A TEMPORAL MULTI-FREQUENCY ENCODING TECHNIQUE FOR CHIPLESS RFID BASED ON C-SECTIONS

Abstract

A time domain chipless RFID tag based on cascaded microstrip coupled transmission line sections (C-sections), which can operate in multi-frequency bands is presented. The group delay characteristics of the C-sections are exploited to generate the tag Identiflcation (ID). The tag comprises cascaded commensurate group of C-sections and two cross-polarized ultra wide-band (UWB) antennas. Since the proposed tag can operate in multi-frequency bands, this paper proves the possibility of increasing the coding capacity compared to the existing time domain designs. A tag operating at ISM (Industrial Scientiflc and Medical) bands at 2.45GHz and 5.8GHz together with conformance of frequency and power regulations is discussed elaborately. The prototype of the device is fabricated and validated experimentally. The time domain characteristic of the tag is also validated experimentally by interrogating a short pulse. Furthermore, measurement results using commercial Ultra Wide Band (UWB) radar which can be used as a chipless RFID reader is also incorporated. The obtained results conflrm the concept and the possibility of using temporal multi-frequency in chipless RFID.