Intelligent station using multiple RF antennae and inventory control system and method incorporating same

Abstract

An inventory control system and method that tracks inventories of items with RFID tags, includes a reader unit and an intelligent station that tracks RFID tags to determine item information of items to be inventoried. The reader unit transmits and receives RF signals. The intelligent station includes a first RF antenna connected to the reader unit by a first transmission cable through a first switch, and one or more additional RF antennae connected to the reader unit by the same first transmission cable through additional switches. An inventory control processing unit receives item information from the intelligent stations to update inventory information regarding the items to be inventoried.

1 - 96 . (canceled)  
     
     
         97 . An RFID reader, comprising: 
 a) a controller;    b) a transmitter for generating a transmitted RF signal operatively connected to said controller, said transmitter having an output;    c) a receiver for receiving a received RF signal operatively coupled to said controller, said receiver having an input;    d) a coupler operatively connected to said output of said transmitter and said input of said receiver;    e) at least one antenna for alternately radiating said transmitted RF signal and receiving said received RF signal operatively connected to said coupler;    f) means for sensing a loading condition of said at least one antenna and producing an output indicative of said loading condition; and    g) means for selectively altering tuning of said at least one antenna operatively connected thereto and responsive to said output of said means for sensing.    
     
     
         98 . The RFID reader as recited in  claim 97 , wherein at least one of said means for sensing and said means for selectively altering tuning is operatively connected to said controller.  
     
     
         99 . The RFID reader as recited in  claim 98 , wherein at least one antenna comprises an array of antennas.  
     
     
         100 . The RFID reader as recited in  claim 99 , further comprising: 
 h) an antenna switch operatively connected to said controller, said coupler, and said array of antennas for selecting at least one antenna from said array of antennas and electrically connecting said selected at least one antenna to said coupler responsive to a command from said controller.    
     
     
         101 . The RFID reader as recited in  claim 100 , wherein said array of antenna are disposed on at least one of the group: shelf, and other merchandise display fixture and said RFID reader forms part of a smart shelf system.  
     
     
         102 . The RFID reader as recited in  claim 100 , wherein said means for altering antenna tuning comprises at least one from the group: a switched capacitor bank and a switched varactor bank.  
     
     
         103 . The RFID reader as recited in  claim 102 , wherein said switched capacitor bank and said switched varactor bank are switched in response to a command from said controller.  
     
     
         104 . The RFID reader as recited in  claim 103 , wherein altering antenna tuning comprises a tuning operation and said tuning operation is performed periodically.  
     
     
         105 . The RFID reader as recited in  claim 103 , wherein altering antenna tuning comprises a tuning operation and said tuning operation is performed responsive to a sensed change in tuning of at least one of said array of antennas.  
     
     
         106 . The RFID reader as recited in  claim 97 , wherein said transmitter further comprises a modulator and said transmitted signal may switched between a continuous wave (CW) RF signal and a selectively modulated RF signal upon commanded from said controller.  
     
     
         107 . The RFID reader as recited in  claim 106 , wherein said selectively modulated RF signal comprises an amplitude modulated (AM) RF signal.  
     
     
         108 . The RFID reader as recited in  claim 97 , further comprising means for arbitrating a data collision.