A wireless W-band 3D-printed temperature sensor operating beyond 1000 °C

Abstract

In addressing high-temperature sensing (above 500 °C), there is a gap in available chipless and wireless sensor systems operating near the high end of the microwave frequency range. This study introduces a novel dielectric wireless temperature sensor, leveraging high-Q cavities within a three-dimensional photonic crystal (PhC). To increase the readout range, a flattened Luneburg lens is added on top of the PhC structure. The sensor’s operating principle is based on detecting shifts in resonance frequency due to changes in the dielectric parameters of its conforming material over temperature. The sensor is 3D-printed using Lithography-based Ceramic Manufacturing in Alumina (Al2O3). Our empirical findings reveal that the sensor’s frequency-coded response, represented by two peaks at 83.5 GHz and 85.5 GHz, is clearly distinguishable at a distance of 50 cm and up to 1200 °C, the maximum capability of our furnace. Furthermore, we draw comparisons between the sensor’s performance and existing material characterization methods, particularly in estimating Al2O3’s dielectric permittivity and losses, with the latter showing a good agreement with literature values. Due to the employed materials, the sensor is suitable for millimeter-wave applications in dynamic, cluttered high-temperature scenarios.