Rfid coupler and associated rfid enabled device

A radio frequency identification (RFID) printer-encoder adapted to print and encode a plurality of media units, at least some of the plurality of media units comprising an RFID transponder, the printer-encoder comprising:

• a printhead for printing indicia onto the media units;
• a media conveyance system adapted to convey the plurality of media units to the printhead and a transponder encoding region along a feed path in a feed direction;
• a transceiver configured to provide communication signals corresponding to information to be encoded on the RFID transponder;
• and,
• a coupler electrically connected to the transceiver and adapted to encode a targeted transponder in the transponder encoding region, the coupler comprising:
• a first ground plane and a second ground plane on opposing sides of the coupler;
• and,
• a conductive strip for propagating a plurality of electromagnetic fields from an edge of the coupler, the conductive strip positioned at least partially between the first and second ground planes, the conductive strip having a bottom edge having a first tapered edge portion, a second tapered edge portion, and a center portion therebetween, the second tapered edge portion being a mirror image of the first tapered edge portion, each of the first and second tapered edge portions comprising two or more steps.