Compact high-frequency heating apparatus with stepped waveguide

摘要

A high-frequency heating apparatus includes an inner casing defining a heating chamber therein, and an outer casing surrounding the inner case. A fixed waveguide is fixed on a top wall of the inner casing to guide high-frequency waves fed from a magnetron to an excitation opening. The waveguide has a step portion facing the excitation opening and located closer to the top wall than the other portion of the fixed waveguide. A motor is mounted on the step portion and has a driving shaft extending through the excitation opening into the heating chamber. A rotating waveguide, for diffusing the high-frequency waves delivered to the excitation opening and radiating the waves into the heating chamber, is disposed in the heating chamber and coupled to the driving shaft to be rotated thereby.