A chipless radio frequency identification( RFID) tag is designed and analyzed. The tag consists of some regularly arranged C-shaped resonators. The bandwidth is effectively used by frequency coding and the corresponding radar cross section( RCS) curve of the tag is observed. A new‘0’bit coding method is proposed to improve the robustness of the tag RCS response
and a new coding method is proposed according to structure characteristics of tag
which double encoding density and achieve 20 bits capacity in a size of 22 mm × 40 mm.Through the simulation
the RCS curve corresponding to the tag is obtained. Compared with previous chipless tags
the tag has more stable RCS response and higher coding capacity