Research On Miniaturization Of Coaxial Cavity Filter

Along with the increase of the rate and capacity of various communication systems, coaxial cavity filter and multiplexer is widely used because of superior performance, but its miniaturization become a big problem in the engineering application, especiallyliner organization structure type.In this paper, through a careful analysis betweenthe history of filterminiaturization and coupling theory of filter disign,finding that they present a mutual promotion relationship.So this paper mainly studied the miniaturization technology based on the theory of the coupling.Coupling technology is more effectivethan resonator technology.The most valuable technology of this paper is mix electromagnetic coupling abased on anti-resonance.First explaining the mix coupling technology more in detail.Then summarizing a simple engineering design method.At last using this method to design mix coupling filter with a new mix coupling structure to reduce the size.The following is the contribution and innovation valueof this article:1、summarizinga variety of coaxial cavity miniaturization technology and thinking coupling theory with engineering value.2、concentrating on studyingthe cross coupling and mix electromagnetic coupling technology.3、Using anti-resonance to expoundthe principle of mixed coupling to achieve transmission zeros.4、Summarizinga new method of mixed coupling filterdesign.5、Creating a new high-performance mix-coupling structure based on the step impedanceof coaxial cavity(SIR).Designning a series of linear mixed coupling filter to test new approaches and new structure.Successfully designning a high performance filter,and the miniaturization degree is more thantwenty-five percent.