A reconfigurable antenna subsystem for the rfid applications by using phased array antennas

The popularity of Radio Frequency IDentification (RFID) in realistic applications has produced a variety of interference problems. Typical ones are the existences of metal structures in the neighborhood of reader or tag antennas, which cause strong electromagnetic (EM) scattering fields. To overcome these types of interferences, an antenna subsystem is proposed and developed for the RFID reader antenna applications at 2.45GHz in the near-zone tag detection. The term “near-zone” indicates that the application region can be relatively arbitrary and can be close to the aperture of a phased array antenna. The potential applications can be illustrated by the scenario of indoor product transportation system in the department stores, where the I/O management system is performed at a designated spot (or the detection zone). In this case, the tags on the commercial products will move on the transportation belt through a detection zone.