Detection of Ethanol Concentration in Liquid Using a Double-Layered Resonator Operating at 5G-mm-Wave Frequencies

A new sensing technique for rapidly detecting ethanol concentration in aqueous solutions based on electromagnetic resonance is discussed. The sensor has two substrate layers and operates at 5G-mm-wave frequencies. An experimental study of the new resonator's configuration determines the sensor's sensitivity. During the measurements, 6 samples were modeled with varying amounts of ethanol concentration in the water. The results showed that S 11 resonance moves linearly towards higher frequencies as the ethanol content increases. The resonant frequency shifted at 0.178 GHz per 10% increase in ethanol towards higher frequencies. As a result, the proposed 5G-mm-wave-sensing technique based on a replaceable sensing layer was proved to be suitable for rapid, accurate, and low-cost alcohol content detection in liquids.