A microwave applicator for uniform irradiation by circularly polarized traveling waves in an anechoic chamber

Microwave applicators are widely employed for materials heating in scientific research and industrial applications For the majority of microwave applicators, materials are heated in the standing waves of a resonant cavity, which can be highly efficient in energy consumption, while often lacks the field uniformity and controllability required for a scientific study. Here, we report a microwave applicator for rapid heating of small samples by highly uniform irradiation. It features an anechoic chamber, a 24-GHz microwave source, and a linear-to-circular polarization converter. With a rather low energy efficiency, such an applicator functions mainly as a research tool. This paper discusses the significance of its special features and describes the structure, in situ diagnostic tools, calculated and measured field patterns, and preliminary heating tests of the overall system.