Metamaterial Based Passive Wireless Temperature Sensor

This paper presents the fabrication, modeling, and testing of a metamaterial based passive wireless temperature sensor consisting of an array of closed ring resonators (CRRs) embedded in a dielectric material matrix. A mixture of 70 vol% Boron Nitride (BN) and 30 vol% Barium Titanate (BTO) is used as the dielectric matrix and copper washers are used as CRRs. Conventional powder compression is used for the sensor fabrication. The feasibility of wireless temperature sensing is demonstrated up to 200 degrees C. The resonance frequency of the sensor decreases from 11.93 GHz at room temperature to 11.85 GHz at 200 degrees C, providing a sensitivity of 0.462MHz degrees C. The repeatability of temperature sensing tests is carried out to quantify the repeatability. The highest standard deviation observed is 0.012 GHz at 200 degrees C.