Rapid heating of dielectric materials at 915 mc

THE HEATING of dielectric materials by means of microwave energy was investigated in the General Electric Company a decade ago by members of the Research Laboratory, who demonstrated the feasibility of preheating plastics and heating foods using a magnetron oscillator at a frequency of 1,000 mc (megacycles). In recent years, the GL-6787 magnetron, operating in the 915-mc Industrial-Scientific-Medical band, has been developed as a source of power for these applications. In order to design equipment for efficient preheating, it is necessary to know the characteristics of the materials as a function of temperature. An initial investigation of the effectiveness of 915-mc heating on various dielectric materials has been conducted.