Research On The Design And Implementation Of Cavity Band- Pass Filter

With the rapid development of mobile communication technology in modern society, the product is updated rapidly, and the price competition becomes more and more fierce. People have higher requirements for filter indexes which are playing important roles in the field of communications. With the rapid development of computer technology, new product design ideas have been put forward, which also brings new opportunities and challenges to the design of the filter.Based on the points above, this thesis takes the actual product design process as the breakthrough point, and makes a detailed study on the design technology of the cavity filter.First, the design principles of the filter were summarized, and simple derivation of some basic theories of the filter is done.Then, detailed derivation and verification about the generalized Chebyshev filter synthesis and simplification method were introduced. Key studies on the transmission properties and simplification of CT/CQ topology are performed, and the relevant MATLAB programs according to the study on this chapter are written to realize synthesis and simplification of the coupling matrix and verify the results using examples.Then, derivation and verification about the generalized Chebyshev filter synthesis and simplification method were introduced. Emphasis on the study of the CT/CQ topology of the transmission characteristics and the simplification, and then the preparation of the relevant MATLAB program, the realization of the coupling matrix synthesis and simplification, and set examples for verification.Finally, from the point of view of practical product development, the method of rapid design of the filter is studied in detail from design to simulation and debugging. First of all, starting with the filter, the given indexes are changed to leave allowance to facilitate the final fabrication. Secondly, this thesis has studied in detail on how to map parameters synthesized from coupling matrix to real object 3D model, combing theory with engineering experiment perspective and from the principle to operation and matters needing attention. Then the rapid modeling and joint simulation technology are discussed, and this thesis puts forward a simple and practical way of optimization. Optimization results were verified from the angle of engineering and the filter was fabricated. The tuning method of the fabricated filter is briefly summarized and the product meeting the requirements is made. The theory of the above method is proved effectively.