A new passive RFID tag system by dual excitation port antenna and frequency doubler

RFID systems is widely utilized for various distribution system for rapid and correct object transportation. In this paper, a new RFID tag consisting of an antenna with dual excitation ports and frequency doubler is proposed. In order to establish the whole system, additonal horn pair operating f0 and 2f0 are required, where the identification condition depends on frequency, transmit/receive antenna directional off-set and polarisation shift. As a proof of concept, system operation of 3–6 GHz is confirmed.