Near field coupling devices and associated systems and methods

Abstract

A near-field coupling device that may facilitate communications with a transponder is provided. The near-field coupling device may include a ground plane, a dielectric substrate, one or more conductive strips and a terminating load. The conductive strips together with the ground planes form coupling elements. The near-field coupling device further includes one or more switching elements for selectively connecting and disconnecting the coupling elements with a transceiver. The connected coupling elements define a total characteristic impedance. Using the switching element, the ratio between the total characteristic impedance of the connected coupling elements and the terminating load may be changed in order to adjust the distribution of an electromagnetic field along the coupling elements according to the type and position of the transponder to be processed.

That which is claimed: 
     
       1. A near-field coupling device for coupling a transceiver with a targeted transponder, the near-field coupling device comprising:
 a ground plane; 
 a dielectric substrate adjacent to the ground plane; 
 a terminating load; 
 a first conductive strip adjacent the dielectric substrate and extending from a port end to a loaded end and connected to the terminating load, the first conductive strip together with the ground plane forming a first coupling element having a length of one half-wavelength or multiple thereof and having a first impedance; 
 a second conductive strip adjacent the dielectric substrate and extending from the port end to the loaded end and connected to the terminating load, the second conductive strip together with the ground plane forming a second coupling element having a length of one half-wavelength or multiple thereof and having a second impedance, wherein the second impedance, in isolation, is different than the first impedance, in isolation; and 
 at least one switching element for selectively electrically connecting one or more of the first and second coupling elements with the transceiver, the connected coupling elements defining a total characteristic impedance of the connected coupling elements, in a first configuration of the switching element, the total characteristic impedance of the connected coupling elements is greater than the terminating load and, in a second configuration of the switching element, the total characteristic impedance of the connected coupling elements is less than the terminating load. 
 
     
     
       2. The near-field coupling device according to  claim 1 , wherein a width of the first conductive strip is approximately equal to a width of the second conductive strip. 
     
     
       3. The near-field coupling device according to  claim 1 , wherein each of the first and second conductive strips defines a linear shape and is parallel to the other conductive strip. 
     
     
       4. The near-field coupling device according to  claim 1 , wherein the first and second conductive strips are configured to generate an electromagnetic field and are capable of activating the targeted transponder as the targeted transponder moves through the electromagnetic field. 
     
     
       5. An apparatus comprising a processor, the processor configured to:
 receive indications of a transponder type and a transponder position justification; and 
 connect one or more coupling elements of a near-field coupling device depending on at least the transponder type and the transponder position justification to configure an impedance ratio between the one or more connected coupling elements and a terminating load of the near-field coupling device, wherein each of the one or more connected coupling elements has, in isolation, a unique impedance. 
 
     
     
       6. The apparatus according to  claim 5 , wherein the processor configured to connect the one or more conductive strips includes being configured to connect the one or more coupling elements to configure a total characteristic impedance of the coupling elements to be greater than the terminating load. 
     
     
       7. The apparatus according to  claim 5 , wherein the processor configured to connect the one or more conductive strips includes being configured to connect the one or more coupling elements to configure a total characteristic impedance of the coupling elements to be greater than the terminating load when the transponder type describes a loop-type transponder and the transponder position justification is edge justified. 
     
     
       8. The apparatus of  claim 5 , wherein the processor configured to connect the one or more coupling elements includes being configured to connect the one or more coupling elements to configure a total characteristic impedance of the coupling elements to be either less than or greater than the terminating load. 
     
     
       9. The apparatus of  claim 5 , wherein the processor configured to connect the one or more coupling elements includes being configured to connect the one or more coupling elements by controlling a respective switching device associated with the one or more coupling elements. 
     
     
       10. The apparatus according to  claim 5 , wherein the processor is further configured to encode one or more transponders by providing RF power transmission to a port of the near-field coupling device. 
     
     
       11. A method comprising:
 receiving indications of a transponder type and a transponder position justification; and 
 connecting one or more coupling elements of a near-field coupling device based on at least the transponder type and the transponder position justification to configure an impedance ratio between the total characteristic impedance of the coupling elements and a terminating load of the near-field coupling device, wherein at least two of the coupling elements have, in isolation, unique impedances. 
 
     
     
       12. The method according to  claim 11 , wherein connecting the one or more conductive strips coupling elements includes connecting the one or more coupling elements to configure the total characteristic impedance of the coupling elements of the near-field coupling device to be greater than the terminating load. 
     
     
       13. The method according to  claim 11 , wherein connecting the one or more coupling elements include connecting the one or more coupling elements to configure the total characteristic impedance of the coupling elements to be greater than the terminating load when the transponder type is a loop-type transponder and the transponder position justification is edge justified. 
     
     
       14. The method according to  claim 11 , wherein connecting the one or more conductive strips coupling elements includes connecting the one or more coupling elements to configure the total characteristic impedance of the coupling elements to be less than or greater than the terminating load. 
     
     
       15. The method according to  claim 11 , wherein connecting the one or more coupling elements includes being configured to connect the one or more coupling elements by controlling a respective switching device associated with the one or more coupling elements. 
     
     
       16. The method according to  claim 11  further comprising encoding one or more transponders by providing for transmission of a signal to a port of the near-field coupling device. 
     
     
       17. The near-field coupling device according to  claim 1 , wherein the first impedance of the first coupling element, in isolation, is greater than the second impedance of the second coupling element, in isolation. 
     
     
       18. The near-field coupling device according to  claim 1 , wherein a width of the first conductive strip is greater than a width of the second conductive strip. 
     
     
       19. The near-field coupling device according to  claim 1  further comprising one or more additional conductive strips, each additional conductive strip forming an additional coupling element having a length of one half-wavelength or multiple thereof, the switching element being further configured to selectively connect the additional coupling elements and further adjust the total characteristic impedance of the connected coupling elements.