A low-cost microwave-based sensor for water content detection

This paper presents a water content sensor. The sensor operates by radiating an electromagnetic wave through an antenna and measuring the reflected field. The magnitude and phase of the reflected waves are used to determine the presence and amount of water. The sensor does not need a direct contact with the sample. Hence, it can be used in a conveyor system or in applications where direct access to the sample is not feasible. The proposed sensor uses low-cost components and easy-to-manufacture antennas. Experimental results with different antennas and water content are presented.