A WiFi-Based System for Ice Monitoring in Harsh Environments Using 2.7 GHz Microwave Sensors

The integration of microwave sensors within wireless sensor nodes enables remote real-time monitoring and detection across diverse sectors. However, the conventional use of a bulky vector network analyzer (VNA) to stimulate the microwave sensor poses limitations for practical applications. This paper presents a WiFi-based ice sensing system utilizing a microwave sensor integrated with a readout circuit that inherently excites the sensor eliminating the need for a VNA. The microwave sensor is designed to monitor ice accumulation in harsh environments and is composed of three split-ring resonator tags coupled to the transmission line. The data collected from the microwave sensor is processed using the integrated readout circuit and transmitted to the server via a WiFi module. The WiFi-based ice sensing system has been successfully tested at a low temperature of -40°C and a frequency range of 1.75 GHz to 2.8 GHz. Measured results show that the WiFi-based ice sensing system can differentiate between ice, water, and air with a reduced number of frequency points, across a broad frequency spectrum, compared to the VNA.