Control of Microwave Heating in Rectangular Waveguide and Rectangular Cavity

微波加热具有电磁波的传输、吸收和反射的特点。加热性能很大程度上依赖于材料中透射波和反射波的干涉。利用矩形波导和矩形腔中频率为2.45 GHz的TE_(lt；10)模微波，研究了反射板和入射波控板对微波加热特性的两种影响。结果表明：(1)在没有反射板的正常情况下，样品的产热量在谐振态出现峰值，对应于样品半波长的整数倍。当反射板安装在最佳位置时，产热量增加。然而，随着样品长度的增加，由于微波的衰减，反射板的影响变小。(2)为了避免样品表面的反射，可以在样品上附加低介电材料。对于矩形腔微波加热，我们提出了反射板和入射波控制板两种微波加热优化方案，为控制反射波和透射波优化微波加热提供了依据。(4)对于矩形腔微波加热，提出了反射板和入射波控制板两种方案，为微波加热的优化提供了依据。

Microwave heating has the features in a transmission, absorption and reflection of an electromagnetic wave. The performance of the heating strongly depends on the interference of the transmitted wave and reflected wave in materials. Using the microwave of TE_<10> mode and frequency of 2.45GHz in a rectangular waveguide and a rectangular cavity, we have investigated two effects of a reflecting plate and an incident wave control plate on the characteristics of microwave heating.The results obtained here are summarized as follows ;(1) In the normal case without the reflecting plate, the quantity of heat generation has peaks at the resonance states, corresponding to the integer multiple of half wavelength of the sample. The quantity of heat generation increases when a reflecting plate is installed in the best position. However, as the sample length becomes longer, the effect of a reflecting plate becomes smaller because of a damping of microwave.(2) In order to avoid the reflection on the surface of the sample, it is available to attach a low dielectric material on the sample. By attaching the wave control plate having the optimum relative permittivity and having a quarter wavelength in thickness, the quantity of heat generation increases, comparing with the normal heating.(3) In order to clarify the optimization of microwave heating in a rectangular waveguide, we proposed two procedures attaching a reflecting plate and an incident wave control plate to the sample and indicated the guideline for the optimization of microwave heating by controlling reflected and transmitted waves.(4) For microwave heating in a rectangular cavity, we similarly proposed two procedures attaching a reflecting plate and an incident wave control plate to the sample and indicated the guideline for the optimization of microwave heating by controlling reflected and transmitted waves.