微波谐振腔内壁水膜对腔体特性的影响

Influence of water film on performance of microwave resonance

应用微波谐振腔微扰理论分析了圆柱形谐振腔内壁水膜对腔体谐振频率和品质因数产生的影响,通过理论推导得到了由水膜引起的谐振频率偏移和品质因数变化的解析式,并对工作于9.6GHz的TE011模圆柱谐振腔进行了仿真分析,给出了谐振腔的谐振频率和品质因数随水膜厚度不同而发生变化的仿真曲线。结果表明,当水膜厚度小于10μm时,水膜对谐振腔的谐振频率和品质因数的影响可以忽略;当水膜厚度超过20μm时,需要考虑水膜的影响,对测量结果进行校正。

Based on perturbation method, the influence of water film on resonant frequency and quality of cavity is analyzed. The analytic expression of the variation of resonant frequency and quality factor are deduced. The variation of quality factor and frequency of the cavity are simulated. And curves of simulation results are presented. Simulation shows that, when the water film is less than 10 μm, its influence on resonant frequency and performance of the cavity can be ignored. While it is more than 20 μm, the influence needs to be taken into account and the result of measurement needs to be corrected.