Design of a metamaterial chipless RFID sensor tag for high temperature

A high temperature sensor based on a metamaterial is proposed as a chipless radio frequency identification sensor tag that can measure temperature wirelessly. The metamaterial, based on a double circular split ring resonator (SRR), is highly frequency selective and has negative permittivity. The double circular SRR is fabricated on the alumina ceramic substrate, which acted as the temperature sensing material. The permittivity of the material varies with the temperature parameter, resulting in a shift of backscattered resonant frequency of the sensor tag. Simulations verify the feasibility of this sensor tag in the microwave band under electromagnetic stimuli. When the temperature increases from 200 to 1000 °C, the resonant frequency monotone decreases from 6.64 to 6.26 GHz with an average sensitivity of 0.475 MHz/°C. The sensor tag has features such as high temperature, being wireless, passive, of comparatively low-cost, and miniature, with diversified application potential, allowing it to compete with other sophisticated temperature devices in terms of performance.