Frequency scan technique for inkjet-printed chipless sensor Tag reading

A novel technique for the remote reading of chipless capacitive sensor Tags and one of its possible applications is presented. For this purpose, a frequency agile reader has been developed using Software Defined Radio (SDR) architectures, capable of scanning with high precision a frequency range given by an external user and extracting the resonant frequency of a Tag. The capacitive sensor Tag has been implemented on a plastic substrate using inkjet printing techniques. In order to demonstrate the feasibility of the technique, the reader analyzes the Tag´s backscatter response and gets its resonant frequency in a case study of a moisture sensor application.