flush engagement with the inlet aperture  70  formed through a correspondingly curved shroud  42 , when the antenna housing is assembled. This front edge surface may be otherwise configured based on, for example, the configuration of the surface (e.g., shroud) it will engage. Further it will be appreciated that a gasket may be disposed around the periphery or peripheries of the inlet(s)  74 . Such a gasket may seal an interface between the inlet and the periphery the inlet aperture  70  in the shroud, when the antenna housing is assembled. The outlet  76  is configured for engagement with an antenna unit. In this regard, the outlet may be contoured to engage a specific antenna unit. In the present embodiment, the peripheral surfaces around the outlet opening contain an adhesive  77  (e.g., pressure sensitive tape) for attaching the inlet duct  72  to the antenna unit. Other connection mechanisms are possible. 
       FIG.  6 B  illustrates a perspective view of a non-limiting embodiment of the outlet duct  82 . The outlet duct  82  is a generally hollow structure having a sidewall  83  that extends from an inlet opening  84  to an outlet opening  86 . The inlet opening  84  is configured for engagement with an antenna unit. In this regard, the inlet opening may be contoured to engage a specific antenna unit. In the present embodiment, the peripheral surfaces around the outlet contain an adhesive  87  for attaching the outlet duct  82  to the antenna unit. 
     In the illustrated embodiment, both the inlet duct  72  and outlet duct  82  are generally elbow-shaped. That is, each duct  72 ,  82  has an inlet opening and an outlet opening that are generally disposed in perpendicular planes. This shape allows the ducts to extend to or through the generally vertical sidewall surface (e.g., shroud) of the antenna housing while being able to connect to top and bottom surfaces of the illustrated antenna unit. However, it will be appreciated that the configuration of the ducts may be varied based on a configuration of the antenna housing and/or a configuration of an antenna unit disposed within the housing. What is important is that the ducts are configured to extend from openings in the peripheral or sidewall surface of the antenna housing and extend to a duct that is utilized to cool the antenna. The duct that cools the antenna may be integrally formed with the antenna unit as illustrated above in  FIG.  5 A . However, this is not a requirement. 
       FIGS.  7 A and  7 B  illustrate another embodiment of inlet and outlet ducts that may be utilized with the antenna housing described above. In this embodiment, the ducts  72 ,  82  attach to the lower and upper ends, respectively, of a central duct or plenum  90  that forms a cooling duct for cooling an antenna unit. In the illustrated embodiment, the plenum  90  is generally box-shaped having a solid rear wall  92 , two elongated sidewalls  94   a ,  94   b , an upper end wall  96   a  and a lower end wall  96   b . As illustrated, the lower wall  96   b  includes an aperture  98  that fluidly connects the interior of the inlet duct  72  to the interior of the plenum  90 . Likewise, the upper wall  96   a  includes an aperture (not shown) that fluidly connects the interior of the outlet duct  82  to the interior of the plenum  90 . The front of the illustrated plenum  90 , as defined by forward edges of the sidewalls  94   a ,  94   b  and end walls  96   a ,  96   b , is open to receive a rearward face of an antenna unit  40 , which may have a heat dissipating on it rearward surface (e.g., fin plate). The sidewalls and end walls of the plenum may be configured to substantially match the dimensions of the antenna unit  40 . A portion of the antenna unit  40  is disposed within or otherwise engages the plenum such that a space remains between the rearward face of the antenna unit and the rear wall  92  of the plenum  90 . That is, once the antenna unit engages the plenum, the plenum effectively becomes a sealed duct that carries cooling air between the inlet duct  72  and the outlet duct  82 . 
     The ducting embodiment illustrated in  FIG.  7 A  is well suited for use with antenna units that rely on passive cooling and lack an integral internal cooling duct. However, this embodiment is not limited to any particular antenna unit. The ducting may rely on natural convection to draw air through in inlet duct  72  and expel air out the outlet duct  82 . Alternatively, forced convection may be utilized. That is, if an antenna unit lacks a blower/fan, a blower or fan may be incorporated into the ducting. For instance, an optional blower or fan may be incorporated within the inlet duct or the outlet duct. Alternatively, an optional blower/fan may be disposed within the plenum and/or between the plenum and the inlet duct or the outlet duct. Further, it will be appreciated that a blower/fan may likewise be incorporated with the embodiments of  FIGS.  4 A- 5 B . For instance, an optional blower  54  (e.g., electric fan) may be incorporated within the inlet duct or the outlet duct  82  as illustrated in  FIG.  5 A . 
     The foregoing description has been presented for purposes of illustration and description. Furthermore, the description is not intended to limit the inventions and/or aspects of the inventions to the forms disclosed herein. Consequently, variations and modifications commensurate with the above teachings, and skill and knowledge of the relevant art, are within the scope of the presented inventions. The embodiments described hereinabove are further intended to explain best modes known of practicing the inventions and to enable others skilled in the art to utilize the inventions in such, or other embodiments and with various modifications required by the particular application(s) or use(s) of the presented inventions. It is intended that the appended claims be construed to include alternative embodiments to the extent permitted by the prior art.