Patent ID: 8078103

Claim:
A near field coupler comprising: a dielectric substrate having a first surface, a second surface, a first end and a second end; a terminating resistor disposed on the dielectric substrate adjacent the second end; a ground plane adjacent to the second surface of the dielectric substrate, a plurality of radiating elements extending proximately from the first end to the second end of the dielectric substrate along the first surface, wherein each of the plurality of radiating elements has a length of one-half wavelength or integer multiple thereof and is connected to the ground plane through the terminating resistor such that each of the plurality of radiating elements and the ground plane together form a one-half wavelength or integer multiple thereof transmission line, the terminating resistor is selected such that the near field coupler operates as one or more unmatched transmission lines; and a switching element electrically connected to the plurality of radiating elements adjacent to the first end of the dielectric substrate, wherein the switching element is provided in electrical communication with the transceiver and configured to selectively deactivate one or more radiating elements among the plurality of radiating elements by decoupling from the one or more radiating elements such that a near field effect is produced by the near field coupler in an operating region, the near field effect moving within the operating region and following the advancement of a targeted transponder.