Modeling And Tuning Strategy Design For Microwave Filter

With the development of information industry,wireless communication technology has become one of the most popular technologies in this century.As a key frequency selection device in wireless communication system,the performance of microwave filter directly affects the communication quality of the forwarder channel.The production process of microwave filters includes three stages: design,processing and tuning.In the processing stage,because of manufacturing tolerance and material uncertainty,the output performance of the product cannot meet the design specifications.In order to compensate for the errors caused by processing,microwave filters need to be tuning.At present,the tuning of microwave filters is mostly done by technicians by hand,which is time-consuming and laborious.The problems such as high production cost and long delivery period restrict the large-scale production of microwave filters.In order to improve the production efficiency of microwave filters and reduce production costs,computer-assisted tuning is used.It will be of great significance to replace manual tuning and improve the automation level of microwave filter production and tuning.Firstly,the electromagnetic characteristics of microwave filters are analyzed,and the key characteristics affecting the output parameters of microwave filters are determined.Aiming at the difficulties in extracting the key characteristic parameters and the poor accuracy at present,the dissipative S-parameters of microwave filters are taken as the object of study.The non-ideal factors such as noise,loss,phase loading are parameterized in the extraction process of coupling matrices.In order to solve the non-ideal factors,eliminate them and solve the difficulty of accurately extracting the coupling matrix,an optimization method for extracting the coupling matrix of non-uniform Q lossy microwave filters is proposed,which can accurately extract the coupling matrix of microwave filters.Finally,the electromechanical characteristic parameter set based on the coupling matrix is constructed.Secondly,on the basis of the set of electromechanical characteristics parameters,a high-precision electromechanical characteristics modeling method of microwave filters is proposed,aiming at the problems of low accuracy of microwave filters modeling and unclear mechanism characteristics of the models.Based on the analysis of the characteristic parameter set of the coupled matrix,a multi-output least squares support vector regression algorithm is designed and optimized to fit the relationship between the input and output of the mechanical and electrical characteristic parameter set.A high-precision mechanical and electrical characteristic model of microwave filter is established to solve the problems of low modeling accuracy and poor generalization ability of microwave cavity filter.Finally,the relationship between the predicted output of the electromechanical characteristic model of microwave filter and its ideal performance is analyzed,and the optimization objective function model is established.Based on the electromechanical characteristic model,the model mapping tuning algorithm for electromechanical characteristics is studied,and the tuning rod adjustment is solved to achieve the ideal goal.The problem of multiple iteration steps of the current intelligent algorithm tuning model is solved,and the tuning is improved.The convergence of the algorithm makes the real-time and efficient tuning of microwave filters possible.In order to visualize the dynamic tuning process,a simulation and experimental system is established,and the extraction algorithm and software are designed to verify the validity and correctness of the theory and technology.This research will provide an efficient tuning guidance method for electronic equipment assembly and adjustment system represented by microwave filter tuning process,which has important research significance and application value.