Analysis On Resonant Characteristic Of HE Mode In Microwave Cavity For Rubidium Frequency Standard

Rubidium standard has been widely used in many fields for its good characteristics such as small size, light weight, low power consumption, low cost, etc. One of the most important microwave components in it is microwave cavity. This makes resonant characteristic analysis of resonator with complicated dielectric essential for promulgating the inherent laws, excavating potential applications, enriching electromagnetic or quantum theory and solving practical problem.The resonant frequency of complicated resonator in rubidium frequency standard, is analysis by mode matching method. Firstly, resonant characteristic of the complicated resonator with glass bubble, is analyzed. By deducing eigen equation of TM 0mn mode, resonant frequency is calculated and compared with CST simulations. The results show that this method is correct and effective. At the same time, resonant frequency of HE111 mode is calculated and compared with CST results. Based on this, main factors influencing resonant frequency is discussed under different structure parameters. The results show that resonant frequency of the complicated resonator decreases when the volume becomes larger or the thickness of the glass bubble increases. Secondly, complicated resonator with ceramics is first modeled. By using mode matching method, resonant frequency for TE011 mode and HE111 mode are calculated. In addition to this, the results are compared with CST results. There is good agreement between the computation and CST simulations. At the same time, the impact of ceramics on frequency is also analyzed. Under certain cavity dimension, resonant frequency of the complicated resonator decreases when the thickness or the relative permittivity of the ceramics dielectric increases. Thirdly, resonant characteristic of the complicated resonator with rubidium in glass bubble and influence of rubidium to resonant characteristic, is analyzed by using CST software. The results show that density of rubidium in glass bubble have certain influence on resonant frequency.In conclusion, the methods and conclusions in this article is of great significance for analyzing resonant characteristic accurately and designing cavity size of microwave cavity in rubidium standard legitimately. It is of great significance for enriching electromagnetic theory and quantum theory.