Frequency-domain chipless RFID transponders: Improvement the reading response

This paper reviews investigations of the authors in the field of frequency-domain chipless RFID transponders. The main issue is to reduce the mutual coupling between adjacent resonant elements in the scatterer array to ensure the robust RCS response for reliable reading of coded information. A major improvement in RCS response of transponders is proposed, using slot-in-plate type transponders. Advantages and drawbacks of the proposed solutions are discussed and several open challenges in the field are emphasized.