Higher order pulse modulators for time domain chipless RFID tags with increased information density

• Published in: 2015 European Microwave Conference (EuMC) pp. 100 - 103
• Main Authors: Mandel, Christian, Schubler, Martin, Nickel, Matthias, Kubina, Bernd, Jakoby, Rolf, Popperl, Maximilian, Vossiek, Martin
• Format: Conference Proceeding
• Language: English
• Published: EuMA 01-09-2015
• Subjects: Impedance; Microwave circuits; modulation; Phase shift keying; Power dividers; Prototypes; radiofrequency identification; RFID tags; Time-domain analysis
• DOI: 10.1109/EuMC.2015.7345709

This paper introduces three novel passive phase modulators for entirely electromagnetic chipless time domain RFID tags. The modulators overcome limitations of earlier approaches and allow for a highly increased signal space coverage, and, therefore, the implementation of high order PSK or QAM schemes. All three modulators are studied in theory and practically implemented up to a 16-PSK on a reconfigurable prototype tag with 4 modulation stages, realizing a 16 bit information content. Besides showing the measurement results, the assets and drawbacks of the three approaches are carefully compared and the achieved information density is related with approaches from literature.