An alumina ceramic inspired high temperature wireless chipless sensor for harsh environment

This paper proposes a wireless passive temperature sensor. The sensitive material as the substrate of the sensor employs an alumina ceramic. The resonator of the sensor is a split ring, which is printed with copper on the substrate. The dimensions of the split ring resonator are optimized to improve the temperature sensitivity of the sensor. A change in environment temperature will lead to a change in the dielectric constant of the sensitive material, thus resulting in the shift of the resonant frequency of the sensor. The variation range of the dielectric constant of the sensitive material is 10.17–11.2 corresponding to 500–1000 °C. The resonant frequency of the signal backscattered from the sensor is obtained through the simulation software with HFSS. The simulation results show that the resonant frequency of the sensor decreases from 5.84 to 5.56 GHz with temperature increasing from 500 to 1000 °C and the temperature sensitivity is 0.56 MHz/°C. The high temperature sensor has the characteristics of wireless and passive operation, low profile, and high sensitivity. It can be widely adapted to a variety of high temperature and harsh environments.