Complex Permittivity Detection by Using the Spectroscopy System

Abstract

A material’s dielectric properties are determined by its molecular structure, other properties of interest such as the interactions with an applied electromagnetic field can be correlated to the dielectric properties. Dielectric detection has various applications in many areas such as human health, food safety, oil industry etc. The techniques for dielectric constant detection are basically classified into time-domain and frequency-domain. The time-domain has its advantage of detecting the permittivity versus frequency at once. However, this method has its inherently disadvantage due to instability in the time axis including jitter, time drift and variation of the sweep speed in the oscilloscope. In this research thesis, we implement a RF system to detect the complex permittivity of organic chemicals by measuring the changes in resonant frequency of the system. All the results will be presented in the following several chapters.