Kilowatt-Level Power-Controlled Microwave Applicator With Multiple Slotted Waveguides for Improving Heating Uniformity

In this article, we propose a kW-level 2.45-GHz microwave applicator for improving heating uniformity. In a conventional microwave applicator, the heating material has low heating uniformity due to various hot and cold spots caused by multiple reflections in the cavity. We propose a power-controlled microwave applicator with multiple slotted waveguides to reduce the hot and cold spots and improve the heating uniformity in the microwave heating process. The proposed microwave applicator consists of three waveguides. Each waveguide consists of longitudinal or transversal slots. To improve heating uniformity in the proposed applicator, we used the power switching method. The input power applied to each waveguide is optimized according to the peak magnitude of the electric field of each waveguide. Conclusively, compared with the conventional microwave applicator, the proposed power-controlled microwave applicator with multiple slotted waveguides improves the heating uniformity up to approximately 67%.