Chipless Wireless Temperature Sensor Based on BST Thin Film

This paper presents a chipless Radio Frequency Identification (RFID) tag with temperature sensing, which combines the structure of a square ring and a V-shaped antenna to reduce the tag size while increasing the resonance point. The tag uses polyvinyl chloride (PVC) as a substrate. The feasibility of the sensor operating at 2.4 GHz frequency is verified by integrating the temperature sensitive material barium-strontium-titanate (BST), which is a ferroelectric material and shows a positive correlation between its Relative permittivity and the ambient temperature. The Radar Cross section(RCS) increases linearly as the ambient temperature increases from 20°C to 80°C, with an average sensitivity of 8.3°C/dB. The sensor tag is wireless, passive, low cost, and miniaturized, and has excellent potential for various applications.