Coaxial resonator and measuring system for dielectric parameter measurements

Our paper presents coaxial resonator based cheap measuring system for nondestructive dielectric parameter measurements. The system is based on ISM band RF transceivers controlled by PC using microcontroller and serial UART-USB interface. The article introduces the coaxial resonator which has a resonance frequency of 780MHz without load. As opposed to sensors based on VNA our system measures the scalar scattering parameter |S₂₁| around this fixed frequency measured and the resonance frequency and the quality factor is considered to evaluate the complex dielectric constant of the measured sample. The simple and cheap measuring system makes this sensor system particularly interesting for moisture monitoring applications in industrial areas such as paper, foil and textile processing.