Multiresonator-based chipless RFID system for low-cost application

Abstract

The major target of chipless RFID tags for telecommunication systems is to achieve low cost, high density, high capacity and minimization. In order to achieve a compact chipless RFID tag with scalable coding capacity, we adopt multi-resonators which can be equivalent to a serious or a parallel of LC resonator circuit to form different data bits. One 8-bit chipless RFID tag with bending arm structure is presented. The tag encodes data bits using different length of bending arms which are arranged on one side of a 50 Ω transmission line, and the bending structure can effectively reduce the coupling between units. The 8-bit chipless RFID tag with dimensions of 49 mm × 12mm is designed with a frequency band from 4.90 GHz to 5.60 GHz. Each bending arm structure represents a logic state ‘1’ when interrogated with an incident wave. The logic state will be changed to ‘0’ when the bending arm structure is removed. An 8-bit chipless RFID tag is composed with eight different bending arm resonators, which is distributed two sides of the main transmission line, with dimensions of 26mm × 17.7 mm in a frequency band from 5.00 GHz to 5.70 GHz. The size of the two-sides distribution tag relative to the one-side distribution tag is reduced by 24.7%. There are two critical factors in achieving small size. One is due to the bending arm structure which decreases the dimension of a single unit. The other critical factor for minimization is that the unit is arranged on the both sides of the main transmission line.