Analysis For Resonant Characteristic Of Microwave Cavity Loaded With Complex Structure Dielectric In Rubidium Frequency Standard

Microwave resonant cavity is one of the important components in rubidium atomic frequency standard's physical part which determines the performance of rubidium atomic frequency standard to a large extent. It is inevitable to load the complex structure dielectric in microwave cavity of rubidium frequency standard. So, the analysis of this cavity's resonant characteristic has great theoretical significance and application value. In this paper, the TE₀₁₁ mode's resonant characteristics of cavities loaded with complex structure dielectric are analyzed approximately by using the mode match method. By calculating the TE₀₁₁ mode's resonant frequency and comparing with reference and CST simulation results, the correctness of this method has been proved. Based on the analysis above, a more rigorous and universal method is used to study the TEon mode's resonant characteristics of resonant cavity loaded with complex structure dielectric, and the accurate theoretical derivation is given. Finally, the HE₁₁₁ mode's resonant characteristics of resonant cavity loaded with complex structure dielectric are analyzed by using the electromagnetic field simulation software CST. The resonant characteristics are analyzed quantitatively while some qualitative explanations are given by using the media perturbation theory and the electromagnetic field distribution. The results show that the resonant frequency is related to the height, thickness and location of the cavity cell as well as the loaded dielectric's relative permittivity of the cavity. Therefore, resonant frequency can be varied by cavity's dimensions and loaded dielectrics to reach the target of optimization design. The obtained outcomes give a certain theoretical value on the theoretical perfection of resonant cavity loaded with dielectric and the design of resonant cavity in atomic frequency standard.