Abstract:
A radio frequency identification (RFID) portal easily installs and integrates any RFID hardware/software systems. The RFID portal may match the size of a traditional dock or be custom sized. The portal takes advantage of a variety of unique features including an antenna bracket that provides for three-dimensional vertical and horizontal movements and a hardware independent reader bracket. The antenna movement capabilities allow for excellent RFID signal coverage. A General Purpose Input/Output (GPIO) bridge enables rapid integration and functionality to other RFID inputs such as Motion Detectors/Photo Eyes, Uninterrupted Power Supply (UPS), Wireless Networking, floor loops, mass detectors, and output signals, such as to light stacks and RFID readers.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   The present application claims the benefit of U.S. patent application Ser. No. 60/795,940 “Radio Frequency Identification (RFID) Portal Antenna Mounting Frame” to Berry et al., filed 28 Apr. 2006, the disclosure of which is hereby incorporated by reference in its entirety. 

   FIELD OF THE INVENTION 
   The present invention relates, in general, to radio frequency identification (RFID) systems, and more particularly to mounting structures for RFIU) system antennas and transceivers. 
   BACKGROUND OF THE INVENTION 
   One aspect of installing a radio frequency identification (RFID) system is antenna mounting and direction sensing. Typically RFID antennas are mounted on an open framework and are gimbaled to positions that provide the best reception. Relocating the antenna racket on the open framework and realigning the antenna is the generally known way to adjust the position of the antenna pattern. In addition, the open framework exposes the RFID antennas and associated equipment to the environment where they are more prone to being damaged. 
   It also generally known to enclose framework for RFID antennas and the associated equipment, as described in U.S. Pat. No. 6,825,766. However, the enclosure tends to limit the flexibility of the placement of the antennas to the detriment of needed reception for some applications. The antennas are mounted on structures in a manner similar to the mounting of car speakers and then covered with a protective cover, thus precluding adjustments in positioning. 
   Antennas also need to occasionally be removed or replaced and, in many cases, the value of the antenna is significant. Typically the antenna bracket is mounted to the support structure and then the antenna is mounted to the bracket. This usually involves several nuts and or bolts, holding the antenna in position, lining up holes and manipulating tools. In many cases this is inconvenient and time consuming and in some cases the antenna can be dropped or damaged because of the complexity of the installation. 
   Consequently, we recognized that the close confines of RFID installations within a facility tend to not benefit from installation flexibility that is generally known for other types of telecommunication systems, for instance U.S. Pat. No. 5,926,151, wherein pole-mounted external antennas may be mounted at a desired height and azimuth. We also recognize that antenna installation can be improved so that it can be done without tools or risking damage to the antennas. 
   Consequently, a significant need exists for a mounting structure for RFID antennas and associated equipment that is readily adapted to a range of applications and equipment variations. 
   BRIEF SUMMARY OF THE INVENTION 
   The invention overcomes the above-noted and other deficiencies of the prior art by providing a mounting structure for a radio frequency identification (RFID) system having at least one antenna and a transceiver controller unit and includes an enclosed mounting pole and a bracket that has a hand-tightened fastener that grips the pole at a selected height and orientation. The bracket has a surface sized to easily engage to a selected component of the RFID system and can be removed from the structure without tools. The structure protects the RFID equipment from environmental or accidental damage and provides an RF transparent view area for transmission and reception. 
   These and other objects and advantages of the present invention shall be made apparent from the accompanying drawings and the description thereof. 

   
     BRIEF DESCRIPTION OF THE FIGURES 
     The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, and, together with the general description of the invention given above, and the detailed description of the embodiments given below, serve to explain the principles of the present invention. 
       FIG. 1  is an isometric view of a radio frequency identification (RFID) reader station. 
       FIG. 2  is an isometric view of the RFID reader station of  FIG. 1  with a radome and top cover removed. 
       FIG. 3  is an isometric cutway view of a portion of the RFID reader station of  FIG. 1  with antenna mounting brackets. 
       FIG. 4  is an isometric view of the antenna mounting bracket of  FIG. 3  depicting a locking lever and engagement to a mounting pole. 
       FIG. 5  is a back isometric view of the antenna mounting bracket of  FIG. 3  with one antenna mounting member omitted. 
       FIG. 6  is a side view along the longitudinal axis of the mounting pole of the antenna mounting bracket of  FIG. 3 . 
       FIG. 7  is an isometric, exploded view of an RFID reader sled assembly for the RFID reader station of  FIG. 1 . 
       FIG. 8  is an isometric view of a dual-sided RFID reader station that includes the RFID reader station of  FIG. 1 . 
       FIG. 9  is an interconnected RFID reader station that inwardly orients and laterally spaces the RFID reader station and a remote RFID reader station of  FIG. 8 . 
       FIG. 10  is a detail view of a deepened channel for encompassing on three sides antenna mounting brackets. 
       FIG. 11  is an isometric view of a portal RFID reader station with flat RF transmissive covers omitted and incorporating the deepened channel of  FIG. 10 . 
       FIG. 12  is an isometric view of the portal RFID reader station of  FIG. 11 . 
       FIG. 13  is a side view of the portal RFID reader station of  FIG. 11  with a front portion of left, right and overhead cabinets omitted. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Turning to the Figures, wherein like numerals denote like components throughout the several views, in  FIGS. 1-2 , a first version of a Radio Frequency Identification (RFID) reader station  10  comprises a stand-alone pedestal cabinet  12  atop a floor plate  14  having fasteners  16  intended for permanent installation into flooring or substrate (e.g., concrete) adjacent to a traffic pathway (e.g., a doorway). A longitudinally bisected elongate half-cylindrical radome  18  encloses a vertical mounting pole  20  ( FIG. 2 ). 
   A motion detector  22  and a light stack  24  may be attached to the RFID reader station  10  for providing guidance to personnel such as forklift operators and/or to indicate operating status. Audible signals may be provided in addition to or as an alternative to visual signals. For example, a red light provided by the light stack  24  may indicate that one or more RFID tags cannot be successfully read, although the motion detector  22  indicates that an object presumed to included RFID tagged contents are within range of the RFID reader station  10 , or that the sensed RFID tagged contents are read but not manifested as being cleared for entry past the RFID reader station  10 . A yellow or white light by the light stack  24  may indicate that interrogation of the RFID tags is in process and to proceed toward, but not pass, the RFID reader station  10 . A green light by the light stack  24  may indicate successful interrogation of the RFID tags, perhaps with wireless verification against a database or other remote tracking system. 
   It should be appreciated that a mobile base may be incorporated onto the RFID reader station  10  instead of fasteners  16 . Wheels may be selected having a diameter, number, lateral offset, and composition appropriate for the intended installation (e.g., smoothness of surface and how much control is necessary for placement). In some instances, the wheels may be omni-directional (e.g., castoring) for expeditious rotation and movement. The ability to lock or to move the wheels up out of contact with the floor (e.g., pivot up or be raised through a slot in a base) may be incorporated to prevent inadvertent movement. In some applications, skids may suffice for limited movement. 
   In  FIG. 2 , the pedestal cabinet  12  has the radome  18  removed to expose the vertical mounting pole  20  spaced away from a back wall  26  of the cabinet  12  by top and bottom pole brackets  28 ,  30 . In addition to the radome  18 , a top panel  32  is removed to expose RFID electrical power and control circuitry  34  including a general purpose input and output (GPIO) plug panel adapted for quick installation of one of a plurality of commercially available RFII) reader systems, a power supply, an electrical outlet, terminal strips, etc. 
   It should be appreciated with the benefit of the present disclosure that a GPIO plug panel may include means of connecting custom cables intended for input and output devices (e.g., light stacks and motion detectors) to a single GPIO Interface Device using a reader specific cable. The reader specific cable may perform simple pin mapping from GPIO pins on the RFID reader to specific pins on the GPIO Interface Device. The interface may convert different signal voltage levels. Input from a manual switch, such as a light switch, may provide control input to the RFID reader in a hardened industrial environment. 
   In  FIG. 3 , a vertical mid-portion of the pedestal cabinet  12  depicts shallow left and right side vertical panels  50 ,  52  extending from the back wall  26  to form an inwardly open channel  54 . The vertical mounting pole  20  is approximately positioned at an opening  56  of the inwardly open channel  54  affording a wide adjustment and reception area of a plurality of antenna mounting brackets  58 , each positioning an RFID antenna  60 . Each bracket  58  advantageously includes a hand-adjusted pole clamp  62  that enables attachment at a desired radial angle and longitudinal position along an axis defined by the mounting pole  20 . 
   In  FIGS. 4-6 , the pole clamp  62  grips the mounting pole  20  by adjustably drawing in a U-shaped channel  64  that substantially encompasses the mounting pole  20  into a pole mounting bracket  66  so that engagement surfaces  68 ,  70  longitudinally spaced along one lateral side of the mounting pole  20  cooperate with an opposite flange  72  of the U-shaped channel  64 . The engagement surfaces  68 ,  70  are recessed to correspond to a portion of the circumference of a mounting pole  20  to enhance the frictional engagement, although it should be appreciated that various contacting contours and finishes may be selected (e.g., roughed, toothed, flat, V-shaped). Similarly, although a flat opposite flange  72  is depicted, it should be appreciated that other contours and finishes may be selected to enhance the contact area and/or frictional contact with the mounting pole  20 . 
   A channel post  74  attached to an inner flange  76  of the U-shaped channel  64  extends laterally within a channel receiving recess  78  formed within the pole mounting bracket  66  outward and extends out through a post hole  80 . It should be appreciated that external threads on the channel post  74  engage internal threads in a hand-adjusted clamp knob  82  such that rotation in one direction (e.g., clockwise) draws the L-shaped channel  64  further into the channel receiving recess  78  in the pole mounting bracket  66 , which also prevents rotation of the U-shaped channel and thus the channel post  74 . Thereby, the lateral spacing between the engagement surface  68 ,  70  of the pole mounting bracket  66  and the opposite flange  72  of the U-shaped channel  64  is narrowed. Rotation in the opposite direction (e.g., counterclockwise) allows greater lateral spacing. With particular reference to  FIG. 6 , radial indicia  84  formed about the engagement surfaces  68 ,  70  on the pole capturing bracket  66  may assist in setting a desired radial angle relative to the longitudinal axis of the mounting pole  20 , which may include corresponding markings. 
   A pivoting flange  86  is attached to the pole mounting bracket  66  and aligned generally with the longitudinal axis of the U-shaped channel  64 . Mirror image first and second antenna mounting members  88 ,  90  each have outward planar portions  92  that are placed adjacent and aligned in a plane for mounting of an RFID antenna (not shown) through fastener holes  94 . Each antenna mounting member  88 ,  90  has an isosceles triangular flange  96  formed at a perpendicular angle from an inner edge of the respective outward planar portion  92 . A locking lever  98  that rotates in a plane parallel to isosceles triangular flanges  96  tightens a locking bolt  100  that passes through holes formed through the triangular flanges  94  and the pivoting flange  84 , allowing the pivoting flange to be set at a desired azimuth angle relative to the longitudinal axis defined by the mounting pole  20 . With particular reference to  FIG. 4 , radial indicia  102  formed on the pivoting flange  86  may be referenced to an apex marking  104  on the isosceles triangular flanges  96  to determine a set azimuth angle. A locking hole  106  is provided through the isosceles triangular flanges  88 ,  90  through which a locking bolt or similar fastener may be inserted to provide additional locking force. 
   To provide additional mounting capabilities in addition to positioning RFID antennas  60 , in  FIG. 7  a reader sled assembly  110  includes a reader sled base  112  with longitudinally spaced first and second attachment brackets  114 ,  116  (similar in design to the pole clamp  62  of  FIGS. 4-6 ) on each end for attachment to the mounting pole  20 . In this instance, a two-piece circular ring  118  of each bracket  114 ,  116  is fastened around the mounting pole  20  by recessed fasteners  120 . The two-piece ring is drawn into a pole engaging structure shaped as a half rectangular box  122  with semi-circular pole engaging recessed surfaces  124 ,  126  by a hand-tightened knob  128 . 
   The reader sled base  112  includes a shallow rectangular channel  130  closed on a first end by a large rectangular plate (bulkhead)  132  with mounting apertures  134  for electronic interconnects suitable for one or more available RFID readers (not shown). A second end of the shallow rectangular channel  130  turns downward into a mounting flange  136  that is fastened to an upturned mounting flange  138  of a horizontal triangular attachment surface  140  that overlies the pole engaging structure  122  and through which the knob  128  operates. On the first end of the shallow rectangular channel  130 , a horizontal triangular attachment surface  144 , which is identical to the horizontal triangular attachment surface  140 , but horizontally rotated a half turn, is attached to the large rectangular plate  132  for supporting the first attachment bracket  114 . Near the first end of the shallow rectangular channel  130  along a top surface, first left and right guides  146  (when viewed from the first end, left one hidden) extend first outwardly and then down. Near the second end of the shallow rectangular channel  130  along a top surface, second left and right guides  150 ,  152  extend first outwardly and then down. 
   Facilitating repair and installation, a reader plate  154  may be detached from the reader sled base  112  for mounting to the RFID reader (not shown). Top accessed finger grip receptacles  156 ,  158  near the first and second ends, respectively, assist in disassembly, carrying, and assembly. Between the grip receptacles  156 ,  158 , a plurality of mounting holes  160  are predrilled into a horizontal portion  162  of the reader plate  154  to accommodate the fastener mounting patterns for available RFID readers. 
   The reader plate  154  is shaped like a shoe box lid with an open first end. In particular, the second end is closed by a downwardly extending flange  164  from the second end of the horizontal portion  162 . Left and right flanges  166 ,  168  extend downwardly respectively from lateral edges of the horizontal portion  162 . Near the first ends of bottom surfaces of the left and right flanges  166 ,  168 , first left and right inward tabs  170 ,  172  respectively extend horizontally for engagement beneath respectively the first left and right guides  146  of the reader sled base  112 . Near the second ends of bottom surfaces of the left and right flanges  166 ,  168 , second left and right inward tabs  174 ,  176  respectively extend horizontally for engagement beneath respectively the second left and right guides  150 ,  152  of the reader sled base  112 . Thus, assembly of the reader plate  154  to the reader sled base  112  to form the reader sled assembly  110  includes placing the reader plate  154  on top of the reader sled base  112  with the reader plate  154  displaced away from the bulkhead  132  such that the first inward tabs  170 ,  172  and second inward tabs  174 ,  176  are offset respectively from the first left and right guides  146  and second left and right guides  150 ,  152 . Movement of the reader plate  154  toward the bulkhead  132  in the direction of an assembly arrow depicted at  178  causes the engagement between the reader plate  154  and reader sled base  112 . 
   In  FIG. 8 , to gain additional coverage in azimuth, a dual-sided RFID reader station  200  includes the features of the RFID reader station  10  of  FIG. 1  but additionally mounts a rectangular pole and radome frame  202  onto a backside of the pedestal cabinet  12 , supporting a second longitudinally bisected elongate half-cylindrical radome  18 . It should be appreciated that another set of RFID antennas  60  and antenna mounting brackets  18  supported within the frame  202  and second radome  202  form a remote RFID reader station  204  monitored by the control circuitry (not shown) of the attached RFID reader station  10 , providing coverage to both sides of the station  200 , such as when placed between two doorways, as may be common when a circular trafficflow pattern in a warehouse is used to minimize collisions. 
   In  FIG. 9 , to gain additional range across a wide traffic way (e.g., large doorway), an interconnected RFID reader station  300  is similar to that described above in  FIG. 8 , but with the remote RFID reader station  204  displaced from the primary RFID reader station  10  such that the radomes  18  of each are aimed toward each other to form a wider interrogation zone. The remote RFID reader station  300  is supported by a pair of right angle bracket supports  302 ,  304  that prevent falling backward. The remote RFID reader station  300  is also supported from falling forward by conduit  306  that extends upwardly from the remote RFID station  300 , then horizontally over the interrogation zone, and then downwardly into the primary RFID reader station  10 . The conduit  306  also serves as a communication conduit between the stations  10 ,  300  so that one RFID reader may operate both. 
   In  FIG. 10 , in some applications, an interrogation zone may advantageously be a relatively narrow field to avoid inadvertent detections. It may be advantageous to provide additional protection to the radome and/or antennas from side impacts. A deeper vertical channel  400  thus fully encompasses the antennas  60 , mounting pole  20 , and antenna mounting bracket  58  from behind and laterally and also allows use of a flat RF transmissive cover (not shown). 
   In  FIGS. 11-13 , a portal RFID reader station  600  comprises left and right antenna cabinets  602 ,  604  that include a deeper vertical channel  400  opening inwardly toward the interrogation zone therebetween and closed by flat RF transmissive covers (not shown). Each cabinet  602 ,  604  includes a vertical mounting pole  20  for mounting a plurality of antenna mounting brackets  58 . An overhead cabinet  606  opening downwardly into the interrogation zone and also formed from a deeper vertical channel  400  connects the left and right antenna cabinets  602 ,  604 . The overhead cabinet  606  includes a horizontal mounting pole  20  for attaching antenna mounting brackets  58  as well as an RFID reader sled assembly  110 . 
   It should be appreciated that applications consistent with the present application may include radomes instead of flat RF transmissive covers for any of the cabinets  602 ,  604 ,  606  of a portal RFID reader station. 
   It should be appreciated that any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated material does not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material. 
   While the present invention has been illustrated by description of several embodiments and while the illustrative embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications may readily appear to those skilled in the art. 
   For example, while mounting poles and RFID antennas and readers are protected within cabinet and radome structures in the exemplary versions, applications consistent with aspects of the inventions may expose portions or such equipment and structure for purposes such as enhanced access and/or increased antenna gain, especially in applications not subject to inadvertent impact or inclement environmental conditions. 
   As another example, while a round mounting pole is depicted in exemplary versions affording continuous adjustment in radial angle and longitudinal position, applications consistent with aspects of the invention may include poles of cross section shapes other than round, such as including indents or protuberances that engage with corresponding features in the clamp to register at discrete angular and/or longitudinal positions. 
   As an additional example, while a mounting bracket that does not require tools for installation has advantages, applications consistent with aspects of the invention may utilize mountings requiring hand tools or preassembled and permanently fixed mountings.