The commonly used oxides of wave-transmitting materials for microwave heating mainly include fused silica, glass-ceramic, alumina-based ceramics, etc. Among them, fused silica has stable chemical properties, high thermal shock resistance and excellent dielectric properties due to its atomic three-dimensional structure cross-linking and long-range disorder; alumina-based ceramics are almost completely converted into α-Al2O3 at high temperature, And at high temperature, ionic crystals can be ionized. Because of its large ionic bond energy, it has the advantages of low dielectric loss, high mechanical strength and good chemical stability, especially corundum is stable at high temperature, and has chemical inertness and Very good microwave transmission performance.

Silica is generally regarded as a microwave transparent material because it has poor absorption capacity at room temperature and good wave transmission performance; alumina ceramics are rich in resources, low in price, high in mechanical strength, and have good insulation and chemical stability. It is widely used in the fields of spacecraft radomes, antenna windows and microwave heating. However, when the temperature is higher than 800 °C, the dielectric parameters of the silica and alumina materials will gradually increase, the wave absorbing ability will be enhanced, and the wave transmission performance will deteriorate.