The Effects of Antenna Properties on Read Distance in Passive Backscatter RFID Systems

One of the obstacles to wide adaptation of passive RFID systems is the limited read distance or relatively high error rate due to radio interferences in the passive backscatter RFID systems. The most important tag performance characteristic is read distance at which RFID reader can detect the backscattered signal from the tag. The read distance in passive backscatter RFID systems depends on many factors, e.g. the transmitted power, the frequency used, the gain of the reader and tag antennae, the aperture of the antennae, the quality factor of the antennae, the sensitivity of the readers, modulation type and depth, and the application environment etc. This paper presented an overview of passive backscatter RFID systems and the read distance performance of these systems. We focus on presenting an overview of several antenna parameters impacting on read distance in the passive backscatter RFID systems. The function of antenna gain, operational frequency, radar cross-section, antenna quality factor, and polarization mismatch were analyzed.