Complex Permittivity Extraction of Layered Biological Samples
In this paper, we present a technique to extract the complex permittivity of the different layers (i.e., pulp and skin) of a biological sample (i.e., mangoes) in broadband dielectric spectroscopy measurements. The proposed approach is based on a newly developed accurate and rapid electromagnetic lumped capacitance equivalent network model for the open-ended coaxial cable, capable of accounting for stratified layered media. Combining broadband dielectric measurement with the model predictions allows to derive the permittivity of the internal layers of the biological sample. The proposed approach is applied to evaluate fruit quality, i.e., staging of the effective fruit ripening and identification of internal fruit defects (not visible externally). Broadband permittivity measurements (0.5GHz to 5GHz) are presented and combined with the EM model to demonstrate the effectiveness of the technique for evaluation of the internal (i.e., pulp) staging and structure disorders in Mangoes.