Rfid system and associated antenna-coupler

Abstract

A RFID system and an associated antenna-coupler are provided. The system may be for selectively communicating with a targeted transponder from among a group of multiple adjacent transponders is provided. The system may include a transponder conveyance, a transceiver, and an antenna-coupler. The transponder conveyance is adapted to transport at least one targeted transponder from a group of multiple adjacent transponders through a transponder operating region. The transceiver is configured to generate one or more electrical signals. The antenna-coupler has first and second microstrips in a cross-like arrangement relative to each other. Each of the first and second microstrips is configured to transmit one or more electromagnetic fields concentrated in a near-field region of the antenna-coupler based on the one or more electrical signals for communicating with the targeted transponder.

1 . A system for selectively communicating with a randomly oriented targeted transponder from among a group of multiple adjacent transponders, the system comprising:
 a transponder conveyance adapted to transport at least one targeted transponder from a group of multiple adjacent transponders through a transponder operating region;   a transceiver configured to generate one or more electrical signals;   an antenna-coupler having first and second microstrips in a cross-like arrangement relative to each other and wherein, each of the first and second microstrips is configured to transmit one or more electromagnetic fields concentrated in a near-field region of the antenna-coupler based on the one or more electrical signals for communicating with the randomly oriented targeted transponder.   
   
   
       2 . The system of  claim 1 , wherein the antenna-coupler includes a first port in communication with both of the first and second microstrips such that both of the first and second microstrips receive the one or more electrical signals concurrently. 
   
   
       3 . The system of  claim 1  further comprising a switch for sending the one or more electrical signals from the transceiver to either one of the first and second microstrips or both. 
   
   
       4 . The system of  claim 1 , wherein the first and second microstrips are spaced apart and separated by at least one substrate. 
   
   
       5 . The system of  claim 1 , wherein the first and second microstrips are substantially co-planer and the first microstrip further includes a first section, a second section, and a bridge; wherein the first section extends from a first end of the first microstrip to approximately the second microstrip, the second section extends from approximately the second microstrip to a second end of the first microstrip, and the first and second sections are linked through the bridge that extends around the second microstrip such that the first and second microstrips do not intersect. 
   
   
       6 . The system of  claim 1 , wherein the antenna-coupler further includes a first resistive load for terminating the first microstrip and a second resistive load for terminating the second microstrip, and wherein the first microstrip defines a characteristic impedance less than the first resistive load and the second microstrip defines a characteristic impedance less than the second resistive load. 
   
   
       7 . The system of  claim 1 , wherein each of the first and second microstrips has a tapered profile. 
   
   
       8 . The system of  claim 1 , wherein each of the first and second microstrips defines a length substantially equal to a multiple of one half a wavelength of an operational frequency of the antenna-coupler. 
   
   
       9 . The system of  claim 1 , wherein the operational frequency of the antenna-coupler is selected from a range of frequencies from 300 MHz to 3 GHz. 
   
   
       10 . The system of  claim 1 , wherein the operational frequency of the antenna-coupler is selected from a range of frequencies from 860 MHz to 960 GHz. 
   
   
       11 . An antenna-coupler for a system having a transceiver and being configured to process one or more smart media and associated transponders of the smart media, the antenna-coupler comprising:
 a first microstrip extending from a first end to a second end, wherein the second end is terminated by a first resistive load and the first end is in communication with the transceiver for receiving and sending one or more electrical signals;   a second microstrip extending from a first end to a second end, wherein the second end is terminated by a second resistive load and the first end is in communication with the transceiver for receiving and sending one or more electrical signal; wherein the first microstrip and the second microstrip are generally orthogonal to each other forming a cross-like arrangement;   a ground plane spaced apart from the first and second microstrip; and   at least one substrate extending at least partially between the ground plane and the first and second microstrips.   
   
   
       12 . The antenna-coupler according to  claim 11 , wherein the first and second microstrips are spaced apart and separated by the at least one substrate. 
   
   
       13 . The antenna-coupler according to  claim 12 , wherein the first and second microstrips are substantially co-planer and the first microstrip further includes a first section, a second section, and a bridge; wherein the first section extends from the first end of the first microstrip to approximately the second microstrip, the second section extends from approximately the second microstrip to the second end of the first microstrip, and the first and second sections are linked through the bridge that extends around the second microstrip such that the first and second microstrips do not intersect. 
   
   
       14 . The antenna-coupler according to  claim 13 , wherein the jumper includes at least a jumper wire. 
   
   
       15 . The antenna-coupler according to  claim 13 , further comprising an input port for connecting both the first end of the first microstrip and the first end of the second microstrip to the transceiver. 
   
   
       16 . The antenna-coupler according to  claim 11 , further comprising a first input port for connecting the first end of the first microstrip to the transceiver and a second input port for connecting the first end of the second microstrip to the transceiver. 
   
   
       17 . The antenna-coupler according to  claim 11 , wherein each of the first and second microstrips define a characteristic impedance and wherein the first resistive load is greater than the characteristic impedance of the first microstrip and the second resistive load is greater than the characteristic impedance of the second microstrip. 
   
   
       18 . The antenna-coupler according to  claim 17 , wherein each of the first and second microstrips define a length and the length of the each of the first and second microstrips is substantially equal to a multiple of one half a wavelength of an operational frequency of the antenna-coupler. 
   
   
       19 . The antenna-coupler according to  claim 18 , wherein each of the first and second microstrips has a tapered profile. 
   
   
       20 . An antenna-coupler for communicating with a card having a transponder, the antenna-coupler comprising:
 a first microstrip and a second microstrip in a cross-like arrangement relative to each other and, wherein each of the first and second microstrips is configured to transmit one or more electromagnetic fields concentrated in a near-field region of the antenna-coupler based on the one or more received electrical signals for communicating with the transponder, and wherein each of the first and second microstrips defines a length substantially equal to one half a wavelength of an operational frequency of the antenna-coupler selected from a range of frequencies from 300 MHz to 3 GHz.   
   
   
       21 . An apparatus for printing and communicating with one or more media cards, each media card includes a transponder configured to operate within a range of frequencies from 300 MHz to 3 GHz, the apparatus comprising:
 a printhead for printing indicia on the one or more media cards; and   a communication device for communicating with the one or more media cards; wherein the communication device is positioned approximate to the printhead such that the printing and the communicating of the printhead and the communication device occur substantially simultaneously.