Automatization of the complex dielectric constant measurement

In this paper are presented two methods for measurement of complex dielectric constant using the microwave cylindrical cavity. One of them is the well known perturbation method, which demands the resonant frequency and Q-factor measurement of empty and loaded cavity, and the other is an approximation method. The measurement configurations for both methods are formed using HP8753C vector network analyzer and an experimental cylindrical metallic cavity with circular cross-section. The measuring process is controlled by PC using programs developed in HP VEE environment. Also, these programs are responsible for data collecting, processing and displaying. In order to verify this experimental set-up, the measurement of complex dielectric constant of ethyl alcohol at microwave frequency range (1.5 GHz-6 GHz) is done and presented.