Planar antenna sensor with thermal stability for detection of ice formation

Abstract

The microstrip patch antenna (MPA) with frequency stability versus temperature is proposed as the ice sensor for de-icing of aerodynamic systems. The operation principle is based on the fact that the formation of ice layer is set to disturb the near fields, thus shifting the resonant frequency. To mitigate the uncertain temperature effect, a thermal stability (TS) strategy is implemented, making the sensor only susceptible to the ice loading effect and enabling stable performance within a large temperature range from − 40∘C to + 80∘C. The proposed ice sensor is in turn interrogated wirelessly by a transmitting (Tx) antenna. Due to the frequency shift, the received signal strength (RSS) is modulated as a function of ice-thickness, allowing for remote ice detection and quantification. Two common types of ices, namely rime and clear ices, are investigated. The ice samples were generated and characterized under different weather conditions in our cold chamber and wind tunnel at Anti-icing Materials International Laboratory (AMIL) with the University of Quebec at Chicoutimi (UQAC). Experimental results show the feasibility of the proposed approach for different real-world scenarios. In particular, the sensor demonstrates the best measurement capability in the case of clear ice with full coverage, achieving the sensitivity of 75 mV/mm.