A new enhanced UHF RFID Sensor-Tag

The huge progress made in Radio Frequency Identification (RFID) technology has led to the development of cost-effective and high performing passive tags, thus paving the way to a widespread diffusion of such a technology. Working distances of almost ten meters and cost of the tag of a few euro cents, in fact, make effectively practicable the RFID-based solution of many auto-identification applications, that were prohibitive before. At present, the new challenge is the realization of a new kind of passive RFID tags which, while preserving low cost, ease of use and performance of traditional RFID, is able to transmit, along with the ID code, the values measured by sensors. In this paper, we propose a new version of our already published RFID Sensor-Tag. The renovated version takes advantage from an overall design of the circuit, including antennas, microwave switches and logical units. In such a way, thanks to consolidate techniques for the circuit miniaturization as well as optimization processes for the minimization of the coupling effects, the proposed device is rather compact and very well-performing.