Cavity Filter Structure Strain And Isolation Performance Analysis

Cavity filter is widely used in current base station communication system. As one of the important electrical requirements for cavitiy filter, isolation performance mainly depends on how big the cavity filter structure strain is. To guarantee the high quality and stable operation for telecom communication system, it is important to study cavity filter structure strain and isolation performance. But for a long period, isolation performance analysis mainly relys on engineers'experience and engineers usually follow "design-verification" way to design. As a result,product development may need more lead time, cost will be increased and over design may be occurred some times. So, it is quite necessary to study how the cavity filter structure strain affects the isolation performance systematically in practice. In this thesis, we investigate the structure strain and isolation for cavity filter by utilizing the FEA method and set up the corresponding testing system to verify the simulation result by experiment with physical prototypes. Based on these, we analysis and summarize the quantitative relations between the cavity filter isolation performance and the structure strain and provide the suggestion for the isolation performance improvement.There are three major tasks in this thesis:First, to identify cavity filter structure factors which may affect its isolation performance and utilize structural FEA to set up the structure-force-strain connection for various cavity filter structure factors.Second, to perform the electromagnetic simulation by taking the structural FEA result as an input, investigate the isolation performance of the cavity filter and set up the quantitative relations between the structure strain and the isolation performance. Then we can get the quantitative structure-force-electric-magnetic relations and find the hidden law inside them to provide advices for the cavity filter isolation performance improvement.At the end, to manufacture the physical protoypes and set up an experimental system to verify the simulation results by the FEA and the isolation performance analysis. This study will be proved to be effective and can provide a reference for the isolation performance analysis and improvement of the cavity filter in actual projects.