A chipless RFID system based on polarization characteristics

This paper presents a chipless RFID system based on polarization characteristics. The system consists of a polarization-recognition reader and a variety of tag antennas with specific polarization. The orthogonal dual-polarization antenna of the reader can form arbitrary polarization wave fed by dual-channelamplitude and phase controllable source. The tag antenna with a particular polarization in irradiated area reflects some wave, and the echo depends on the polarization of the tag antenna. Thus, the reader can determine the polarization mode of the tag antenna according to the echo signal. This method has the advantages of large coding capacity, simple signal processing and low cost. Analysis and measured results show that the chipless RFID system can determine the polarization mode of the tag antenna according to two echo signals.