Wireless high-temperature sensing with a chipless tag based on a dielectric resonator antenna

This paper presents a wireless temperature sensor, which enables high-temperature operation due to its passive and chipless design. The sensor uses radio-frequency backscattering techniques to encode and transmit the measured value: The resonance frequency of a dielectric resonator on the sensor tag is determined as a peak in its radar cross section. The tag is built from a half-split cylindrical ceramic resonator with temperature-dependent permittivity and resonance frequency. It offers wireless reading without need for reference measurements of radar clutter due to the resonator´s high quality factor and applied time-gating. Wireless indoor measurements have proven the sensor concept. These measurements were performed in a temperature range between 20°C and 370°C, where the resonance frequency of the tag lies around 3GHz with a temperature sensitivity of 307 kHz/K.