A Flexible CSRR-Based Array Icing Sensor With Defective Microstrip Structure

In recent decades, the unmanned aerial vehicle (UAV) industry has rapidly developed, with UAVs finding applications in various fields. With the large number of UAVs being put into use, icing problems ensue. In this article, a microwave icing sensor with a flexible array is introduced for measuring icing on the windward surface of UAVs, and a complementary coupled split-ring resonator (CCSRR) structure sensitive to ice thickness is proposed based on the evolved CSRR structure. The sensor film consists of a metal defect microstrip, a polyimide (PI) film, a flexible medium, and a metallic ground. The resonance frequencies corresponding to different ice thicknesses are obtained by icing the surface of the sensor defective microstrip structure and then observing the transmission coefficient (S21) fed back from the experimental setup, and a functional relationship between the ice thickness and resonance frequency is established. Compared with traditional icing sensors, flexible structures can better adhere to the surface of a UAV, and the array-based design expands the detection capability of the sensor. This sensor not only measures the thickness of a single point but also provides feedback on the ice morphology in the icing-sensitive area, which is convenient for the operator to formulate a deicing program.