Abstract
Most materials heated by microwaves contain water. As water's temperature rises from 0°C to 100°C, its permittivity decreases from 88 to 56. During this process, the electromagnetic field within the heating chamber undergoes complex changes, causing extreme fluctuations in reflected waves. In this study, we developed a precisely designed elliptical heating chamber and an automatic adjustment mechanism that efficiently heats the target material while simultaneously reducing reflected waves during the heating process. This achieved a heating efficiency exceeding 80%.
