Research On Key Technologies Of Auxiliary Diagnosis And Design Of Microwave Filter

Microwave filter is a kind of important Passive components in communication system.With the communication technology developing rapidly,the requirements of the system for the filter performance are higher and higher.In terms of its performance,it requires better selectivity and insertion loss in the filter band,better suppression effect outside the band and smaller overall size.In its design process,it requires high design efficiency.On this basis,the research of CAD and diagnosis technology of microwave filter is very important.Computer aided design technology covers several key links of the whole filter design,including index verification in the early stage,model determination in the middle stage and production debugging in the later stage.The introduction of CAD and diagnosis technology into the design of microwave filter can effectively reduce the production cycle and cost of the filter,and realize the large-scale design and production of microwave filter.The main work of this paper is to study the computer-aided design and diagnosis technology involved in the design process of microwave filter,including the extraction of zero point and order in index verification,the synthesis of Generalized Chebyshev polynomials and coupling matrix based on zero order,the simplification of transverse coupling matrix,and the parameter extraction algorithm for filter aided diagnosis in the later stage of design,etc.In this paper,the design basis of microwave filter is reviewed,and the synthesis theory of polynomial and coupling matrix of Generalized Chebyshev filter is introduced.On the basis of this theory,this paper improves the zero point and order optimization method and the rotation reduction method of coupling matrix,proposes the extraction of zero point and order based on multi-objective optimization for zero point optimization,and proposes the reduction method of coupling matrix based on eigenvalue optimization for coupling matrix reduction.In addition,in this paper,the parameter extraction method in the computer-aided diagnosis method of microwave filter is studied deeply.Based on the premise of adaptive interpolation fitting algorithm,firstly,the matrix gradient optimization parameter extraction method of directly extracting coupling matrix is carried out by using its feature of extracting less sampling points;in addition,the polynomial fraction obtained by adaptive interpolation fitting is used to reduce the order The method of parameter extraction for S-parameter polynomials is realized.These two parameter extraction methods,on the one hand,can directly and well fit the phase information,on the other hand,can effectively eliminate the noise interference,the calculation process is simple,and the extraction results are good.In this paper,the effectiveness of the two methods is verified by several examples.