Optimum Design of an Rectangular Antenna Element used in Microwave Irradiation of Liquid Objects

Abstract

　To eliminate microwave reflections from a rectangular antenna element used to irradiate liquid objects with microwaves, the element needs to be designed optimally. Two design parameters: relative permittivity and thickness of the antenna, were used in the optimization, the objective function to be minimized being power reflection coefficient of the microwaves. An applicable range of relative permittivity for the liquid objects was identified. The characteristics of the antenna were checked in numerical simulation and experiments using water. Also the temperature dependencies of the antennas with existing material were checked in both numerical and experimental tests.