Wireless resonant frequency detection of SiCN ceramic resonator for sensor applications

A wireless passive sensing approach is proposed to measure the resonant frequency of a dielectrically-loaded cavity resonator. This resonator is made of SiCN ceramic material which is very stable inside harsh environments with temperatures up to 1500°C. The resonator is coupled to CPW lines with one antenna placed at each end of the CPW lines. A wide-band signal is transmitted through two antenna pairs and passes the resonator with the maximum transfer of energy at the resonant frequency of the resonator, i.e. 12.6 GHz. This allows for measuring the resonant frequency of the resonator in a wireless manner. Measurement results are provided for distances up to 40 mm with good agreement with simulations. The proposed methodology is aimed for temperature/pressure sensor development inside gas turbine engines.