Non-Contact Time Domain Ultra Wide Band Milk Spectroscopy

Recently, wideband dielectric spectroscopy (WBDS) has been applied for material characterization. Milk spectroscopy is usually done with high-cost contact-based methods using a vector network analyzer (VNA). Non-contact WBDS of milk is a novel and convenient technique, which can be utilized for milk qualification. In this paper, an ultra-wideband time domain dielectric spectroscopy system for milk characterization is presented. The proposed setup is a quasi-monostatic free space dielectric spectroscopy in which all measurements are done with Xethru X4 sensor. Material under test is located in the far-field of Xethru sensor. The Fast Fourier Transform (FFT) of received time domain signals is computed and the permittivity of low-fat pasteurized cow milk and mixture of untreated raw cow milk and water have been estimated by mapping phase and amplitude differences of calibration materials. Mean squared error (MSE) of permittivity for low-fat milk and milk with different water content are 0.29% and below 0.056%, respectively.