Chipless RFID systems

Abstract

In the course of this BTP,low cost chipless RFID tags have been designed. The proposed RFID tags are fully passive devices. They do not require chip assembly or any power supply. In the previous semester, the tag studied had the information encoded in the tag as impedance discontinuities along a matched transmission line. In this work, The RFID system designed is based on pulse position modulation using Group delayed Engineered microwave C-sections.These do not require any external components like capacitance which the previously designed system used, thus reducing the cost and simplifying the design. This design uses microstrip transmission lines cascaded to give various group delay structures. The input signal is modulated at a frequency and sent to the tag and the time-delayed response gives the information encoded based on the delay threshold set by the tag designer.