Measurement of temperature dependent permittivity of liquid under microwave heating

Microwave heating is one of the key technologies in medicine such as sterilization, synthesis of pharmacy and also uses in diagnostic and treatment. In application, it is necessary to obtain temperature dependent complex permittivity of material. For accurate measurement, one way is to apply a cylindrical cavity resonator. To apply microwave heating using the cavity resonator, it becomes possible to measure the temperature dependent permittivity of liquid material. In this study, TM010 cylindrical cavity resonator is designed of 2.45GHz band and developed the system to measure complex permittivity of liquid material in various temperatures. The cylindrical cavity resonator allows high microwaves power excitation and it can heat the sample dynamically with the measurement. The characteristics of the material as the temperature are measured by measuring transmission coefficient of the cylindrical cavity resonator with high power transmission.