Complex-Permittivity Measurement and Modeling of Moso Bamboo From 0.5 to 18 GHz

Abstract

Accurate measurement of the complex permittivity of plant is essential for remote-sensing applications. The complex dielectric properties of moso bamboo (Phyllostachys heterocycla) were measured from 0.5 to 18 GHz based on the coaxial transmission/reflection method. A high-precision numerically controlled machine was used to process the bamboo samples. Based on the measured data, the complex permittivity can be better modeled as a second-order polynomial about the moisture content than the traditional exponential function. The real parts of the relative dielectric permittivity decrease with the increase in the frequency, while the imaginary parts decline first and then rise. The dielectric permittivity of the longitudinal direction is larger than that of the cross-sectional direction due to the anisotropic fibrocyte structure of moso bamboo.