Design of Metamaterial-Inspired High-Temperature Microwave Sensor on Alumina Ceramics

The issues of high costs and sophisticated circuit structures limit applicability of traditional chipped sensors. This paper innovatively designs a chipless sensor based on the split-ring resonator combined with temperature-sensitive material as the substrate. The alumina ceramics are used as the sensitive material for reflecting the environment temperature in accordance with its characteristic that its dielectric constant increases monotonically with rising temperature. The simulation demonstrates that the resonant frequency of the sensor monotonically decreases from 8.58 GHz to 8.22 GHz with an offset of 0.36 GHz and a sensitivity of 0.9 MHz/°C for a variation from 500 °C and 900 °C. The sensor designed in this paper has good resonance characteristics, is wireless, passive, and low cost, has a planar structure, and is suitable for various harsh environments.