Microwave Dielectric Spectrum of Vegetation - Part II: Dual-Dispersion Model

This paper is the second in a series evaluating the microwave dielectric behavior of vegetation material. It draws upon the data presented in Part I to develop a Debye-Cole dual-dispersion dielectric model consisting of a component that accounts for the volume fraction occupied by water in free form and another that accounts for the volume fraction occupied by the mixture comprised of water molecules bound to bulk-vegetation molecules. To determine the dielectric dispersion properties of the latter, measurements were made for sucrosewater solutions of known volume ratios. The proposed dielectric model is found to give excellent agreement with data over a wide range of moisture conditions and over the entire 0.2-20 GHz range examined in this study.