For industrial applications, microwave heating is an important technique. However, the homogenization problem must be taken into account to obtain rapid and reliable processes. Some industrial microwave heating systems are complex and expensive. In this paper, we propose a simple technique which use a cavity excited by a linear or a circular electric field polarization. A better microwave heating homogenization is obtain on ferrite and ethanol samples when the circular polarization is used. A specific test bench was made to perform temperature measurements on several sample points.