A Frequency Steerable Multi-Mode Parasitic Patch Array for Passive RFID Applications

Passive radio frequency identification (RFID) tags derive their power from the incident RF signal and modulate the backscatter. To improve the inherently limited range, we present a novel adaptive passive RFID tag. The structure is a parasitic array having multiple resonant frequencies, each with an associated high-gain radiation pattern. The RFID reader may change position while still being able to communicate with the RFID tag. Hardware has been fabricated and tested, with good correlation between simulated and measured results