Characterization of high-temperature ceramic materials at microwave frequencies for MEMS applications

In this paper, the dielectric constant and loss tangent of two new high-temperature ceramic materials, SiCN and AlPO₄, are characterized using a novel measurement technique at microwave frequencies with high accuracy. These ceramic materials exhibit high thermal stabilities and corrosion resistance, enabling their use for high-temperature sensing applications. The dielectric properties of these ceramic materials are critical parameters in order to develop high-temperature sensors for turbine engines. It is found that the dielectric constant and loss tangent of SiCN are 4.358 and 5.26 times 10^-3, respectively. For AlPO₄, the two parameters are 2.637 and 4.23 times 10^-3, respectively. The standard deviation is less than 0.58% for the dielectric constant measurement and less than 5.72% for the loss tangent measurement, demonstrating excellent measurement repeatability.